---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 07/23/05: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:29 AM - Re: Best architecture for two alternator all-electric 912S Kitfox (Mark & Lisa) 2. 05:30 AM - Re: Cherokee bouncing loadmeterCherokee bouncing loadmeter (Mark & Lisa) 3. 06:42 AM - Re: Bouncing loadmeter (Robert L. Nuckolls, III) 4. 06:50 AM - Re: Re: Tach source for EIS (Robert L. Nuckolls, III) 5. 07:33 AM - Re: Best architecture for two alternator (Paul Wilson) 6. 10:21 AM - Re: Tach source for EIS () 7. 02:35 PM - Re: Slow starter (Eric M. Jones) 8. 03:50 PM - Re: Re: Tach source for EIS (DonVS) 9. 06:31 PM - Compound on Rotax plug threads? (Ronald J. Parigoris) 10. 06:41 PM - Re: Slow starter (jerb) 11. 06:44 PM - Silicone and O2 sensor? (Ronald J. Parigoris) 12. 07:55 PM - Re: Silicone and O2 sensor? (Paul McAllister) 13. 08:20 PM - Re: Re: Bouncing loadmeter (jdalton77) 14. 09:06 PM - Re: Silicone and O2 sensor? (Jim Baker) ________________________________ Message 1 _____________________________________ Time: 05:29:04 AM PST US From: "Mark & Lisa" Subject: AeroElectric-List: Re: Best architecture for two alternator all-electric 912S Kitfox --> AeroElectric-List message posted by: "Mark & Lisa" Jon, Try these: http://www.trutrakflightsystems.com/ttfsinstruments.html Mark & Lisa Sletten Legacy FG N828LM http://www.legacyfgbuilder.com ________________________________ Message 2 _____________________________________ Time: 05:30:13 AM PST US From: "Mark & Lisa" Subject: AeroElectric-List: Re: Cherokee bouncing loadmeterCherokee bouncing loadmeter --> AeroElectric-List message posted by: "Mark & Lisa" I've heard of this problem being solved by replacing the master switch. I can't remember the specifics... Mark & Lisa Sletten Legacy FG N828LM http://www.legacyfgbuilder.com ________________________________ Message 3 _____________________________________ Time: 06:42:46 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Bouncing loadmeter --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:29 AM 7/23/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "Mark & Lisa" > > >I've heard of this problem being solved by replacing the master switch. I >can't remember the specifics... This problem has been "fixed" by replacing a myriad of devices on as many airplanes. The problem is quite common on all DC power systems where the POWER TO EXCITE THE ALTERNATOR FIELD comes through the same wire as REGULATION VOLTAGE SENSE. I'm working on an article that is a compilation of many responses to this subject over the last 10 years or so. I published a similar article a long time ago on Compuserve's AVSIG forum but I don't find it in my archives . . . need to do it over. This time it will go up on aeroelectric.com This is a very special case problem understood by very few a/p mechanics that has cost the flying public $millions$ of unnecessary expense over the years. I'll try to finish it up over the weekend and get it posted. You'll hear about it here first. Bob . . . ________________________________ Message 4 _____________________________________ Time: 06:50:42 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:22 AM 7/22/2005 -0700, you wrote: >--> AeroElectric-List message posted by: "DonVS" > >John, >You can't do it with the device that George recommended. Both of your mag >drive holes are in use. You only need one lead to the EIS from a single >PMAG. The rpm reading will come through even with the PMAG shut off. This >is assuming that you have the new PMAG with the green wire for tach drive. >Don You lost me. The transducer George recommends goes into the stock tach drive port on the accessory case and has nothing to do with the mag drives. When Beech went to 2" engine instruments (trying to look like a bizjet) about 25 years ago, we (Electromech) built a similar transducer to screw into the tach drive and produce counts/revolution compatible with the instrument Beech had selected. Many electronic tachs can be "programmed" with jumpers or dip-switches to interpret a variety of pulse-per-revolution signals from external transducers. I seem to recall that the tach drive on Bonanzas ran at camshaft speed (1/2 crankshaft) and we had 8 magnets on the transducer rotor. This means that the transducer generated 4 pulses per propeller revolution. The independent transducer is an excellent way to drive an electronic tach. However, I'll suggest that tach signal failure on an e-mag/p-mag is on the same order of reliability as the transducer. So, if one can comfortably settle for a single source of tach signal from a dedicated transducer, then system reliability for taking tach drives from a single ignition system are in the same ball park which suggests that a dedicated transducer may elevate parts count without adding materially to reliablity. Bob . . . ________________________________ Message 5 _____________________________________ Time: 07:33:43 AM PST US From: Paul Wilson all-electric 912S Kitfox Subject: Re: AeroElectric-List: Best architecture for two alternator all-electric 912S Kitfox --> AeroElectric-List message posted by: Paul Wilson all-electric 912S Kitfox Morning Jon, Lots of us are disappointed that Rotax (or the Jabaru) have such a minimal electrical system. The certified Rotax equipped planes used for IFR training are using the Rotax$$ optional belt drive second alternator with one battery. Don't have the schematic but you are in good hands on this list. I suspect that these planes use an architecture with the stator alternator off line as a backup and use the belt drive unit normally. Your quoted amps are higher than expected. Here are the accurate details on what to expect for your proposed alternator solution. (Prices are 2 years old). The gear ratio for the 912S is 2.43:1. (the 912 ratio is more favorable @ 2.273:1). The accessory drive is 1.3182:1 for both engines & is applied to the prop revs not the engine revs. So the SD20 will put out 7.4amps@5000rpm, 12.0amps@5500, 14.3amps@5800. Not enough to use solo, so both alternators will have to be on line all the time. Thus you will have a permanent magnet unit with a different SD20 trying to provide the power at the same time. This topic has been discussed at length lately, but I haven followed it in detail. Weight increase is 6.1lbs+ regulator, cost is ~$700 if your engine came with the gears, ~$400 more if the gear box has to be revised to add the gears, but I think the S model has the gears?. Add ~$200+ for a new regulator. Suggestion: Alternatives: - A non Rotax belt drive should cost from $400 to ~$600 for about 40 amps? for a commercial model, and around $100 for a DIY setup using a Denso from a salvage yard. Then you can use the second alternator and use the Rotax unit as a backup. - A second battery should cost around $50 for lots of amps and lots of flying time. More reliable and a lot less complexity. Just make sure all your electrical stuff works on 12+v instead of 14+v, and you still have a redundant electrical power system. Now that I have written the details I hope others will jump in to suggest solutions to this issue. Regards, Paul =========================== At 03:28 PM 7/22/2005, you wrote: >--> AeroElectric-List message posted by: Jon Goguen > >We've just decided to commit to an all-electric system, in part because >we're convinced it's more reliable than vacuum, but also because a >second alternator to supplement the built-in PM alternator on the 912S >will make the energy budgeting less critical. I think we could make it >work with original alternator only, but would need to go to LED >position lights and take a series of other power efficiency measures. >On the whole, the redundancy of the second alternator seems best, and >will get the project completed more quickly: we're determined to be in >the air this fall. > >We plan to use an SD-20 on the vacuum pump pad. I've been given >figures ranging from 12-17 amps as reasonable expectations from the >SD-20 in this installation, and figure I can count on a conservative 30 >amps from both alternators in combination. I'm looking for >recommendations regarding the most reasonable architecture for this >combination. Two batteries or one? A big one and a little one? Both >alternators on line all the time? I've read the 'Connection (don't >know my Z-numbers yet without looking and don't have the book handy), >but it's clear that several choices are possible. Anyone see a strong >reason to favor one arrangement for our proposed alternator >combination? We do plan eventual IFR operation, (Garmin 300XL IFR >GPS/Com, one Nav radio, VAL single-hole ILS system, and electric gyros, > supplemented with the an Anywhere map system including weather). > >Thanks in advance for any and all suggestions. We had already acquired >much of the vacuum stuff (pump, regulator, and gyros) so now I need to >get the electric versions. Any suggests regarding sources for >cost-effective AI and DG would also be welcome. I will be at OshKosh >from Thursday evening through Sunday AM, and hope to do some some to >complete the equipment list. (If you have any interest in the vacuum >stuff, enquiries are welcome.) > >Jon > >Jon Goguen >jon.goguen@umassmed.edu >Central Massachusetts >Kitfox Series V Rotax 912S / N456JG (reserved) >Complete except for electrics and avionics ________________________________ Message 6 _____________________________________ Time: 10:21:10 AM PST US From: Subject: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: John: "George, does that UMA tack drive convert mechanical to electronic to supply the EIS?" John, 5 volt (4.8v) excitation is common for many sensors for electronic engine monitors, and this is not just limited a hall effect tach sender. (Note sender, probe, transducer and sensor all mean the same thing for this discussion). 5 VOLTS IS STANDARD FOR ELECTRONIC ENGINE MONITORS: EIS has its own 5 volt output power supply (actually 4. 8 volts) to drive the sensors or probes that require it. It may sound odd but some of the EIS probes work on +4.8 volt bias, not ground or 12 or 14 volts. In fact 12-14 volt going into any of the EIS probe input lines will damage the unit. If you read the manual for the EIS the optional or auxiliary inputs for: fuel flow, capacitive fuel level probes , fuel pressure and hall effect amp probe all require 4.8v to power them. HALL EFFECT: The hall effect tach sender converts the rotation of the tach drive into an electrical pulse. That pulse is what the EIS is set up to measure and turn into RPM. The standard way to get a pulse is off the magneto p-lead, lighting or ignition coil (like on a rotax) or magnetic tach sensor. Some of these produce their own voltage, others like a hall effect sender need a small voltage to give the proper output. Basics of Hall effect involve magnetic fields and electrical currents. The hall effect needs a little input voltage to work. The UMA is a "Hall Effect" device. Here is link explaining how "hall effect" works if you want to know: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html GRT's EIS 4000: The EIS works on +4.8 Volt Bias for many input signals. 4.8 Volts is the MAX volts input on any probe input for the EIS. 5 volts is common power supply level at the sub-component electronics level, by the way. Once you buy the EIS4000 and the hall effect device and read the installation manual it will be obvious. Even the optional amp sender GRT sells is a hall effect device and requires a positive 4.8 volt input. The nice part of a hall effect amp probe is the wire passes thru a coil with out a need to make a break in the wire. The hall effect amp sensor measures the magnetic field and converts it into a bias voltage your EIS can read. Cool. The EIS for the most part simply measures steady state voltage levels from a probe. With the software (and scale factor), it displays the correct value for you to read, like: fuel pressure oil temp, EGT, CHT, fuel level, etc. (EGT and CHT probes produce their own (very small) voltage. The oil pressure is set up to a ground bias and requires no external excitation voltage. Other probes like the fuel pressure requires an excitation voltage.) Some of the probe inputs are self powered (EGT/CHT) and others in the EIS are designed to measure a ground bias (oil pressure). Some EIS inputs measure a pulse (tach and fuel flow). It sounds odd or confusing I know, but it is super easy to connect. The wires are color coded. The EIS know what to do. As far as the Tach and the EIS, GRT does not sell tach transducers and expects you to provide a pulse. The software has user settings to adjust the number of pulses per engine revolution to account for different input sources from 0.5 to 12. How you get the pulse is your business but it must not be higher than 4.8 volts. IF using a coil or p-lead off a magneto you need to add resistors. The fuel flow requires the 4.8 volt excitation and the tach may or may not depending on the way you are measuring it. A pulse is a simple 0 to 5v signal that last a few Milli seconds. The rate of this pulse is read buy the EIS and converted to the proper display value to read as RPM or Gal/Hr. Regardless of the pulse the max magnitude of the pulse can not exceed 4.8 volts. Good Luck, George Time: 05:46:10 AM PST US From: "John Swartout" Subject: RE: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "John Swartout" George, does that UMA tack drive convert mechanical to electronic to supply the EIS? 5 volts is sort of odd. How do you supply 5 volts to yours? I'll be using toggle switches per Z13-8 for the Pmags, so can turn off either one at any time. John --------------------------------- ________________________________ Message 7 _____________________________________ Time: 02:35:46 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Re: Slow starter --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: "Charlie Burton" >I have a condition in my O-360 Glastar that puzzles me. I can turn the key >switch >(Aircraft Spruce) to START and the engine starts to turn but at a slow rate >like a low battery, high compression, too small a battery cable, etc. The >strange >part is that I just let go of the key and then try it again and the engine >turns over very nicely and starts on the first revolution through. I have >one >mag on the left side and a Lightspeed ignition on the right. Any ideas? >Charlie Burton & N331Fox Charlie, I got nothing BUT ideas.... Sounds like a bad ignition switch. So if you leave your Glastar parked on the street in a bad part of town, it'll be gone in the morning. Seriously, jumping around the switch would isolate the switch problem. Assuming it's not the switch or battery--measure the voltage across each joint of the high-current path from the battery to the starter and look for more than a volt drop when you crank the starter. Check the battery voltage too. It should drop to only 9.5 volts or so when starting. There are stranger problems like seriously retarded timing ar a slipped timing belt, but these are rare. Let us know. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "America is a nation that conceives many odd inventions for getting somewhere but it can think of nothing to do once it gets there." --Will Rogers ________________________________ Message 8 _____________________________________ Time: 03:50:36 PM PST US From: "DonVS" Subject: RE: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "DonVS" Bob, As usuall you are right. I mistook the device for one that would drive off the mag drive. My mistake, sorry George. Don -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert L. Nuckolls, III Subject: RE: AeroElectric-List: Re: Tach source for EIS --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:22 AM 7/22/2005 -0700, you wrote: >--> AeroElectric-List message posted by: "DonVS" > >John, >You can't do it with the device that George recommended. Both of your mag >drive holes are in use. You only need one lead to the EIS from a single >PMAG. The rpm reading will come through even with the PMAG shut off. This >is assuming that you have the new PMAG with the green wire for tach drive. >Don You lost me. The transducer George recommends goes into the stock tach drive port on the accessory case and has nothing to do with the mag drives. When Beech went to 2" engine instruments (trying to look like a bizjet) about 25 years ago, we (Electromech) built a similar transducer to screw into the tach drive and produce counts/revolution compatible with the instrument Beech had selected. Many electronic tachs can be "programmed" with jumpers or dip-switches to interpret a variety of pulse-per-revolution signals from external transducers. I seem to recall that the tach drive on Bonanzas ran at camshaft speed (1/2 crankshaft) and we had 8 magnets on the transducer rotor. This means that the transducer generated 4 pulses per propeller revolution. The independent transducer is an excellent way to drive an electronic tach. However, I'll suggest that tach signal failure on an e-mag/p-mag is on the same order of reliability as the transducer. So, if one can comfortably settle for a single source of tach signal from a dedicated transducer, then system reliability for taking tach drives from a single ignition system are in the same ball park which suggests that a dedicated transducer may elevate parts count without adding materially to reliablity. Bob . . . ________________________________ Message 9 _____________________________________ Time: 06:31:18 PM PST US From: "Ronald J. Parigoris" Subject: AeroElectric-List: Compound on Rotax plug threads? --> AeroElectric-List message posted by: "Ronald J. Parigoris" This is a bit off topic, but not too far. Rotax calls for a specific Denso Spark Plug for their 914UL. They also call for coating the threads with a Silicone based heat conductive compound "OR ELSE" The cost for a small tube from Rotax is outrageous. I have heard that you can use a Silicon Based heat sink compound from Radio Shack. I picked up a tube, and it is a very light white and translucent in color. I have a tube of silicone based Dow 340 and is very white and not translucent at all, temp range is -40F to 390F. I also have some coppaslip. Any comments? Thx. Ron Parigoris ________________________________ Message 10 ____________________________________ Time: 06:41:04 PM PST US From: jerb Subject: Re: AeroElectric-List: Slow starter --> AeroElectric-List message posted by: jerb Do you have an impulse mag that retards the timing for starting? If now that could well be your problem, fighting against compression power stroke and firing to far before TDC. Don't think the problem is key switch - how many amp hours battery do you have? Is there any chance your using a master solenoid for a starter solenoid? There different, starter solenoid is made for high current short duration where the master is made for lower current and full timer operation. Feel the battery and cable terminals immediately after trying to start - if the noticeably warm that may be your problem. Taking voltage readings between the start high current components can tell you a lot of where the power loss is occurring. Do you have a good ground between the starter, engine and battery? You can take reading on that also. jerb At 09:36 AM 7/22/05 -0700, you wrote: >--> AeroElectric-List message posted by: "Charlie Burton" > > >I have a condition in my O-360 Glastar that puzzles me. I can turn the key >switch (Aircraft Spruce) to START and the engine starts to turn but at a >slow rate like a low battery, high compression, too small a battery cable, >etc. The strange part is that I just let go of the key and then try it >again and the engine turns over very nicely and starts on the first >revolution through. I have one mag on the left side and a Lightspeed >ignition on the right. Any ideas? > >Charlie Burton & N331Fox > > ________________________________ Message 11 ____________________________________ Time: 06:44:51 PM PST US From: "Ronald J. Parigoris" Subject: AeroElectric-List: Silicone and O2 sensor? --> AeroElectric-List message posted by: "Ronald J. Parigoris" This is a afterthought from prior post about using a Silicone based (grease?) compound on spark plug thrteads. I have a O2 sensor that will be installed on my 914UL to drive a Split Second Mixture monitor. I know there are O2 safe sealants. I am not why some types of silicones kill O2 sensors. Is it the fumes from acidic smelling Silicone running through the combustion chamber that kills O2 sensors? Will low odor, non acidic aluminium and electronic safe silicone sealant fumes run through engine kill a O2 sensor? Will silicone grease, if a small amount that is on the spark plug threads have a chance to kill a O2 sensor? If silicone does hurt a O2 sensor, is it either alive, or dead? Or does it effect like lead killing a O2 sensor, lead will slow down O2 operation. Where a very quick responce is needed in a fuel injected auto, if you slow just a little it will have quite a adverse effect, yet when a O2 sensor is driving a monitor a few second delay is moot, thus it will tolerate a certain amount of lead. Once you learn your monitor, on start up/test it is easy to pick up that your sensor is not behaving properly and will not read out full range. Thx. Ron Parigoris ________________________________ Message 12 ____________________________________ Time: 07:55:53 PM PST US From: "Paul McAllister" Subject: Re: AeroElectric-List: Silicone and O2 sensor? --> AeroElectric-List message posted by: "Paul McAllister" Ron, Would the O2 sensor likely to be damaged by 100 low lead ? Paul do not archive ________________________________ Message 13 ____________________________________ Time: 08:20:38 PM PST US From: "jdalton77" Subject: RE: AeroElectric-List: Re: Bouncing loadmeter --> AeroElectric-List message posted by: "jdalton77" Bob, That would be great and MUCH appreciated by many. I've been asking A&Ps about this for three years and I have heard at least ten "sure" answers. Maybe it's a combination of all of them ? -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: AeroElectric-List: Re: Bouncing loadmeter --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" --> At 07:29 AM 7/23/2005 -0500, you wrote: >--> AeroElectric-List message posted by: "Mark & Lisa" >--> > > >I've heard of this problem being solved by replacing the master switch. >I can't remember the specifics... This problem has been "fixed" by replacing a myriad of devices on as many airplanes. The problem is quite common on all DC power systems where the POWER TO EXCITE THE ALTERNATOR FIELD comes through the same wire as REGULATION VOLTAGE SENSE. I'm working on an article that is a compilation of many responses to this subject over the last 10 years or so. I published a similar article a long time ago on Compuserve's AVSIG forum but I don't find it in my archives . . . need to do it over. This time it will go up on aeroelectric.com This is a very special case problem understood by very few a/p mechanics that has cost the flying public $millions$ of unnecessary expense over the years. I'll try to finish it up over the weekend and get it posted. You'll hear about it here first. Bob . . . ________________________________ Message 14 ____________________________________ Time: 09:06:54 PM PST US From: "Jim Baker" Subject: Re: AeroElectric-List: Silicone and O2 sensor? --> AeroElectric-List message posted by: "Jim Baker" > prior post about using a Silicone based > (grease?) compound on spark plug thrteads. Whoa! No silicone grease on plug treads, please. Use appropriate antiseize only. The silicone grease, such as Dow DC4, or FHC (don't mix the two..one or the other) is used on the spark plug boots. > I know there are O2 safe sealants. I am not why some types of > silicones kill O2 sensors. Just use appropriate antiseize...... Jim Baker 580.788.2779 '71 SV, 492TC Elmore City, OK