---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 07/17/06: 33 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:48 AM - Re: Help needed: continued strobe noise & weak radio (FLYaDIVE@aol.com) 2. 03:48 AM - Re: Re: Help needed: OFF TOPIC (FLYaDIVE@aol.com) 3. 04:03 AM - Re: Re: Help needed: continued strobe noise & weak radio (FLYaDIVE@aol.com) 4. 04:18 AM - Re: Hall effect amp meter telling the truth? () 5. 04:36 AM - Re: Help needed: continued strobe noise & weak radio (Brian Lloyd) 6. 04:41 AM - Re: Landing lights & relays (FLYaDIVE@aol.com) 7. 04:41 AM - Electrical Systems For Vintage Aircraft (Bill Denton) 8. 04:48 AM - Re: Help needed: continued strobe noise (Tommy Walker) 9. 04:55 AM - Re: Help needed: continued strobe noise & weak radio (Brian Lloyd) 10. 04:57 AM - Re: Re: Help needed: continued strobe noise & weak radio (Brian Lloyd) 11. 05:12 AM - Re: Landing lights & relays (Belue, Kevin) 12. 05:15 AM - Re: Help needed: continued strobe noise (Bill Maxwell) 13. 05:22 AM - Re: Electrical Systems For Vintage Aircraft (Brian Lloyd) 14. 06:02 AM - Re: Re: Help needed: continued strobe noise (Robert L. Nuckolls, III) 15. 06:11 AM - Re: Main bus wire feed (Robert L. Nuckolls, III) 16. 06:44 AM - Re: braided bonding straps (RV Builder (Michael Sausen)) 17. 07:45 AM - Re: Hall effect amp meter telling the truth? (Hinde, Frank George (Corvallis)) 18. 08:34 AM - LED flags (rd2@evenlink.com) 19. 08:46 AM - VM1000 light system failure () 20. 12:19 PM - TKM MX 300 RADIO QUIRK (Brinker) 21. 12:35 PM - Re: VM1000 light system failure () 22. 12:54 PM - Re: Help needed: continued strobe noise (Robert L. Nuckolls, III) 23. 01:01 PM - Coax connector technologies (Robert L. Nuckolls, III) 24. 01:02 PM - Re: Help needed: continued strobe noise & (Robert L. Nuckolls, III) 25. 03:44 PM - Re: LED flags (Brian Lloyd) 26. 03:44 PM - Re: TKM MX 300 RADIO QUIRK (Brian Lloyd) 27. 04:29 PM - Re: TKM MX 300 RADIO QUIRK (Brinker) 28. 04:55 PM - Re: LED flags (rd2@evenlink.com) 29. 07:22 PM - Re: LED flags (Brian Lloyd) 30. 07:44 PM - Re: Re: Landing lights & relays (N1deltawhiskey@comcast.net) 31. 09:07 PM - Wiring batteries in parallel? (Deems Davis) 32. 09:24 PM - Re: Wiring batteries in parallel? (TimRhod@aol.com) 33. 09:35 PM - Re: Wiring batteries in parallel? (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 03:48:35 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Help needed: continued strobe noise & weak radio --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 7/16/06 8:11:43 AM Eastern Daylight Time, luckymacy@comcast.net writes: > Lucky: I used Van's pre-made wiring kit but I don't recall if the wiring to > the strobes was shielded or not. ===================================== Lucky: I think you found the problem. I say that because of the above statement about the pre-made harness. If they are running the strobe's wires right along side the wires for your other lights AND if they are not shielded then it would be very easy for the other wires to pick up the noise from the strobes. Try running a separate SHIELDED pair of wires and ground the shield ONLY at the strobe. The shielded pair should have three wires ... B+. Neg and SHIELD. The Neg is grounded at both ends, while the shield is only at the strobe. I would still use the filter, just for S&Gs. Run the strobe wires away from the other wires. I have a similar strobe system as you with the power supplies. The strobes mounted at the wing tips and tail; three power supplies. I found that there is a small amount of noise from the tail strobe. I know I can get rid of it with an RS type filter, but it is on a GA aircraft so I'm not allowed to use RS or Lowe's aviation components ;-) You did say you tried mounting the filter at each location, Strobe and Radio. Another thing to check and I have not seen it mentioned is LEAD LENGTH. You must keep the leads as short as possible between the filter and the strobe. Still another trick you may want to try is to install a ferrite bead (tolroid) on the B+ lead, close to the strobe. Me still being a bit redundant, make sure you have extra clean ground connections; aluminum is not a good material for electrical connections. Well, beyond all the techniques and trick I mentioned in this post and my other. My other offer would be ... Where are you located, maybe we could meet up? I'd bet dollars to doughnuts I can solve your problem. I'd be glad to help. Barry "Chop'd Liver" ________________________________ Message 2 _____________________________________ Time: 03:48:35 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Re: Help needed: OFF TOPIC --> AeroElectric-List message posted by: FLYaDIVE@aol.com Hey Group: Being a bit off topic I am in need of some Web Site information. I am having problems with an engine driven ground bound device - 1999 Hyundai Elantra and I'm looking for a Web Site half as good as this one that can offer some help. Would anyone have a site recordation? Thanks for the assistance, Barry "Chop'd Liver" ________________________________ Message 3 _____________________________________ Time: 04:03:34 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Re: Help needed: continued strobe noise & weak radio --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 7/17/06 12:00:46 AM Eastern Daylight Time, n3eu@comcast.net writes: > FLYaDIVE(at)aol.com wrote: > > CRIMPS! You do not want a crimped coax. > > > > NO self-respecting RF Man will accept a CRIMPED coax. > > > > Why do you say that? You mean a soldered, and hex-nut BNC connector > fashioned by a homebuilder wil be better? On avg, don't think so. > > Fred F. ================================ Yup! Fred ... Soldered, Hex Nut BNC connector. As far as who fashions it ... Why not the homebuilder? After all the homebuilder was not born knowing how to rivet, why not just learn how to do a proper BNC connection. They are SOOooooo much better, water proof (or at least highly resistant), vibration proof, dust proof and of course a damn good RF electrical connection. AND you can do a field repair on them. Can't do that on crimp crap. The BNC was born out of the SO & PL fittings. It is better for maintaining the impedance of the cable especially at low power VHF frequencies. The higher power, higher frequency version is the Type N. Barry "Chop'd Liver" ________________________________ Message 4 _____________________________________ Time: 04:18:20 AM PST US From: Subject: AeroElectric-List: Re: Hall effect amp meter telling the truth? Duane: I have the same setup and it is dead on. You reading does sound low but depending on the setting of your EIS How do you have the S.F. and offset set up? Write me and I can help you double check the settings. You also need to have sense and decimal setting correct. I assume you are trying to read +/- current and have software version 45 or greater? Some settings (+/- 50 or 100 amps) are designed for no decimal, meaning resolution is 1 amp and there is no decimal 1/10th in the display. I am curious to know why you have 0.6 displayed? May be it is 6 amps? The sensor is somewhere between 0.5% to 2%. which should not cause that much difference. You may need to adjust the Aux offset. You change it 2 at a time and must remain a odd number. I assume it reads zero other wise with all devices off. (except the master relay will draw about 0.60 amps alone) I guess it is a setting issue and not a sensor issue. I am wondering why you choose to route the battery cable through the sensor and not the alternator b-lead? Cheers George >posted by: Duane Wilson > > I have a Hall effect current sensor hooked up to my GRT EIS-4000. > I have set the parameters in the EIS as stated on the instillation >sheet for the Hall effect sensor. > > When I turn on my 2 GRT Horizon 1 displays, my Val avionics VOR, > Garmin 300XL, transponder (standby) and panel lights I get a reading > of about .6 on the EIS. > > This seems low to me. How can I verify the current draw. I don't > have an amp meter. > > Duane Wilson --------------------------------- How low will we go? Check out Yahoo! Messengers low PC-to-Phone call rates. ________________________________ Message 5 _____________________________________ Time: 04:36:06 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Help needed: continued strobe noise & weak radio --> AeroElectric-List message posted by: Brian Lloyd On Jul 16, 2006, at 9:25 PM, lucky wrote: > I'll take a look at them next time I get out there and I think the > mike and headphone jacks are fitted correctly. If they weren't, > wouldn't I have a problem all the time? In fact, would they work at > all? Yes, but the problem of the grounded mic jacks is that noise from other audio sources gets impressed on the mic audio. > For example, even when using the radio's internal VOX intercom > system wouldn't I get a bad signal and wouldn't there be a lot of > noise from other components whey they are turned on? The VOX works > very well (except that when the strobes are on, yes, you hear them > loud and clear as well). This is why I think you have a problem with your mic jacks being grounded. > I haven't noticed any other electrical component causing a problem > that's audible and the radio itself hasn't seemed to bother any > other electrical system. Most other devices don't generate AC at audio frequencies in the grounding system. Solve the problem of the bad audio first. After you deal with that and set the modulation levels correctly you can go from there. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 6 _____________________________________ Time: 04:41:45 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Landing lights & relays --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 7/16/06 9:58:05 AM Eastern Daylight Time, tomcostanza@comcast.net writes: > What is your opinion of using mechanical relays to implement wig-wag flashing > of landing lights? > I would like to use a rotary switch with the following pattern: off, wig-wag, > landing, taxi (4 positions). Otherwise I would need to use 3 toggle switches > and a complicated switch operation. Using transistors would lower the voltage > at the light by about 1.5 volts. To confuse the issue further, I have wingtip > landing and taxi lights (1 landing and 1 taxi on each wing) 4 lights total. > Using relays would solve my problems, but I don't know the longevity of the > relay. > What are your thoughts? > Thanks, > Tom Costanza > RV-7A Fuselage =============================== Tom: My thoughts: 1 - NO Rotary switch. a> Cost b> Why the cost? Because it would have to be a heavy duty silver plated rotary switch. c> Size probably would be large due to the current handling problem. 2 - Not easy to repair. 3 - If you have a failure on one contact you would have to replace the entire rotary switch. 4 - You can do it with two toggle switches: a> A three position switch ... OFF - LANDING LIGHTS - TAXI LIGHTS When the Taxi lights come on the Landing Lights CAN go off. This would be up to you and the current handling capability of the alternator. b> Wig - Wag Switch. 4 - A relay type Wig - Wag system would work, BUT! ! ! You are introducing a strong point for: a> Failure - Lots of Opening and Closing of the relay b> Lots of NOISE - Static, Lots of Opening and Closing of the relay points causing small arcs. c> You will need additional filtering and spark suppression for the relay contacts. d> You will need to install the relay using plug in sockets. 5 - I would go with a solid state system. Barry "Chop'd Liver" ________________________________ Message 7 _____________________________________ Time: 04:41:51 AM PST US From: "Bill Denton" Subject: AeroElectric-List: Electrical Systems For Vintage Aircraft --> AeroElectric-List message posted by: "Bill Denton" Is it possible to add a full electrical system (alternator/generator, starter, battery, lights, etc) to a vintage aircraft such as a Piper Cub, Aeronca, Taylorcraft, etc? I am looking for a light sport aircraft, but I don't relish the idea of hand-propping one by myself. What is required for the FAA? If an STC, does it have to be for the engine, the aircraft, or both? Does anyone know of a shop that does this type of work that I could contact? Thanks! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=47786#47786 ________________________________ Message 8 _____________________________________ Time: 04:48:51 AM PST US From: "Tommy Walker" Subject: Re: AeroElectric-List: Help needed: continued strobe noise I'm not a sparky so I can't contribute much to this, but I am in the process of wiring up my Rotax 912ULS and the Rotax wiring diagram calls for a 22,000 uF capacitor. I bought one when I ordered the XCom radio ($40.00 U.S). Haven't had the opportunity to test it yet. Do Not Archive Tommy Walker in Alabama --> AeroElectric-List message posted by: "europa flugzeug fabrik" luckymacy(at)comcast.net wrote: > BTW, after I originally bought and installed the Xcom radio, they revised their drawing and FAQ section to REQUIRE owners install a 22,000 uF cap betwee the xcom and it's power source near the radio. If Microair said that's a fix, they're admitting to bad design of the XCOM box. At high freq, diminishing returns, that big, I propose. Simpler ways to fix. Fred F. ________________________________ Message 9 _____________________________________ Time: 04:55:10 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Help needed: continued strobe noise & weak radio --> AeroElectric-List message posted by: Brian Lloyd On Jul 17, 2006, at 6:37 AM, FLYaDIVE@aol.com wrote: > --> AeroElectric-List message posted by: FLYaDIVE@aol.com > > In a message dated 7/16/06 8:11:43 AM Eastern Daylight Time, > luckymacy@comcast.net writes: > >> Lucky: I used Van's pre-made wiring kit but I don't recall if the >> wiring > to >> the strobes was shielded or not. > ===================================== > Lucky: > > I think you found the problem. I say that because of the above > statement > about the pre-made harness. If they are running the strobe's wires > right along > side the wires for your other lights AND if they are not shielded > then it would > be very easy for the other wires to pick up the noise from the > strobes. > Try running a separate SHIELDED pair of wires and ground the shield > ONLY at > the strobe. The shielded pair should have three wires ... B+. Neg > and SHIELD. > The Neg is grounded at both ends, while the shield is only at the > strobe. I > would still use the filter, just for S&Gs. Run the strobe wires > away from the > other wires. Barry, you keep making statements like this but I am not sure you have really thought through what you are saying. When you run two wires in parallel there are two coupling modes: capacitive and inductive. When impedances are very high (it is difficult to get current to flow) then capacitive coupling dominates. When impedances are very low, as in power circuits, coupling is inductive, with the current in one wire inducing a current in the other wire by magnetic (inductive) coupling. The problem with non-magnetic braid-type shielding is that it does almost nothing for inductive coupling. The magnetic lines of force go right through the shielding and induce currents in the shielded conductor just as if the shield wasn't there. That is why shielding on the alternator 'B' lead is useless to reduce noise. So you aren't going to fix noise from your strobe power supply getting into your other power wiring with a nonmagnetic shielding braid. BTW, a shielding braid grounded at only one end is an electrostatic shield and only works to reduce capacitive coupling. If the problem is inductive coupling between wires there are only two solutions: 1. separation; 2. the use of a magnetic shielding material like mu-metal. If you have a severe inductive coupling problem and you can't get separation you can get magnetic shielding braid and sheets to help fix the problem. I used that to solve a problem with the motor in my T&B affecting my compass in my RV-4. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 10 ____________________________________ Time: 04:57:03 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Re: Help needed: continued strobe noise & weak radio --> AeroElectric-List message posted by: Brian Lloyd On Jul 16, 2006, at 11:55 PM, europa flugzeug fabrik wrote: > --> AeroElectric-List message posted by: "europa flugzeug fabrik" > > > > FLYaDIVE(at)aol.com wrote: >> CRIMPS! You do not want a crimped coax. >> >> NO self-respecting RF Man will accept a CRIMPED coax. Crimped connectors on cables tend to be better than hand-constructed and soldered cables. They last longer. A crimped connector with adhesive heat-shrink over is just about the best, most long-lived cable connection you can make. You learn stuff like this very quickly on a boat. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 11 ____________________________________ Time: 05:12:56 AM PST US From: "Belue, Kevin" Subject: RE: AeroElectric-List: Landing lights & relays --> AeroElectric-List message posted by: "Belue, Kevin" I have used a three-position switch for: ON, wig-wag, OFF. This controlled a $19 relay-type wig-wag from Gall's to drive two 100W bulbs. I have used this for 4.5 yrs, 700 hrs. If it's hazy I leave the wig-wag on for the whole flight, hours at a time. I have never had any noise, extra filters, and have never replaced anything. Kevin RV-6A RV-10 > -----Original Message----- > From: FLYaDIVE@aol.com [mailto:FLYaDIVE@aol.com] > Sent: Monday, July 17, 2006 6:38 AM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: Landing lights & relays > > --> AeroElectric-List message posted by: FLYaDIVE@aol.com > > In a message dated 7/16/06 9:58:05 AM Eastern Daylight Time, > tomcostanza@comcast.net writes: > > > What is your opinion of using mechanical relays to implement wig-wag > flashing > > of landing lights? > > I would like to use a rotary switch with the following pattern: off, > wig-wag, > > landing, taxi (4 positions). Otherwise I would need to use 3 toggle > switches > > and a complicated switch operation. Using transistors would lower the > voltage > > at the light by about 1.5 volts. To confuse the issue further, I have > wingtip > > landing and taxi lights (1 landing and 1 taxi on each wing) 4 lights total. > > Using relays would solve my problems, but I don't know the longevity of the > > relay. > > What are your thoughts? > > Thanks, > > Tom Costanza > > RV-7A Fuselage > =============================== > Tom: > > My thoughts: > 1 - NO Rotary switch. > a> Cost > b> Why the cost? Because it would have to be a heavy duty silver plated > rotary switch. > c> Size probably would be large due to the current handling problem. > > 2 - Not easy to repair. > > 3 - If you have a failure on one contact you would have to replace the entire > rotary switch. > > 4 - You can do it with two toggle switches: > a> A three position switch ... OFF - LANDING LIGHTS - TAXI LIGHTS > When the Taxi lights come on the Landing Lights CAN go off. This would be up > to you and the current handling capability of the alternator. > b> Wig - Wag Switch. > > 4 - A relay type Wig - Wag system would work, BUT! ! ! You are introducing > a strong point for: > a> Failure - Lots of Opening and Closing of the relay > b> Lots of NOISE - Static, Lots of Opening and Closing of the relay points > causing small arcs. > c> You will need additional filtering and spark suppression for the relay > contacts. > d> You will need to install the relay using plug in sockets. > > 5 - I would go with a solid state system. > > Barry > "Chop'd Liver" > > > > > > > > > > ________________________________ Message 12 ____________________________________ Time: 05:15:53 AM PST US From: "Bill Maxwell" Subject: Re: AeroElectric-List: Help needed: continued strobe noise I think we have been here before, maybe more than once. As I recall, the capacitor is a Rotax requirement rather than a XCOM stipulation. XCOM now merely reflect that fact in their drawing. Bill ----- Original Message ----- From: Tommy Walker To: aeroelectric-list@matronics.com Sent: Monday, July 17, 2006 9:45 PM Subject: Re: AeroElectric-List: Help needed: continued strobe noise I'm not a sparky so I can't contribute much to this, but I am in the process of wiring up my Rotax 912ULS and the Rotax wiring diagram calls for a 22,000 uF capacitor. I bought one when I ordered the XCom radio ($40.00 U.S). Haven't had the opportunity to test it yet. Do Not Archive Tommy Walker in Alabama --> AeroElectric-List message posted by: "europa flugzeug fabrik" luckymacy(at)comcast.net wrote: > BTW, after I originally bought and installed the Xcom radio, they revised their drawing and FAQ section to REQUIRE owners install a 22,000 uF cap betwee the xcom and it's power source near the radio. If Microair said that's a fix, they're admitting to bad design of the XCOM box. At high freq, diminishing returns, that big, I propose. Simpler ways to fix. Fred F. ________________________________ Message 13 ____________________________________ Time: 05:22:44 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Electrical Systems For Vintage Aircraft --> AeroElectric-List message posted by: Brian Lloyd On Jul 17, 2006, at 7:40 AM, Bill Denton wrote: > --> AeroElectric-List message posted by: "Bill Denton" > > > Is it possible to add a full electrical system (alternator/ > generator, starter, battery, lights, etc) to a vintage aircraft > such as a Piper Cub, Aeronca, Taylorcraft, etc? Yes. The main cost will be weight. > > I am looking for a light sport aircraft, but I don't relish the > idea of hand-propping one by myself. > > What is required for the FAA? If an STC, does it have to be for the > engine, the aircraft, or both? If the aircraft was certified with an electrical system at one time, reference that. That should eliminate the need for an STC and will probably make it with just a logbook entry by your A&P. > > Does anyone know of a shop that does this type of work that I could > contact? Why not do it yourself? Copy one that exists, get the blessing of the FSDO, and then get an A&P to look over your shoulder. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 14 ____________________________________ Time: 06:02:36 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Help needed: continued strobe noise --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:00 PM 7/16/2006 -0700, you wrote: >--> AeroElectric-List message posted by: "europa flugzeug fabrik" > > > >luckymacy(at)comcast.net wrote: > > BTW, after I originally bought and installed the Xcom radio, they > revised their drawing and FAQ section to REQUIRE owners install a 22,000 > uF cap betwee the xcom and it's power source near the radio. > >If Microair said that's a fix, they're admitting to bad design of the XCOM >box. At high freq, diminishing returns, that big, I propose. Simpler >ways to fix. I have written Xcom to inquire into the science behind the external capacitor's benefits but received no reply. I'm mystified as to the value or need. This is the first time I've seen the manufacturer of any appliance require power conditioning hardware be installed in addition to and external of their product. It does not speak well of the product's capabilities. I'll drop them another note and see if I can get their attention. Bob . . . ________________________________ Message 15 ____________________________________ Time: 06:11:52 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Main bus wire feed --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:51 PM 7/16/2006 -0600, you wrote: >I was reviewing the Z diagrams in Bob's book and am curious about the >circuit protection coming into the cockpit from the battery contactor. >There is an ANL fuse shown between the alternator and the batt contactor, >but there is no fuse on the (typically) 6 or 8 ga wire coming from the >batt contactor into the cockpit. What is the reason to not protect such a >large wire as it goes through the firewall? I'm sure Bob has thought this >through, I just don't know the reasoning behind it and am hoping someone >here might know. Thanks. Steve What risk is to be mitigated by adding such protection? There are numerous instances of "exposed" or seemingly risky situations in configuring hardware. For example, there's an invisible, fast moving, deadly body basher on the nose of your airplane that will turn you into hamburger in a heartbeat. Why don't we put a wire cage around it to protect against such events? The cost-benefit ratio study says that operationally we can conduct due-diligence in making sure fragile things don't get into the prop and therefore, the weight and performance losses for protecting it are of no practical value. Okay, apply the same thinking to the piece of "un protected" wire you've identified. Get out your hammer, crowbar or any other favored instrument of force and then look over the wire and it's terminating bus installation. See if you can identify any piece of the airplane that even MIGHT come against it such that there is risk of a fault. I believe you will find (as have many who have studied this problem before us) that there are no risks associated with leaving this wire unprotected beyond observing due diligence in supporting the pieces so that vibration or other motion does not compromise insulation. Study the wiring diagrams for any production aircraft and see if builders of those airplanes deduced any risks that warranted the protection you've cited. It's a good question. The answer is, "Risks associated with this practice have been deduced by analysis and proven by field experience to be insignificant." Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 16 ____________________________________ Time: 06:44:18 AM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: braided bonding straps Rob, I probably wouldn't use it for anything too heavy, but it is perfect for static bonding and other lightweight grounds. Michael Sausen RV-10 #352 Working on Fuselage Do Not Archive Recent RV-10 Build Activity [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert G. Wright Sent: Sunday, July 16, 2006 9:28 PM I know I can order these to a pre-set length, but I've removed probably 2.5' of braid shield from some RG-58 and wondering what all I can do with it. I know I can use attach a connector and use it as a circuit ground, but I'm wondering if it will also work for some of these static charge installations: aileron to wing, flap to wing, elevator to HS; and some of the heftier installations: engine to firewall stud, battery negative post to airframe, etc. Rob Wright RV-10 ________________________________ Message 17 ____________________________________ Time: 07:45:46 AM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: Hall effect amp meter telling the truth? Yes I bought one and tested it against a calibrated meter from work...The current meter was remarkably accurate! Frank ________________________________ [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Hopperdhh@aol.com Sent: Sunday, July 16, 2006 12:46 PM Duane, I was in at our new Harbor Freight store and they had neat little digital meters on sale for $2.99. Had a 10 amp scale, too. I don't need another meter, but I almost bought a couple anyway. Dan do not archive In a message dated 7/16/2006 3:29:13 P.M. Eastern Daylight Time, klehman@albedo.net writes: --> AeroElectric-List message posted by: Ken Hi Duane The stuff you mentioned doesn't draw much so it might be OK but I do seem to recall having to tweak the settings to get mine to read accurately. Best way is a cheap digital meter as I've seen ones that will read 10 amps for under $10. You almost have to have something like that in your bag of tools anyway. For a gross check within 10 or 20% how about connecting up something with a known resistance or current draw like perhaps a landing light? Ken. Duane Wilson wrote: > --> AeroElectric-List message posted by: Duane Wilson > > I have a Hall effect current sensor hooked up to my GRT EIS-4000. I > have set the parameters in the EIS as stated on the instillation sheet > for the Hall effect sensor. > > When I turn on my 2 GRT Horizon 1 displays, my Val avionics VOR, > Garmin 300XL, transponder (standby) and panel lights I get a reading > of about .6 on the EIS. > > This seems low to me. How can I verify the current draw. I don't > have an amp meter. > > Duane ========================= = = Use lities Day --> ========================= ========================= - NEW MATRONICS LIST WIKI - ========================= p; - List Contribution Web Site ========================= ========================= ________________________________ Message 18 ____________________________________ Time: 08:34:41 AM PST US From: rd2@evenlink.com Subject: AeroElectric-List: LED flags --> AeroElectric-List message posted by: rd2@evenlink.com I am considering adding LEDs to indicate which source signal is used by the autopilot (S-Tec System 50). A rotary switch will select between 3 sources (NAV/GS, NAV2, GPS). It might be a good idea to also use the same LEDs as flags for the source in use (not just which source was selected but also if the source is on/working). Sure, the indicators already have flags but it is logical to have flags where the source selector is located. I am using 2 KX-155s and KI 208/KI 209 indicators. Has anyone done this? What signal are you using to make the LEDs act like flags? Thanks Rumen ________________________________ Message 19 ____________________________________ Time: 08:46:16 AM PST US From: Subject: AeroElectric-List: VM1000 light system failure --> AeroElectric-List message posted by: Responding to an Avionics-List message previously posted by: "Ralph E. Capen" 7/17/2006 Hello Ralph, I went through a struggle with my VM 1000 instrument lighting. I have VM instruments in addition to the main display. I won't bore you with all the details but here are some of the essential elements. 1) The instrument lights require alternating current that is generated by a small inverter inside the DPU. VM says to determine if this inverter is running or not by listening for the hum. This never worked for me. 2) You can do a check on the electrical output of the inverter to the lights. Disconnect the ribbon cable connector farthest from the DPU and probe the last two sockets on the ribbon cable (opposite the Red striped pin). You should have at least 89V AC (rms) across them with the unit operating and the lights turned on. 3) Do this check very carefully. Use a couple pieces of the the smallest size safety wire (0.020 diameter) to probe the sockets on the ribbon cable so that you don't destroy the sockets. Probe only those two sockets which are ground and the AC supply. If you happen to send the AC supply back to the DPU on one of the other sockets you can damage the DPU. Don't ask how I know this. 4) If it turns out that you are not getting the desired AC voltage across these two sockets then you probably have one of three problems. Either the inverter is not working, or the AC supply wire is broken, or the AC supply wire is grounded out somewhere along the ribbon cable. 5) Before you pack up your DPU and send it off to VM for inverter repair you can check out the ribbon cable. Remove the cable completely from the aircraft and probe the sockets in the end connectors for the ground wire, the AC supply wire, and the wire next to the AC supply wire separately to ensure continuity and no cross connection. If all three wires check out OK you probably have a failed inverter. 6) If the ribbon cable checks out bad you can get a replacement cable from VM or you can buy the parts and make up a cable yourself. (Contact me for parts identification.) In either case you will be required to fasten the connectors onto the ribbon cable. Be careful about how you orient those connectors so that they align properly with your DPU and instruments. 7) After ribbon cable assembly I would check out every single socket on every connector for continuity and no cross talk before installing in airplane. 8) VM, and particularly David McCluskey, are great people to do business with. Please keep us informed on your progress. OC > > Fellow listers, > > Anyone out there experience a failure mode with their VM1000 internal > lighting system? The lights worked up until a few days ago...I'm trying > to > remember if I have done anything to the lighting system that might cause > the > failure mode sooooo........ > > Here's the troubleshooting that I have already done: > > Pin 20 has 13.3 VDC > Pin 21 has between 4.1 VDC and 10.8 VDC depending on the dimmer setting > Pin 22 has continuity to ground > > These three are 'as designed' in my opinion - so the proper stuff is at > least getting to the DPU. > Is there something that I can check on the cable between the DPU and the > display? > > I've sent a note to Vision Microsystems - I'll post their > response......... > > Ralph Capen ________________________________ Message 20 ____________________________________ Time: 12:19:25 PM PST US From: "Brinker" Subject: AeroElectric-List: TKM MX 300 RADIO QUIRK --> AeroElectric-List message posted by: "Brinker" I have a friend with a TKM mx300 radio that has a strange problem. He cannot hear KLIT approach on one of thier frequencies but he can talk to them. He can hear other planes around him and talk to other planes on that frequency. He can change over to the other approach frequency and he can hear and talk just fine to control. This has happened to him twice. I his radio possesed ? Can it be excersied ? Randy ________________________________ Message 21 ____________________________________ Time: 12:35:25 PM PST US From: Subject: AeroElectric-List: Re: VM1000 light system failure --> AeroElectric-List message posted by: 7/17/2006 Hello Ralph, Obtaining the right replacement ribbon cable and the proper connecters was a little tricky because parts from the supplier to VM were not available. Went out of business or was bought out. I did some research and came up with equivalent parts from Mouser. 1) The 26 wire IDC (Insulation Displacement Connector) flat ribbon cable made by 3M that could be bought by the foot was Mouser part number 517-3365/26FT. It was $1.65 per foot. http://www.mouser.com/search/ProductDetail.aspx?R=3365%2f26-CUT-LENGTHvirtualkey51750000 2) The socket type connectors were Mouser part number 571-7462856. They were $1.18 each. http://www.mouser.com/search/refine.aspx?Ntt=571-7462856 3) If you buy a replacement display cable from VM (cost $54) the connector that goes onto the DPU is already installed and the wire folds back over itself and that fold is held in place for strain relief by a little plastic clip that slides onto the connectors in 2 above. That strain relief is Mouser part number 571-499252-3. Costs about $0.20 each. http://www.mouser.com/search/ProductDetail.aspx?R=499252-3virtualkey57100000 Please keep us informed of your progress. OC PS: My problem started when one of the connectors on the original display cable from VM had a hidden slight bend in one of the insulation displacement prongs. When I squashed that connector into place on the cable at the proper location for one of my VM instruments the prong went slightly sideways and cross connected the AC supply wire for the lights and the ground wire. Finding that problem and correcting it was difficult and expensive. (Could have been even more expensive if not for the gracious help of VM). That is why I recommend that after assembly every wire on every socket of that IDC cable be checked on the bench for continuity and no cross connection before the cable is installed in the airplane. ----- Original Message ----- Sent: Monday, July 17, 2006 1:16 PM > OC, > > I'll take the part numbers for the ribbon cable and connectors , please. > > I'm guessing that they can be procured through digi-key/mouser/etc. > > Thanks, > Ralph ________________________________ Message 22 ____________________________________ Time: 12:54:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Help needed: continued strobe noise --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:45 AM 7/17/2006 -0500, you wrote: >I'm not a sparky so I can't contribute much to this, but I am in the >process of wiring up my Rotax 912ULS and the Rotax wiring diagram calls >for a 22,000 uF capacitor. I bought one when I ordered the XCom radio >($40.00 U.S). Haven't had the opportunity to test it yet. > >Do Not Archive > >Tommy Walker in Alabama The need for that capacitor is unique to PM alternators (low frequency, single phase ac) and is commonly found on all diagrams where PM alternators are wired. See Z-13/8, Z-16, Z-17, Z-20 and Z-25. This capacitor is conspicuous by its absence on wound field, three phase alternators used in other applications. I recall now having some conversation with either XCom or someone associated with them where the 22,000 uf cap callout was unique to PM alternator systems and only echos requirements already in place for those systems. If you don't have a PM alternator, you don't need the capacitor. Bob . . . ________________________________ Message 23 ____________________________________ Time: 01:01:04 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Coax connector technologies --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:00 AM 7/17/2006 -0400, you wrote: >--> AeroElectric-List message posted by: FLYaDIVE@aol.com > >In a message dated 7/17/06 12:00:46 AM Eastern Daylight Time, >n3eu@comcast.net writes: > > > FLYaDIVE(at)aol.com wrote: > > > CRIMPS! You do not want a crimped coax. > > > > > > NO self-respecting RF Man will accept a CRIMPED coax. > > > > > > > Why do you say that? You mean a soldered, and hex-nut BNC connector > > fashioned by a homebuilder wil be better? On avg, don't think so. > > > > Fred F. >================================ >Yup! Fred ... Soldered, Hex Nut BNC connector. As far as who fashions it >... Why not the homebuilder? After all the homebuilder was not born knowing >how to rivet, why not just learn how to do a proper BNC connection. They are >SOOooooo much better, water proof (or at least highly resistant), vibration >proof, dust proof and of course a damn good RF electrical connection. AND >you can >do a field repair on them. Can't do that on crimp crap. > >The BNC was born out of the SO & PL fittings. It is better for maintaining >the impedance of the cable especially at low power VHF frequencies. The >higher >power, higher frequency version is the Type N. We haven't use a solder-n-clampnut connector on a production airplane in probably 25 years. I'll bet nobody on the production line was sorry to see them go either. Ease of installation and consistency of the electrical joints made it a no-brainer. I keep some UG-88 clampnut connectors around to build adapters and test tools. The wide open, threaded rear barrel is skunk-werks friendly. But when putting a connector on a coax, wouldn't consider anything other than crimped connectors. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 24 ____________________________________ Time: 01:02:31 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Help needed: continued strobe noise & --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:37 AM 7/17/2006 -0400, you wrote: >--> AeroElectric-List message posted by: FLYaDIVE@aol.com > >In a message dated 7/16/06 8:11:43 AM Eastern Daylight Time, >luckymacy@comcast.net writes: > > > Lucky: I used Van's pre-made wiring kit but I don't recall if the wiring >to > > the strobes was shielded or not. >===================================== >Lucky: > >I think you found the problem. I say that because of the above statement >about the pre-made harness. If they are running the strobe's wires right >along >side the wires for your other lights AND if they are not shielded then it >would >be very easy for the other wires to pick up the noise from the strobes. >Try running a separate SHIELDED pair of wires and ground the shield ONLY at >the strobe. The shielded pair should have three wires ... B+. Neg and >SHIELD. >The Neg is grounded at both ends, while the shield is only at the strobe. I >would still use the filter, just for S&Gs. Run the strobe wires away from >the >other wires. > >I have a similar strobe system as you with the power supplies. The strobes >mounted at the wing tips and tail; three power supplies. I found that >there is >a small amount of noise from the tail strobe. I know I can get rid of it >with an RS type filter, but it is on a GA aircraft so I'm not allowed to >use RS >or Lowe's aviation components ;-) > >You did say you tried mounting the filter at each location, Strobe and Radio. > Another thing to check and I have not seen it mentioned is LEAD > LENGTH. You >must keep the leads as short as possible between the filter and the strobe. >Still another trick you may want to try is to install a ferrite bead >(tolroid) on the B+ lead, close to the strobe. >Me still being a bit redundant, make sure you have extra clean ground >connections; aluminum is not a good material for electrical connections. > >Well, beyond all the techniques and trick I mentioned in this post and my >other. My other offer would be ... Where are you located, maybe we could >meet >up? I'd bet dollars to doughnuts I can solve your problem. I'd be glad >to help. > >Barry What is the nature of the noise? Whine from the power supply or "popping" when the tubes fire? Have any noise isolation experiments described in chapter 16 been conducted? Bob . . . ________________________________ Message 25 ____________________________________ Time: 03:44:34 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: LED flags --> AeroElectric-List message posted by: Brian Lloyd On Jul 17, 2006, at 11:16 AM, rd2@evenlink.com wrote: > --> AeroElectric-List message posted by: rd2@evenlink.com > > I am considering adding LEDs to indicate which source signal is > used by the > autopilot (S-Tec System 50). A rotary switch will select between 3 > sources > (NAV/GS, NAV2, GPS). It might be a good idea to also use the same > LEDs as > flags for the source in use (not just which source was selected but > also if > the source is on/working). Sure, the indicators already have flags > but it > is logical to have flags where the source selector is located. > I am using 2 KX-155s and KI 208/KI 209 indicators. > > Has anyone done this? What signal are you using to make the LEDs > act like > flags? A standard ARINC "flag" signal is a low-current bipolar (+/-) current designed to drive a standard "flag" which is actually a meter movement. The meter movement has a specific DC resistance (about 300 ohms as I recall) and the radio is supposed to source about 2mA to flip the flag. (I am probably wrong about the exact number as I am working from memory but I am in the ballpark.) The current is either positive or negative depending on the sense of the flag. (BTW, the flag resistances and currents are the same as for the CDI if I recall correctly.) Your GPS probably has a Nav Super Flag output. Basically this is a generic good/bad signal and is probably what you want for this case. Check your GPS's manual for the behavior of the Nav super flag for your GPS. You can probably drive a LED directly with this signal. The KX-155 is a bit more difficult. The VOR/LOC nav converter is in the KI-208 or KI-209, not in the radio. You will have to steal the signal from the indicator. I know the KI-208 or KI-209 have CDI outputs but do they have flag outputs? (I don't recall -- it has been a really long time since I have messed with those indicators.) My guess is that you are going to have to cook up an amplifier circuit to drive the LED without loading the flag driver circuit too much. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 26 ____________________________________ Time: 03:44:40 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: TKM MX 300 RADIO QUIRK --> AeroElectric-List message posted by: Brian Lloyd On Jul 17, 2006, at 3:15 PM, Brinker wrote: > --> AeroElectric-List message posted by: "Brinker" internet.com> > > I have a friend with a TKM mx300 radio that has a strange problem. > He cannot hear KLIT approach on one of thier frequencies but he > can talk to them. He can hear other planes around him and talk to > other planes on that frequency. He can change over to the other > approach frequency and he can hear and talk just fine to control. > This has happened to him twice. I his radio possesed ? Can it be > excersied ? My guess would be a null in the antenna pattern in one direction. Obviously the radio is receiving and transmitting. It could also be a null off of ATC's transmitting antenna. I have had this happen to me before too. Turning the airplane and/or getting to a different place usually fixes the problem. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 27 ____________________________________ Time: 04:29:05 PM PST US From: "Brinker" Subject: Re: AeroElectric-List: TKM MX 300 RADIO QUIRK --> AeroElectric-List message posted by: "Brinker" I suggested to him that his altitude and placement from the atc antenna might be the problem, but he explained to me that he did try it from several radials and also when he was within sight of the airport. Randy ----- Original Message ----- Sent: Monday, July 17, 2006 5:42 PM > --> AeroElectric-List message posted by: Brian Lloyd > > > On Jul 17, 2006, at 3:15 PM, Brinker wrote: > >> --> AeroElectric-List message posted by: "Brinker" > internet.com> >> >> I have a friend with a TKM mx300 radio that has a strange problem. >> He cannot hear KLIT approach on one of thier frequencies but he can >> talk to them. He can hear other planes around him and talk to other >> planes on that frequency. He can change over to the other approach >> frequency and he can hear and talk just fine to control. This has >> happened to him twice. I his radio possesed ? Can it be excersied ? > > My guess would be a null in the antenna pattern in one direction. > Obviously the radio is receiving and transmitting. It could also be a > null off of ATC's transmitting antenna. I have had this happen to me > before too. Turning the airplane and/or getting to a different place > usually fixes the problem. > > Brian Lloyd 361 Catterline Way > brian-yak AT lloyd DOT com Folsom, CA 95630 > +1.916.367.2131 (voice) +1.270.912.0788 (fax) > > I fly because it releases my mind from the tyranny of petty things . . . > Antoine de Saint-Exupry > > > http://www.matronics.com/Navigator?AeroElectric-List > http://wiki.matronics.com > > > ________________________________ Message 28 ____________________________________ Time: 04:55:42 PM PST US From: rd2@evenlink.com Subject: Re: AeroElectric-List: LED flags --> AeroElectric-List message posted by: rd2@evenlink.com Brian, thanks > I know the KI-208 or KI-209 have CDI outputs but do they have flag outputs? > Not to my knowledge. This may not be easy to solve. The GS flag ouput comes from the KX155 (if I recall correctly). It could be spliced into a hi-impedance amp for the led. The GPS is the lesser problem to tackle. Rumen do not archive _____________________Original message __________________________ (received from Brian Lloyd; Date: 06:38 PM 7/17/2006 -0400) ________________________________________________________________ --> AeroElectric-List message posted by: Brian Lloyd On Jul 17, 2006, at 11:16 AM, rd2@evenlink.com wrote: > --> AeroElectric-List message posted by: rd2@evenlink.com > > I am considering adding LEDs to indicate which source signal is > used by the > autopilot (S-Tec System 50). A rotary switch will select between 3 > sources > (NAV/GS, NAV2, GPS). It might be a good idea to also use the same > LEDs as > flags for the source in use (not just which source was selected but > also if > the source is on/working). Sure, the indicators already have flags > but it > is logical to have flags where the source selector is located. > I am using 2 KX-155s and KI 208/KI 209 indicators. > > Has anyone done this? What signal are you using to make the LEDs > act like > flags? A standard ARINC "flag" signal is a low-current bipolar (+/-) current designed to drive a standard "flag" which is actually a meter movement. The meter movement has a specific DC resistance (about 300 ohms as I recall) and the radio is supposed to source about 2mA to flip the flag. (I am probably wrong about the exact number as I am working from memory but I am in the ballpark.) The current is either positive or negative depending on the sense of the flag. (BTW, the flag resistances and currents are the same as for the CDI if I recall correctly.) Your GPS probably has a Nav Super Flag output. Basically this is a generic good/bad signal and is probably what you want for this case. Check your GPS's manual for the behavior of the Nav super flag for your GPS. You can probably drive a LED directly with this signal. The KX-155 is a bit more difficult. The VOR/LOC nav converter is in the KI-208 or KI-209, not in the radio. You will have to steal the signal from the indicator. I know the KI-208 or KI-209 have CDI outputs but do they have flag outputs? (I don't recall -- it has been a really long time since I have messed with those indicators.) My guess is that you are going to have to cook up an amplifier circuit to drive the LED without loading the flag driver circuit too much. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) ________________________________ Message 29 ____________________________________ Time: 07:22:15 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: LED flags --> AeroElectric-List message posted by: Brian Lloyd On Jul 17, 2006, at 7:38 PM, rd2@evenlink.com wrote: > --> AeroElectric-List message posted by: rd2@evenlink.com > > Brian, thanks > >> > I know the KI-208 or KI-209 have CDI outputs but do they have flag > outputs? >> > Not to my knowledge. This may not be easy to solve. No. That would involve hacking the guts of the KI-209. I wouldn't do that if it were mine. BTW, the KX-165 has an internal VOR/LOC converter which is why it is usually used for driving an HSI. Nowadays you want to look for a NAV/COM that outputs the nav info in ARINC-429 format. That means that instead of having to have two wires for CDI, two wires for VDI, two wires for NAV flag, two wires for GS flag, and 5 wires for OBS, you just need a data-out wire, a data-in wire, and ground. It sure makes wiring the avionics stack a LOT easier. > > The GS flag ouput comes from the KX155 (if I recall correctly). It > could be > spliced into a hi-impedance amp for the led. Yes, the GS receiver in the KX-155 has the converter built in and just outputs nav-valid, CDI, and flag. > > The GPS is the lesser problem to tackle. Right. Brian Lloyd 361 Catterline Way brian-yak AT lloyd DOT com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . Antoine de Saint-Exupry ________________________________ Message 30 ____________________________________ Time: 07:44:40 PM PST US From: N1deltawhiskey@comcast.net Subject: Re: AeroElectric-List: Re: Landing lights & relays Tom, Keep in mind that I am not a proponent of relays in critical circuits. Having said that, I would not be uncomfortable with your relay circuit proposal for your system. The other thing I would look at is the consequences of the possible failure modes. It is not clear to me why you would think a relay would go belly up any more frequently than a toggle switch. Junk is junk, but a quality relay should have a similar reliability as a quality switch. Why you would expect more RFI in the relay than in other circuit component? How would a relay interfer with navigation or cause noise in your audio system? A relay is a switch which is electrically activated. Do you have the same concerns about your battery contactors (a relay) or starter relay? I am using manual switches in my light system and am comfortable with that approach. But I would not exclude or be uncomfortable with the use of relays in this system either. Regards, Doug -------------- Original message -------------- Doug, That's reasonable as long as the relay doesn't go South every couple months.I don't spend all my time replacing relays. The other concern was RFI.I also don't want to listen to the lights flashing or have them interferewith navigation. Thanks for the reply. If you have any further thoughts, I would be very interested. Regards,Tom Costanza Tom, One way to look at this is that if landing/taxi lights (nor wig/wag) are not required for night flight, so what does it matter if the relay fails? One landing without the benefit of them? I would just get a quality relay and let the longevity concern take care of itself - don't plan to do much night flying anyway. Do you preflight check all the lights and wig/wag function? (This is rhetorical. If not, then how do you not know whether a light has burned out, a more likely event that losing a relay, I think. I would check light function only if I thought I would have the potential to use them during a flight. Obviously, if you use wig-wag as a safety feature during normal flights, one would check proper operation before takeoff.) Regards, Doug Windhorn ----- Original Message ----- From: tomcostanza@comcast.net To: aeroelectric-list@matronics.com Sent: Sunday, 16 July, 2006 6:53 Subject: Landing lights & relays What is your opinion of using mechanical relays to implement wig-wag flashing of landing lights? I would like to use a rotary switch with the following pattern: off, wig-wag, landing, taxi (4 positions). Otherwise I would need to use 3 toggle switches and a complicated switch operation. Using transistors would lower the voltage at the light by about 1.5 volts. To confuse the issue further, I have wingtip landing and taxi lights (1 landing and 1 taxi on each wing) 4 lights total. Using relays would solve my problems, but I don't know the longevity of the relay. What are your thoughts? Thanks, Tom Costanza RV-7A Fuselage
Tom,
 
Keep in mind that I am not a proponent of relays in critical circuits. Having said that, I would not be uncomfortable with your relay circuit proposal for your system.  The other thing I would look at is the consequences of the possible failure modes.
 
It is not clear to me why you would think a relay would go belly up any more frequently than a toggle switch. Junk is junk, but a quality relay should have a similar reliability as a quality switch.  Why you would expect more RFI in the relay than in other circuit component?  How would a relay interfer with navigation or cause noise in your audio system?  A relay is a switch which is electrically activated.  Do you have the same concerns about your battery contactors (a relay) or starter relay? 
 
I am using manual switches in my light system and am comfortable with that approach.  But I would not exclude or be uncomfortable with the use of relays in this system either. 
 
Regards, Doug 
 
-------------- Original message --------------
From: tomcostanza@comcast.net 
Doug,
That's reasonable as long as the relay doesn't go
South every couple months.
I don't spend all my time replacing relays.  The
other concern was RFI.
I also don't want to listen to the lights flashing
or have them interfere
with navigation.
Thanks for the reply.  If
you have any further thoughts, I would be very interested.
Regards,
Tom
Costanza
 
Tom,

One way to look at this is that if landing/taxi lights (nor wig/wag) are 
not required for night flight, so what does it matter if the relay 
fails?  One landing without the benefit of them?  I would just get a 
quality relay and let the longevity concern take care of itself - don't 
plan to do much night flying anyway.

Do you preflight check all the lights and wig/wag function?  (This is 
rhetorical. If not, then how do you not know whether a light has burned 
out, a more likely event that losing a relay, I think.  I would check 
light function only if I thought I would have the potential to use them 
during a flight.  Obviously, if you use wig-wag as a safety feature 
during normal flights, one would check proper operation before takeoff.)

Regards, 

Doug Windhorn
  ----- Original Message ----- 
  From: tomcostanza@comcast.net 
  To: aeroelectric-list@matronics.com 
  Sent: Sunday, 16 July, 2006 6:53
  Subject: Landing lights & relays


  What is your opinion of using mechanical relays to implement wig-wag 
flashing of landing lights? 

  I would like to use a rotary switch with the following pattern: off, 
wig-wag, landing, taxi (4 positions). Otherwise I would need to use 3 
toggle switches and a complicated switch operation. Using transistors 
would lower the voltage at the light by about 1.5 volts. To confuse the 
issue further, I have wingtip landing and taxi lights (1 landing and 1 
taxi on each wing) 4 lights total. Using relays would solve my problems, 
but I don't know the longevity of the relay. 

  What are your thoughts?

  Thanks,

  Tom Costanza

  RV-7A Fuselage






________________________________  Message 31  ____________________________________


Time: 09:07:44 PM PST US
From: Deems Davis 
Subject: AeroElectric-List: Wiring batteries in parallel?

--> AeroElectric-List message posted by: Deems Davis 

When  I built my battery tray, I was anticipating a dual battery (Z14) 
architecture. I'm now convinced that a z13 would be a better match. I'm 
having trouble finding a single battery that will fit my tray footprint 
(7.3"x6.2") I built the tray for 2 Odessey PC680's @ 17ah ea. Can I wire 
the 2 batteries together in parallel and treat them (architecturally) as 
a single battery w/ 34 ah capacity? Are there any special considerations 
for the wiring  (I assume #2 welders cable)?

THANKS
(all this electrical stuff is voodoo to me)

Deems Davis # 406
Fuse
http://deemsrv10.com/


________________________________  Message 32  ____________________________________


Time: 09:24:03 PM PST US
From: TimRhod@aol.com
Subject: Re: AeroElectric-List: Wiring batteries in parallel?

Deems;        IN Z-14 when you crossfeed the  systems that is precisly what 
you are doing. Combining two 17 amp to make one 34  amp battery.

________________________________  Message 33  ____________________________________


Time: 09:35:37 PM PST US
From: "Robert L. Nuckolls, III" 
Subject: Re: AeroElectric-List: Wiring batteries in parallel?

--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" 

At 09:01 PM 7/17/2006 -0700, you wrote:

>--> AeroElectric-List message posted by: Deems Davis 
>
>When  I built my battery tray, I was anticipating a dual battery (Z14) 
>architecture. I'm now convinced that a z13 would be a better match. I'm 
>having trouble finding a single battery that will fit my tray footprint 
>(7.3"x6.2") I built the tray for 2 Odessey PC680's @ 17ah ea. Can I wire 
>the 2 batteries together in parallel and treat them (architecturally) as a 
>single battery w/ 34 ah capacity?

  Yes, but why so much battery? You could stick a block of styrofoam
  in to take up the space and use the recovered 13# for baggage or
  passengers.

>  Are there any special considerations for the wiring  (I assume #2 
> welders cable)?

  #4 is fine for battery jumpers. #2 is considered for bringing
  widely separated battery and engine together . . . but if both
  are up-front, #4 suffices for all fat wires.


>THANKS
>(all this electrical stuff is voodoo to me)

  Hang around here and we'll attempt to make it less
  mystifying.


        Bob . . .


      ---------------------------------------------------------
      < What is so wonderful about scientific truth...is that >
      < the authority which determines whether there can be   >
      < debate or not does not reside in some fraternity of   >
      < scientists; nor is it divine. The authority rests     >
      < with experiment.                                      >
      <                            --Lawrence M. Krauss       >
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