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)
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Subject: | 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 . . .
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Subject: | Re: AC ground prong question |
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
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http://forums.matronics.com/viewtopic.php?p=331606#331606
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Subject: | Re: Voltage Regulator Problem |
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
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http://forums.matronics.com/viewtopic.php?p=331608#331608
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Subject: | Re: Permanent Magnet Alternators - Over Voltage Protection |
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
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http://forums.matronics.com/viewtopic.php?p=331611#331611
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Subject: | Re: Permanent Magnet Alternators - Over Voltage Protection |
> 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
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http://forums.matronics.com/viewtopic.php?p=331613#331613
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Subject: | Re: AC ground prong question |
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
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http://forums.matronics.com/viewtopic.php?p=331614#331614
Attachments:
http://forums.matronics.com//files/dabbling_with_electricity_357.pdf
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Subject: | 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 . . .
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Subject: | 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 . . .
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Subject: | 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 . . .
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Subject: | Re: Honeywell Rocker lamp wiring |
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
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Subject: | Re: Voltage Regulator Problem |
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
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http://forums.matronics.com/viewtopic.php?p=331639#331639
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Subject: | Re: Permanent Magnet Alternators - Over Voltage Protection |
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
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http://forums.matronics.com/viewtopic.php?p=331658#331658
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Subject: | 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 . . .
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Subject: | 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.
Bob . . .
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