---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 04/04/18: 22 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:19 AM - Re: two different Z-33 diagrams (Robert L. Nuckolls, III) 2. 07:21 AM - Warm Toggle Switch (Charles Brame) 3. 07:39 AM - Re: two different Z-33 diagrams (Mickey Coggins) 4. 08:41 AM - Re: insulation support for crimps (Robert L. Nuckolls, III) 5. 08:44 AM - Re: Warm Toggle Switch (John) 6. 08:45 AM - Re: Warm Toggle Switch (Robert L. Nuckolls, III) 7. 08:56 AM - Starter SURGES (user9253) 8. 12:01 PM - Re: Starter SURGES (Alec Myers) 9. 01:47 PM - Re: Starter SURGES (Ernest Christley) 10. 01:50 PM - Re: Starter SURGES (Robert L. Nuckolls, III) 11. 02:37 PM - Re: Warm Toggle Switch (FLYaDIVE) 12. 02:38 PM - Re: Starter SURGES (Robert L. Nuckolls, III) 13. 02:51 PM - Re: Warm Toggle Switch (Robert L. Nuckolls, III) 14. 03:20 PM - Re: Warm Toggle Switch (Charlie England) 15. 03:27 PM - Re: Warm Toggle Switch (Alec Myers) 16. 04:16 PM - Re: Warm Toggle Switch (FLYaDIVE) 17. 05:38 PM - Re: Warm Toggle Switch (Robert L. Nuckolls, III) 18. 05:50 PM - Re: Starter SURGES (Richard Girard) 19. 06:15 PM - Re: Starter SURGES (Charlie England) 20. 07:11 PM - Re: Starter SURGES (Richard Girard) 21. 07:47 PM - Re: Starter SURGES (Charlie England) 22. 09:20 PM - Re: Starter SURGES (Richard Girard) ________________________________ Message 1 _____________________________________ Time: 06:19:22 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: two different Z-33 diagrams At 12:06 AM 4/4/2018, you wrote: >Hi Bob, for hand propping, my understanding is >that the device would need at least a bit of >power.=C2 There is some discussion on some forums >about just using a tiny 9v battery.=C2 I don't >see anything in your diagram that would help or >hinder hand propping - there would still need to >be some external power source.=C2 The manual says this: > >Emergency Prop Starting ' Both the E-models and >P-models need outside electrical power to start. >You cannot prop-start the engine with either >type ignition if the battery is missing, or >totally dead. However, a low battery that barely >=9Cbumps=9D the starter motor, or can only >=9Cclick=9D the solenoid will likely have enough >energy to power=C2 the ignition for prop starting. >After startup, P-model ignitions can then power >themselves. Caution: Do not attempt a prop start >unless you are trained and are comfortable with the procedure. > >I think your drawing would be a useful addition >to the 13th and further editions of the AEC. I do too . . . just need to refresh my thought processes for publication of the drawing and it's companion narrative. The hand-propping and Revision L thing was mystifying absent any recollection of the conversation at the time. The drawing could be modified to include a helper-battery feature . . . if a 9v battery does it, the current drain cannot be very high. Hmmmm . . . maybe the drawing just needs modification to take 'maintenance' power directly from the battery bus through a small fuse. Even a very depleted battery will produce energy at milliampere loads. With this change, the maintenance procedure could be conducted normally . . . and the hand starting procedure attempted with a high probability of success. The indicator light could be an LED paired with a zener such that no light is produced unless the voltage is, say 8 volts or more. This would provide the double purpose of annunciating "maintenance mode active" and/or "hand propping success probable". What do ye think? Bob . . . ________________________________ Message 2 _____________________________________ Time: 07:21:59 AM PST US From: Charles Brame Subject: AeroElectric-List: Warm Toggle Switch I went through several warm, hot, and/or shorted switches that operated my strobes. Tried several brands of switches all with the same results. Finally trouble shot the whole system and found a bad connector crimp on the positive wire that connected at the strobe power pack. Repaired same, and haven=99t had a switch problem since. Charlie RV-6A, N11CB San Antonio ________________________________ Message 3 _____________________________________ Time: 07:39:00 AM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: two different Z-33 diagrams Hi Bob, The drawing is absolutely perfect for my application as-is. Last time I hand propped an aircraft was my boss's tri-pacer in 1978 or 79, so that feature is not a high priority for me. Might be worth an email to Brad to get his benediction, but what you drew in the z-33 seems to exactly match the recommendations in the installation guide, and in a way that is very clear. Regards, Mickey Mickey Coggins On 4 April 2018 at 15:18, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 12:06 AM 4/4/2018, you wrote: > > Hi Bob, for hand propping, my understanding is that the device would need > at least a bit of power.=C3=82 There is some discussion on some forums a bout > just using a tiny 9v battery.=C3=82 I don't see anything in your diagram that > would help or hinder hand propping - there would still need to be some > external power source.=C3=82 The manual says this: > > Emergency Prop Starting =93 Both the E-models and P-models need out side > electrical power to start. You cannot prop-start the engine with either > type ignition if the battery is missing, or totally dead. However, a low > battery that barely =C3=A2=82=AC=C5=93bumps=C3=A2=82=AC the starter motor, or can only =C3=A2=82=AC=C5=93click=C3=A2=82=AC > the solenoid will likely have enough energy to power=C3=82 the ignition f or prop > starting. After startup, P-model ignitions can then power themselves. > *Caution: Do not attempt a prop start unless you are trained and are > comfortable with the procedure. * > I think your drawing would be a useful addition to the 13th and further > editions of the AEC. > > > I do too . . . just need to refresh my thought processes > for publication of the drawing and it's companion narrative. > The hand-propping and Revision L thing was mystifying > absent any recollection of the conversation at the time. > > The drawing could be modified to include a helper-battery > feature . . . if a 9v battery does it, the current drain > cannot be very high. Hmmmm . . . maybe the drawing > just needs modification to take 'maintenance' power > directly from the battery bus through a small fuse. > Even a very depleted battery will produce energy > at milliampere loads. With this change, the > maintenance procedure could be conducted normally > . . . and the hand starting procedure attempted with > a high probability of success. > > The indicator light could be an LED paired with a > zener such that no light is produced unless the > voltage is, say 8 volts or more. This would provide > the double purpose of annunciating "maintenance mode > active" and/or "hand propping success probable". > > What do ye think? > > > Bob . . . > ________________________________ Message 4 _____________________________________ Time: 08:41:53 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: insulation support for crimps At 05:18 PM 4/3/2018, you wrote: >It=99s not something you=99ve specifically >recommended: google for =9Ckrimptite=9D and >you=99ll see some examples of to what I was referring. > Okay. Found this .pdf that speaks to the spectrum of Waldom termnials https://goo.gl/XKMA71 The generic Krimptite devices are the bottom of the features ladder. No insulation grip, rolled, non-welded wire grips. Next step up through the product line adds insulation grips to the non-welded terminals. Next are uninsulated but more robust terminals specifically designed for solid wire and wire grips intended for facilitating 'pulls' of wire thorough a conduit. Stationary applications. Next step up are the AviKrimps . . . the Molex offering to higher performance vehicular applications (like airplanes). These are equivalents to Tyco-Amp PIDG, Panduit PN series and others designed to the spirit and intent of M25036/T7928 The next steps up the ladder are pretty self explanatory. There's a 'high temperature' version of the un=insulated ring terminals designed for use in products like heaters, ovens, furnaces, etc where even companion wires are expected to stand off extra ordinary environmental temperatures . . . temperatures too high for legacy insulation grips but un-necessary since the terminals are not expected to perform under vibration. One does not save much money with the use of terminals outside the bubble of M25036/T7928 products. The uninsulated Krimptite devises would reside outside that bubble. Here's a quick run-down on acme of terminal technologies with about 80 years of history on aircraft and similar applications. Emacs! Bob . . . ________________________________ Message 5 _____________________________________ Time: 08:44:47 AM PST US From: John Subject: Re: AeroElectric-List: Warm Toggle Switch Thanks Charlie. John C RV6A > On Apr 4, 2018, at 10:21 AM, Charles Brame wrote: > > I went through several warm, hot, and/or shorted switches that operated my strobes. Tried several brands of switches all with the same results. Finally trouble shot the whole system and found a bad connector crimp on the positive wire that connected at the strobe power pack. Repaired same, and havent had a switch problem since. > > Charlie > RV-6A, N11CB > San Antonio ________________________________ Message 6 _____________________________________ Time: 08:45:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Warm Toggle Switch At 09:21 AM 4/4/2018, you wrote: >I went through several warm, hot, and/or shorted >switches that operated my strobes. Tried several >brands of switches all with the same results. >Finally trouble shot the whole system and found >a bad connector crimp on the positive wire that >connected at the strobe power pack. Repaired >same, and haven=99t had a switch problem since. What were your observations for condition of the materials at the failure . . . and do you recall whether the failure was related to materials, installation technique or perhaps both? You mentioned 'shorted' switch . . . were you the builder who was experiencing fuse popping when the strobes were turned OFF? Bob . . . ________________________________ Message 7 _____________________________________ Time: 08:56:07 AM PST US Subject: AeroElectric-List: Starter SURGES From: "user9253" The following was posted today on Vansairforce. Are the statements below true? > "Starters that use a permanent magnet instead of a wound field most certainly can and will cause voltage surges that will take out avionics. The EXP2 will not filter out surges. Strongly recommend you rewire the EXP2 to have the Avionics shut down on cranking or better yet don't turn the avionics on until engine is started and running. Voltage spikes are of a quick transient nature and can exceed several hundred volts. They can be fast enough that the clamping diode will not completely shunt the spike." -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=479039#479039 ________________________________ Message 8 _____________________________________ Time: 12:01:46 PM PST US From: Alec Myers Subject: Re: AeroElectric-List: Starter SURGES I dont know about the first bit but Im very dubious about They can be fast enough that the clamping diode will not completely shunt the spike. I dont think it takes more than a few nanoseconds for a junction diode to go into conduction; they rectify very high frequency signals, after all. And the junction looks like a small capacitance which at a high enough frequency will short a signal even without conducting. On Apr 4, 2018, at 11:55, user9253 wrote: The following was posted today on Vansairforce. Are the statements below true? > "Starters that use a permanent magnet instead of a wound field most certainly can and will cause voltage surges that will take out avionics. The EXP2 will not filter out surges. Strongly recommend you rewire the EXP2 to have the Avionics shut down on cranking or better yet don't turn the avionics on until engine is started and running. Voltage spikes are of a quick transient nature and can exceed several hundred volts. They can be fast enough that the clamping diode will not completely shunt the spike." -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=479039#479039 ________________________________ Message 9 _____________________________________ Time: 01:47:53 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Starter SURGES If the bendix gear is sticky, such that the engine is able to drive the sta rter, I could imagine that it could push a fairly high (albeit short) numbe r of joules back up the wire. =C2-Right? On Wednesday, April 4, 2018 3:03 PM, Alec Myers wr ote: I don=99t know about the first bit but I=99m very dubious about =9CThey can be fast enough that the clamping diode will not complete ly shunt the spike=9D. I don=99t think it takes more than a few nanoseconds for a junction d iode to go into conduction; they rectify very high frequency signals, after all. And the junction looks like a small capacitance which at a high enoug h frequency will =9Cshort=9D a signal even without conducting. ________________________________ Message 10 ____________________________________ Time: 01:50:02 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Starter SURGES At 10:55 AM 4/4/2018, you wrote: > >The following was posted today on Vansairforce. Are the statements >below true? > > > "Starters that use a permanent magnet instead of a wound field > most certainly can and will cause voltage surges that will take out > avionics. The EXP2 will not filter out surges. Strongly recommend > you rewire the EXP2 to have the Avionics shut down on cranking or > better yet don't turn the avionics on until engine is started and > running. Voltage spikes are of a quick transient nature and can > exceed several hundred volts. They can be fast enough that the > clamping diode will not completely shunt the spike." Some ol' hangar tales just never die. 99.9% of the legacy 'spikes' narratives are simply unfounded in physics and not demonstrated in practice. I spent 45+ years chasing gremlins, goblins and poltergeists in aircraft DC power systems. Not once was the root event of a problem attributable to an UNEXPECTED transient condition on the bus. UNEXPECTED is the operative word here . . . DO160/M-Std-704 are teamed up to define what hazards are EXPECTED and what firewalls are recommended for meeting those expectations. We've been successfully building and operating all manner of electronic and electrical accessory under these guidelines for about 80 years. The narrative cited above is pretty strange . . . "fast enough that the clamping diode will not completely shunt the spike". Really? Such assertions should be able to cite supporting documentation where a test setup was fabricated, tests conducted, measurements taken and deductions made. Graybeards on the List may recall numerous discussions wherein I went to the bench, did the setup, recorded the results and published the deductions. The 'cranking spike' thingy doesn't exist. What ever bus voltage perturbations exist are NORMAL, EXPECTED and well addressed by rudimentary and now cookie-cutter design philosophies nearly a century old. I'd be pleased to send $100 to any individual who can document any conditions to the contrary and publish them here on the List. Bob . . . ________________________________ Message 11 ____________________________________ Time: 02:37:24 PM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Warm Toggle Switch Bob: You are ALMOST right. The Rating of a Switch has to do NOT ONLY Voltage and Amperage, but with AC or DC. There are different ratings of Amperage for the same switch and physical size when you talk AC & DC. An amp is an amp, but, when you deal with the physical size of the switch - HOW MANY AMPS a switch can handle changes with the type of voltage... All the way from DC up to RF. ------------------------------- I think Charlie is directing his email to me? Charlie England ceengland7@gmail.com via matronics.com Apr 3 (1 day ago) Reply to aeroelectric-l. Care to show us how you arrive at that last statement, using Ohm's Law? Barry- It is NOT Ohms Law. There is more to electronics than just Ohms law .. 0.637 is know as Average. 0.707 is know as RMS (Root Mean Squared) They are points of power on a Sine Wave. Example: A 110 VAC outlet has MORE that 110 VAC coming out of it. It is more like 180.07 Volts PEAK. How much WORK the Peak Voltage can do is AVERAGED to be: Peak x 0.637 Average. Or 180.07 x 0.637 = 110 VAC Now to really confuse ya... The equivalent of 180.07 VAC in DC would be: Peak x 0.707 = RMS Or 180.07 x 0.707 = 127.30 VAC That is why you will see AC ratings ranging from 110 VAC to 130 VAC. I know, clear as mud. It is under AC Theory. Barry On Tue, Apr 3, 2018 at 11:24 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 08:39 PM 4/2/2018, you wrote: > > John: > > Yes, the switch may be the problem.=C3=82 Your sw > > itch S700-1-3=C3=82 is a 15 Amp rating on AC.=C3=82 Which is NOT 15 Amps on DC.=C3=82 A > good rule of thumb is the switch should be able to handle DOUBLE the DC > amperage that the circuit draws.=C3=82 There are a couple of ways of > determining=C3=82 the DC rating of an AC Switch.=C3=82 You can say take .707 x > Rating or .637 x Rating.=C3=82 So: 15 Amps x .707 = 10.6 Amps // or 15 Amps x > .637 = 9.5 Amps. > Not so. > > An ampere is equal to flow of 1 Coulomb per second of electrons > past a point in the conductor. The electrons don't know if they're > AC, DC or some combination of the two. 1 amp flowing with a force > of 1 volt for 1 second represents 1 Joule of energy . . . and again, > this packet of energy knows not from which system it was generated. > > This particular problem with the Carling switches has a history. > Graybeards on the List will recall a builder's repeated loss > of the switch that controlled his strobes. Something relaively > new in the Carling switches saga given that this same style of > switch had been in service on single engine Cessnas since the > middle 60's. > > If you consider the physics for conducting Coulombs of electrons > to the strobes, we can count 10 metallic joints in the > switch's power path. NONE of those joints can have a resistance > of ZERO . . . it's ideally small but cannot be zero. > > Four of those joints (1, 2, 9, 10_ are directly acted upon by the > installer. Two more (3, 8) can be influenced by the installer's > action when pressing the fast-on terminals into place. Those > same two joints can be adversely affected by operational > vibrations of wire bundles too tightly installed to the > back of switches (short or no service loops in wires). > > > [image: http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Fa] > > All of said joints can be adversely influenced by > environmental effects and/or manufacturing variations. > > Suffice it to say, any switch that is noticeably > warm after some time in the ON condition is probably > suffering a rise in resistance in on or more of the > 10 joints illustrated. > > A change in strobe system design architecture precipitated > the exchange we had about 10 years ago. You can go to > the AeroElectric List search feature on > > http://www.matronics.com/forums/search.php > > and search on Carling+failure+strobe+rivet > > This was about the time when strobe systems were > migrating from the legacy Royer oscillator, high > voltage power supplies to the high efficiency, > high frequency constant-power supplies. Unlike > older strobes that drew LESS than normal running > current at low bus voltage, these systems were > designed to maintain strobe output at a wide range > of bus voltages, hence current draw went UP as > bus voltage goes down. > > Operating strobes on the ground at idle and taxi > rpms placed extra stress on the switch. > > Here'a a narrative that goes to a particular > kind of failure in the Carling swtiches: > > https://goo.gl/oiZjeG > > I've done teardowns on about a half dozen > switch failures with locus of the failure > was seldom repeated. > > Here'a a general article on switch rating > as it relates to our use of them in airplanes. > > https://goo.gl/CPtPYJ > > Yes, the Carling products are inexpensive > but as Cessna and others have demonstrated for > decades, this does NOT make them unsuited to > our tasks. The laws of physics that govern > their failures are inviolate . . . meaning that > there are deducible reasons for every failure > or rash of failures. > > Bob . . . > ________________________________ Message 12 ____________________________________ Time: 02:38:38 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Starter SURGES At 03:46 PM 4/4/2018, you wrote: >If the bendix gear is sticky, such that the engine is able to drive >the starter, I could imagine that it could push a fairly high >(albeit short) number of joules back up the wire. Right? the 'Bendix' drive is gone. All starters use direct engagement solenoids. https://upload.wikimedia.org/wikipedia/commons/f/fb/Starter_mot A return spring retracts the pinion gear upon removal of power from the motor. In fact, electrical power to the motor is interrupted during the initial retraction so there is no torque being transmitted from motor to ring gear. At the same time, an overrun clutch https://tinyurl.com/y7prvn7b prevents the accelerating engine from back-driving the starter. If this clutch were not present, first motion of the engine during pinion gear retraction would break things. This feature was built into the legacy 'bendix' drive. Starter motor acceleration working against pinion gear mass would drive it outward on the shaft by means of a spiral groove on the shaft . . . engine acceleration tending to over-run the starter would drive the pinion back from the ring gear with the same groove. Emacs! There have been some hangar-tales of starter pinions 'sticking' and back driving starters. There have been cases of contactor sticking keeping power on the starter thus maintaining pinion engagement. But no back driving could have occurred due to action of the clutch. Had the motor been driven backwards at the pinion to ring gear ratio, it would probably have slung wires out of the armature and/or stripped gear teeth. The same gear reduction of pinion-to-ring allows starter armature to run at several thousand rpm to generated 200 rpm at the crankshaft. Okay, after engine start and run at 1000 rpm, a back-driving situation would spin the starter armature 10000 rpm plus? Bob . . . ________________________________ Message 13 ____________________________________ Time: 02:51:52 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Warm Toggle Switch At 04:35 PM 4/4/2018, you wrote: >Bob: > >You are ALMOST right. > >The Rating of a Switch has to do NOT ONLY >Voltage and Amperage, but with AC or DC. >There are different ratings of Amperage for the >same switch and physical size when you talk AC & DC. >An amp is an amp, but, when you deal with the >physical size of the switch - HOW MANY AMPS a >switch can handle changes with the type of >voltage...=C2 All the way from DC up to RF. Switch WARMING is a function of a switch's CARRY current. I.e. I(squared)R losses across the metallic joints I illustrated in the earlier posting. This energy dissipation is independent of the nature of system voltage. The device's ability to MAKE and BREAK a circuit is another matter . . . and indeed is influenced by the nature of system voltage. This is explained in an article I published at: http://aeroelectric.com/articles/Switch_Ratings.pdf A study of the published ratings from Honeywell literature supports the notion that the 125VAC ratings of commercial, off the shelf switches are on a par with the switch's 14VDC ratings. Hence my advice to builders over the years suggests that a hardware store switch rated for 10A at 125VAC was suited to operation in an airplane at 14VDC. Bob . . . ________________________________ Message 14 ____________________________________ Time: 03:20:57 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Warm Toggle Switch Yes, I was, but you didn't include in your reply, the line I was asking about. These are DC circuits. Explain how higher resistance causes higher current in a DC circuit. Note that I'm not asking about a switching power supply drawing more current as its supply voltage decreases; I'm asking you to explain how an increase in a DC circuit's resistance causes a higher current to flow in the circuit. Charlie On Wed, Apr 4, 2018 at 4:35 PM, FLYaDIVE wrote: > I think Charlie is directing his email to me? > > Charlie England ceengland7@gmail.com via > matronics.com > Apr 3 (1 day ago) > Reply > to aeroelectric-l. > Care to show us how you arrive at that last statement, using Ohm's Law? > > Barry- It is NOT Ohms Law. There is more to electronics than just Ohms > law. > 0.637 is know as Average. > 0.707 is know as RMS (Root Mean Squared) > They are points of power on a Sine Wave. > Example: A 110 VAC outlet has MORE that 110 VAC coming out of it. > It is more like 180.07 Volts PEAK. > How much WORK the Peak Voltage can do is AVERAGED to be: Peak x 0.637 > Average. > Or 180.07 x 0.637 = 110 VAC > Now to really confuse ya... > The equivalent of 180.07 VAC in DC would be: Peak x 0.707 = RMS > Or 180.07 x 0.707 = 127.30 VAC > That is why you will see AC ratings ranging from 110 VAC to 130 VAC. > I know, clear as mud. > > It is under AC Theory. > > Barry > > > On Tue, Apr 3, 2018 at 11:24 AM, Robert L. Nuckolls, III < > nuckolls.bob@aeroelectric.com> wrote: > >> At 08:39 PM 4/2/2018, you wrote: >> >> John: >> >> Yes, the switch may be the problem.=C3=82 Your sw >> >> itch S700-1-3=C3=82 is a 15 Amp rating on AC.=C3=82 Which is NOT 15 Amp s on DC.=C3=82 >> A good rule of thumb is the switch should be able to handle DOUBLE the D C >> amperage that the circuit draws.=C3=82 There are a couple of ways of >> determining=C3=82 the DC rating of an AC Switch.=C3=82 You can say take .707 x >> Rating or .637 x Rating.=C3=82 So: 15 Amps x .707 = 10.6 Amps // or 1 5 Amps x >> .637 = 9.5 Amps. >> Not so. >> >> An ampere is equal to flow of 1 Coulomb per second of electrons >> past a point in the conductor. The electrons don't know if they're >> AC, DC or some combination of the two. 1 amp flowing with a force >> of 1 volt for 1 second represents 1 Joule of energy . . . and again, >> this packet of energy knows not from which system it was generated. >> >> This particular problem with the Carling switches has a history. >> Graybeards on the List will recall a builder's repeated loss >> of the switch that controlled his strobes. Something relaively >> new in the Carling switches saga given that this same style of >> switch had been in service on single engine Cessnas since the >> middle 60's. >> >> If you consider the physics for conducting Coulombs of electrons >> to the strobes, we can count 10 metallic joints in the >> switch's power path. NONE of those joints can have a resistance >> of ZERO . . . it's ideally small but cannot be zero. >> >> Four of those joints (1, 2, 9, 10_ are directly acted upon by the >> installer. Two more (3, 8) can be influenced by the installer's >> action when pressing the fast-on terminals into place. Those >> same two joints can be adversely affected by operational >> vibrations of wire bundles too tightly installed to the >> back of switches (short or no service loops in wires). >> >> >> >> [image: http://aeroelectric.com/Pictures/Switches/Toggle_Switch_with_Fa] >> >> >> All of said joints can be adversely influenced by >> environmental effects and/or manufacturing variations. >> >> Suffice it to say, any switch that is noticeably >> warm after some time in the ON condition is probably >> suffering a rise in resistance in on or more of the >> 10 joints illustrated. >> >> A change in strobe system design architecture precipitated >> the exchange we had about 10 years ago. You can go to >> the AeroElectric List search feature on >> >> http://www.matronics.com/forums/search.php >> >> and search on Carling+failure+strobe+rivet >> >> This was about the time when strobe systems were >> migrating from the legacy Royer oscillator, high >> voltage power supplies to the high efficiency, >> high frequency constant-power supplies. Unlike >> older strobes that drew LESS than normal running >> current at low bus voltage, these systems were >> designed to maintain strobe output at a wide range >> of bus voltages, hence current draw went UP as >> bus voltage goes down. >> >> Operating strobes on the ground at idle and taxi >> rpms placed extra stress on the switch. >> >> Here'a a narrative that goes to a particular >> kind of failure in the Carling swtiches: >> >> https://goo.gl/oiZjeG >> >> I've done teardowns on about a half dozen >> switch failures with locus of the failure >> was seldom repeated. >> >> Here'a a general article on switch rating >> as it relates to our use of them in airplanes. >> >> https://goo.gl/CPtPYJ >> >> Yes, the Carling products are inexpensive >> but as Cessna and others have demonstrated for >> decades, this does NOT make them unsuited to >> our tasks. The laws of physics that govern >> their failures are inviolate . . . meaning that >> there are deducible reasons for every failure >> or rash of failures. >> >> Bob . . . >> > > Virus-free. www.avast.com <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> ________________________________ Message 15 ____________________________________ Time: 03:27:07 PM PST US From: Alec Myers Subject: Re: AeroElectric-List: Warm Toggle Switch It=99s understandably easy to (incorrectly) jump from TRUE (higher res istance creates more heat) via another TRUE (more current means more heat) t o a FALSE: higher resistance means more current. Of course higher resistance means less current. Actually higher resistance means less heat overall, but increasing the resis tance of one part of a circuit (like a switch) can increase the heat in that spot, causing the trouble. On Apr 4, 2018, at 18:20, Charlie England wrote: Yes, I was, but you didn't include in your reply, the line I was asking abou t. These are DC circuits. Explain how higher resistance causes higher curren t in a DC circuit. Note that I'm not asking about a switching power supply d rawing more current as its supply voltage decreases; I'm asking you to expla in how an increase in a DC circuit's resistance causes a higher current to f low in the circuit. Charlie > On Wed, Apr 4, 2018 at 4:35 PM, FLYaDIVE wrote: > > > I think Charlie is directing his email to me? > > Charlie England ceengland7@gmail.com via matronics.com > Apr 3 (1 day ago) > Reply > to aeroelectric-l. > Care to show us how you arrive at that last statement, using Ohm's Law? > > Barry- It is NOT Ohms Law. There is more to electronics than just Ohms la w. > 0.637 is know as Average. > 0.707 is know as RMS (Root Mean Squared) > They are points of power on a Sine Wave. > Example: A 110 VAC outlet has MORE that 110 VAC coming out of it. > It is more like 180.07 Volts PEAK. > How much WORK the Peak Voltage can do is AVERAGED to be: Peak x 0.637 = A verage. > Or 180.07 x 0.637 = 110 VAC > Now to really confuse ya... > The equivalent of 180.07 VAC in DC would be: Peak x 0.707 = RMS > Or 180.07 x 0.707 = 127.30 VAC > That is why you will see AC ratings ranging from 110 VAC to 130 VAC. > I know, clear as mud. > > It is under AC Theory. > > Barry > > > > >> On Tue, Apr 3, 2018 at 11:24 AM, Robert L. Nuckolls, III wrote: >> At 08:39 PM 4/2/2018, you wrote: >>> John: >>> >>> Yes, the switch may be the problem.=C3=82 Your sw >> itch S700-1-3=C3=82 is a 15 Amp rating on AC.=C3=82 Which is NOT 15 Amps on DC.=C3=82 A good rule of thumb is the switch should be able to handle D OUBLE the DC amperage that the circuit draws.=C3=82 There are a couple of w ays of determining=C3=82 the DC rating of an AC Switch.=C3=82 You can say t ake .707 x Rating or .637 x Rating.=C3=82 So: 15 Amps x .707 = 10.6 Amps / / or 15 Amps x .637 = 9.5 Amps. >> Not so. >> >> An ampere is equal to flow of 1 Coulomb per second of electrons >> past a point in the conductor. The electrons don't know if they're >> AC, DC or some combination of the two. 1 amp flowing with a force >> of 1 volt for 1 second represents 1 Joule of energy . . . and again, >> this packet of energy knows not from which system it was generated. >> >> This particular problem with the Carling switches has a history. >> Graybeards on the List will recall a builder's repeated loss >> of the switch that controlled his strobes. Something relaively >> new in the Carling switches saga given that this same style of >> switch had been in service on single engine Cessnas since the >> middle 60's. >> >> If you consider the physics for conducting Coulombs of electrons >> to the strobes, we can count 10 metallic joints in the >> switch's power path. NONE of those joints can have a resistance >> of ZERO . . . it's ideally small but cannot be zero. >> >> Four of those joints (1, 2, 9, 10_ are directly acted upon by the >> installer. Two more (3, 8) can be influenced by the installer's >> action when pressing the fast-on terminals into place. Those >> same two joints can be adversely affected by operational >> vibrations of wire bundles too tightly installed to the >> back of switches (short or no service loops in wires). >> >> >> >> >> >> All of said joints can be adversely influenced by >> environmental effects and/or manufacturing variations. >> >> Suffice it to say, any switch that is noticeably >> warm after some time in the ON condition is probably >> suffering a rise in resistance in on or more of the >> 10 joints illustrated. >> >> A change in strobe system design architecture precipitated >> the exchange we had about 10 years ago. You can go to >> the AeroElectric List search feature on >> >> http://www.matronics.com/forums/search.php >> >> and search on Carling+failure+strobe+rivet >> >> This was about the time when strobe systems were >> migrating from the legacy Royer oscillator, high >> voltage power supplies to the high efficiency, >> high frequency constant-power supplies. Unlike >> older strobes that drew LESS than normal running >> current at low bus voltage, these systems were >> designed to maintain strobe output at a wide range >> of bus voltages, hence current draw went UP as >> bus voltage goes down. >> >> Operating strobes on the ground at idle and taxi >> rpms placed extra stress on the switch. >> >> Here'a a narrative that goes to a particular >> kind of failure in the Carling swtiches: >> >> https://goo.gl/oiZjeG >> >> I've done teardowns on about a half dozen >> switch failures with locus of the failure >> was seldom repeated. >> >> Here'a a general article on switch rating >> as it relates to our use of them in airplanes. >> >> https://goo.gl/CPtPYJ >> >> Yes, the Carling products are inexpensive >> but as Cessna and others have demonstrated for >> decades, this does NOT make them unsuited to >> our tasks. The laws of physics that govern >> their failures are inviolate . . . meaning that >> there are deducible reasons for every failure >> or rash of failures. >> >> Bob . . . >> > Virus-free. www.avast.com ________________________________ Message 16 ____________________________________ Time: 04:16:07 PM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Warm Toggle Switch Bob: " A study of the published ratings from Honeywell literature supports the notion that the 125VAC ratings of commercial, off the shelf switches are on a par with the switch's 14VDC ratings. Hence my advice to builders over the years suggests that a hardware store switch rated for 10A at 125VAC was suited to operation in an airplane at 14VDC. Bob . . ." What do you consider "on a par with..." One can go to just about any electronics catalog and look up a switch with dual ratings and you will ALWAYS find the DC Amperage is lower than the AC Amperage of that same switch. The point(s) I was making were: 1 - There are many reasons why John's switch can be getting warm. 2 - A poorly chosen switch can be one of those reasons. Not that John chose the switch, it could have been recommended by the instructions. After all it lasted for 9+ years. 3 - Maybe it was just its time to DIE! 4 - How the plane is stored? Hanger? Outside? High Humidity? 5 - Poor connections ie: Fast-On connectors, No Lock Washer, Undersized Wire, etc. 6 - Vibration! ALL planes suffer from Vibration. My rule of thumb is: For every hour you fly, there is 4 hours of maintenance. And one of my Favorites: 7 - Chinese JUNK! MANY components are NOT what the SAY they are! Just because it is stamped 10 Amps does not mean it is 10 Amps. And when working close to the edge of specifications one is taking a chance. On a switch that is rated at 9 / 10 Amps and the circuit draws 7.5 Amps. That is not good design practice. One of my tricks is to use a DPST switch and tie both sides to the same circuit. The rating for a DP switch is for each side. So, by tying them together you DOUBLE the rating, As well as doubling the physical properties of the switch. Funny thing in engineering: When you design for the COMPANY you design with the pocketbook in mind. When you design for yourself and especially for your OWN plane... To HELL with the pocketbook! I don't ever want to repair that Dang Circuit Again! It was HELL to get at!!! So, yes, we will put in a $4.00 switch instead of that $2.35 Chinese Switch. The COMPANY won't... But, I will!!! Barry On Wed, Apr 4, 2018 at 5:51 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 04:35 PM 4/4/2018, you wrote: > > Bob: > > You are ALMOST right. > > The Rating of a Switch has to do NOT ONLY Voltage and Amperage, but with > AC or DC. > There are different ratings of Amperage for the same switch and physical > size when you talk AC & DC. > An amp is an amp, but, when you deal with the physical size of the switch > - HOW MANY AMPS a switch can handle changes with the type of voltage... =C3=82 > All the way from DC up to RF. > > > Switch WARMING is a function of a switch's > CARRY current. I.e. I(squared)R losses > across the metallic joints I illustrated in > the earlier posting. This energy dissipation > is independent of the nature of system > voltage. > > The device's ability to MAKE and BREAK a > circuit is another matter . . . and indeed > is influenced by the nature of system > voltage. This is explained in an article > I published at: > > http://aeroelectric.com/articles/Switch_Ratings.pdf > > A study of the published ratings from Honeywell > literature supports the notion that the 125VAC > ratings of commercial, off the shelf switches > are on a par with the switch's 14VDC ratings. > Hence my advice to builders over the years suggests > that a hardware store switch rated for 10A at > 125VAC was suited to operation in an airplane > at 14VDC. > > Bob . . . > ________________________________ Message 17 ____________________________________ Time: 05:38:34 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Warm Toggle Switch > > >What do you consider "on a par with..." One can >go to just about any electronics catalog and >look up a switch with dual ratings and you will >ALWAYS find the DC Amperage is lower than the AC Amperage of that same switch. What statement in the article I cited was questionable? Did you read the article? I cited a ratings chart purloined directly from the Honeywell/Microswich catalog which I repeat here: Emacs! I observe that for a switch with any particular "electrical code rating" the 115 VAC ratings are not seriously different from 28VDC ratings. I further deduced that 14VDC ratings should be equal to or better than 28VDC ratings. Consider a switch of code 3: 115 vac resistive 15A 28 vdc resistive 20A Why would such a switch not be comfortably incorporated into a 14VDC system working a 20A load? Take any OTHER rating and cite the situation where the builder's choice of switches is at-risk for using the device? Further, assume that a switch is incorporated into a 14VDC system at say 3x the switch's 'ratings'. What are the likely effects for such oversight? How would a 3x 'overload' affect service life? Given that most lightplanes fly 50 hours per year, assiming two switch operations per flight hour, what might we expect for service longevity of this 'severely' overloaded switch? Forgive me, that's a loaded question. Referring to the the chart above, the 'severely overloaded' switch would would have to be applied in a circuit that controls at least 15 x 3 or 45 amps. No such system exists in light aircraft where such currents flow in crew operated switches. The point to be considered here is that the 'warm switch' in question has an easily deduced root cause based on simple physics and the extensive experience base for members of this List. >The point(s) I was making were:=C2 =C2 > >1 - There are many reasons=C2 why John's switch can be getting warm. > >2 - A poorly chosen switch can be one of those >reasons. Not that John chose the switch, it >could have been recommended=C2 by the >instructions.=C2 After all it lasted for 9+ years. > >3 - Maybe it was just its time to DIE! > >4 - How the plane is stored?=C2 Hanger?=C2 Outside?=C2 High Humidity? > >5 - Poor connections ie: Fast-On connectors, No >Lock Washer, Undersized=C2 Wire, etc. > >6 - Vibration!=C2 ALL planes suffer from >Vibration.=C2 My rule of thumb is:=C2 For every >hour you fly, there is 4 hours of maintenance. > >And one of my Favorites: > >7 - Chinese=C2 JUNK! Whoa!!! You've thrown the kitchen sink into the discussion. One of the goals for this List is to combine a knowledge of history with a good grasp on the simple ideas in physics viewed through a narrow-spectrum lens of demonstrable cause/effect. In what way has anything I've offered in this thread conflicted with physics and/or 50 years experience/lessons-learned? You have asserted that some instances of INCREASED resistance can manifest as an INCREASED current. I'm mystified by this assertion . . . yet if correct . . . is easily demonstrated. Can you shoot a video on you mobile phone for any assortment of components powered from a source of your choice where INCREASING a resistance INCREASES current. If we've mis-interpreted your words, then you have my profound apologies . . . we only seek to understand. Bob . . . ________________________________ Message 18 ____________________________________ Time: 05:50:29 PM PST US From: Richard Girard Subject: Re: AeroElectric-List: Starter SURGES Bob, all, When I graduated high school back in the dark ages I had a 1959 Alfa Romeo Giullietta Spider that had a nightmare starter system. First, the electrical system was positive ground. That alone made things interesting but the starter, or rather the starter switch was the flash point of failure. Why? Because it had no spring return. You had to physically turn the starter motor off or the starter would stay connected with the ring gear and the engine would drive the starter. I was warned by the guy who sold me the car and I only left it engaged once for a few seconds. The grinding sound was kind of a give away and I got away with it. When I sold the car to my best friend I told him what I'd been told, "Never, ever let anyone else drive this car". About four weeks after Dave bought it, he let his step brother drive the car. He left the starter engaged for the entire 10 miles he drove it. The next day, the battery was dead. When checked, it had internal shorts and was junk. Dave bought a new Die Hard, the new thing in battery advertising, if not battery technology. It lasted a couple of weeks and Dave took it back to Sears. The battery was tested and failed. He got a new one. It too failed in short order. This went on for FOUR batteries before the manager at the Arden Way Sears gave my friend a full refund and refused to sell him any more batteries. Somewhere in the mess the starter failed and was replaced, the generator failed, the headlights would burn out on a regular basis and my friend almost became my ex-friend. He was a poor college student trying to fix the car with suggestions from his dad and some mechanics he knew. Finally his folks loaned him the money to take it to a garage that worked on Alfas and they determined that the voltage regulator was fried, too. This had gone on for almost six months before he finally had the car back in a dependable condition. So my take is, yeah, drive the starter and turn it into a generator and things are going to screw up in a major way. Rick Girard PS Probably the worst part came when Dave was finally able to enjoy the car again he took it for a drive on a beautiful day. A truck in front of him kicked up a stone that went right through the radiator. He pulled into a service station and the engine rattled to a stop. The kid at the pump popped open the hood and started filling the radiator before Dave could stop him. Put a crack all the way across the roof of the number three combustion chamber. On Wed, Apr 4, 2018 at 4:37 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 03:46 PM 4/4/2018, you wrote: > > If the bendix gear is sticky, such that the engine is able to drive the > starter, I could imagine that it could push a fairly high (albeit short) > number of joules back up the wire. Right? > > > the 'Bendix' drive is gone. All starters > use direct engagement solenoids. > > [image: https://upload.wikimedia.org/wikipedia/commons/f/fb/Starter_mot] > > A return spring retracts the pinion > gear upon removal of power from the > motor. In fact, electrical power to > the motor is interrupted during the initial > retraction so there is no torque being > transmitted from motor to ring gear. > At the same time, an overrun clutch > > * https://tinyurl.com/y7prvn7b * > > prevents the accelerating engine > from back-driving the starter. If > this clutch were not present, first > motion of the engine during pinion gear > retraction would break things. > > This feature was built into the legacy > 'bendix' drive. Starter motor acceleration > working against pinion gear mass would > drive it outward on the shaft by means > of a spiral groove on the shaft . . . > engine acceleration tending to over-run > the starter would drive the pinion back > from the ring gear with the same groove. > > > [image: Emacs!] > > > There have been some hangar-tales of starter > pinions 'sticking' and back driving starters. > There have been cases of contactor sticking > keeping power on the starter thus maintaining > pinion engagement. But no back driving could > have occurred due to action of the clutch. > Had the motor been driven backwards at the > pinion to ring gear ratio, it would probably > have slung wires out of the armature and/or > stripped gear teeth. > > The same gear reduction of pinion-to-ring > allows starter armature to run at several > thousand rpm to generated 200 rpm at the > crankshaft. Okay, after engine start and > run at 1000 rpm, a back-driving situation would > spin the starter armature 10000 rpm plus? > > Bob . . . > -- =9CBlessed are the cracked, for they shall let in the light.=9D Groucho Marx ________________________________ Message 19 ____________________________________ Time: 06:15:36 PM PST US Subject: Re: AeroElectric-List: Starter SURGES From: Charlie England At 1st glance, I'd suspect there's a flaw in the analysis. If the switch wasn't releasing, then the starter was still powered, regardless of whether the engine could drive it or not. That would mean it was running the entire time the car was running, and starters are not designed for that. Given the obvious lack of knowledge about the car and limited expertise of the people working on it, with that many service operations by those people working on it I'd find it difficult to pick any likely failure mode for the stuff that failed. Just one thought about the failure of the regulator: uninformed installation of the battery, even once. FWIW, Charlie On 4/4/2018 7:49 PM, Richard Girard wrote: > Bob, all, When I graduated high school back in the dark ages I had a > 1959 Alfa Romeo Giullietta Spider that had a nightmare starter system. > First, the electrical system was positive ground. That alone made > things interesting but the starter, or rather the starter switch was > the flash point of failure. Why? Because it had no spring return. You > had to physically turn the starter motor off or the starter would stay > connected with the ring gear and the engine would drive the starter. I > was warned by the guy who sold me the car and I only left it engaged > once for a few seconds. The grinding sound was kind of a give away and > I got away with it. When I sold the car to my best friend I told him > what I'd been told, "Never, ever let anyone else drive this car". > About four weeks after Dave bought it, he let his step brother drive > the car. He left the starter engaged for the entire 10 miles he drove > it. The next day, the battery was dead. When checked, it had internal > shorts and was junk. Dave bought a new Die Hard, the new thing in > battery advertising, if not battery technology. It lasted a couple of > weeks and Dave took it back to Sears. The battery was tested and > failed. He got a new one. It too failed in short order. This went on > for FOUR batteries before the manager at the Arden Way Sears gave my > friend a full refund and refused to sell him any more batteries. > Somewhere in the mess the starter failed and was replaced, the > generator failed, the headlights would burn out on a regular basis and > my friend almost became my ex-friend. He was a poor college student > trying to fix the car with suggestions from his dad and some mechanics > he knew. Finally his folks loaned him the money to take it to a garage > that worked on Alfas and they determined that the voltage regulator > was fried, too. This had gone on for almost six months before he > finally had the car back in a dependable condition. > So my take is, yeah, drive the starter and turn it into a generator > and things are going to screw up in a major way. > > Rick Girard > > PS Probably the worst part came when Dave was finally able to enjoy > the car again he took it for a drive on a beautiful day. A truck in > front of him kicked up a stone that went right through the radiator. > He pulled into a service station and the engine rattled to a stop. The > kid at the pump popped open the hood and started filling the radiator > before Dave could stop him. Put a crack all the way across the roof of > the number three combustion chamber. > > On Wed, Apr 4, 2018 at 4:37 PM, Robert L. Nuckolls, III > > > wrote: > > At 03:46 PM 4/4/2018, you wrote: >> If the bendix gear is sticky, such that the engine is able to >> drive the starter, I could imagine that it could push a fairly >> high (albeit short) number of joules back up the wire. Right? > > > the 'Bendix' drive is gone. All starters > use direct engagement solenoids. > > https://upload.wikimedia.org/wikipedia/commons/f/fb/Starter_mot > > A return spring retracts the pinion > gear upon removal of power from the > motor. In fact, electrical power to > the motor is interrupted during the initial > retraction so there is no torque being > transmitted from motor to ring gear. > At the same time, an overrun clutch > > *https://tinyurl.com/y7prvn7b * > > prevents the accelerating engine > from back-driving the starter. If > this clutch were not present, first > motion of the engine during pinion gear > retraction would break things. > > This feature was built into the legacy > 'bendix' drive. Starter motor acceleration > working against pinion gear mass would > drive it outward on the shaft by means > of a spiral groove on the shaft . . . > engine acceleration tending to over-run > the starter would drive the pinion back > from the ring gear with the same groove. > > > Emacs! > > > There have been some hangar-tales of starter > pinions 'sticking' and back driving starters. > There have been cases of contactor sticking > keeping power on the starter thus maintaining > pinion engagement. But no back driving could > have occurred due to action of the clutch. > Had the motor been driven backwards at the > pinion to ring gear ratio, it would probably > have slung wires out of the armature and/or > stripped gear teeth. > > The same gear reduction of pinion-to-ring > allows starter armature to run at several > thousand rpm to generated 200 rpm at the > crankshaft. Okay, after engine start and > run at 1000 rpm, a back-driving situation would > spin the starter armature 10000 rpm plus? > > Bob . . . > > > -- > > > Blessed are the cracked, for they shall let in the light. Groucho > Marx > > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 20 ____________________________________ Time: 07:11:57 PM PST US From: Richard Girard Subject: Re: AeroElectric-List: Starter SURGES Charlie, You're right, the starter was engaged and running but the minute the engine revved over starting rpm the engine was driving it, too. It's probably no surprise that the car had English electrics, a mix of Smith and Lucas. Me experience with it was too many ghost problems. The horn began to blow one night right as I was on my way out for a date. Disconnected the horn, went on the date and tried to get the horn working the next day. Reconnected it and nothing wrong. Never failed again. Then there was the night the passing lights started flashing on their own. Pulled the whole steering wheel off, went through it, couldn't find anything, put it back together, worked fine. Never failed again. As much as I loved the car I began to think of it as Mussolini's revenge. I didn't know about Lucas then..... Rick On Wed, Apr 4, 2018 at 8:14 PM, Charlie England wrote: > At 1st glance, I'd suspect there's a flaw in the analysis. If the switch > wasn't releasing, then the starter was still powered, regardless of wheth er > the engine could drive it or not. That would mean it was running the enti re > time the car was running, and starters are not designed for that. Given t he > obvious lack of knowledge about the car and limited expertise of the peop le > working on it, with that many service operations by those people working on > it I'd find it difficult to pick any likely failure mode for the stuff th at > failed. Just one thought about the failure of the regulator: uninformed > installation of the battery, even once. > > FWIW, > > Charlie > > On 4/4/2018 7:49 PM, Richard Girard wrote: > > Bob, all, When I graduated high school back in the dark ages I had a 1959 > Alfa Romeo Giullietta Spider that had a nightmare starter system. First, > the electrical system was positive ground. That alone made things > interesting but the starter, or rather the starter switch was the flash > point of failure. Why? Because it had no spring return. You had to > physically turn the starter motor off or the starter would stay connected > with the ring gear and the engine would drive the starter. I was warned b y > the guy who sold me the car and I only left it engaged once for a few > seconds. The grinding sound was kind of a give away and I got away with i t. > When I sold the car to my best friend I told him what I'd been told, > "Never, ever let anyone else drive this car". About four weeks after Dave > bought it, he let his step brother drive the car. He left the starter > engaged for the entire 10 miles he drove it. The next day, the battery wa s > dead. When checked, it had internal shorts and was junk. Dave bought a ne w > Die Hard, the new thing in battery advertising, if not battery technology .. > It lasted a couple of weeks and Dave took it back to Sears. The battery w as > tested and failed. He got a new one. It too failed in short order. This > went on for FOUR batteries before the manager at the Arden Way Sears gave > my friend a full refund and refused to sell him any more batteries. > Somewhere in the mess the starter failed and was replaced, the generator > failed, the headlights would burn out on a regular basis and my friend > almost became my ex-friend. He was a poor college student trying to fix t he > car with suggestions from his dad and some mechanics he knew. Finally his > folks loaned him the money to take it to a garage that worked on Alfas an d > they determined that the voltage regulator was fried, too. This had gone on > for almost six months before he finally had the car back in a dependable > condition. > So my take is, yeah, drive the starter and turn it into a generator and > things are going to screw up in a major way. > > Rick Girard > > PS Probably the worst part came when Dave was finally able to enjoy the > car again he took it for a drive on a beautiful day. A truck in front of > him kicked up a stone that went right through the radiator. He pulled int o > a service station and the engine rattled to a stop. The kid at the pump > popped open the hood and started filling the radiator before Dave could > stop him. Put a crack all the way across the roof of the number three > combustion chamber. > > On Wed, Apr 4, 2018 at 4:37 PM, Robert L. Nuckolls, III < > nuckolls.bob@aeroelectric.com> wrote: > >> At 03:46 PM 4/4/2018, you wrote: >> >> If the bendix gear is sticky, such that the engine is able to drive the >> starter, I could imagine that it could push a fairly high (albeit short) >> number of joules back up the wire. Right? >> >> >> >> the 'Bendix' drive is gone. All starters >> use direct engagement solenoids. >> >> [image: https://upload.wikimedia.org/wikipedia/commons/f/fb/Starter_mot] >> >> >> A return spring retracts the pinion >> gear upon removal of power from the >> motor. In fact, electrical power to >> the motor is interrupted during the initial >> retraction so there is no torque being >> transmitted from motor to ring gear. >> At the same time, an overrun clutch >> >> * https://tinyurl.com/y7prvn7b * >> >> prevents the accelerating engine >> from back-driving the starter. If >> this clutch were not present, first >> motion of the engine during pinion gear >> retraction would break things. >> >> This feature was built into the legacy >> 'bendix' drive. Starter motor acceleration >> working against pinion gear mass would >> drive it outward on the shaft by means >> of a spiral groove on the shaft . . . >> engine acceleration tending to over-run >> the starter would drive the pinion back >> from the ring gear with the same groove. >> >> >> [image: Emacs!] >> >> >> >> There have been some hangar-tales of starter >> pinions 'sticking' and back driving starters. >> There have been cases of contactor sticking >> keeping power on the starter thus maintaining >> pinion engagement. But no back driving could >> have occurred due to action of the clutch. >> Had the motor been driven backwards at the >> pinion to ring gear ratio, it would probably >> have slung wires out of the armature and/or >> stripped gear teeth. >> >> The same gear reduction of pinion-to-ring >> allows starter armature to run at several >> thousand rpm to generated 200 rpm at the >> crankshaft. Okay, after engine start and >> run at 1000 rpm, a back-driving situation would >> spin the starter armature 10000 rpm plus? >> >> Bob . . . >> > > > -- > =9CBlessed are the cracked, for they shall let in the light. =9D Groucho Marx > > > > ------------------------------ > [image: Avast logo] > > This email has been checked for viruses by Avast antivirus software. > www.avast.com > > <#m_-7793493755374373132_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > -- =9CBlessed are the cracked, for they shall let in the light.=9D Groucho Marx ________________________________ Message 21 ____________________________________ Time: 07:47:41 PM PST US Subject: Re: AeroElectric-List: Starter SURGES From: Charlie England Oh, Lucus. You buried the lead. And explained all the problems in one word. Just so you know, it didn't get much better in the intervening 11 years; the '70 Spyder I owned housed a demon who made sure I never knew when it would start. Always turned over, but the bizarre and primitive electro-mechanical injection had a mind (or demon) of its own. On 4/4/2018 9:11 PM, Richard Girard wrote: > Charlie, You're right, the starter was engaged and running but the > minute the engine revved over starting rpm the engine was driving it, > too. It's probably no surprise that the car had English electrics, a > mix of Smith and Lucas. Me experience with it was too many ghost > problems. The horn began to blow one night right as I was on my way > out for a date. Disconnected the horn, went on the date and tried to > get the horn working the next day. Reconnected it and nothing wrong. > Never failed again. Then there was the night the passing lights > started flashing on their own. Pulled the whole steering wheel off, > went through it, couldn't find anything, put it back together, worked > fine. Never failed again. As much as I loved the car I began to think > of it as Mussolini's revenge. I didn't know about Lucas then..... > > Rick > > On Wed, Apr 4, 2018 at 8:14 PM, Charlie England > wrote: > > At 1st glance, I'd suspect there's a flaw in the analysis. If the > switch wasn't releasing, then the starter was still powered, > regardless of whether the engine could drive it or not. That would > mean it was running the entire time the car was running, and > starters are not designed for that. Given the obvious lack of > knowledge about the car and limited expertise of the people > working on it, with that many service operations by those people > working on it I'd find it difficult to pick any likely failure > mode for the stuff that failed. Just one thought about the failure > of the regulator: uninformed installation of the battery, even once. > > FWIW, > > Charlie > > On 4/4/2018 7:49 PM, Richard Girard wrote: >> Bob, all, When I graduated high school back in the dark ages I >> had a 1959 Alfa Romeo Giullietta Spider that had a nightmare >> starter system. First, the electrical system was positive ground. >> That alone made things interesting but the starter, or rather the >> starter switch was the flash point of failure. Why? Because it >> had no spring return. You had to physically turn the starter >> motor off or the starter would stay connected with the ring gear >> and the engine would drive the starter. I was warned by the guy >> who sold me the car and I only left it engaged once for a few >> seconds. The grinding sound was kind of a give away and I got >> away with it. When I sold the car to my best friend I told him >> what I'd been told, "Never, ever let anyone else drive this car". >> About four weeks after Dave bought it, he let his step brother >> drive the car. He left the starter engaged for the entire 10 >> miles he drove it. The next day, the battery was dead. When >> checked, it had internal shorts and was junk. Dave bought a new >> Die Hard, the new thing in battery advertising, if not battery >> technology. It lasted a couple of weeks and Dave took it back to >> Sears. The battery was tested and failed. He got a new one. It >> too failed in short order. This went on for FOUR batteries before >> the manager at the Arden Way Sears gave my friend a full refund >> and refused to sell him any more batteries. Somewhere in the mess >> the starter failed and was replaced, the generator failed, the >> headlights would burn out on a regular basis and my friend almost >> became my ex-friend. He was a poor college student trying to fix >> the car with suggestions from his dad and some mechanics he knew. >> Finally his folks loaned him the money to take it to a garage >> that worked on Alfas and they determined that the voltage >> regulator was fried, too. This had gone on for almost six months >> before he finally had the car back in a dependable condition. >> So my take is, yeah, drive the starter and turn it into a >> generator and things are going to screw up in a major way. >> >> Rick Girard >> >> PS Probably the worst part came when Dave was finally able to >> enjoy the car again he took it for a drive on a beautiful day. A >> truck in front of him kicked up a stone that went right through >> the radiator. He pulled into a service station and the engine >> rattled to a stop. The kid at the pump popped open the hood and >> started filling the radiator before Dave could stop him. Put a >> crack all the way across the roof of the number three combustion >> chamber. >> >> On Wed, Apr 4, 2018 at 4:37 PM, Robert L. Nuckolls, III >> > > wrote: >> >> At 03:46 PM 4/4/2018, you wrote: >>> If the bendix gear is sticky, such that the engine is able >>> to drive the starter, I could imagine that it could push a >>> fairly high (albeit short) number of joules back up the >>> wire. Right? >> >> >> the 'Bendix' drive is gone. All starters >> use direct engagement solenoids. >> >> https://upload.wikimedia.org/wikipedia/commons/f/fb/Starter_mot >> >> A return spring retracts the pinion >> gear upon removal of power from the >> motor. In fact, electrical power to >> the motor is interrupted during the initial >> retraction so there is no torque being >> transmitted from motor to ring gear. >> At the same time, an overrun clutch >> >> *https://tinyurl.com/y7prvn7b * >> >> prevents the accelerating engine >> from back-driving the starter. If >> this clutch were not present, first >> motion of the engine during pinion gear >> retraction would break things. >> >> This feature was built into the legacy >> 'bendix' drive. Starter motor acceleration >> working against pinion gear mass would >> drive it outward on the shaft by means >> of a spiral groove on the shaft . . . >> engine acceleration tending to over-run >> the starter would drive the pinion back >> from the ring gear with the same groove. >> >> >> Emacs! >> >> >> >> There have been some hangar-tales of starter >> pinions 'sticking' and back driving starters. >> There have been cases of contactor sticking >> keeping power on the starter thus maintaining >> pinion engagement. But no back driving could >> have occurred due to action of the clutch. >> Had the motor been driven backwards at the >> pinion to ring gear ratio, it would probably >> have slung wires out of the armature and/or >> stripped gear teeth. >> >> The same gear reduction of pinion-to-ring >> allows starter armature to run at several >> thousand rpm to generated 200 rpm at the >> crankshaft. Okay, after engine start and >> run at 1000 rpm, a back-driving situation would >> spin the starter armature 10000 rpm plus? >> >> Bob . . . >> >> >> >> >> -- >> >> >> Blessed are the cracked, for they shall let in the light. >> Groucho Marx >> >> >> > > > ------------------------------------------------------------------------ > Avast logo > > This email has been checked for viruses by Avast antivirus software. > www.avast.com > > > <#m_-7793493755374373132_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > > -- > > > Blessed are the cracked, for they shall let in the light. Groucho > Marx > > ________________________________ Message 22 ____________________________________ Time: 09:20:18 PM PST US From: Richard Girard Subject: Re: AeroElectric-List: Starter SURGES Good to know I'm not the only one. Mine wouldn't start one day and I started going through the manual. Check the condenser with this method it said. Bad condenser. The guy at the NAPA store told me, "condensers never go bad, you need a coil". No, I need a condenser. HA HA HA, kid doesn't know anything about cars, does he. They all got a big laugh out of. Finally got them to sell me a damn condenser. Put it in, started right up, took the bad condenser back to NAPA and dared the guy to put it in his car. It wasn't until I was on my way home that it occurred to me, why do you always change points, plugs and condenser if the condenser never fails? Last time I ever went to that store. The manual also said to re-torque the head every 1300 miles. I found out the hard way it was because the head gasket would blow at 1305 miles. Still in all. I loved that car, I cut my teeth on it mechanically and I love Alfas to this day. If I ever hit the Lotto I'm going to blow part of it on a 1938 8C Mille Miglia. And a Tipo 51 Bugatti. The two most beautiful cars made before WWII. IMHO, anyway. Rick On Wed, Apr 4, 2018 at 9:46 PM, Charlie England wrote: > Oh, Lucus. You buried the lead. And explained all the problems in one wor d. > > Just so you know, it didn't get much better in the intervening 11 years; > the '70 Spyder I owned housed a demon who made sure I never knew when it > would start. Always turned over, but the bizarre and primitive > electro-mechanical injection had a mind (or demon) of its own. > > > On 4/4/2018 9:11 PM, Richard Girard wrote: > > Charlie, You're right, the starter was engaged and running but the minute > the engine revved over starting rpm the engine was driving it, too. It's > probably no surprise that the car had English electrics, a mix of Smith a nd > Lucas. Me experience with it was too many ghost problems. The horn began to > blow one night right as I was on my way out for a date. Disconnected the > horn, went on the date and tried to get the horn working the next day. > Reconnected it and nothing wrong. Never failed again. Then there was the > night the passing lights started flashing on their own. Pulled the whole > steering wheel off, went through it, couldn't find anything, put it back > together, worked fine. Never failed again. As much as I loved the car I > began to think of it as Mussolini's revenge. I didn't know about Lucas > then..... > > Rick > > On Wed, Apr 4, 2018 at 8:14 PM, Charlie England > wrote: > >> At 1st glance, I'd suspect there's a flaw in the analysis. If the switch >> wasn't releasing, then the starter was still powered, regardless of whet her >> the engine could drive it or not. That would mean it was running the ent ire >> time the car was running, and starters are not designed for that. Given the >> obvious lack of knowledge about the car and limited expertise of the peo ple >> working on it, with that many service operations by those people working on >> it I'd find it difficult to pick any likely failure mode for the stuff t hat >> failed. Just one thought about the failure of the regulator: uninformed >> installation of the battery, even once. >> >> FWIW, >> >> Charlie >> >> On 4/4/2018 7:49 PM, Richard Girard wrote: >> >> Bob, all, When I graduated high school back in the dark ages I had a 195 9 >> Alfa Romeo Giullietta Spider that had a nightmare starter system. First, >> the electrical system was positive ground. That alone made things >> interesting but the starter, or rather the starter switch was the flash >> point of failure. Why? Because it had no spring return. You had to >> physically turn the starter motor off or the starter would stay connecte d >> with the ring gear and the engine would drive the starter. I was warned by >> the guy who sold me the car and I only left it engaged once for a few >> seconds. The grinding sound was kind of a give away and I got away with it. >> When I sold the car to my best friend I told him what I'd been told, >> "Never, ever let anyone else drive this car". About four weeks after Dav e >> bought it, he let his step brother drive the car. He left the starter >> engaged for the entire 10 miles he drove it. The next day, the battery w as >> dead. When checked, it had internal shorts and was junk. Dave bought a n ew >> Die Hard, the new thing in battery advertising, if not battery technolog y. >> It lasted a couple of weeks and Dave took it back to Sears. The battery was >> tested and failed. He got a new one. It too failed in short order. This >> went on for FOUR batteries before the manager at the Arden Way Sears gav e >> my friend a full refund and refused to sell him any more batteries. >> Somewhere in the mess the starter failed and was replaced, the generator >> failed, the headlights would burn out on a regular basis and my friend >> almost became my ex-friend. He was a poor college student trying to fix the >> car with suggestions from his dad and some mechanics he knew. Finally hi s >> folks loaned him the money to take it to a garage that worked on Alfas a nd >> they determined that the voltage regulator was fried, too. This had gone on >> for almost six months before he finally had the car back in a dependable >> condition. >> So my take is, yeah, drive the starter and turn it into a generator and >> things are going to screw up in a major way. >> >> Rick Girard >> >> PS Probably the worst part came when Dave was finally able to enjoy the >> car again he took it for a drive on a beautiful day. A truck in front of >> him kicked up a stone that went right through the radiator. He pulled in to >> a service station and the engine rattled to a stop. The kid at the pump >> popped open the hood and started filling the radiator before Dave could >> stop him. Put a crack all the way across the roof of the number three >> combustion chamber. >> >> On Wed, Apr 4, 2018 at 4:37 PM, Robert L. Nuckolls, III < >> nuckolls.bob@aeroelectric.com> wrote: >> >>> At 03:46 PM 4/4/2018, you wrote: >>> >>> If the bendix gear is sticky, such that the engine is able to drive the >>> starter, I could imagine that it could push a fairly high (albeit short ) >>> number of joules back up the wire. Right? >>> >>> >>> >>> the 'Bendix' drive is gone. All starters >>> use direct engagement solenoids. >>> >>> [image: https://upload.wikimedia.org/wikipedia/commons/f/fb/Starter_mot ] >>> >>> >>> A return spring retracts the pinion >>> gear upon removal of power from the >>> motor. In fact, electrical power to >>> the motor is interrupted during the initial >>> retraction so there is no torque being >>> transmitted from motor to ring gear. >>> At the same time, an overrun clutch >>> >>> * https://tinyurl.com/y7prvn7b * >>> >>> prevents the accelerating engine >>> from back-driving the starter. If >>> this clutch were not present, first >>> motion of the engine during pinion gear >>> retraction would break things. >>> >>> This feature was built into the legacy >>> 'bendix' drive. Starter motor acceleration >>> working against pinion gear mass would >>> drive it outward on the shaft by means >>> of a spiral groove on the shaft . . . >>> engine acceleration tending to over-run >>> the starter would drive the pinion back >>> from the ring gear with the same groove. >>> >>> >>> [image: Emacs!] >>> >>> >>> >>> There have been some hangar-tales of starter >>> pinions 'sticking' and back driving starters. >>> There have been cases of contactor sticking >>> keeping power on the starter thus maintaining >>> pinion engagement. But no back driving could >>> have occurred due to action of the clutch. >>> Had the motor been driven backwards at the >>> pinion to ring gear ratio, it would probably >>> have slung wires out of the armature and/or >>> stripped gear teeth. >>> >>> The same gear reduction of pinion-to-ring >>> allows starter armature to run at several >>> thousand rpm to generated 200 rpm at the >>> crankshaft. Okay, after engine start and >>> run at 1000 rpm, a back-driving situation would >>> spin the starter armature 10000 rpm plus? >>> >>> Bob . . . >>> >> >> >> >> -- >> =9CBlessed are the cracked, for they shall let in the light. =9D Groucho >> Marx >> >> >> >> >> ------------------------------ >> [image: Avast logo] >> >> This email has been checked for viruses by Avast antivirus software. >> www.avast.com >> >> >> <#m_-5736806203088520134_m_-7793493755374373132_DAB4FAD8-2DD7-40BB-A1B8- 4E2AA1F9FDF2> >> > > > -- > =9CBlessed are the cracked, for they shall let in the light. =9D Groucho Marx > > > -- =9CBlessed are the cracked, for they shall let in the light.=9D Groucho Marx ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.