---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 09/09/06: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:42 AM - Re: Alternator Problem - Not in plane (FLYaDIVE@aol.com) 2. 12:42 AM - Re: Alternator Problem - Not in plane (FLYaDIVE@aol.com) 3. 02:16 AM - Re: OV Module additional requirement (Bob Lee) 4. 06:34 AM - Re: Transponder antenna location (Gilles Tatry) 5. 07:50 AM - Re: Alternator Problem - Not in plane (Charlie England) 6. 07:54 AM - Re: Alternator Problem - Not in plane (Bob White) 7. 08:18 AM - Fuel Pump Switch(es) (Kevin Kinney) 8. 12:26 PM - Switch contact rattings which is best for this app (Jeffrey W. Skiba) 9. 01:04 PM - Re: Switch contact rattings which is best for this app (Richard E. Tasker) 10. 01:31 PM - John Deere PM alternator regulator (Ken) 11. 01:40 PM - Re: Fuel Pump Switch(es) (Bob McCallum) 12. 06:43 PM - Re: Fuel Pump Switch(es) (Hinde, Frank George (Corvallis)) 13. 08:00 PM - Re: AOPA battery article (Cleone Markwell) 14. 08:12 PM - Re: AOPA battery article (Cleone Markwell) 15. 09:37 PM - Re: John Deere PM alternator regulator (David Carter) ________________________________ Message 1 _____________________________________ Time: 12:42:00 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Alternator Problem - Not in plane --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 9/8/06 8:52:29 PM Eastern Daylight Time, altoq@cebridge.net writes: > Barry, > > Diode (One of three pressed into the case) or diode trio. > > Shot in the Dark > John D. ================================ John: I don't believe the diode pack would be bad in ALL 4 alternators, especially 2 NEW alternators right off the shelf. I know, I know, weirder things have happened but the logic says no. And why would I get the 60 to 80 Amps output? Unfortunately none of these test benches have a 'O' Scope hooked up to them. Barry ________________________________ Message 2 _____________________________________ Time: 12:42:00 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Alternator Problem - Not in plane --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 9/8/06 11:43:19 PM Eastern Daylight Time, ceengland@bellsouth.net writes: > Are they really rated to put out 60-80 amps? If not, try loading them at > rated output current. ============================================= Charlie: What is that going to do? I already get 60 to 80 Amps out and that is way more than what the load requires. Barry ________________________________ Message 3 _____________________________________ Time: 02:16:45 AM PST US From: "Bob Lee" Subject: RE: AeroElectric-List: OV Module additional requirement --> AeroElectric-List message posted by: "Bob Lee" Bob Nuckolls wrote: (my reply in << brackets >> Not sure you need to resort to manual switching. If you wire per Z-12 with B&C hardware, automatic assumption of loads by the auxiliary alternator is built in. Both alternators are ON all the time . . . Aux alternator is set for 13.0 volts while main alternator is set for 14.2 volts. The aux alternator regulator sees "too high" bus voltage and relaxes. If main altenrator goes off line, bus voltage sags and aux alternator comes alive. If loads on the Aux Alternator exceed rated output of 20A, then the "AUX ALT LOADED" light flashes. You turn things off until the light stops flashing. << The 20 amp dynamo supplied with the engine has a regulator that seems to be a type of zenor that meerly clamps the voltage to a limit. There are only three connections on the regulator: AC(1), [AC(2) and +12], and ground. I cannot use the B&C hardware here because it is a permanant magnet unit, therefore Z-13. >> But your load analysis suggests that Z-13/8 would be all you need. How much RUNNING current does the pitot heater draw when submerged in an ice bath? This is the real load-analysis current. << Will need to test this because I don't know - see below >> Are the position lights LED? if not, 2.0A for nav lights is too low. << Yes, LED >> The dynamo relay would be an E-bus load, not a battery bus load. << It ends up on the battery bus because I have used the method suggested on Z-13/8 that brings the ground to the panel through a circuit-breaker that gets tripped for an OV event. The positive side of the relay is just connected to the b+ lead on the battery side of the disconnect relay. >> Ignition of 8A is REALLY big . . . what engine are you using and what ignition system? << Great Plains Aircraft Supply 2600cc. It is an auto conversion based on the VW TypeIV engine. The ignition is a Comp-u-Fire electronic ignition. There are several flying and they measure 8 amps. >> Landing and taxi lights are generally not combined with pitot heat. You may adopt an operating protocol that runs pitot heat in VMC when lights would be off. << Certainly this is an option that can work. I was trying to develop a solution that reduced the number of electrical events that the pilot got involved in. Let the airplane solve any problem it can and reduce the types of events that the pilot was responsible for managing is the design goal here. In reality, I don't intend to need pitot heat by flying in VMC. I meerly want to have the legal equipment to allow me to regularly file IFR. I find that flying IFR all the time makes you a better pilot on those extremely rare ocassions where you end up in less than VFR weather by mistake. If pitot heat gets turned on though, the charging system needs to handle it. >> Let's tweak this analysis a bit. I'm not convinced that you need a 40/20 system . . . and 40/8 may well get done what you need to do. << The engine is supplied with a 20 amp perminant-magnet dynamo so the 8/20 decision has already been made by the engine supplier. The 40 amp alternator is from a Honda Gold Wing motorcycle. I selected it because it is driven off the transmission end of the primary drive (1/2 engine speed). This makes the rpm range of my engine a very close match to the design rpm range of this alternator. I have modified it's mounting to allow it to be placed in the mag drive of my engine. I also modified the alternator to remove the internal regulator and use an external regulator. The faston male connector that was the idot light is now the field input. >> Bob . . . << me to! >> ________________________________ Message 4 _____________________________________ Time: 06:34:22 AM PST US From: "Gilles Tatry" Subject: AeroElectric-List: Re: Transponder antenna location --> AeroElectric-List message posted by: "Gilles Tatry" Should the bottom of the front fuselage, 2 ft behind the engine, be a proper location? Is it a problem to be so close to the engine, isn't it far better at the rear? Thanks, Gilles --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:28 AM 9/7/2006 -0400, you wrote: >--> AeroElectric-List message posted by: Ken > >Has anyone tried mounting a transponder antenna on the bottom of the rear >fuselage? That location (about 2/3 of the length of the fuselage back) >slopes upward on a Rebel but it is the location least blanked by large >gear fairings, and metal radiator ducting. Unfortunately the worst signal >would likely be forward to where the ground station I'm trying to reply to >is likely to be during first contact. I am willing to mount the >transponder behind me to keep the coax within the 8.8 feet max specified >by Garmin. > >The other option seems to be on the roof. That is apparently not >recommended and it would be near skylights and my head which I'm not >comfortable with. I could get it the minimum recommended 3 feet away from >the VHF antenna but the high wing might tend to blank ground stations to >the side. I suspect that roof mounting would provide a better signal to >other aircraft which is probably more important to me than a signal to >ground so I guess I could put the antenna on the roof back near the >tail. It seems silly to invest in a transponder though unless it is >likely to perform well with both ATC and also traffic warning devices on >other aircraft. Any place on the bottom would be preferable to top mounted. The aft fuselage location you cited would be fine. 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 5 _____________________________________ Time: 07:50:54 AM PST US From: Charlie England Subject: Re: AeroElectric-List: Alternator Problem - Not in plane --> AeroElectric-List message posted by: Charlie England FLYaDIVE@aol.com wrote: >--> AeroElectric-List message posted by: FLYaDIVE@aol.com > >In a message dated 9/8/06 11:43:19 PM Eastern Daylight Time, >ceengland@bellsouth.net writes: > > > >>Are they really rated to put out 60-80 amps? If not, try loading them at >> rated output current. >> >> >============================================= >Charlie: > >What is that going to do? I already get 60 to 80 Amps out and that is way >more than what the load requires. > >Barry > If they came off small cars, they might not be rated for that much current & unable to maintain voltage if you demand excess current. Another thought: are they internally or externally regulated? If external & you're using a regulator built into the test set, are you sure the test set regulator is set correctly and are you sure the test set voltmeter is accurate? Getting the same volt reading for all using one test set & a different, same volt reading for all on another test set seems to point at the test sets. ________________________________ Message 6 _____________________________________ Time: 07:54:58 AM PST US From: Bob White Subject: Re: AeroElectric-List: Alternator Problem - Not in plane --> AeroElectric-List message posted by: Bob White On Sat, 9 Sep 2006 03:38:42 EDT FLYaDIVE@aol.com wrote: > --> AeroElectric-List message posted by: FLYaDIVE@aol.com > > In a message dated 9/8/06 11:43:19 PM Eastern Daylight Time, > ceengland@bellsouth.net writes: > > > Are they really rated to put out 60-80 amps? If not, try loading them at > > rated output current. > ============================================= > Charlie: > > What is that going to do? I already get 60 to 80 Amps out and that is way > more than what the load requires. > > Barry > Hi Barry, What Charlie is saying is maybe you are overloading the alternator. Put a smaller load on, no more than the rated output and see what the voltage is. Bob W. -- http://www.bob-white.com N93BD - Rotary Powered BD-4 (first engine start 1/7/06) Custom Cables for your rotary installation - http://www.roblinphoto.com/shop/ ________________________________ Message 7 _____________________________________ Time: 08:18:45 AM PST US From: Kevin Kinney Subject: AeroElectric-List: Fuel Pump Switch(es) --> AeroElectric-List message posted by: Kevin Kinney I'm planning a left/right fuel system each with an on/off valve and an aux pump on each incoming line. I'm thinking of using an on/off/on switch for pumps rather than an on/off switch for each pump. Can anyone offer any thoughts on the downside of this? Regards, Kevin Kinney -- Non-parent - I don't see how you can raise children & stay sane. Parent - You don't. You pick one and go with it. ________________________________ Message 8 _____________________________________ Time: 12:26:52 PM PST US From: "Jeffrey W. Skiba" Subject: AeroElectric-List: Switch contact rattings which is best for this app --> AeroElectric-List message posted by: "Jeffrey W. Skiba" Okay, I Have gone and confused myself, I am looking at ordering some switches for my OBAM aircraft and can't rember which would be better Higher current switch The catalog states two options: 1: Silver Rated 3A @ 125V AC 2: Gold Rated 0.4 VA max @ 28V AC/DC max My application will be used in a 12-14 Volt system I want the switch with the higher switch capability which is it? THANKS in advance P.s. my guess is option one the silver contacts but for some reason I don't think that is correct.... -- ________________________________ Message 9 _____________________________________ Time: 01:04:52 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Switch contact rattings which is best for this app --> AeroElectric-List message posted by: "Richard E. Tasker" It is definitely the first, as you guessed. However, what are you planning to switch with this? The silver one you list still doesn't have a very high rating. Perfectly fine for most avionics, but definitely not so good for landing lights or pitot heat, or other high current applications. The gold one listed would be perfect for a low contact control switch for avionics - a PTT switch or an acknowledge switch for a warning light, etc. Dick Tasker Jeffrey W. Skiba wrote: >--> AeroElectric-List message posted by: "Jeffrey W. Skiba" > > Okay, > >I Have gone and confused myself, I am looking at ordering some switches for >my OBAM aircraft and can't rember which would be better Higher current >switch > >The catalog states two options: > >1: Silver Rated 3A @ 125V AC > > >2: Gold Rated 0.4 VA max @ 28V AC/DC max > > >My application will be used in a 12-14 Volt system I want the switch with >the higher switch capability which is it? > >THANKS in advance > > >P.s. my guess is option one the silver contacts but for some reason I don't >think that is correct.... > > > -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 10 ____________________________________ Time: 01:31:30 PM PST US From: Ken Subject: AeroElectric-List: John Deere PM alternator regulator --> AeroElectric-List message posted by: Ken I can now say for certain that the AM101406 regulator will not come to life with a totally dead battery. Since I was at homebase, without power for a charger, and like to experiment, I attempted to charge the dead battery by closing the Z-14 cross feed contactor and charging the dead battery with the good alternator for a few minutes until the PM alternator came to life. I wouldn't recommend that and in this case it seems to have caused the regulator to fail full on. I don't really know why it failed as the rpm was modest (well below the max output capability of the 20 amp PM alternator) and it is not particularly uncommon to have dead batteries on the small tractors that these are original equipment on. Further the regulator is on the cool side of the firewall. My best theory is that the totally dead small AGM battery allowed the output to overvoltage some component in the regulator. I do not have a battery contactor so I felt that there was no need for a large electrolytic capacitor on the output since the battery would never be disconnected. The oem application doesn't have a capacitor. AFAIK totally dead batteries can be reluctant to take a charge at first so maybe it wasn't absorbing enough current initially to dampen the output pulses?? Again I wouldn't have expected that to fail a regulator designed to work with up to 200vac open circuit voltage from the alternator. The OVM worked perfectly. It is wired to interupt the line from the alternator to the regulator. In further experimenting, the little 40 amp relay does not seem to have suffered noticeably from a few 20 amp disconnects. I also learned that a single 9ah battery will start the subaru rather nicely so all in all I have obtained some value for the cost of my experimentation ;) I guess I also obtained some value from the OVM modules ;) As a shot in the dark I am thinking of putting a capacitor on the output of the regulator. That would leave the capacitor permanently wired across the battery through the b-lead circuit breaker. I don't think transorbs there would help. Any other suggestions? The obvious one is to charge the battery first but that is not always convenient as sooner or later I will likely run a battery dead again in some out of the way place. I do not have a charging indicator lamp wired to the regulator but I am assuming that is irrelevant. Ken ________________________________ Message 11 ____________________________________ Time: 01:40:16 PM PST US From: "Bob McCallum" Subject: Re: AeroElectric-List: Fuel Pump Switch(es) --> AeroElectric-List message posted by: "Bob McCallum" Kevin; One downside is "single point of failure". If the switch fails you loose both pumps. Also, if one pump fails and blows the fuse you loose both pumps. Two switches allows two fuses, two circuits, redundancy. Bob McC ----- Original Message ----- From: "Kevin Kinney" Sent: Saturday, September 09, 2006 11:17 AM Subject: AeroElectric-List: Fuel Pump Switch(es) > --> AeroElectric-List message posted by: Kevin Kinney > > I'm planning a left/right fuel system each with an on/off valve and an aux pump on each incoming line. > I'm thinking of using an on/off/on switch for pumps rather than an on/off switch for each pump. > > Can anyone offer any thoughts on the downside of this? > > Regards, > Kevin Kinney > > -- > Non-parent - I don't see how you can raise children & stay sane. > Parent - You don't. You pick one and go with it. > > ________________________________ Message 12 ____________________________________ Time: 06:43:42 PM PST US Subject: RE: AeroElectric-List: Fuel Pump Switch(es) From: "Hinde, Frank George (Corvallis)" --> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" Sure!.. if the single point of failure (namely the switch)...er...fails...You crash! If you are dependant on those electric pumps (like I am) always wire them seperatly all the way back to the battery...If you have two batteries make sure they are isolated and feed one pump from each battery. Frank RV7a, IO360 electic pump in each wing root. No mechanical pump, single Odyssey and dual alternator. Flying as of yesterday. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Kevin Kinney Sent: Saturday, September 09, 2006 8:18 AM Subject: AeroElectric-List: Fuel Pump Switch(es) --> AeroElectric-List message posted by: Kevin Kinney I'm planning a left/right fuel system each with an on/off valve and an aux pump on each incoming line. I'm thinking of using an on/off/on switch for pumps rather than an on/off switch for each pump. Can anyone offer any thoughts on the downside of this? Regards, Kevin Kinney -- Non-parent - I don't see how you can raise children & stay sane. Parent - You don't. You pick one and go with it. ________________________________ Message 13 ____________________________________ Time: 08:00:45 PM PST US From: Cleone Markwell Subject: Re: AeroElectric-List: AOPA battery article At 11:24 AM 9/7/2006, you wrote: >--> AeroElectric-List message posted by: "Carlos Trigo" > > >OBAM stands for Owner Built and Maintained, which the designation >that Bob prefers to call Experimental / Amateur Built aircraft. > >Carlos Thanks Carlos, now I know. Cleone > > >----- Original Message ----- From: "Cleone Markwell" >To: >Sent: Thursday, September 07, 2006 4:31 PM >Subject: Re: AeroElectric-List: AOPA battery article > > >>--> AeroElectric-List message posted by: Cleone Markwell >> >>Bob, What does OBAM mean? >> >> >> >>At 09:29 PM 9/6/2006, you wrote: >>>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >>> >>> >>>At 09:04 AM 9/6/2006 -0700, you wrote: >>> >>> >>>>---- "Robert L. Nuckolls wrote: >>>> > --> AeroElectric-List message posted by: "Robert L. Nuckolls, >>>>III" >>>> > >>>> > At 12:44 AM 9/6/2006 -0400, you wrote: >>>> > >>>> > >The article is in the AOPA pilot magazine Aug or Sept issue, >>>> on > >aircraft >>>> > >batteries. >>>> > >Bobs name is mentioned right in the introduction of the >>>> article and > >later >>>> > >near the end with a reference to the connection. I have a rotax >>>>912 with a >>>> > >20Amp generater, was setting up >>>> > >for an RG battery from B&C, but took out the vented battery box >>>>I got with >>>> > >my kit and dusted it off wondering if this article is correct. >>>> > >>>> > I don't subscribe to AOPA Pilot any more so I missed >>>> > the article. It would be interesting/useful to review >>>> > it. If someone could scan it and email it to me, I'd >>>> > appreciate it. >>>> > >>>> > Bob . . . >>>> >>>>Listers, >>>> The relevent article is on page 133 of the September issue >>>>Charlie Kuss >>> >>> Dave sent me a copy. It's an innocuous piece and relatively >>> accurate. If I were to expand beyond where it stopped short >>> would be to explain the value in KNOWING what your endurance >>> loads are and KNOWING if your battery is likely to support >>> this load for whatever endurance YOU decide. >>> >>> There was one rather glaring error on the top of page >>> 138 where it's stated that a 1C rated battery is discharged >>> at 2C, it will deliver energy for 1/2 hour. Twice the >>> load is ALWAYS less than half the previous capacity. By >>> the same token, 0.1C load is always more than 10X the >>> 1C label capacity. >>> >>> Exemplar capacity vs. discharge rates are illustrated >>> in . . . >>> >>>http://www.aeroelectric.com/Pictures/Curves/37AH_Capacity_vs_Load.gif >>> >>> and >>> >>>http://www.aeroelectric.com/Pictures/Curves/17AH_Capcity_vs_Load.gif >>> >>> These graphs from manufacturer's data show that increasing >>> loads increases internal losses and that apparent >>> capacity drops as load increases. >>> >>> Our perpetual parents on the TC side have decided that >>> "30 minutes" is the magic number for endurance and >>> "85% of label capacity" is end of life for the battery. >>> This makes the certification effort easy and makes FBOs >>> task of selling batteries easier. This is an excellent example of >>> standardization that benefits the manufacturers and >>> regulators while limiting the owner's ability to tailor >>> realistic targets to match his/her own mission requirements. >>> >>> Neither one of the 30-minute/85% assertions suggest that >>> the owner/operator of an airplane might possess tools and >>> be willing to acquire skills needed increase personal endurance >>> target to say 1 hour. Or, take the time to monitor a battery >>> with an eye toward meeting the endurance level such that >>> 70% of label capacity is the TRUE end of life for the battery >>> in that particular airplane. >>> >>> Aren't you guys glad you don't have to salute those >>> flags? I still like "duration of fuel aboard" for >>> endurance and "pitch it when e-bus loads cannot be >>> supported for duration of fuel aboard." Of course, >>> on the OBAM side of the house we're free to select >>> and operate to our personal design goals. >>> >>> >>> 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 14 ____________________________________ Time: 08:12:19 PM PST US From: Cleone Markwell Subject: Re: AeroElectric-List: AOPA battery article At 01:10 PM 9/7/2006, you wrote: >--> AeroElectric-List message posted by: "David M." > >Owner Built and Maintained. Invented while searching for a >politically correct term for homebuilt. > >David M. Thanks David. Cleone > > >Cleone Markwell wrote: > >>--> AeroElectric-List message posted by: Cleone Markwell >> >>Bob, What does OBAM mean? >> >> >> >>At 09:29 PM 9/6/2006, you wrote: >> >>>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >>> >>> >>>At 09:04 AM 9/6/2006 -0700, you wrote: ><<>> > > ________________________________ Message 15 ____________________________________ Time: 09:37:16 PM PST US From: "David Carter" Subject: AeroElectric-List: Re: John Deere PM alternator regulator --> AeroElectric-List message posted by: "David Carter" Ken, For my info what is your last name? I thought at first you would be Ken Powell who I have shared info with about Deere PM alternators, but the e-mail address is different. In any case, could you will in some of the "scenario": 1. The battery was dead, and you charged the battery from a non-PM alternator after starting the engine. . . . So, you have two batteries, 1 was dead, 1 was OK enough to start engine. . . . You have two alternators (a PM and a "standard" - not a bad idea when building experience with an unproven application like a Deere on an airplane) . . . . . and used the non-PM to attempt to charge the dead battery. 2. Was the PM alternator isolated from the good battery so it or its Deere voltage regulator lacked some needed "excitation"? Looks like we need a "functional test" (experiment) to determine characteristics of a Deere PM alternator and VR to see how it performs in our application: We should find out "on a bench" that the Deere system won't work with a dead battery. Actually, there are two dead battery cases that come to mind: 1. Before flight, battery is dead. Don't fly with dead battery - so this is a ground maintenance scenario. 2. During flight, battery dies and I want to continue flight with my PM alternator to some suitable landing spot, either "soon" or "procede to final destination" (whatever my risk analysis and good judgement and experience and prior planning for this scenario may indicate is "safe enough") . . . I plan to have two batteries, so 2. would have to include loss of BOTH batteries or some portion of the electrical circuit. Does you experience in this case you are reporting indicate that the PM alternator system might stop putting out voltage and current if battery power is lost? David Carter ----- Original Message ----- From: "Ken" Sent: Saturday, September 09, 2006 2:31 PM Subject: AeroElectric-List: John Deere PM alternator regulator > --> AeroElectric-List message posted by: Ken > > I can now say for certain that the AM101406 regulator will not come to > life with a totally dead battery. Since I was at homebase, without power > for a charger, and like to experiment, I attempted to charge the dead > battery by closing the Z-14 cross feed contactor and charging the dead > battery with the good alternator for a few minutes until the PM alternator > came to life. I wouldn't recommend that and in this case it seems to have > caused the regulator to fail full on. I don't really know why it failed as > the rpm was modest (well below the max output capability of the 20 amp PM > alternator) and it is not particularly uncommon to have dead batteries on > the small tractors that these are original equipment on. Further the > regulator is on the cool side of the firewall. > > My best theory is that the totally dead small AGM battery allowed the > output to overvoltage some component in the regulator. I do not have a > battery contactor so I felt that there was no need for a large > electrolytic capacitor on the output since the battery would never be > disconnected. The oem application doesn't have a capacitor. AFAIK totally > dead batteries can be reluctant to take a charge at first so maybe it > wasn't absorbing enough current initially to dampen the output pulses?? > Again I wouldn't have expected that to fail a regulator designed to work > with up to 200vac open circuit voltage from the alternator. > > The OVM worked perfectly. It is wired to interupt the line from the > alternator to the regulator. In further experimenting, the little 40 amp > relay does not seem to have suffered noticeably from a few 20 amp > disconnects. I also learned that a single 9ah battery will start the > subaru rather nicely so all in all I have obtained some value for the cost > of my experimentation ;) I guess I also obtained some value from the OVM > modules ;) > > As a shot in the dark I am thinking of putting a capacitor on the output > of the regulator. That would leave the capacitor permanently wired across > the battery through the b-lead circuit breaker. I don't think transorbs > there would help. Any other suggestions? The obvious one is to charge the > battery first but that is not always convenient as sooner or later I will > likely run a battery dead again in some out of the way place. > > I do not have a charging indicator lamp wired to the regulator but I am > assuming that is irrelevant. > > Ken > > >