---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 07/09/16: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:35 PM - Current Sensor basic question (donjohnston) 2. 12:52 PM - Re: Current Sensor basic question (C&K) 3. 01:32 PM - Re: Current Sensor basic question (Bill Putney) 4. 01:43 PM - Re: Current Sensor basic question (Daniel Hooper) 5. 01:46 PM - Re: Current Sensor basic question (Alec Myers) 6. 02:00 PM - Re: Current Sensor basic question (C&K) 7. 02:12 PM - Re: Current Sensor basic question (donjohnston) 8. 02:13 PM - Re: Current Sensor basic question (donjohnston) 9. 04:06 PM - Re: Current Sensor basic question (Robert L. Nuckolls, III) 10. 04:27 PM - Re: Z-13/8 Questions (MMiller) 11. 04:27 PM - Re: Re: Current Sensor basic question (C&K) 12. 05:13 PM - Re: Re: Z-13/8 Questions (Charlie England) ________________________________ Message 1 _____________________________________ Time: 12:35:41 PM PST US Subject: AeroElectric-List: Current Sensor basic question From: "donjohnston" I'm using the 50a hall effect sensor which came with my Grand Rapids EIS 6000. But the current numbers don't jibe with the VPX. It's not a huge difference, but enough that I don't like it. I've talked with GRT and verified the offset and scale factor configuration but it's still not right. While searching to see if anyone else was having this issue I ran across an aftermarket sensor. High accuracy current sensor http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ Interestingly, it looks just like the GRT sensor. I contacted them to make sure it would work with the EIS6000 and if it came with the offset and scale factor values that needed to be configured on the EIS. They said yes and that the correct values were based on the wire size being used. There is nothing in the GRT documentation about the wire size having an effect on the offset and scale factor settings. Is it true that the size of the wire effects the reading of a hall effect sensor? Don Read this topic online here: http://forums.matronics.com/viewtopic.php?p=457996#457996 ________________________________ Message 2 _____________________________________ Time: 12:52:41 PM PST US Subject: Re: AeroElectric-List: Current Sensor basic question From: C&K I can believe that wire size affects that sensor but not the hollow round 60 amp sensor that GRT sold me several years ago. The wonderful thing about the GRT sensor is that you can adjust the offset and scale for almost any sensor. IMO the values from GRT are simply a recommended starting value and all of my sensors benefited from some tweaking when I calibrated them. Ken On 09/07/2016 3:34 PM, donjohnston wrote: > > I'm using the 50a hall effect sensor which came with my Grand Rapids EIS 6000. But the current numbers don't jibe with the VPX. It's not a huge difference, but enough that I don't like it. > > I've talked with GRT and verified the offset and scale factor configuration but it's still not right. > > While searching to see if anyone else was having this issue I ran across an aftermarket sensor. > > High accuracy current sensor > http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ > > Interestingly, it looks just like the GRT sensor. > > I contacted them to make sure it would work with the EIS6000 and if it came with the offset and scale factor values that needed to be configured on the EIS. They said yes and that the correct values were based on the wire size being used. There is nothing in the GRT documentation about the wire size having an effect on the offset and scale factor settings. > > Is it true that the size of the wire effects the reading of a hall effect sensor? > > Don > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=457996#457996 > > ________________________________ Message 3 _____________________________________ Time: 01:32:22 PM PST US Subject: Re: AeroElectric-List: Current Sensor basic question From: Bill Putney If it's a Hall Effect sensor the wire size doesn't matter. Magnetic field is what the Hall Effect device is measuring. What dictates the magnetic field strength is Ampere-Turns. I assume you have the wire only passing through the sensor once (one turn). A smaller wire will have more voltage drop across it for any given current flow than a larger one, but won't change the current measurement. Look at your installation. If the wire and the sensor is laying tightly with other wires, the field may be effected. This should be a very localized effect so if you have about 1/2" from other wires carrying current you should be OK. Bill Putney - WB6RFW Chief Engineer KPTZ - Port Townsend, WA PP-SEL/A&P-IA "...you know me to be a very smart man. Don't you think if I were wrong, I'd know it?" -Sheldon Cooper On 7/9/16 12:34 PM, donjohnston wrote: > > I'm using the 50a hall effect sensor which came with my Grand Rapids EIS 6000. But the current numbers don't jibe with the VPX. It's not a huge difference, but enough that I don't like it. > > I've talked with GRT and verified the offset and scale factor configuration but it's still not right. > > While searching to see if anyone else was having this issue I ran across an aftermarket sensor. > > High accuracy current sensor > http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ > > Interestingly, it looks just like the GRT sensor. > > I contacted them to make sure it would work with the EIS6000 and if it came with the offset and scale factor values that needed to be configured on the EIS. They said yes and that the correct values were based on the wire size being used. There is nothing in the GRT documentation about the wire size having an effect on the offset and scale factor settings. > > Is it true that the size of the wire effects the reading of a hall effect sensor? > > Don > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=457996#457996 > > ________________________________ Message 4 _____________________________________ Time: 01:43:35 PM PST US Subject: Re: AeroElectric-List: Current Sensor basic question From: Daniel Hooper In general that is 100% correct, but this sensor doesnt appear to have a split ring to concentrate the magnetic field into a Hall sensor. When youre not collecting the whole field, geometry has a large effect on field strength. Im curious how this sensor works or if they expect some sort of calibration step after installation. > On Jul 9, 2016, at 3:29 PM, Bill Putney wrote: > > > If it's a Hall Effect sensor the wire size doesn't matter. Magnetic field is what the Hall Effect device is measuring. What dictates the magnetic field strength is Ampere-Turns. I assume you have the wire only passing through the sensor once (one turn). > > A smaller wire will have more voltage drop across it for any given current flow than a larger one, but won't change the current measurement. > > Look at your installation. If the wire and the sensor is laying tightly with other wires, the field may be effected. This should be a very localized effect so if you have about 1/2" from other wires carrying current you should be OK. > > Bill Putney - WB6RFW > Chief Engineer > KPTZ - Port Townsend, WA > > PP-SEL/A&P-IA > > "...you know me to be a very smart man. Don't you think if I were wrong, I'd know it?" -Sheldon Cooper > > On 7/9/16 12:34 PM, donjohnston wrote: >> >> I'm using the 50a hall effect sensor which came with my Grand Rapids EIS 6000. But the current numbers don't jibe with the VPX. It's not a huge difference, but enough that I don't like it. >> I've talked with GRT and verified the offset and scale factor configuration but it's still not right. >> While searching to see if anyone else was having this issue I ran across an aftermarket sensor. >> High accuracy current sensor >> http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ >> >> Interestingly, it looks just like the GRT sensor. >> I contacted them to make sure it would work with the EIS6000 and if it came with the offset and scale factor values that needed to be configured on the EIS. They said yes and that the correct values were based on the wire size being used. There is nothing in the GRT documentation about the wire size having an effect on the offset and scale factor settings. >> Is it true that the size of the wire effects the reading of a hall effect sensor? >> Don >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=457996#457996 >> >> >> >> >> >> >> >> >> >> > > > > > ________________________________ Message 5 _____________________________________ Time: 01:46:40 PM PST US Subject: Re: AeroElectric-List: Current Sensor basic question From: Alec Myers It appears from the photograph that it's sensing the magnetic field at only one or two points; The field decays in strength with distance away from the conductor, and measured at the surface surface a larger conductor has a smaller field than a small conductor carrying the same current (because of the 1/r rule) so I would expect the size of the conductor to make a difference. If the current sensor were a transformer (which effectively integrates the field strength around a closed loop surrounding the conductor) then no, the size of the conductor wouldn't make a difference; but this doesn't appear to be such a thing. Of course a transformer wouldn't be able to detect a DC current so you'd have to be doing something very smart like integrating the transformer output which would be expensive, and probably inaccurate. If it's a Hall Effect sensor the wire size doesn't matter. Magnetic field is what the Hall Effect device is measuring. What dictates the magnetic field strength is Ampere-Turns. I assume you have the wire only passing through the sensor once (one turn). A smaller wire will have more voltage drop across it for any given current flow than a larger one, but won't change the current measurement. Look at your installation. If the wire and the sensor is laying tightly with other wires, the field may be effected. This should be a very localized effect so if you have about 1/2" from other wires carrying current you should be OK. Bill Putney - WB6RFW Chief Engineer KPTZ - Port Townsend, WA PP-SEL/A&P-IA "...you know me to be a very smart man. Don't you think if I were wrong, I'd know it?" -Sheldon Cooper On 7/9/16 12:34 PM, donjohnston wrote: > > I'm using the 50a hall effect sensor which came with my Grand Rapids EIS 6000. But the current numbers don't jibe with the VPX. It's not a huge difference, but enough that I don't like it. > I've talked with GRT and verified the offset and scale factor configuration but it's still not right. > While searching to see if anyone else was having this issue I ran across an aftermarket sensor. > High accuracy current sensor > http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ > > Interestingly, it looks just like the GRT sensor. > I contacted them to make sure it would work with the EIS6000 and if it came with the offset and scale factor values that needed to be configured on the EIS. They said yes and that the correct values were based on the wire size being used. There is nothing in the GRT documentation about the wire size having an effect on the offset and scale factor settings. > Is it true that the size of the wire effects the reading of a hall effect sensor? > Don > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=457996#457996 > > > > > > > > > > ________________________________ Message 6 _____________________________________ Time: 02:00:37 PM PST US Subject: Re: AeroElectric-List: Current Sensor basic question From: C&K Bill I certainly agree for what I'd call a common hall effect transformer with the sensor in a gap of a magnetic torus and the wire through the center hole but the pic that came up when I clicked on Don's link just appeared to be hall sensors strapped directly on both the sides of the wire. I would expect such an arrangement to be affected by wire diameter? Ken On 09/07/2016 4:29 PM, Bill Putney wrote: > > If it's a Hall Effect sensor the wire size doesn't matter. Magnetic > field is what the Hall Effect device is measuring. What dictates the > magnetic field strength is Ampere-Turns. I assume you have the wire > only passing through the sensor once (one turn). > > A smaller wire will have more voltage drop across it for any given > current flow than a larger one, but won't change the current measurement. > > Look at your installation. If the wire and the sensor is laying > tightly with other wires, the field may be effected. This should be a > very localized effect so if you have about 1/2" from other wires > carrying current you should be OK. > > Bill Putney - WB6RFW > Chief Engineer > KPTZ - Port Townsend, WA > > PP-SEL/A&P-IA > > "...you know me to be a very smart man. Don't you think if I were > wrong, I'd know it?" -Sheldon Cooper > > On 7/9/16 12:34 PM, donjohnston wrote: >> >> >> I'm using the 50a hall effect sensor which came with my Grand Rapids >> EIS 6000. But the current numbers don't jibe with the VPX. It's not >> a huge difference, but enough that I don't like it. >> I've talked with GRT and verified the offset and scale factor >> configuration but it's still not right. >> While searching to see if anyone else was having this issue I ran >> across an aftermarket sensor. >> High accuracy current sensor >> http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ >> >> >> Interestingly, it looks just like the GRT sensor. >> I contacted them to make sure it would work with the EIS6000 and if >> it came with the offset and scale factor values that needed to be >> configured on the EIS. They said yes and that the correct values were >> based on the wire size being used. There is nothing in the GRT >> documentation about the wire size having an effect on the offset and >> scale factor settings. >> Is it true that the size of the wire effects the reading of a hall >> effect sensor? >> Don >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=457996#457996 >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 7 _____________________________________ Time: 02:12:27 PM PST US Subject: AeroElectric-List: Re: Current Sensor basic question From: "donjohnston" Can you elaborate on the tweaking process? For example did you adjust the scale factor or offset? Which direction did you change for what effect? yellowduckduo(at)gmail.co wrote: > I can believe that wire size affects that sensor but not the hollow > round 60 amp sensor that GRT sold me several years ago. > The wonderful thing about the GRT sensor is that you can adjust the > offset and scale for almost any sensor. IMO the values from GRT are > simply a recommended starting value and all of my sensors benefited from > some tweaking when I calibrated them. > Ken > > On 09/07/2016 3:34 PM, donjohnston wrote: > Read this topic online here: http://forums.matronics.com/viewtopic.php?p=458012#458012 ________________________________ Message 8 _____________________________________ Time: 02:13:57 PM PST US Subject: AeroElectric-List: Re: Current Sensor basic question From: "donjohnston" Only one pass through the sensor. No other wires within about 4-6". billp(at)wwpc.com wrote: > If it's a Hall Effect sensor the wire size doesn't matter. Magnetic > field is what the Hall Effect device is measuring. What dictates the > magnetic field strength is Ampere-Turns. I assume you have the wire only > passing through the sensor once (one turn). > > A smaller wire will have more voltage drop across it for any given > current flow than a larger one, but won't change the current measurement. > > Look at your installation. If the wire and the sensor is laying tightly > with other wires, the field may be effected. This should be a very > localized effect so if you have about 1/2" from other wires carrying > current you should be OK. > > On 7/9/16 12:34 PM, donjohnston wrote: > Read this topic online here: http://forums.matronics.com/viewtopic.php?p=458013#458013 ________________________________ Message 9 _____________________________________ Time: 04:06:44 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Current Sensor basic question > >High accuracy current sensor >http://www.crazedpilot.com/high-accuracy-current-sensor-for-5v-input-7-30v-supply-engine-monitor-systems-dynon-mgl-grand-rapids-garmin-and-more-ems-efis-systems/ > This is obviously not a 'cored' sensor. Because there is no control over the concentration of flux in the measured wire, there is similarly no physical filtering of external magnetic fields normally afforded by the use of a gapped core. Hence, the need for two sensors on opposite sides of the wire. Magnetic lines of force will be equal/opposite in the two sensors where the sum of the two will represent a field proportional to flux surrounding the wire. Flux from outside the sensor pair will affect each sensor approximately the same and since they're wired for adding opposing fields, non-opposing fields tend to cancel each other. As long as the instrumentation system has adequate accommodation of scale factor and offset, then this 'coreless' approach seems reasonable. I use a closed loop, gapped core sensors in my instrumentation packages. One of my favorites is this critter http://tinyurl.com/zxsdyj4 [] [] Emacs! It's core function is a plus-minus 6A sensor but easy to 'jeep' into fractional multiples and sub multiples of 6A. Of course, it's designed to mount on an ECB but I've converted dozens of them to remotely installed sensors at the end of pendant cables. These are gapped-core, closed-loop sensors with great linearity and calibration numbers. They too could probably be adapted to the popular displays. The price sure is right. Bob . . . ________________________________ Message 10 ____________________________________ Time: 04:27:44 PM PST US Subject: AeroElectric-List: Re: Z-13/8 Questions From: "MMiller" Bob Here are the details of about a dozen Rotax regulator failures. Draw your own conclusion(s). First some background. There are several versions of the Rotax 912/Ducati regulator. Older versions include Rotax PN 965-345/Ducati 383475, I believe this is the version examined on the http://contrails.free.fr/elec_ducati_en.php website. This was replaced by Rotax PN 965-347/Ducati 343620. This version was manufactured until late 2009 and was replaced by the current version, Rotax PN 965-349/Ducati 362001. I believe this change was driven by component obsolescence, the button case diode was no longer produced. My findings show there are two failure modes, depending on the version of the regulator. The older pre 2010 regulators fail from the inability to adequately transfer heat from the diode assembly to the case. This causes the diodes to unsolder themselves from the assembly. Both diodes show signs of unsoldering, but, If look closely, the inboard diode always shows more heat damage then the outboard diode. This asymmetrical failure is likely caused by the asymmetrical geometry of the enclosure/heat sink. This is the only failure I have seen in this version regulator. This includes regulators with melted supply terminals (G pin,) the solder connections on these diodes show the same failure mode. I have not seen any component fail out of spec in any regulator examined. Here a schematic/assy for this version https://drive.google.com/open?id=0ByPxADyU-DwPdTQ3NWp5LW9iOHc Typical failure mode https://drive.google.com/open?id=0ByPxADyU-DwPTnlXcUVEQTdfcVU Current production since 2010 uses a different diode package. This resolved the internal heatsinking issue of the older regulator versions. Unfortunately, at this time they changed to gel type potting compound. All the examined failures of this version are likely caused by vibration. This failure is unique to the regulators with the new gel potting compound, this failure mode is nonexistent on the older version regulators. Here a schematic/assy for this version https://drive.google.com/open?id=0ByPxADyU-DwPWTBBcGlUeENTcHc Here are some failure photos https://drive.google.com/open?id=0ByPxADyU-DwPYm1rYUVsbUJyQ3M Heat is often the cause of failure in electronics, but these regulators fail from poor mechanical design and poor material choices, long before heat would kill them. nuckolls.bob(at)aeroelect wrote: > At 06:37 AM 7/5/2016, you wrote: > > > > > Mike Miller has done autopsies on several failed Ducati regulators and he attributes the failures to poor manufacturing and vibration, > > vibration in a potted assembly? > > > > not from heat. > > Has he published a teardown report? > > > > Some RV-12 owners have reported a gradual failure where they get low voltage alarms at RPMs where they used to have normal voltage. Each regulator could fail differently. > > Color me skeptical . . . these regulators have > been in production for decades. There must have > been thousands sold. Over that period of time > and numbers of examples, I find it curious that > a constellation of failure modes would emerge. > > ..... > > Bob . . . Read this topic online here: http://forums.matronics.com/viewtopic.php?p=458023#458023 ________________________________ Message 11 ____________________________________ Time: 04:27:55 PM PST US Subject: Re: AeroElectric-List: Re: Current Sensor basic question From: C&K Don The formula is in Section 7.1.5 "Transfer Function" in my GRT manual. From a quick refresher it seems that increasing the Aux Scale Factor increases your reading by MULTIPLYING all sensor outputs by a larger scale factor. Increases or decreases each reading by a similar percentage so to speak. Changing the offset simply adds (or subtracts) the same value to all readings. For example you could change this by some value that adds say 5 amps to all indications. It would then add 5 amps to the indication even when no current is flowing, and 5 amps to all readings. Tweak this by an even number such as -2 or +2. Changing it by an odd number such as 1 or 3 reverses the direction for example from adding to subtracting. If you describe what you are seeing on the display and what it actually should be at one point preferably somewhere near a normal cruising current and also with zero current flowing (such as with no wire or a disconnected wire in the sensor) we can make a suggestion as to what tweaking might help. There is an interaction in that we get the multiplier correct and then use the offset to make it read zero when no current is flowing. Sometimes it takes a couple of tries. The suggested values from GRT for my sensor were Aux Scale Factor = 93 and Aux Offset = 177 so you probably have those set as a starting point if it is the same sensor and you are setting it for +/- 50 amps. Increasing the Aux Scale Factor to 94 would slightly raise all displayed readings especially the highest readings. If it then reads above zero with no current flowing you'd try tweaking the Aux Offset to maybe 175 to lower the zero current display a bit. Ken On 09/07/2016 5:11 PM, donjohnston wrote: > > Can you elaborate on the tweaking process? For example did you adjust the scale factor or offset? Which direction did you change for what effect? > > > yellowduckduo(at)gmail.co wrote: >> I can believe that wire size affects that sensor but not the hollow >> round 60 amp sensor that GRT sold me several years ago. >> The wonderful thing about the GRT sensor is that you can adjust the >> offset and scale for almost any sensor. IMO the values from GRT are >> simply a recommended starting value and all of my sensors benefited from >> some tweaking when I calibrated them. >> Ken >> >> On 09/07/2016 3:34 PM, donjohnston wrote: >> > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=458012#458012 > > > . > ________________________________ Message 12 ____________________________________ Time: 05:13:52 PM PST US Subject: Re: AeroElectric-List: Re: Z-13/8 Questions From: Charlie England FWIW, I spent a lot of years doing electronics repair, first on consumer products and then industrial products. The post-2010 failure pics all look like what electronics techs call 'cold solder joints'. Either bad prep (dirty contacts or leads), or inadequate heat when soldering. I've seen joint failures on circuit boards from TV sets that never move after installation to industrial equipment valued at 6-7 figures. Every time I dealt with it, cleaning the lead either mechanically (scraping) or by using a good electronics grade flux during the re-soldering process, cured the problem. I have no reason to doubt your word that the components can move if embedded in 'soft' potting compound, but.... in my opinion, a properly soldered joint on a pc board pad like that would not fail due to vibration. The pad/trace would peal up from the substrate, or the lead would break, before the solder joint to the lead would fail. Properly executed solder joints are much stronger than most people think. Charlie On 7/9/2016 6:24 PM, MMiller wrote: > > Bob > Here are the details of about a dozen Rotax regulator failures. Draw your own conclusion(s). > > First some background. There are several versions of the Rotax 912/Ducati regulator. Older versions include Rotax PN 965-345/Ducati 383475, I believe this is the version examined on the http://contrails.free.fr/elec_ducati_en.php website. This was replaced by Rotax PN 965-347/Ducati 343620. This version was manufactured until late 2009 and was replaced by the current version, Rotax PN 965-349/Ducati 362001. I believe this change was driven by component obsolescence, the button case diode was no longer produced. My findings show there are two failure modes, depending on the version of the regulator. > > The older pre 2010 regulators fail from the inability to adequately transfer heat from the diode assembly to the case. This causes the diodes to unsolder themselves from the assembly. Both diodes show signs of unsoldering, but, If look closely, the inboard diode always shows more heat damage then the outboard diode. This asymmetrical failure is likely caused by the asymmetrical geometry of the enclosure/heat sink. This is the only failure I have seen in this version regulator. This includes regulators with melted supply terminals (G pin,) the solder connections on these diodes show the same failure mode. I have not seen any component fail out of spec in any regulator examined. > Here a schematic/assy for this version > https://drive.google.com/open?id=0ByPxADyU-DwPdTQ3NWp5LW9iOHc > Typical failure mode > https://drive.google.com/open?id=0ByPxADyU-DwPTnlXcUVEQTdfcVU > > Current production since 2010 uses a different diode package. This resolved the internal heatsinking issue of the older regulator versions. Unfortunately, at this time they changed to gel type potting compound. All the examined failures of this version are likely caused by vibration. This failure is unique to the regulators with the new gel potting compound, this failure mode is nonexistent on the older version regulators. > Here a schematic/assy for this version > https://drive.google.com/open?id=0ByPxADyU-DwPWTBBcGlUeENTcHc > Here are some failure photos > https://drive.google.com/open?id=0ByPxADyU-DwPYm1rYUVsbUJyQ3M > > Heat is often the cause of failure in electronics, but these regulators fail from poor mechanical design and poor material choices, long before heat would kill them. > > > nuckolls.bob(at)aeroelect wrote: >> At 06:37 AM 7/5/2016, you wrote: >> >>> >>> Mike Miller has done autopsies on several failed Ducati regulators and he attributes the failures to poor manufacturing and vibration, >> vibration in a potted assembly? >> >> >>> not from heat. >> Has he published a teardown report? >> >> >>> Some RV-12 owners have reported a gradual failure where they get low voltage alarms at RPMs where they used to have normal voltage. Each regulator could fail differently. >> Color me skeptical . . . these regulators have >> been in production for decades. There must have >> been thousands sold. Over that period of time >> and numbers of examples, I find it curious that >> a constellation of failure modes would emerge. >> >> ..... >> >> Bob . . . > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.