---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 06/10/09: 21 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:24 AM - Re: Z12 questions (Bob Barrow) 2. 06:10 AM - Re: Z12 questions (Robert L. Nuckolls, III) 3. 06:18 AM - Re: problem in Bob's Wigwag.pdf circuit? (Robert L. Nuckolls, III) 4. 07:04 AM - Re: problem in Bob's Wigwag.pdf circuit? (dave.gribble@mchsi.com) 5. 08:37 AM - Re: Canopy Switch (Greg Young) 6. 09:32 AM - Re: Z12 questions (Jim Berry) 7. 10:17 AM - Circuit for "alternator emulator" for SEC-1223 (DCS317@aol.com) 8. 10:22 AM - Reverse flow in Shunt and Hall Effect (Speedy11@aol.com) 9. 10:23 AM - IFR Certification (Speedy11@aol.com) 10. 11:25 AM - Re: IFR Certification (Hinde, Frank George (Corvallis)) 11. 11:40 AM - Re: IFR Certification (Neal George) 12. 12:14 PM - Help witn Dynon 180 and RAC Parts (Gig Giacona) 13. 12:14 PM - Measuring voltage on aircraft and engine sensors? (mosquito56) 14. 12:27 PM - Re: IFR Certification (SteinAir, Inc.) 15. 02:15 PM - Re: Canopy Switch (Phil Birkelbach) 16. 04:26 PM - Burning up Vans Engine Gauges - Part Two. (JakeTheBosun) 17. 05:09 PM - Re: Burning up Vans Engine Gauges - Part Two. (Matt Prather) 18. 05:13 PM - Re: Burning up Vans Engine Gauges - Part Two. (n801bh@netzero.com) 19. 07:51 PM - Re: Reverse flow in Shunt and Hall Effect (Robert L. Nuckolls, III) 20. 07:53 PM - Re: Canopy Switch (bcondrey) 21. 08:22 PM - Re: Reverse flow in Shunt and Hall Effect (Matt Prather) ________________________________ Message 1 _____________________________________ Time: 05:24:28 AM PST US From: Bob Barrow Subject: RE: AeroElectric-List: Z12 questions From: nuckolls.bob@aeroelectric.com Subject: Re: AeroElectric-List: Z12 questions > Yes=2C you can run both alternators together but >getting them to share proportionately is difficult >without special paralleling regulators. Bob=2C what exactly happens with architecture Z12 (with specifically one L R3 and one SB-1 regulator) if you keep turning on major loads (pitot=2C lan ding lights=2C etc) until the primary L40 alternator can no longer cope and the voltage sags. Will the SD20 come on and run concurrently. I presume it will... until some of the loads are shed..but from your comment above it may not be a happy event over time. Can you please elaborate on this. Is it possible that one or both of the alternators (or the regulators) could be damaged if both alternators are running concurrently in Z12. I'm trying to work out whether with Z12 I need to ensure that my primary al ternator is never pushed beyond its capacity (ie swap the L40 for an L60). Regards Bob Barrow _________________________________________________________________ POP access for Hotmail is here! Click here to find out more http://windowslive.ninemsn.com.au/article.aspx?id2246 ________________________________ Message 2 _____________________________________ Time: 06:10:06 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Z12 questions At 07:22 AM 6/10/2009, you wrote: > > >---------- > >Date: Tue, 9 Jun 2009 15:20:29 -0500 >To: aeroelectric-list@matronics.com >From: nuckolls.bob@aeroelectric.com >Subject: Re: AeroElectric-List: Z12 questions > > > > Yes, you can run both alternators together but > >getting them to share proportionately is difficult > >without special paralleling regulators. > > Bob, what exactly happens with architecture Z12 (with specifically > one LR3 and one SB-1 regulator) if you keep turning on major loads > (pitot, landing lights, etc) until the primary L40 alternator can > no longer cope and the voltage sags. Will the SD20 come on and run > concurrently. I presume it will... until some of the loads are > shed..but from your comment above it may not be a happy event over > time. Can you please elaborate on this. Is it possible that one or > both of the alternators (or the regulators) could be damaged if > both alternators are running concurrently in Z12. > >I'm trying to work out whether with Z12 I need to ensure that my >primary alternator is never pushed beyond its capacity (ie swap the >L40 for an L60). The "sharing" scenario you described is correct when the SD-20 is regulated by the SB-1 and the aux alternator setpoint is about 1 volt lower than the main alternator. As long as your main alternator is adequately cooled, there is no risk of damage to the main alternator. I was curious as to what kind of loads you are anticipating that would require over 30A of continuous engine driven power. For example, you wouldn't have any exterior lights on along with pitot heat. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 3 _____________________________________ Time: 06:18:29 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: problem in Bob's Wigwag.pdf circuit? At 07:49 PM 6/9/2009, you wrote: >Hello - I am new to the list so please don't flame me for posting >this. I am designing my landing lights around the circuit on page 4 >of Bob's Wigwg.pdf. > >This is the circuit that uses the 4PDT switch, marked "4TL1-10 or >equal" I just ordered my switch today. My design goal of this >circuit is to have the switch function as OFF-WIGWAG-ON, with OFF in >the bottom position. > >In completing my design, I noticed in the Honeywell datasheet for >the 4TL1-10 switch (available at this link: >http://www.datasheetarchive.com/4TL1-10-datasheet.html >) does not match the one in Bob's schematic. > >The problem is that for the -10 switch in the datasheet, there are >two poles (pins 8 & 11) that are open in the center condition. The >switch in Bob's circuit requires all poles to be active in all positions. > >After careful datasheet reading, I think that Bob's design will work >with a 4TL1-12 switch. It is supposedly the same circuitry as a -50 >(which looks right) and has no momentary positions. > >Can anyone confirm that I need to cancel my order for the -10 and >get a -12 instead? I'm hoping to find out quickly to avoid buying >the wrong switch. > >I did search the archive and found a single poster mentioning that >the circuit didn't work... maybe this was why? I just checked the data package for wig-wag options I published at: http://www.aeroelectric.com/PPS/Lighting/WigWag.pdf The single control switch option on page 4 calls out the 4TL1-12 switch. Where did you see a recommendation for the 4TL1-10? I note that this drawing was updated in January of 07. I don't recall now but perhaps this change was to correct the part number. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 4 _____________________________________ Time: 07:04:06 AM PST US From: dave.gribble@mchsi.com Subject: Re: AeroElectric-List: problem in Bob's Wigwag.pdf circuit? ________________________________ Message 5 _____________________________________ Time: 08:37:54 AM PST US From: "Greg Young" Subject: RE: AeroElectric-List: Canopy Switch The RV-10 guys have the same issue and can have a really bad day if they launch without the doors being latched. I've got two friends with RV-10s that have switches that are triggered by the door pins. I can't give you part numbers but check the RV-10 sites. I think they are 3rd party and not Van's. Regards, Greg Young > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On > Behalf Of longg@pjm.com > Sent: Tuesday, June 09, 2009 4:23 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Canopy Switch > > > I want to add a canopy (open) warning switch to my Lanciar > Legacy. I've got a Dynon 180 which handles all the high tech > stuff but I need the appropriate switch and vendor > information from which to source it. > Naturally the switch should be low profile or recessed and > perhaps be adjustable in depth such that it could be adjusted > to the canopy tightness. > > The premise of the Dynon is to alert via a contact light of a > normally closed or normally open item. Basically if it's > grounded, it closes the switch and allows the turns the light green. > > If you have completed such an installation I'd be glad to > hear of what switch you used and related frustrations if any. > > > Thanks in advance, > Glenn ________________________________ Message 6 _____________________________________ Time: 09:32:27 AM PST US Subject: AeroElectric-List: Re: Z12 questions From: "Jim Berry" Bob, This raises a question that I know has been discussed before, but I could not find in the archives. I have a Plane Power 60A and a SD20. What are the pros and cons of using two LR3 's versus one LR3 and one SB-1? Thanks. Jim Berry RV10 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247562#247562 ________________________________ Message 7 _____________________________________ Time: 10:17:50 AM PST US From: DCS317@aol.com Subject: AeroElectric-List: Circuit for "alternator emulator" for SEC-1223 Bob, Have you found (in your paper stack) the circuit for a battery backup module or "alternator emulator" used to convert SEC-1223 power supply for battery backup application? I want to run my avionics while the battery backup module is used between the SEC-1223 and the aircraft battery. My previous thread on Aerolectrics was about the problem of running my avionics with the SEC-1223 wired to the the aircraft battery. As I under stand this, there is a problem with the battery backfeeding the SEC-1223 and a problem with a discharged battery damaging the SEC-1223 by drawing too mu ch current. Would this simple circuit work? Input Negative (from SEC-1223)----------------------------Battery Negative-------------Load Negative (Avionics) Input Positive(from SEC-1223)----------!>------------------Battery Positive-------------Load Positive (Avionics) !> is a Schottky Diode to protect the Battery backfeeding the Power Supply. Unfortunately, this gives no protection to the power supply (over-current) AND too much charging current for my recombinant gas batte ry in the case of a discharged battery. The circuit also lowers the voltage to th e battery because of the diode forward voltage drop of 0.4 to 0.5 volt depe nding on the current draw, leaving 13.4 to 13.3 volts to the battery. My battery is a 34AHr Concorde CB35 RGXC. Recommended charging current woul d be 34 divided by 20 = 1.7 amps. Adding power resistors to the series circ uit to protect the power supply from providing too much current would only reduce the current to the battery and limit the voltage to the avionics from battery drawdown? 1. Recommended circuit to solve my problems? OR 2. Don't worry about a discharged battery if I know it is reasonably full y charged and just us the simple circuit above to protect the Battery backfeeding the Power Supply? Adequate forward voltage? Source and specs for the Shottky diode? OR 3. Just use the b-lead to the alternator as you recommended before? How to identify b-lead and attach which suitable connector so I can get to it easily on a regular basis? Run wire to my cowling cooling air outlet wit h which connector. OR Install a cigarette lighter outlet under my panel to energize the avionics master and leave the battery master switch off? Help! Don Schmiesing **************Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop Dell =99s full line of laptops. =http:%2F%2Fad.doubleclick.net%2Fclk%3B215566094%3B3786435 8%3Bv) ________________________________ Message 8 _____________________________________ Time: 10:22:04 AM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Reverse flow in Shunt and Hall Effect I have a HE device on the B lead from the Alternator to the main battery. It is oriented so that current is measured from the alternator to the mai n battery thus indicating the load imposed on the alternator. I have a shunt on the standby battery to measure current being used from the battery. If current flows in the opposite direction from the planned flow, does one get a negative amperage indication? Stan Sutterfield **************Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop Dell =99s full line of laptops. =http:%2F%2Fad.doubleclick.net%2Fclk%3B215566094%3B3786435 8%3Bv) ________________________________ Message 9 _____________________________________ Time: 10:23:41 AM PST US From: Speedy11@aol.com Subject: AeroElectric-List: IFR Certification This may not be the ideal forum for asking this question, but I'll try it anyway. I want to certify my RV-8 for IFR flight. I know the FARs - I've looked at them. I have the Blue Mountain EFIS One as primary instrumentation. I have the Blue Mountain EFIS Lite as a backup. Both EFISs are on different electrical busses - the main and the standby. - which can be tied together, if needed. I asked a local avionics guy about doing a pitot-static and transponder check for IFR. He said I would have to install a separate altimeter and encoder in order to get IFR certification. The EFIS has a built-in encod er. Has anyone else encountered this obstacle? Stan Sutterfield **************Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop Dell =99s full line of laptops. =http:%2F%2Fad.doubleclick.net%2Fclk%3B215566094%3B3786435 8%3Bv) ________________________________ Message 10 ____________________________________ Time: 11:25:52 AM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: IFR Certification Nonsence!..He'll be telling you you need a vacuum pump next! I have a Dynon D100 that does the altitude encoding and there is certainly no requirement for a second altimeter. Go elsewhere.. Frank 7a IFR ________________________________ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectr ic-list-server@matronics.com] On Behalf Of Speedy11@aol.com Sent: Wednesday, June 10, 2009 10:21 AM Subject: AeroElectric-List: IFR Certification This may not be the ideal forum for asking this question, but I'll try it a nyway. I want to certify my RV-8 for IFR flight. I know the FARs - I've looked at them. I have the Blue Mountain EFIS One as primary instrumentation. I have the Blue Mountain EFIS Lite as a backup. Both EFISs are on different electrical busses - the main and the standby. - which can be tied together, if needed. I asked a local avionics guy about doing a pitot-static and transponder che ck for IFR. He said I would have to install a separate altimeter and encod er in order to get IFR certification. The EFIS has a built-in encoder. Has anyone else encountered this obstacle? Stan Sutterfield ________________________________ Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop Dell's full line of redir=http:%2F%2Fad.doubleclick.net%2Fclk%3B215566094%3B37864358%3Bv> ________________________________ Message 11 ____________________________________ Time: 11:40:46 AM PST US From: "Neal George" Subject: RE: AeroElectric-List: IFR Certification Stan =93 Other folks have had similar issues. Some avionics shops demand TSOd equipment, then can=99t quote chapter and verse of the reg that requires it. The technician=99s task is to test the equipment as installed and verify that the data it puts out is accurate within limits, not to pass judgment on your choice of hardware. Find yourself another shop. Neal ------------------------ This may not be the ideal forum for asking this question, but I'll try it anyway. I want to certify my RV-8 for IFR flight. I know the FARs - I've looked at them. I have the Blue Mountain EFIS One as primary instrumentation. I have the Blue Mountain EFIS Lite as a backup. Both EFISs are on different electrical busses - the main and the standby. - which can be tied together, if needed. I asked a local avionics guy about doing a pitot-static and transponder check for IFR. He said I would have to install a separate altimeter and encoder in order to get IFR certification. The EFIS has a built-in encoder. Has anyone else encountered this obstacle? Stan Sutterfield ________________________________ Message 12 ____________________________________ Time: 12:14:47 PM PST US Subject: AeroElectric-List: Help witn Dynon 180 and RAC Parts From: "Gig Giacona" Anyone have a wiring diagram for where they installed with a Dynon 180... 2 RAC trim servos, 1 RAC Flap Sensor, 1 five button RAC grip? -------- W.R. "Gig" Giacona 601XL Under Construction See my progress at www.peoamerica.net/N601WR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247593#247593 ________________________________ Message 13 ____________________________________ Time: 12:14:47 PM PST US Subject: AeroElectric-List: Measuring voltage on aircraft and engine sensors? From: "mosquito56" I am trying to connect my aircraft to a microcontroller and some adc's. Will a hall effect rpm sensor work on 5vdc? Are the oil temp and oil pressure sensors just pots? I am using a Jabiruu 3300. Thanx much Don Zodiac 601xl N601NV Soon beginning engine install. -------- Don Merritt- Laredo, Tx Apologies if I seem antagonistic. I believe in the freeflowing ideas and discussions between individuals for assistance in this thing we call life. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247592#247592 ________________________________ Message 14 ____________________________________ Time: 12:27:38 PM PST US From: "SteinAir, Inc." Subject: RE: AeroElectric-List: IFR Certification This is a rather common occurance by shops that are either uneducated or inexperienced with experimental aircraft. Sometimes it's also as a result of naiive FSDO people as well. Basically the information provided to you is completely false and not correct. The EFIS with it's encoder is just fine....so is it's altimeter - assuming both will pass an IFR check. We have our FAA Repair Station Certification and do a lot of said pitot static and/or transponder checks on both certified and experimentals. Should be no problem if you find the right people or right shop. Cheers, Stein -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Speedy11@aol.com Sent: Wednesday, June 10, 2009 12:21 PM To: aeroelectric-list@matronics.com Subject: AeroElectric-List: IFR Certification This may not be the ideal forum for asking this question, but I'll try it anyway. I want to certify my RV-8 for IFR flight. I know the FARs - I've looked at them. I have the Blue Mountain EFIS One as primary instrumentation. I have the Blue Mountain EFIS Lite as a backup. Both EFISs are on different electrical busses - the main and the standby. - which can be tied together, if needed. I asked a local avionics guy about doing a pitot-static and transponder check for IFR. He said I would have to install a separate altimeter and encoder in order to get IFR certification. The EFIS has a built-in encoder. Has anyone else encountered this obstacle? Stan Sutterfield ---------------------------------------------------------------------------- -- Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop Dell's full line of laptops. ________________________________ Message 15 ____________________________________ Time: 02:15:22 PM PST US From: Phil Birkelbach Subject: Re: AeroElectric-List: Canopy Switch I put a switch on the canopy latch of my RV-7. It indicates that the canopy is "closed and latched." I don't remember the part number of the switch but it was just a tiny little limit switch. it has worked well for 180 hours. Occasionally it even reminds me to close the canopy. :-) There are a couple of pictures here... http://www.myrv7.com/viewlog.php?year 05&month=2 Any switch that is a SPDT should work for what you want to do, I seriously doubt that the detection circuit carries more than a few milliamps. You just need to find one that fits the geometry. Phil On Jun 9, 2009, at 4:23 PM, wrote: > > I want to add a canopy (open) warning switch to my Lanciar Legacy. > I've > got a Dynon 180 which handles all the high tech stuff but I need the > appropriate switch and vendor information from which to source it. > Naturally the switch should be low profile or recessed and perhaps be > adjustable in depth such that it could be adjusted to the canopy > tightness. > > The premise of the Dynon is to alert via a contact light of a normally > closed or normally open item. Basically if it's grounded, it closes > the > switch and allows the turns the light green. > > If you have completed such an installation I'd be glad to hear of what > switch you used and related frustrations if any. > > > Thanks in advance, > Glenn > > ________________________________ Message 16 ____________________________________ Time: 04:26:33 PM PST US Subject: AeroElectric-List: Burning up Vans Engine Gauges - Part Two. From: "JakeTheBosun" Well I'm stumped....my simple RV8, basic analog instruments only, Nipon Denso 40 amp Alternator, Oddeysey battery, worked well for 200 hours. Saturday Volt Meter burned (resistor on circuit board overheated and melted case), then Oil Temperature gauge did same thing, now today while testing Manifold Pressure full of smoke. I have; -checked - no loose wires found ground or power. -Good Battery-engine-ground (heavy cable, short runs, tight connections.) -Good bus connections (one central ground bus located at firewall) -14.2 Volts on meter at gauges while running, but instruments overheat. -12+ volts on meter when engine stopped, instruments seem not to overheat. -Removed alternator and took to shop for evaluation....tested on stand and found good output and diodes. Anybody got a next step? Nice weather........need to fly George -------- Jake Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247617#247617 ________________________________ Message 17 ____________________________________ Time: 05:09:14 PM PST US Subject: Re: AeroElectric-List: Burning up Vans Engine Gauges - Part Two. From: "Matt Prather" Interesting.. Can you see what in the instrument is fried? Is it a component connected to the V+ or from the signal/sensor (or something else)? I assume the 14.2V value is measured on the instrument supply (V+) terminal. Can you compare this with the voltage at the bus. Can you measure the voltage drop between the instrument (display) ground and the engine ground (with the engine running)? I understand that all of the connections appear solid. Have you done any recent maintenance or mods? Regards, Matt- > > > Well I'm stumped....my simple RV8, basic analog instruments only, Nipon > Denso 40 amp Alternator, Oddeysey battery, worked well for 200 hours. > > Saturday Volt Meter burned (resistor on circuit board overheated and > melted case), then Oil Temperature gauge did same thing, now today while > testing Manifold Pressure full of smoke. > > I have; > -checked - no loose wires found ground or power. > -Good Battery-engine-ground (heavy cable, short runs, tight connections.) > -Good bus connections (one central ground bus located at firewall) > -14.2 Volts on meter at gauges while running, but instruments overheat. > -12+ volts on meter when engine stopped, instruments seem not to overheat. > -Removed alternator and took to shop for evaluation....tested on stand and > found good output and diodes. > > > Anybody got a next step? Nice weather........need to fly > George > > -------- > Jake > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=247617#247617 > > ________________________________ Message 18 ____________________________________ Time: 05:13:43 PM PST US From: "n801bh@netzero.com" Subject: Re: AeroElectric-List: Burning up Vans Engine Gauges - Part Two. This is really strange for sure.. The only common denominator is all gau ges burning out are engine gauges, your nav lights landing light and all other bulbs. radios etc, seem ok... My .02 cents goes to a bad ground g oing to the engine from the airframe do not archive Ben Haas N801BH www.haaspowerair.com ---------- Original Message ---------- From: "JakeTheBosun" Subject: AeroElectric-List: Burning up Vans Engine Gauges - Part Two. ing.com> Well I'm stumped....my simple RV8, basic analog instruments only, Nipon Denso 40 amp Alternator, Oddeysey battery, worked well for 200 hours. Saturday Volt Meter burned (resistor on circuit board overheated and mel ted case), then Oil Temperature gauge did same thing, now today while te sting Manifold Pressure full of smoke. I have; -checked - no loose wires found ground or power. -Good Battery-engine-ground (heavy cable, short runs, tight connections. ) -Good bus connections (one central ground bus located at firewall) -14.2 Volts on meter at gauges while running, but instruments overheat. -12+ volts on meter when engine stopped, instruments seem not to overhea t. -Removed alternator and took to shop for evaluation....tested on stand a nd found good output and diodes. Anybody got a next step? Nice weather........need to fly George -------- Jake Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247617#247617 ======================== =========== ======================== =========== ======================== =========== ======================== =========== ____________________________________________________________ Get your dream car or truck. Click here. http://thirdpartyoffers.netzero.net/TGL2241/fc/BLSrjpYYjRT5iiFXGL8U7NaBn GOgmJRwwOzQvuOcsBcpTgtawilvs8KTxqI/ ________________________________ Message 19 ____________________________________ Time: 07:51:40 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Reverse flow in Shunt and Hall Effect At 12:15 PM 6/10/2009, you wrote: >I have a HE device on the B lead from the Alternator to the main >battery. It is oriented so that current is measured from the >alternator to the main battery thus indicating the load imposed on >the alternator. > >I have a shunt on the standby battery to measure current being used >from the battery. > >If current flows in the opposite direction from the planned flow, >does one get a negative amperage indication? > >Stan Sutterfield Probably. But it's dependent upon the display software. I've never encountered a system that wouldn't show both +/- indications accurately but that doesn't mean they don't exist. Chances are your indicator will show a value for both charge and discharge currents just fine. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 20 ____________________________________ Time: 07:53:26 PM PST US Subject: AeroElectric-List: Re: Canopy Switch From: "bcondrey" The mechanism referred to in RV-10s is a simple magnetic reed switch arrangement. There is a magnet in each door pin and the reed switches mounted in the door frames. Bob RV-10 N442PM Read this topic online here: http://forums.matronics.com/viewtopic.php?p=247644#247644 ________________________________ Message 21 ____________________________________ Time: 08:22:36 PM PST US Subject: Re: AeroElectric-List: Reverse flow in Shunt and Hall Effect From: "Matt Prather" Yes.. Current going the opposite direction through the shunt will generate a negative voltage. The sensor connected to the shunt should interpret/display that as a negative current. One other thought is that a large discharge current is created by operating the engine starter which will generate a significant negative voltage across the shunt. If using a mechanical display it will slap the needle around pretty hard. Maybe not a big deal, but something to consider. One might install a normally-closed relay in the lead to the shunt which. Connect the controlling coil to the starter switch so that when the starter is engaged, the meter is disabled. I wouldn't think a digital display input would have any problems. If the shunt drops 50mV at full scale alternator output (not an unusual scheme). Alternator output might be 50A, and starter current might be 250A, so the shunt might drop 500mV (-0.5V) when operating the starter. Round numbers. Regards, Matt- > I have a HE device on the B lead from the Alternator to the main battery. > It is oriented so that current is measured from the alternator to the > main > battery thus indicating the load imposed on the alternator. > > I have a shunt on the standby battery to measure current being used from > the battery. > > If current flows in the opposite direction from the planned flow, does one > get a negative amperage indication? > > Stan Sutterfield > **************Dell Inspiron 15 Laptop: Now in 6 vibrant colors! Shop > Dells > full line of laptops. > =http:%2F%2Fad.doubleclick.net%2Fclk%3B215566094%3B3786435 > 8%3Bv) > ------------------------------------------------------------------------------------- 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.