---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 02/20/11: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:59 AM - Ramsey UHF Counter for Sale (Robert L. Nuckolls, III) 2. 06:05 AM - Re: AC ground prong question (user9253) 3. 06:37 AM - Re: Voltage Regulator Problem (frank3) 4. 07:24 AM - Re: Permanent Magnet Alternators - Over Voltage Protection (user9253) 5. 07:56 AM - Re: Permanent Magnet Alternators - Over Voltage Protection (user9253) 6. 08:04 AM - Re: AC ground prong question (Eric M. Jones) 7. 09:19 AM - Re: Re: Permanent Magnet Alternators - Over Voltage Protection (Robert L. Nuckolls, III) 8. 09:19 AM - Re: Re: Permanent Magnet Alternators - Over Voltage Protection (Robert L. Nuckolls, III) 9. 09:56 AM - Re: Re: Voltage Regulator Problem (Robert L. Nuckolls, III) 10. 10:32 AM - Re: Honeywell Rocker lamp wiring (jonlaury) 11. 01:48 PM - Re: Voltage Regulator Problem (frank3) 12. 04:35 PM - Re: Permanent Magnet Alternators - Over Voltage Protection (user9253) 13. 10:18 PM - Re: Re: Permanent Magnet Alternators - Over Voltage Protection (Robert L. Nuckolls, III) 14. 10:25 PM - Re: Re: Voltage Regulator Problem (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 05:59:12 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Ramsey UHF Counter for Sale This one-owner Ramsey CT-90 UHF counter with high accuracy/stability time base option has become surplus to my needs. It has been listed on Ebay at: http://tinyurl.com/6dyy753 This will directly display the transmitter's center frequency for both handhelds and panel mounted radios. It's also a rough field strength test for a transmitted signal. Might be a good tool for an EAA chapter to have for loan to members. Bob . . . ________________________________ Message 2 _____________________________________ Time: 06:05:42 AM PST US Subject: AeroElectric-List: Re: AC ground prong question From: "user9253" Here is website that gives the voltage and frequency of countries around the world: http://users.telenet.be/worldstandards/electricity.htm Half of Japan has 50hz and half has 60hz. Although Japan's 50hz and 100 volt power is different from the USA, it is similar enough to operate most U.S. appliances. However, there may be some sensitive devices that will not work. The person who suggested that Japan could have two phase power is completely wrong. Two phase power is very rare and would require more than two wires. I would NOT cut off the grounding prong from a cord plug. Doing so could create a shock hazard in certain situations. Some sensitive electronic devices will malfunction without being grounded. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331606#331606 ________________________________ Message 3 _____________________________________ Time: 06:37:30 AM PST US Subject: AeroElectric-List: Re: Voltage Regulator Problem From: "frank3" Let me try sending again--only part of note came through on first try. I have a 912ULS with the Ducati regulator wired into the Z16 diagram that I have been flying for three years. Today on run-up I noted low voltage (under 11 volts) in the Grand Rapid EIS & the Dynon EFIS displays, regardless of RPM. Normally I get 13.1 volts indicated with load. With Master off & engine not running the yellow dynamo wires feeding the regulator show continuity with no resistance. I am thinking there should be some resistance--am I correct or is the reading OK? At fast idle (2400 RPM) the yellow wires indicate 18 volts AC and correspondingly increases with increasing RPM. The regulator output B+ terminal reads 8.5 volts DC--I believe I should expect 14 v DC. The system voltmeter reads about 11 volts with minimal load. Battery was 12.5 v. I traded out the regulator with one that I was told was good. Very similar results (8.3 volts output). I assume both regulators are faulty??? Any suggestions to further trouble shoot? If I replace the regulator I'm considering the Key West. Question about integrating into the Z16 wiring scheme. I assume the + & - input terminals are connected to the yellow wires from the dynamo. Not sure how to hook-up the + & - output terminals. Can anyone help me with that? Thanks much -------- Frank Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331608#331608 ________________________________ Message 4 _____________________________________ Time: 07:24:09 AM PST US Subject: AeroElectric-List: Re: Permanent Magnet Alternators - Over Voltage Protection From: "user9253" Bob, I intend to build an over-voltage circuit for my Rotax powered RV-12. I found a couple of designs on your website: http://www.aeroelectric.com/DIY/DIY_Crowbar_OVP_F.pdf and http://www.aeroelectric.com/Catalog/AEC/9003/CbOV-14_Installation_A.pdf I like the latter circuit due to its fewer parts count. Unfortunately, the MBS4991 Silicon Bilateral Switch is no longer available. Question: Can I substitute a zener (8.7 or 9 volt) diode for the MBS4991? I did find a replacement for the MBS4991 at Mouser: the NTE6403 although it is relatively expensive at $8. I am not sure how to connect it because your schematic only shows 2 of the 3 leads connected. Question: Do the Gate and the A1 terminal of the bilateral switch connect to the pot? Thanks for your help. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331611#331611 ________________________________ Message 5 _____________________________________ Time: 07:56:54 AM PST US Subject: AeroElectric-List: Re: Permanent Magnet Alternators - Over Voltage Protection From: "user9253" > who could confirm whether or not they agree that the 505 seems suitable as a generic PMA OV device Mark, I agree with your thoughts on this. But I have no experience with the B&C 505-1 to back up my opinion. You could build your own over-voltage protection using one of Bob's schematics mentioned in my post above. Bob sells over-voltage protection for $30 on his website: http://www.aeroelectric.com/Catalog/AECcatalog.html If you go to there and scroll down and click on CBOV-14, the link takes you here: http://www.aeroelectric.com/Catalog/AEC/9003/CbOV-14_Installation_A.pdf I believe the aircraft schematic at the bottom of the PDF will work for a permanent magnet alternator. I am sure that someone will correct me if I am wrong. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331613#331613 ________________________________ Message 6 _____________________________________ Time: 08:04:15 AM PST US Subject: AeroElectric-List: Re: AC ground prong question From: "Eric M. Jones" Dear Lincoln (and Joe) Joe is right. I actually designed devices to operate worldwide, and I can tell you Brazil is the worst. The voltage has been known to be from 90-250 from any outlet type! Intermittent, too! Grounds? fahgedaboutit...but it is rapidly improving. The world seems to be "harmonizing" on 230V 50 Hz. But to answer some of your puzzle: The neutral conductor in US systems is the white wire (the larger blade). Black is higher voltage, measured against white or ground. The green wire and the U-ground is attached to the white at the main transformer, but the green is also attached to any metal "likely to be energized in a fault condition." So you see, the ground and white wire are both "neutral" in a sense, but the green ground is for safety. If you are plugging in a device that has "no metal likely to become energized in a fault condition", and you stay out of the water, then you are good to go with only two prongs. Since this condition is usually hard to know with 100% certainly, three is always a better choice. But be aware: Worldwide 230 VAC 50 Hz outlets do not have the neutral and ground connected anywhere. For additional credit: Q: Should the "face" on the US plug be installed right-side up or upside-down? A: The socket should be installed so that upon the inadvertent extraction of the plug (getting yanked out), The U-ground connection is the last prong to be disconnected. This usually means that plugs near the floor should have right-side-up faces, plugs way up high should have upside down faces. Cool huh? Also, be aware that everyone makes mistakes. In the Southwest, Mexican construction plumbers work for peanuts. "C" in Mexico is "Caliente" (hot) and an "F" looks like an "H" if you are illiterate. I have seen branded, UL, CSA, ETL approved, where grievous errors were not caught. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331614#331614 Attachments: http://forums.matronics.com//files/dabbling_with_electricity_357.pdf ________________________________ Message 7 _____________________________________ Time: 09:19:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Permanent Magnet Alternators - Over Voltage Protection At 10:20 AM 2/20/2011, you wrote: > >Bob, >I intend to build an over-voltage circuit for my Rotax powered >RV-12. I found a couple of designs on your website: >http://www.aeroelectric.com/DIY/DIY_Crowbar_OVP_F.pdf >and >http://www.aeroelectric.com/Catalog/AEC/9003/CbOV-14_Installation_A.pdf >I like the latter circuit due to its fewer parts >count. Unfortunately, the MBS4991 Silicon Bilateral Switch is no >longer available. Yes, the two-transistor emulation of the MBS4991 was crafted after the former part went obsolete. >Question: Can I substitute a zener (8.7 or 9 volt) diode for the MBS4991? No. If you study both the specs for the 4991 and noodle out the behavior of the PNP/NPN transistor pair, you'll deduce that the device is both voltage sensing AND avalanche-trigger that dumps the energy stored on the time delay capacitor into the gate of the crowbar SCR. >I did find a replacement for the MBS4991 at Mouser: the NTE6403 >although it is relatively expensive at $8. I am not sure how to >connect it because your schematic only shows 2 of the 3 leads connected. If it's a bilateral device, it doesn't matter which two outside leads are connected where. The center lead (gate) is cut off. There is a new device (at least new to me!) offered by Digikey. See: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=835-1126-1-ND It's typically an 8v device so you might have to diddle the voltage divider values a tad to get a trip point well inside the pot travel. The temperature drift numbers look good. As you can see, the 2-transistor+zener circuit is a synthesis of 1/2 of the bilateral trigger diode. All the parts are readily available and the circuit as shown has been constructed by many OBAM aircraft builders. Here's a handy test fixture for setting your finished OVM. http://tinyurl.com/4k455p5 The relay+lamp/resistor should draw about 1A when energized. Set the bench supply for 16.3 volts. Adjust the trigger calibration pot on the OV module so that the relay "clicks" about once per second. Bob . . . ________________________________ Message 8 _____________________________________ Time: 09:19:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Permanent Magnet Alternators - Over Voltage Protection At 10:54 AM 2/20/2011, you wrote: > > > > who could confirm whether or not they agree that the 505 seems > suitable as a generic PMA OV device correct Bob . . . ________________________________ Message 9 _____________________________________ Time: 09:56:19 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Voltage Regulator Problem At 09:34 AM 2/20/2011, you wrote: > >Let me try sending again--only part of note came through on first try. > > I have a 912ULS with the Ducati regulator wired into the Z16 > diagram that I have been flying for three years. Today on run-up I > noted low voltage (under 11 volts) in the Grand Rapid EIS & the > Dynon EFIS displays, regardless of RPM. Normally I get 13.1 volts > indicated with load. Alternator/regulator is NOT producing power. >With Master off & engine not running the yellow dynamo wires feeding >the regulator show continuity with no resistance. This is a very low resistance . . . less than 1 ohm that you cannot measure without special attention to test equipment - like the low ohms adapter on my website. > I am thinking there should be some resistance--am I correct or is > the reading OK? If your plain vanilla volt-ohmeter shows continuity, the windings are probably fine. Are they discolored, i.e. insulation very dark and/or cracked? >At fast idle (2400 RPM) the yellow wires indicate 18 volts AC and >correspondingly increases with increasing RPM. That's good . . . >The regulator output B+ terminal reads 8.5 volts DC--I believe I >should expect 14 v DC. The system voltmeter reads about 11 volts >with minimal load. Battery was 12.5 v. I traded out the regulator >with one that I was told was good. Very similar results (8.3 volts >output). I assume both regulators are faulty??? Any suggestions to >further trouble shoot? Is your control relay closing? Try bypassing the OV/control system and connect your R/R output wire directly to the system (unplug fat wires from relay and connect them together). Then do your voltage checks. >If I replace the regulator I'm considering the Key West. Question >about integrating into the Z16 wiring scheme. I assume the + & - >input terminals are connected to the yellow wires from the dynamo. >Not sure how to hook-up the + & - output terminals. Can anyone help >me with that? Do you have the Key West installation instructions? If it is this device: Emacs! The terminal markings are pretty definitive. AC input is from your alternator winding, NEG(-) goes to ground, POS(+) would go to the control relay. But check your control relay closure first. It seems unlikely that you would suffer TWO Rectifier/Regulator failures. Bob . . . ________________________________ Message 10 ____________________________________ Time: 10:32:31 AM PST US Subject: AeroElectric-List: Re: Honeywell Rocker lamp wiring From: "jonlaury" Bill, Thanks for your thoughts on wiring the AML series switches. After discussions with Perehelion, I've worked out a scheme to run the switch lamps at 12v (using http://www.semicon.panasonic.co.jp/ds4/AN7712SP_BEB_discon.pdf) for dimming, but when the switch is ON, the lamp gets the bus voltage of 13.5v making them brighter than the dimmer circuit. I may have to adjust the max voltage of the dimmer circuit to get the bingo brightness differential. Or this whole idea may end up in the trash and I simplify to just hooking the dimmer directly to the lamps like you have done. John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331625#331625 ________________________________ Message 11 ____________________________________ Time: 01:48:07 PM PST US Subject: AeroElectric-List: Re: Voltage Regulator Problem From: "frank3" Bob Thanks for your input. As you suggested I removed the relay "C" input and jumped it across to the "A" lead. The reading from the regulator B+ lead was initially about 11 volts with the engine running but steadily decreased to yesterday's reading of about 8.4 volts. Reading was not influenced by increase in RPM. I reconnected to the relay "C" terminal and took a reading from the "C" terminal to the starter relay to check the circuit through the relay & across the fuse link and got a reading of 8.3 volts with the master on ALT. Battery still above 12 v. Any other suggestions? -------- Frank Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331639#331639 ________________________________ Message 12 ____________________________________ Time: 04:35:36 PM PST US Subject: AeroElectric-List: Re: Permanent Magnet Alternators - Over Voltage Protection From: "user9253" I read about the Silicon Bilateral Switch on the internet today. Evidently it is not necessary to connect the gate because the SBS will start conducting when the voltage reaches a certain value without the gate connected. I am still wondering if a zener diode could be used instead of the SBS. If not, it would be interesting to know what the disadvantages of the zener diode are, or if it would even work at all. Thanks for any advice. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=331658#331658 ________________________________ Message 13 ____________________________________ Time: 10:18:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Permanent Magnet Alternators - Over Voltage Protection At 07:31 PM 2/20/2011, you wrote: > >I read about the Silicon Bilateral Switch on the internet >today. Evidently it is not necessary to connect the gate because >the SBS will start conducting when the voltage reaches a certain >value without the gate connected. > I am still wondering if a zener diode could be used instead of > the SBS. If not, it would be interesting to know what the > disadvantages of the zener diode are, or if it would even work at all. It MIGHT work sort of if you used a sensitive gate SCR but that offers a potential for other problems like nuisance tripping due to noises on the bus. The non-sensitive crowbar SCR needs a swift kick in the gate to insure a good trigger at all temperatures. The simple zener has a soft conduction 'knee' in it's V/I curve so is a poor voltage reference at the threshold of conduction. Further, the current that can be delivered to the gate of the SCR due to zener conduction is limited by the source impedance of the calibration voltage divider. The diac has a more predictable trigger voltage which produces an avalanche conduction mode that dumps the time delay capacitor into the gate of the SCR. That pulse is hundreds of mA to over 1A. This same characteristic is also desired for the triggering of triacs in dimmers . . . the #1 commercial use for diacs of any voltage. See: http://aeroelectric.com/Pictures/Products/9003_B&C/OVM_14_Prototype.jpg This was the first crowbar OVM we offered many moons ago. This configuration was modified early in the production experience to add the 10 ohm gate to cathode resistor to negate nuisance tripping. The diac in this version visible on the left was a really cool part. An SD10 as I recall with very good tolerances on a 10v trip calibration. This part went obsolete and we went to the MBS4991. That part went obsolete and I synthesized the diac functionality with the pnp/npn pair. At this time, I think B&C has both the diac and transistor versions in production on the fleet of products. They made a life-time buy on the MBX4991. I bought a couple hundred too so that I can support my own production though it's probable market life. It is similar to this configuration http://aeroelectric.com/Pictures/Products/9003_B&C/OVM-14_A.jpg http://aeroelectric.com/Pictures/Products/9003_B&C/OVM-14_B.jpg except that we now offer a 15 turn calibration potentiometer that can be accessed in the field. This is why the DIY project features the transistor pair. But it appears that the new kid on the block from Digikey would allow one to fabricate the diac version. Your choice. Bob . . . ________________________________ Message 14 ____________________________________ Time: 10:25:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Voltage Regulator Problem At 04:44 PM 2/20/2011, you wrote: > >Bob >Thanks for your input. >As you suggested I removed the relay "C" input and jumped it across >to the "A" lead. The reading from the regulator B+ lead was >initially about 11 volts with the engine running but steadily >decreased to yesterday's reading of about 8.4 volts. Reading was >not influenced by increase in RPM. > >I reconnected to the relay "C" terminal and took a reading from the >"C" terminal to the starter relay to check the circuit through the >relay & across the fuse link and got a reading of 8.3 volts with the >master on ALT. Battery still above 12 v. It's not clear that you understood my suggestion. I intended that you bypass the control relay entirely. If you're using Z-16 of more than 3 years ago, then the relay is probably in the DC output wire from the rectifier-regulator. The current version uses the control relay to switch AC power out of the alternator. Unplug both the heavy gage wires from the control relay and connect them together thus eliminating the relay as a means by which the alternator can be disconnected from the system. Then see how things perform. The point of this experiment is to eliminate the relay and its control wiring as potential cause for your observed malfunction. While the relay is bypassed and you're making other voltage measurements, see what voltage you read on the relay's skinny wires too with the battery/alternator control switch full up. One should be seeing battery voltage, the other should be zero volts. 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