Today's Message Index:
----------------------
1. 01:32 AM - Amperage runaway (BobD)
2. 03:29 AM - Re: Amperage runaway (William Daniell)
3. 10:46 AM - Testing crowbar (Ken Ryan)
4. 11:12 AM - Re: Testing crowbar (user9253)
5. 12:30 PM - Re: Re: Testing crowbar (Ken Ryan)
6. 12:40 PM - Re: Testing crowbar (Robert L. Nuckolls, III)
7. 01:02 PM - Re: new toy (Gautier, Thomas N (3262))
8. 01:35 PM - Re: Testing crowbar (user9253)
9. 02:15 PM - Re: Re: Testing crowbar (Ken Ryan)
10. 03:21 PM - Re: Re: Testing crowbar (Charlie England)
11. 05:08 PM - Re: Re: Testing crowbar (Ken Ryan)
12. 05:35 PM - Re: Testing crowbar (user9253)
13. 05:38 PM - Re: Testing crowbar (user9253)
14. 06:03 PM - Re: Low Battery Voltage Blows Fuel Pump Fuse? (user9253)
15. 08:55 PM - Re: B&C switches (blues750)
16. 08:55 PM - Re: B&C switches (blues750)
Message 1
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| Subject: | Amperage runaway |
During a flight test of my Europa on Friday, The AMPS display on my Dynon Skyview
failed (the big red cross) for a while, then came back again, then failed again,
and finally came back until the end of the flight of about 1 hour. I have
attached a screen-shot of the Savvy Analysis tool, which shows that at the time
of the failure, there appeared to be an Amperage runaway, although the voltage
remains fairly constant. At the time of the first failure, we were conducting
climb tests, so the engine got fairly hot (as you can see from the lower
graph showing Oil Temperature), but engine temperature was normal during the second
failure. Dynon suggested checking the wiring at the Shunt, or a potential
EMS module failure. I took of the cowl, and inspected the wiring around the
Shunt, but this seemed OK.
I wondered if anyone you had seen anything similar anywhere, or have a potential
explanation for what happened ?
--------
Bob Dawson
XS TG || 912 ULS || G-NHRJ
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480340#480340
Attachments:
http://forums.matronics.com//files/screenshot_2_175.png
Message 2
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| Subject: | Re: Amperage runaway |
Identical symptoms on my skyview....hi Bob.
My europa Tri had runaway amps followed by red x. Cycling the alt cb reset
the instrument but sooner or later it would happen again.
We know that on a good day the rotax can produce 17 amps so I wasn't
worried. And if 70 amps were really running through the system one would
expect some exciting sparks and smoke none of which ocurred.
I dismantled everything and found that the little screws on shunt
connectors were loose.
I am in a major overhaul of the electrcial system so i havent started the
engine again however if i were you i would check everything but not do
anything drastic. My assumption would be that it is an instrument issue
and not a fundamental issue.
Will
William Daniell
LONGPORT
+57 310 295 0744
On Wed, May 23, 2018, 03:38 BobD <rjd@bobdawson.plus.com> wrote:
>
> During a flight test of my Europa on Friday, The AMPS display on my Dynon
> Skyview failed (the big red cross) for a while, then came back again, then
> failed again, and finally came back until the end of the flight of about 1
> hour. I have attached a screen-shot of the Savvy Analysis tool, which shows
> that at the time of the failure, there appeared to be an Amperage runaway,
> although the voltage remains fairly constant. At the time of the first
> failure, we were conducting climb tests, so the engine got fairly hot (as
> you can see from the lower graph showing Oil Temperature), but engine
> temperature was normal during the second failure. Dynon suggested checking
> the wiring at the Shunt, or a potential EMS module failure. I took of the
> cowl, and inspected the wiring around the Shunt, but this seemed OK.
> I wondered if anyone you had seen anything similar anywhere, or have a
> potential explanation for what happened ?
>
> --------
> Bob Dawson
> XS TG || 912 ULS || G-NHRJ
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=480340#480340
>
>
> Attachments:
>
> http://forums.matronics.com//files/screenshot_2_175.png
>
>
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For initial and periodic testing of the crowbar ov module would it be
acceptable to connect two little 9v batteries in series as the power source?
Sent from my Android. Sorry Steve.
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| Subject: | Re: Testing crowbar |
How about this circuit. Picture attached.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480351#480351
Attachments:
http://forums.matronics.com//files/ov_test_142.jpg
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| Subject: | Re: Testing crowbar |
Joe, I should have mentioned that I am still in "kindergarten" regarding
electronics. I am just not following your diagram. It looks to me like it
shows disconnecting the ground wire from the ov module and connecting it to
the negative terminal of a 3-6 volt battery, and then connecting the
positive terminal to ground? Somehow I think I cannot be reading it
correctly, and even if I am, I am baffled as to how this would test the 16
volt set point for the ov module. Ken
On Wed, May 23, 2018 at 10:11 AM, user9253 <fransew@gmail.com> wrote:
>
> How about this circuit. Picture attached.
>
> --------
> Joe Gores
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=480351#480351
>
>
> Attachments:
>
> http://forums.matronics.com//files/ov_test_142.jpg
>
>
Message 6
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| Subject: | Re: Testing crowbar |
At 12:45 PM 5/23/2018, you wrote:
>For initial and periodic testing of the crowbar ov module would it
>be acceptable to connect two little 9v batteries in series as the power source?
YES
Bob . . .
Message 7
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Sent from my iPhone
>
> Time: 10:48:58 AM PST US
> From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
> Subject: AeroElectric-List: New toy . . .
>
>
> For those of you who suffer from quantitative
> OCD like I do, there is a class of measurement
> tool that has trickled down in price to where
> us po' folk can afford them.
>
> GPS disciplined signal sources can exploit
> the extra-ordinary time-keeping features of
> the GPS system to produce accurate reference
> signals with accuracies/stabilities out to
> a buckets-full-of-zeros.
>
> https://goo.gl/B4hqTm
>
>
> I've been eyeing these for several years but
> finally yielded to temptation with this
> puppy on eBay
>
> https://goo.gl/zVviDZ
>
> With this device driving the 10MHz reference
> port on my 40 year old HP signal generator,
> proving legality of the radios on our
> emergency services hand-helds and trucks
> is a no-brainer.
>
> You may have to mount an antenna outside your
> facility with good sky view . . . beyond
> that, these things are plug-n-play.
>
>
> Bob . . .
>
Bob,
For your interest and any one who misses out on the e-bay offer (they are almost gone) there is another source of low cost GPSDOs: www.sdr-kits.net
They have one at a similar price to the e-bay offer but with more output frequency
capability and a slightly pricier one with dual flexible frequency outputs.
I dont have one and I dont know how the sdr-kits compare with e-bay precision wise
but they look interesting.
I know about sdr-kits because they offer a low cost 1khz-1.3Ghz vector network
analyzer that I have been eyeing. Might be interesting to some of your following.
Nick Gautier
Message 8
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| Subject: | Re: Testing crowbar |
Ken,
You are reading the diagram correctly. When batteries are connected in series,
they are connected negative to positive to negative to positive. When the over-voltage
module is disconnected from ground, the loose wire will be positive.
If you insert 3 flashlight batteries in series as shown, the voltages add up.
12 volts for the aircraft battery plus 4.5 volts for the flashlight batteries
equals 16.5
If you want to trip a 5 amp circuit breaker, "D" cells should do it.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480356#480356
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| Subject: | Re: Testing crowbar |
Thanks Joe. I understand now (mostly). I tried the two 9 volt batteries and
that didn't work. I completely forgot about "current" needed to trip the
breaker. Also, I guess I didn't really understand how the ov module works.
I thought it was just a normally open micro switch that "magically" closes
at 16 volts. I would have thought the ground wire of the ov module would be
"dead" at less than 16 volts. But now I realize it must be more than that.
It must be that current constantly flows through the ov module, but at 16
volts something else happens. I must have read an explanation in the
"Connection" but obviously it didn't stick.
Also, I will be tripping a 7.5 amp breaker. The buss will be powered by a
17 amp power supply (max setting is 13.9v). Do you think the three D cells
will trip the larger breaker?
Ken
On Wed, May 23, 2018 at 12:34 PM, user9253 <fransew@gmail.com> wrote:
>
> Ken,
> You are reading the diagram correctly. When batteries are connected in
> series, they are connected negative to positive to negative to positive.
> When the over-voltage module is disconnected from ground, the loose wire
> will be positive. If you insert 3 flashlight batteries in series as shown,
> the voltages add up. 12 volts for the aircraft battery plus 4.5 volts for
> the flashlight batteries equals 16.5
> If you want to trip a 5 amp circuit breaker, "D" cells should do it.
>
> --------
> Joe Gores
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=480356#480356
>
>
Message 10
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| Subject: | Re: Testing crowbar |
Ken,
If you've got Bob's (B&C) OV module with red & black wires, it's
effectively "God's own" zener diode, with voltage adjustment. Whenever
voltage between red and black exceeds the set point (which you adjust with
the little control), then the red & black wires are shorted together.
You can run the test with a 12V light bulb or 12V LED between the 12V
battery and the red wire, and the lamp will light when the OV module fires.
That would avoid needing enough power to trip a 7.5A breaker.
Charlie
On Wed, May 23, 2018 at 4:13 PM, Ken Ryan <keninalaska@gmail.com> wrote:
> Thanks Joe. I understand now (mostly). I tried the two 9 volt batteries
> and that didn't work. I completely forgot about "current" needed to trip
> the breaker. Also, I guess I didn't really understand how the ov module
> works. I thought it was just a normally open micro switch that "magically"
> closes at 16 volts. I would have thought the ground wire of the ov module
> would be "dead" at less than 16 volts. But now I realize it must be more
> than that. It must be that current constantly flows through the ov module,
> but at 16 volts something else happens. I must have read an explanation in
> the "Connection" but obviously it didn't stick.
>
> Also, I will be tripping a 7.5 amp breaker. The buss will be powered by a
> 17 amp power supply (max setting is 13.9v). Do you think the three D cells
> will trip the larger breaker?
>
> Ken
>
>
> On Wed, May 23, 2018 at 12:34 PM, user9253 <fransew@gmail.com> wrote:
>
>>
>> Ken,
>> You are reading the diagram correctly. When batteries are connected in
>> series, they are connected negative to positive to negative to positive.
>> When the over-voltage module is disconnected from ground, the loose wire
>> will be positive. If you insert 3 flashlight batteries in series as shown,
>> the voltages add up. 12 volts for the aircraft battery plus 4.5 volts for
>> the flashlight batteries equals 16.5
>> If you want to trip a 5 amp circuit breaker, "D" cells should do it.
>>
>> --------
>> Joe Gores
>
>
Message 11
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| Subject: | Re: Testing crowbar |
I rigged up three D cells as Joe suggested and the OV protection system
checked out okay. The breaker tripped as expected. Thanks everybody.
On Wed, May 23, 2018 at 2:19 PM, Charlie England <ceengland7@gmail.com>
wrote:
> Ken,
>
> If you've got Bob's (B&C) OV module with red & black wires, it's
> effectively "God's own" zener diode, with voltage adjustment. Whenever
> voltage between red and black exceeds the set point (which you adjust with
> the little control), then the red & black wires are shorted together.
>
> You can run the test with a 12V light bulb or 12V LED between the 12V
> battery and the red wire, and the lamp will light when the OV module fires.
> That would avoid needing enough power to trip a 7.5A breaker.
>
> Charlie
>
> On Wed, May 23, 2018 at 4:13 PM, Ken Ryan <keninalaska@gmail.com> wrote:
>
>> Thanks Joe. I understand now (mostly). I tried the two 9 volt batteries
>> and that didn't work. I completely forgot about "current" needed to trip
>> the breaker. Also, I guess I didn't really understand how the ov module
>> works. I thought it was just a normally open micro switch that "magically"
>> closes at 16 volts. I would have thought the ground wire of the ov module
>> would be "dead" at less than 16 volts. But now I realize it must be more
>> than that. It must be that current constantly flows through the ov module,
>> but at 16 volts something else happens. I must have read an explanation in
>> the "Connection" but obviously it didn't stick.
>>
>> Also, I will be tripping a 7.5 amp breaker. The buss will be powered by a
>> 17 amp power supply (max setting is 13.9v). Do you think the three D cells
>> will trip the larger breaker?
>>
>> Ken
>>
>>
>> On Wed, May 23, 2018 at 12:34 PM, user9253 <fransew@gmail.com> wrote:
>>
>>>
>>> Ken,
>>> You are reading the diagram correctly. When batteries are connected in
>>> series, they are connected negative to positive to negative to positive.
>>> When the over-voltage module is disconnected from ground, the loose wire
>>> will be positive. If you insert 3 flashlight batteries in series as shown,
>>> the voltages add up. 12 volts for the aircraft battery plus 4.5 volts for
>>> the flashlight batteries equals 16.5
>>> If you want to trip a 5 amp circuit breaker, "D" cells should do it.
>>>
>>> --------
>>> Joe Gores
>>
>>
Message 12
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| Subject: | Re: Testing crowbar |
The over-voltage module normally conducts very little current. I do not know how
much but perhaps microamps or a few milliamps. Unless there is a good reason
for using a 7.5 amp breaker, I would replace it with a 5 amp so that it will
trip sooner. I tested a homemade over-voltage circuit one time and the breaker
smoked instead of tripping. Many power supplies will automatically shut down
when short circuited.
I do not know the maximum current of a D cell. That 7.5 amp breaker will require
more than 7.5 amps for a certain amount of time before it will trip. That
is asking a lot out of a D cell.
If you only want to test the O.V. module and not the breaker, disconnect at least
one of the O.V. module wires from the aircraft. Connect the O.V. module
and your two 9 volt batteries and a 24 volt test light all in series. Make sure
battery polarity is correct, positive to red.
Even if the O.V. module works at 18 volts, you will not know if it works at 16
volts.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480364#480364
Message 13
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| Subject: | Re: Testing crowbar |
I should have checked for Ken's post before posting myself. :-)
I am happy that it worked for you Ken.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480365#480365
Message 14
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| Subject: | Re: Low Battery Voltage Blows Fuel Pump Fuse? |
I conducted an experiment today on my RV-12. Not wanting to ruin the PC680 aircraft
battery, I disconnected it. In its place, I used the riding lawn mower
battery connected with jumper cables. I thought that the lawn mower battery might
have trouble cranking the Rotax 912ULS, but it cranked just fine. I left
the ignition switches turned off so that the engine would not actually start.
I turned on all electrical loads, including landing light, to run the battery
down. I periodically cranked the engine as the battery slowly ran down. It
took an hour and a half for that cheap $35 lawn mower battery to drop its voltage
down to 11.5 volts. The engine still cranked, albeit noticeably slower.
The fuel pump fuse never did blow. I was not able to duplicate the symptoms
reported by others. Perhaps there is some magic voltage that causes the fuse
to blow and I never happened to crank the engine at that particular voltage.
In my airplane, the fuel pump is the only load on that 5 amp fuse. Other aircraft
may have other loads on the same fuse. I know that all E-LSA and S-LSA RV-12s
also have two 80 mm computer fans on the same circuit.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480366#480366
Message 15
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| Subject: | Re: B&C switches |
nuckolls.bob(at)aeroelect wrote:
> At 08:09 PM 5/22/2018, you wrote:
>
> >
> > Preparing to wire up a small hydraulic pump to operate amphibious float wheels.
> > Spec sheet on the parker pump unit indicates to use a DPDT center off switch
> > rated for up to 20A DC at 12V. Looking at B&C S700 series -1. My concern
is that the switch is rated for up to 15 VAC. Equivalent, or should I continue
my search for a switch? If so, any pointers appreciated. [Wink]
> >
> > Dave (the novice electrician/soon to be float flyer)
>
> What's the make and part number for the pump/motor
> you're working with?
>
> Bob . . .
Hi Bob. thanks for replying... the pump is a Parker /OilDyne 108 series hydraulic
power unit. Product code 108 AE S 32 C LB 1 V 03 03.
The product code breaks down to the following:
A 108 power unit, 12 VDC Permanent Magnet, Standard Pump, .0321 CIPR, 46 cu. in.
reservoir, reversible locking with back pressure, 7/16-20 ports, Vertical mount,
300 psi ports.
Again, based off the tech info performance chart, I find the current draw plot
versus pressure comes out to be approx 13 Amps. I assume that is steady state
versus start up.
If the B&C 15A rated switch can tolerate the amps but with a shorter life cycle
that might be OK. The switch is not going to see 10,000 cycles in my lifeftime!
A diode in-line may help as well?
Thanks for your interest, looking forward to seeing what I can learn!!
Dave
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480369#480369
Message 16
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| Subject: | Re: B&C switches |
nuckolls.bob(at)aeroelect wrote:
> At 08:09 PM 5/22/2018, you wrote:
>
> >
> > Preparing to wire up a small hydraulic pump to operate amphibious float wheels.
> > Spec sheet on the parker pump unit indicates to use a DPDT center off switch
> > rated for up to 20A DC at 12V. Looking at B&C S700 series -1. My concern
is that the switch is rated for up to 15 VAC. Equivalent, or should I continue
my search for a switch? If so, any pointers appreciated. [Wink]
> >
> > Dave (the novice electrician/soon to be float flyer)
>
> What's the make and part number for the pump/motor
> you're working with?
>
> Bob . . .
Hi Bob. thanks for replying... the pump is a Parker /OilDyne 108 series hydraulic
power unit. Product code 108 AE S 32 C LB 1 V 03 03.
The product code breaks down to the following:
A 108 power unit, 12 VDC Permanent Magnet, Standard Pump, .0321 CIPR, 46 cu. in.
reservoir, reversible locking with back pressure, 7/16-20 ports, Vertical mount,
300 psi ports.
Again, based off the tech info performance chart, I find the current draw plot
versus pressure comes out to be approx 13 Amps. I assume that is steady state
versus start up.
If the B&C 15A rated switch can tolerate the amps but with a shorter life cycle
that might be OK. The switch is not going to see 10,000 cycles in my lifeftime!
A diode in-line may help as well?
Thanks for your interest, looking forward to seeing what I can learn!!
Dave
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=480370#480370
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