---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 07/28/03: 20 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:09 AM - Re: Amp Faston tabs (Neville Kilford) 2. 04:16 AM - Re: Re: AeroElectric-List Digest: 54 Msgs - 07/25/03 (Neville Kilford) 3. 05:53 AM - schematics vs. electron flow (Eric M. Jones) 4. 05:53 AM - Re: Over Voltage protection, figure 6.2 (Robert L. Nuckolls, III) 5. 06:22 AM - Re: Amp Faston tabs and Panel Flood Dimmers (Robert L. Nuckolls, III) 6. 06:48 AM - Re: The duplicity of schematics v. electron (Robert L. Nuckolls, III) 7. 07:13 AM - Re: AeroElectric-List Digest: 14 Msgs - 07/26/03 (Weed, Michael) 8. 07:20 AM - Re: schematics vs. electron flow (drew.schumann@us.army.mil) 9. 07:43 AM - Re: Sigtronics SPA-400 interface with microair radio (MikeM) 10. 08:24 AM - Re: Sensing low coolant level (MikeM) 11. 09:08 AM - Re: schematics vs. electron flow (Robert L. Nuckolls, III) 12. 12:01 PM - Re: LED landing lights (jmfpublic@comcast.net) 13. 12:22 PM - Re: AMP Faston Tabs (cary rhodes) 14. 03:21 PM - Re: Re: LED landing lights (Jerzy Krasinski) 15. 03:22 PM - Re: Over Voltage protection, figure 6.2 (mailbox bob at mail.flyboybob.com) 16. 03:37 PM - (Eric M. Jones) 17. 06:09 PM - Re: The duplicity of schematics v. electron theory (drew.schumann@us.army.mil) 18. 07:03 PM - Re: Re: AMP Faston Tabs (Robert L. Nuckolls, III) 19. 08:40 PM - Re: (Paul Messinger) 20. 10:14 PM - Re: (Jerzy Krasinski) ________________________________ Message 1 _____________________________________ Time: 03:09:09 AM PST US From: "Neville Kilford" Subject: Re: AeroElectric-List: Amp Faston tabs --> AeroElectric-List message posted by: "Neville Kilford" Ron, Are you aware that B&C sell exactly the ground plate you're describing? It certainly saves a lot of soldering. I just bought one with 48 tabs, but I fancy they also sell a 24-way version. It came with brass bolt, etc. to go through the firewall. Cheers. Nev ----- Original Message ----- From: "rondefly" Subject: AeroElectric-List: Amp Faston tabs > --> AeroElectric-List message posted by: "rondefly" > > I am not having to much luck finding the AMP faston tabs to bolt or solder > to a brass plate for the grounding block. I have printed out the part # > 41480 from the AMP site and have a picture of it but cant find it in mouser > online or catalog. can anyone help > Ron Triano > > ________________________________ Message 2 _____________________________________ Time: 04:16:02 AM PST US From: "Neville Kilford" Subject: Re: AeroElectric-List: Re: AeroElectric-List Digest: 54 Msgs - 07/25/03 --> AeroElectric-List message posted by: "Neville Kilford" Fred, Great! Thanks a lot. Nev do not archive ----- Original Message ----- From: "Frederic Livesey" Subject: AeroElectric-List: Re: AeroElectric-List Digest: 54 Msgs - 07/25/03 > --> AeroElectric-List message posted by: Frederic Livesey > > Hi, JB Weld is available from Halfords in the UK > Regards > Fred > > ________________________________ Message 3 _____________________________________ Time: 05:53:32 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: schematics vs. electron flow --> AeroElectric-List message posted by: "Eric M. Jones" Excellent article on the subject: http://www.rare-earth-magnets.com/magnet_university/magnets_conventional_vs_electron_flow.htm Ben Franklin is given the blame for this mess. By the time electrons flowing in a vacuum were studied it became apparent that Franklin was wrong. Holes are not the same as positive charges. When I become King all this will be changed with a wave of my scepter. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net ________________________________ Message 4 _____________________________________ Time: 05:53:32 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Over Voltage protection, figure 6.2 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:58 AM 7/27/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "mailbox bob at >mail.flyboybob.com" > >Bob (Nuckolls), > >I am using a Z-14 and a permanent magnet dynamo with external regulator. I >am building an over voltage disconnect to disconnect B+ of the dynamo from >the battery bus using your figure 6.2 as a pattern. The over voltage >circuit also illuminates a dynamo disconnected LED or an under voltage >warning LED on the instrument panel. > >In figure 6.2 you have a resistor and capacitor in series across the >contacts of the disconnect relay. There is nothing on the diagram to >indicate what their values should be. I have searched The AeroElectric >Connection and Aeroelectric.com and have not found anything covering this >detail. Do you have any recommendations for the values of C3 and R1 in the >below referenced circuit? Figure 6.2 is how we did it 30 years ago. Today I'd recommend a crowbar detection and supply interruption architecture like that illustrated in Figure Z-16. Crowbar ov protection is illustrated in http://216.55.140.222/articles/crowbar.pdf companion LV warning circuitry is illustrated in http://216.55.140.222/articles/lvwarn/9021-620.pdf >Schematic of over voltage circuit: >http://flyboybob.com/images/kr2/n52bl/electric%20and%20instrument/ov001-rev1 >-1.jpg If you go this route, check out specifications for the LM124 . . . I don't think its common mode range includes the +rail . . . I think you need to stay at least 1.5 volts below the Vcc supply. Add current limiting resistor between output of U1-1 and gate of SCR to make life easier for your OP amp. 470 ohms would be about right. Tie gate of SCR to ground with a 100 ohm resistor. This diagram was intended to be more instructive than constructive. If you proceed with architecture you've proposed, don't worry about the arc suppression network R1/C3 . . . this is most useful when switching the VERY inductive wound field of an alternator. I don't think I'd recommend any connector at J1 in your schematic . . . Alternator wiring should go right to the high current relay as illustrated in Figure Z-16 . . . >The power distribution diagram shows how the over voltage disconnect fits >into the wiring scheme. I am using electronic ignition powered from the >essential bus. I have decided to connect the battery busses directly to the >essential bus and then power the main bus from the essential bus. This >allows me to shed the main bus load by opening one circuit breaker as a >first step in an electrical power emergency. > >Power distribution diagram: >http://flyboybob.com/kr2/wd0002.htm > I am mystified as to what you are trying to do with the architecture cited above that a figure Z-14 type architecture doesn't achieve . . and I'm unclear as to the rational for number, size and placement of the breakers. Bob . . . ________________________________ Message 5 _____________________________________ Time: 06:22:26 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Amp Faston tabs and Panel Flood Dimmers --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:34 PM 7/27/2003 -0700, you wrote: >--> AeroElectric-List message posted by: "rondefly" > >I am not having to much luck finding the AMP faston tabs to bolt or solder >to a brass plate for the grounding block. I have printed out the part # >41480 from the AMP site and have a picture of it but cant find it in mouser >online or catalog. can anyone help >Ron Triano These ARE difficult to find, especially in long, dual-row strips. They are not a common part for field service activities. When we did find the parts, they were offered in reels of 5,000 or more pairs. That's why we designed and fabricated the system of ground bus blocks offered at: http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?26X358218 and http://www.bandc.biz/GroundBlock.html >-----Original Message----- >From: owner-aeroelectric-list-server@matronics.com >[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Ronald >Cox >To: aeroelectric-list@matronics.com >Subject: AeroElectric-List: Cessna-type panel light dimmer replacement? > > >--> AeroElectric-List message posted by: "Ronald Cox" > >If one were to do so, not that I ever would, but if... > >What would the appropriate value be for a generic replacement variable >resistor for use in an older Cessna panel light dimmer be? I'd love to use >one of Bob's dimmer setups, but it is a certified spam-can. > >I recently replaced it with what was supposed to be a cross-referenced part, >but it wasn't the right value, lights only came on near full on position, >and now it's already burned out. This is an older ship ('63) with the only >lights in the overhead, so not much power. Radios, etc., each have their >own dimming circuits built-in > >The value would allow me to check a supposed replacement part for the >correct resistance range. Yeah, that's it. > >What resistance range do (would) I need, and linear or audio taper? How many lights are in the overhead? Most of the airplanes I've worked with had a single, lamp rated at 200 to 250 mA. The rheostat for this lamp was a special, 75 ohm, 12 watt, wirewound device with a discontinuity at the max ccw end so that full left rotation would shut the lamp completely OFF. These were ordered from Ohmite by the thousands but were never a catalog item. If you are dimming a single lamp as described above, you can get a CR-12.5-100 at http://www.alliedelec.com/catalog/pf.asp?FN=546.pdf and get reasonable behavior or you can order one of our SDK-1 dimmer kits at: http://www.aeroelectric.com/Catalog/AECcatalog.html which contains the rheostat used in the Cessnas. I found a quantity of these surplus about a year ago and they are nearly gone. Bob . . . ________________________________ Message 6 _____________________________________ Time: 06:48:21 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: The duplicity of schematics v. electron theory --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 04:53 AM 7/28/2003 +0400, you wrote: >--> AeroElectric-List message posted by: drew.schumann@us.army.mil > >I am the kind of guy that needs to really understand an object to be much >good at dealing with it. Therefore, I find it necessary to study >fundamentals in order to mess with electronics. So far, I've had a very >shallow survey in A&P school and am doing some in-depth study on my own >prior to messing around with electrons. In both places, we learned how >electron theory "worked", with negative flowing to positive. And also, in >both places, the study material has made the blithe statement, "But >schematics work using conventional electron theory, so they read exactly >the opposite" and "it doesn't matter which way you read schematics, as >long as you are consistent." > >To my, sometimes too literal mind, this is difficult to do. I just get >used to electrons entering the diode on the narrow part and exiting the >wide part of the schematic representation, and then the schematic expects >me to work it exactly the opposite. I've taught and trained people for a >few years, now, and this doesn't seem like a coherent and rational method >of instruction. > >So, do I just have to accept the fact that electron theory works one way, >and schematics are drawn to be read the other? Unfortunately, my mind is >not set up to accept that. Is there a "third way?" Nope. Just two, both positive and negative "current" works. I prefer to work and teach in electron flow or negative negative current 'cause the electron is an entity with mass that moves. Since there is no mobile entity with a positive charge and mass, positive current is visualized as the absence of an electron where one might normally be expected to exist. For example, if an electron hops from the outer shell of a copper atom to the next atom, for some very small instance in time, a "hole" exists in that shell giving the atom a net positive charge. An electron from another atom jumps into that slot leaving a hole behind it as well. It's easy to visualize electrons moving in one direction as negative current and holes moving in the opposite direction as positive current. These visualizations are used all the time in the discussion of conductors and semiconductors. The only place that holes and electrons cannot exist together is in vacuum tubes where the electron is king. It is the ONLY kind of current that can move across an open space where nothing else exists. This won't be the only time you'll encounter overtly opposing conventions. The laws of physics, like the rules of language, were described by individuals widely separated in place and time. Each contributed to our understanding in the best way they could deduce at the time. But as in English you have "write", "right", and "wright" all sounding the same but having different meanings, so too in physics will you encounter explanations with seemingly contradictory qualities. Some folks view these instances with frustration and often with derision. I prefer to view these as a gage of understanding. It's no different than studying the a topic described by authors who wrote in English, German, and Swedish. Your goal is to UNDERSTAND what is going on so completely that the language describing it is not a barrier. The rudimentary simple-ideas that makes all the stuff around us work are consistent, predictable and understandable irrespective of the language by which they are described. The day that your frustration fades will be the day when you KNOW you've achieved a grasp of what matters. Bob . . . ________________________________ Message 7 _____________________________________ Time: 07:13:47 AM PST US Subject: AeroElectric-List: RE: AeroElectric-List Digest: 14 Msgs - 07/26/03 From: "Weed, Michael" --> AeroElectric-List message posted by: "Weed, Michael" >--> AeroElectric-List message posted by: "Steve Glasgow" > > >Does anyone have any experience with Falcon AH and DG. I understand they >are made in China and are clones of the RC Allen gyros. They are >guaranteed >for 1 year but not TSO'd. > >Any INFO would be greatly appreciated. > >Steve Glasgow Steve, In my opinion they are garbage. I have an AI and DG that came with my RV with 93 hrs. The AI is already bad and since I've heard that shops won't work on them, I took it apart to see if I could fix it. The gimbal bearings are crap. I replaced them and it might work now, we'll see, but I wouldn't trust it as far as I can throw it. The Chinese are very good at copying things, but they copied a poor design (Air Italia) and "cheaped" out on the components. If you are going with vacuum, buy a US made. I personally think that in 5 years nobody will be putting vacuum instruments in new airframes (RC Allen & SigmaTek, are you listening?). They'll go the way of the slide-rule, fascinating mechanical objects for sure, but completely obsolete. Mike ________________________________ Message 8 _____________________________________ Time: 07:20:08 AM PST US From: drew.schumann@us.army.mil Subject: Re: AeroElectric-List: schematics vs. electron flow --> AeroElectric-List message posted by: drew.schumann@us.army.mil I would also ban forever the phrase: "As you can clearly see from the following schematic..." Ten times out of ten, you CAN'T! Drew ----- Original Message ----- From: "Eric M. Jones" Subject: AeroElectric-List: schematics vs. electron flow > --> AeroElectric-List message posted by: "Eric M. Jones" > > Excellent article on the subject: > > http://www.rare-earth- > magnets.com/magnet_university/magnets_conventional_vs_electron_flow.htm > Ben Franklin is given the blame for this mess. By the time > electrons flowing in a vacuum were studied it became apparent that > Franklin was wrong. > > Holes are not the same as positive charges. > > When I become King all this will be changed with a wave of my scepter. > > Regards, > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge MA 01550-2705 > Phone (508) 764-2072 > Email: emjones@charter.net > > > _- > _- > _- > _- > ====================================================================== > > > > ________________________________ Message 9 _____________________________________ Time: 07:43:41 AM PST US From: MikeM Subject: AeroElectric-List: Re: Sigtronics SPA-400 interface with microair radio --> AeroElectric-List message posted by: MikeM > --> AeroElectric-List message posted by: "Ian Scott" > > Do you have any pointers on this intercom with this radio? Do you have a > cool schematic? > > I already have the radio and am thinking of the sigtronics, as I can get > one cheap from an aircraft dismantlers (USD $100) or so. > > Should I do it? And can I input things like a cd player into this > intercom? My PA22/20 Pacer had a SPA-400 intercom and a RES-400 stereo entertainment switcher installed when I bought it. The SPA-400 works just fine as a basic 4 place intercom. Nothing fancy! I had to redo the installation to get rid of the alternator whine/strobe squeal. The previous installer had violated the "single point ground" principle, grounding the mic and headphone jacks locally to the airframe, and not grounding the intercom to the same point as the com radio. The original Sigtronics installation instructions for the SPA-400 are in error about how to tie the grounds. After rewiring it, there is no discernable whine/squeal using hi-fi noise cancelling aviation headsets (Lightspeed 20s). The Pacer also has a RES-400 stereo switcher/adapter. It converts the monaural SPA-400 to stereo, and provides muting of the entertainment during either intercom or com radio activity, switching both L&R headphones to mono. The RES-400 provides no amplification of the entertainment stereo input signals; it just switches them straight through to the LR headphones (using a relay). This raises a problem if you plan to take your entertainment source from something like a Sony Discman! The Sony output level (intended to drive 30 Ohms headsets) is insufficient to drive the Lightspeed headsets (nominally several hundred Ohms). The music is just not loud enough! To solve this problem in the Pacer, I had to build a Stereo Amplifier, and put it between the Sony and the RES-400 input. Said amplifier has a voltage gain of about 4, which makes the entertainment level just right... By the time you do all of this, you might just think about getting a "modern" stereo/entertainment intercom... Mike Mladejovsky Pacer '00Z Skylane '1MM ________________________________ Message 10 ____________________________________ Time: 08:24:16 AM PST US From: MikeM Subject: AeroElectric-List: Re: Sensing low coolant level --> AeroElectric-List message posted by: MikeM > --> AeroElectric-List message posted by: bob@flyboybob.com > I suggest that you ignore the water level issue all together. Once the > water level is low it's too late, you've already cooked the goose! What you > need is a water pressure gauge. Before the water level gets low, the system > has to loose some H2O molecules. For this to happen, the pressure in the > system must be vented somewhere. Normally the water system will operate at > some pressure between ambient and the pressure cap release pressure. If the > needle stays in the green between these limits, you haven't lost coolant > yet. As soon as a leak occurs, the pressure will drop to zero or peg at the > pressure cap release pressure and you can take action before the water > actually gets low. Bob, I respectfully disagree!!! The PRESSURE in the cooling system has absolutely nothing to do with the QUANTITY of coolant in the radiator; the pressure is determined primarily by the TEMPERATURE, which is usually determined by the THERMOSTAT. Under normal operating conditions, the radiator cap never vents; the system pressure is lower than the cap's venting pressure. The pressure would stay constant as long as there is sufficient coolant to fill the block. The water pump/therostat always keeps the block/heads full of coolant, regardless of the coolant level in the radiator. If there is a small leak, the coolant will be forced out through the pinhole, with no detectable change in system pressure. Unless you see water droplets on the windshield, the only indication that this is happening would be dropping cooling level in the radiator, so the orginal poster has the right idea! Dropping level in the radiator is your first indication that there is leak!!! Mike Mladejovsky ________________________________ Message 11 ____________________________________ Time: 09:08:36 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: schematics vs. electron flow --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:14 PM 7/28/2003 +0400, you wrote: >--> AeroElectric-List message posted by: drew.schumann@us.army.mil > >I would also ban forever the phrase: "As you can clearly see from the >following schematic..." Ten times out of ten, you CAN'T! > >Drew This is where real teachers provide a bridge between the textbook and the student . . . Bob . . . ________________________________ Message 12 ____________________________________ Time: 12:01:51 PM PST US From: jmfpublic@comcast.net (Aeroelectric-List) Subject: AeroElectric-List: Re: LED landing lights --> AeroElectric-List message posted by: jmfpublic@comcast.net Ok, Mr. Jones, stand and deliver. Where did you find this source of white LEDs for 20 cents each? I plan to do cabin lighting with LEDs and combine this fixture with the headphone plugs. Jim Foerster Jabiru J400, under construction ________________________________ Message 13 ____________________________________ Time: 12:22:36 PM PST US From: cary rhodes Subject: AeroElectric-List: RE: AMP Faston Tabs --> AeroElectric-List message posted by: cary rhodes I offer a contrary opinion here. I also had trouble finding some solder-on male tabs. I bought a copper plate and dimpled for a #6 brass screw, soldered the head in place in the dimple, then bolted the pair of plates to the firewll. One on the inside and one in the engine comp. Then you can use ring terminal and stack up several grounds wires on each post. cary rhodes __________________________________ http://sitebuilder.yahoo.com ________________________________ Message 14 ____________________________________ Time: 03:21:11 PM PST US From: Jerzy Krasinski Subject: Re: AeroElectric-List: Re: LED landing lights --> AeroElectric-List message posted by: Jerzy Krasinski If you wait a little you will have a chance to get nice factory made LED headlights. A japanese company demonstrated such headlights last year on a wide gap semiconductor conference in Achen, Germany. I forgot the name of the company but it was probably Nichia. They did not use thousands of regular low power LEDs. They used a few newly developed high power and high efficiency heatsink mounted LEDs. Jerzy jmfpublic@comcast.net wrote: >--> AeroElectric-List message posted by: jmfpublic@comcast.net > >Ok, Mr. Jones, stand and deliver. Where did you find this source of white LEDs >for 20 cents each? I plan to do cabin lighting with LEDs and combine this >fixture with the headphone plugs. > >Jim Foerster Jabiru J400, under construction > > > > ________________________________ Message 15 ____________________________________ Time: 03:22:56 PM PST US From: "mailbox bob at mail.flyboybob.com" Subject: RE: AeroElectric-List: Over Voltage protection, figure 6.2 --> AeroElectric-List message posted by: "mailbox bob at mail.flyboybob.com" Bob, Thanks for the modern day recommendation to build a crowbar Over voltage circuit. I've got all the parts except the SCR so I should be able to build the circuit tonight. Your comments regarding my power distribution lead me to the conclusion that I am trying to use the essential bus as a bad fit for my application. I do not meet the low amperage requirement because of fuel injection and electronic ignition. I'm looking at Z-12 as a simpler solution for me powering the fuel pumps and electronic ignition from the battery bus as you describe in that diagram. This will also be an easier rewire job from my existing panel. Thank you so much for your comments. You make it possible for a homebuilder to build a quality aircraft electrical system. Regards, Bob Lee ______________________________ N52BL KR2 Suwanee, GA 30024 91% done only 51% to go! Phone/Fax: 770/844-7501 mailto:bob@flyboybob.com http://flyboybob.com -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: Over Voltage protection, figure 6.2 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:58 AM 7/27/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "mailbox bob at >mail.flyboybob.com" > >Bob (Nuckolls), > >I am using a Z-14 and a permanent magnet dynamo with external regulator. I >am building an over voltage disconnect to disconnect B+ of the dynamo from >the battery bus using your figure 6.2 as a pattern. The over voltage >circuit also illuminates a dynamo disconnected LED or an under voltage >warning LED on the instrument panel. > >In figure 6.2 you have a resistor and capacitor in series across the >contacts of the disconnect relay. There is nothing on the diagram to >indicate what their values should be. I have searched The AeroElectric >Connection and Aeroelectric.com and have not found anything covering this >detail. Do you have any recommendations for the values of C3 and R1 in the >below referenced circuit? Figure 6.2 is how we did it 30 years ago. Today I'd recommend a crowbar detection and supply interruption architecture like that illustrated in Figure Z-16. Crowbar ov protection is illustrated in http://216.55.140.222/articles/crowbar.pdf companion LV warning circuitry is illustrated in http://216.55.140.222/articles/lvwarn/9021-620.pdf >Schematic of over voltage circuit: >http://flyboybob.com/images/kr2/n52bl/electric%20and%20instrument/ov001-rev 1 >-1.jpg If you go this route, check out specifications for the LM124 . . . I don't think its common mode range includes the +rail . . . I think you need to stay at least 1.5 volts below the Vcc supply. Add current limiting resistor between output of U1-1 and gate of SCR to make life easier for your OP amp. 470 ohms would be about right. Tie gate of SCR to ground with a 100 ohm resistor. This diagram was intended to be more instructive than constructive. If you proceed with architecture you've proposed, don't worry about the arc suppression network R1/C3 . . . this is most useful when switching the VERY inductive wound field of an alternator. I don't think I'd recommend any connector at J1 in your schematic . . . Alternator wiring should go right to the high current relay as illustrated in Figure Z-16 . . . >The power distribution diagram shows how the over voltage disconnect fits >into the wiring scheme. I am using electronic ignition powered from the >essential bus. I have decided to connect the battery busses directly to the >essential bus and then power the main bus from the essential bus. This >allows me to shed the main bus load by opening one circuit breaker as a >first step in an electrical power emergency. > >Power distribution diagram: >http://flyboybob.com/kr2/wd0002.htm > I am mystified as to what you are trying to do with the architecture cited above that a figure Z-14 type architecture doesn't achieve . . and I'm unclear as to the rational for number, size and placement of the breakers. Bob . . . ________________________________ Message 16 ____________________________________ Time: 03:37:23 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: --> AeroElectric-List message posted by: "Eric M. Jones" A really good deal is Besthongkong on eBay (search for items sold by him). 50pcs 8000mcd Ultra Bright White LEDs-BestHK Item number: 2548007745 Buy-it-now price $3.49. Astonishing....unbelievable (well yes, he adds a hefty "handling" charge)! Also check the eBay stores of Chi Wing LED product shop, Dynamic Electronics and IT Products, and HKCityShop. There are others. Just searching eBay for "leds" is an education. Some details on the 15000 mcd for less than $0.20----You would have to buy thousands, and run them 2X current. Running leds even at 3X current is commonly done and quite reasonable. Just watch the temperatures. Now the cynical might say....oh, so you overcurrent them--that's cheating. But remember there's no 13th power rule here. LEDs have no filament, evaporate nothing and do not fail suddenly. By the way...as I am learning. The 100,000 hours cited for leds (to 50% brightness) does not extend to white leds regardless of what anybody claims. Maybe later. But for now expect 10,000 hours to 50%. But that probably exceeds the life of your airframe. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net "A man's got to know his limitations." (Clint Eastwood's Dirty Harry in Magnum Force, 1973) ________________________________ Message 17 ____________________________________ Time: 06:09:36 PM PST US From: drew.schumann@us.army.mil Subject: Re: AeroElectric-List: The duplicity of schematics v. electron theory --> AeroElectric-List message posted by: drew.schumann@us.army.mil Thanks. Your last sentence broke it for me. I have now started "ignoring" those parts that don't seem to matter, and only refer to them if the schematic doesn't make sense without them. This helps me break down the circuit, rather than try to tackle the circuit as a whole. Drew ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: The duplicity of schematics v. electron theory > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 04:53 AM 7/28/2003 +0400, you wrote: > >--> AeroElectric-List message posted by: drew.schumann@us.army.mil > > > >I am the kind of guy that needs to really understand an object to > be much > >good at dealing with it. Therefore, I find it necessary to study > >fundamentals in order to mess with electronics. So far, I've had > a very > >shallow survey in A&P school and am doing some in-depth study on > my own > >prior to messing around with electrons. In both places, we > learned how > >electron theory "worked", with negative flowing to positive. And > also, in > >both places, the study material has made the blithe statement, > "But > >schematics work using conventional electron theory, so they read > exactly > >the opposite" and "it doesn't matter which way you read > schematics, as > >long as you are consistent." > > > >To my, sometimes too literal mind, this is difficult to do. I > just get > >used to electrons entering the diode on the narrow part and > exiting the > >wide part of the schematic representation, and then the schematic > expects > >me to work it exactly the opposite. I've taught and trained > people for a > >few years, now, and this doesn't seem like a coherent and > rational method > >of instruction. > > > >So, do I just have to accept the fact that electron theory works > one way, > >and schematics are drawn to be read the other? Unfortunately, my > mind is > >not set up to accept that. Is there a "third way?" > > Nope. Just two, both positive and negative "current" > works. I prefer to work and teach in electron flow or > negative negative current 'cause the electron is an > entity with mass that moves. Since there is no mobile > entity with a positive charge and mass, positive current > is visualized as the absence of an electron where one > might normally be expected to exist. > > For example, if an electron hops from the outer shell > of a copper atom to the next atom, for some very small > instance in time, a "hole" exists in that shell giving > the atom a net positive charge. An electron from another > atom jumps into that slot leaving a hole behind it as well. > > It's easy to visualize electrons moving in one direction > as negative current and holes moving in the opposite > direction as positive current. These visualizations are > used all the time in the discussion of conductors and > semiconductors. > > The only place that holes and electrons cannot exist > together is in vacuum tubes where the electron is king. > It is the ONLY kind of current that can move across an > open space where nothing else exists. > > This won't be the only time you'll encounter overtly > opposing conventions. The laws of physics, like the rules > of language, were described by individuals widely separated > in place and time. Each contributed to our understanding > in the best way they could deduce at the time. But > as in English you have "write", "right", and "wright" all > sounding the same but having different meanings, so > too in physics will you encounter explanations with > seemingly contradictory qualities. > > Some folks view these instances with frustration and often with > derision. I prefer to view these as a gage of understanding. > It's no different than studying the a topic described > by authors who wrote in English, German, and Swedish. > Your goal is to UNDERSTAND what is going on so completely > that the language describing it is not a barrier. > > The rudimentary simple-ideas that makes all the stuff > around us work are consistent, predictable and understandable > irrespective of the language by which they are described. > The day that your frustration fades will be the day when > you KNOW you've achieved a grasp of what matters. > > Bob . . . > > > _- > _- > _- > _- > ====================================================================== > > > > ________________________________ Message 18 ____________________________________ Time: 07:03:16 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: AMP Faston Tabs --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:22 PM 7/28/2003 -0700, you wrote: >--> AeroElectric-List message posted by: cary rhodes > >I offer a contrary opinion here. > >I also had trouble finding some solder-on male tabs. > >I bought a copper plate and dimpled for a #6 brass >screw, soldered the head in place in the dimple, then >bolted the pair of plates to the firewll. One on the >inside and one in the engine comp. > >Then you can use ring terminal and stack up several >grounds wires on each post. Many kit suppliers have offered variations on this theme for a long time . . . I'll suggest that it is a good thing to reduce and/or eliminate threaded fasteners as much as possible. I looked at a captive, threaded stud design before opting in favor of fast-ons. In fact, the debut of the fast-on ground block prompted a market search to add faston equipped switches to the catalog shortly thereafter. But irrespective of which fasteners you choose, the magic comes from single point grounding . . . Bob . . . ________________________________ Message 19 ____________________________________ Time: 08:40:00 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: "Paul Messinger" Thanks for your complete reply. The white leds I have seen appear to be IR leds with a white phosphor for visible light. Thus life is likely to be shorter than the "Normal" design for led's. Not that shorter is a design concern for most of mear mortals :-) BTW your electronic designs are innovative and interesting to me as so many are just recycled older stuff. From a retired aerospace and electronics engineer. Paul PS keep up the good work. ----- Original Message ----- From: "Eric M. Jones" Subject: AeroElectric-List: > --> AeroElectric-List message posted by: "Eric M. Jones" > > A really good deal is Besthongkong on eBay (search for items sold by him). > 50pcs 8000mcd Ultra Bright White LEDs-BestHK Item number: 2548007745 > Buy-it-now price $3.49. Astonishing....unbelievable (well yes, he adds a > hefty > "handling" charge)! Also check the eBay stores of Chi Wing LED product shop, > Dynamic Electronics and IT Products, and HKCityShop. There are others. > > Just searching eBay for "leds" is an education. > > Some details on the 15000 mcd for less than $0.20----You would have to buy > thousands, and run them 2X current. Running leds even at 3X current is > commonly done and quite reasonable. Just watch the temperatures. > > Now the cynical might say....oh, so you overcurrent them--that's cheating. > But remember > there's no 13th power rule here. LEDs have no filament, evaporate nothing > and do not fail > suddenly. > > By the way...as I am learning. The 100,000 hours cited for leds (to 50% > brightness) does not > extend to white leds regardless of what anybody claims. Maybe later. But for > now > expect 10,000 hours to 50%. But that probably exceeds the life of your > airframe. > > Regards, > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge MA 01550-2705 > Phone (508) 764-2072 > Email: emjones@charter.net > > "A man's got to know his limitations." > (Clint Eastwood's Dirty Harry in Magnum Force, 1973) > > ________________________________ Message 20 ____________________________________ Time: 10:14:41 PM PST US From: Jerzy Krasinski Subject: Re: AeroElectric-List: --> AeroElectric-List message posted by: Jerzy Krasinski They are UV LEDs not IR. For that reason (wide gap) they require more voltage than IR LEDS. Typically its ~3.5V per diode Jerzy Paul Messinger wrote: >--> AeroElectric-List message posted by: "Paul Messinger" > >Thanks for your complete reply. The white leds I have seen appear to be IR >leds with a white phosphor for visible light. Thus life is likely to be >shorter than the "Normal" design for led's. Not that shorter is a design >concern for most of mear mortals :-) > > > > >