Today's Message Index:
----------------------
1. 04:38 AM - Re: Pitot Heat Ground (JDA_BTR)
2. 05:03 AM - Engine Starter Stalling (todehnal)
3. 05:46 AM - Re: Engine Starter Stalling (Charlie England)
4. 07:11 AM - Re: Re: Pitot Heat Ground (Kelly McMullen)
5. 07:31 AM - Re: Active VOR antenna ()
6. 07:31 AM - Re: Engine Starter Stalling (Kelly McMullen)
7. 07:50 AM - Fuse links (John Tipton)
8. 09:06 AM - Re: Engine Starter Stalling (todehnal)
9. 09:48 AM - Re: Re: Engine Starter Stalling (Charlie England)
10. 10:05 AM - Re: Engine Starter Stalling (Robert L. Nuckolls, III)
11. 10:07 AM - Re: Pitot Heat Ground (Robert L. Nuckolls, III)
12. 11:16 AM - Re: Pitot Heat Ground (Lyle Peterson)
13. 11:52 AM - Re: Pitot Heat Ground (Ryan Brown)
14. 11:54 AM - Re: Re: Engine Starter Stalling (Tim Andres)
Message 1
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Subject: | Re: Pitot Heat Ground |
I spoke with a knowledgeable person at Dynon and was told that the MOSFET power
transistor in the controller uses the case for a heat sink and thus is grounded
to same; so the ground to the chassis is by design and necessary. It will
also be low impedance in this configuration. In a metal airplane even if a wire
is carried back to the battery most if not all of the current will pass to
the mounting points of the controller box; so grounding the box to the airframe
locally will make as much sense as carrying a wire back to the battery.
There won't be a way to make a balanced wire run for the pitot heat controller.
I could mount the controller in the fuselage and run the actual pitot wires balanced
out to the heater. Will have to consider that; but I'm thinking now to
just wire it up and if the magnetometer is affected (likely) then I'll remote
it to another location, or relocate the ADAHRS/magnetometer.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=446911#446911
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Subject: | Engine Starter Stalling |
Hi Guys, New kid on the block, and I am looking for some advice. I have been
having starter stall on cold starts. It will stop the prop a couple of times,
and then spin up and start fine. I have been chasing this for a couple of months
now. By the way, this is a Rotax powered RV-12. I know that when this happens
the starter solenoid chatters. I can hear it. This chatter is caused
by another starter circuit interrupt on the RV-12 called the spar pin relay.
This safety device ensures that the removable wings spar pins are fully engaged,
then completed the circuit to the start relay. I am now analyzing the battery.
I downloaded data from the Dynon skyview, searched the spreadsheet and came
up with a chart that shows the battery voltage during a typical start. If
someone could take a look at the link below and offer some thoughts about the
battery performance, or offer other advice, I would greatly appreciate it. Neat
chart, and you can see the compression cycles on the chart. Thanks.........Tom
http://i296.photobucket.com/albums/mm182/tomscub/img002_zpsujxtzrle.jpg
--------
RV-12 with Skyview Panel built EAB by my wife & I.
First Flight: 11/21/13. It's a keeper....Tom
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=446912#446912
Message 3
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Subject: | Re: Engine Starter Stalling |
On Wed, Sep 9, 2015 at 7:01 AM, todehnal <tomscub@gmail.com> wrote:
>
> Hi Guys, New kid on the block, and I am looking for some advice. I have
> been having starter stall on cold starts. It will stop the prop a couple
> of times, and then spin up and start fine. I have been chasing this for a
> couple of months now. By the way, this is a Rotax powered RV-12. I know
> that when this happens the starter solenoid chatters. I can hear it. This
> chatter is caused by another starter circuit interrupt on the RV-12 called
> the spar pin relay. This safety device ensures that the removable wings
> spar pins are fully engaged, then completed the circuit to the start
> relay. I am now analyzing the battery. I downloaded data from the Dynon
> skyview, searched the spreadsheet and came up with a chart that shows the
> battery voltage during a typical start. If someone could take a look at
> the link below and offer some thoughts about the battery performance, or
> offer other advice, I would greatly appreciate it. Neat chart, and you can
> see the compression cycles on!
> the chart. Thanks.........Tom
>
> http://i296.photobucket.com/albums/mm182/tomscub/img002_zpsujxtzrle.jpg
>
> --------
> RV-12 with Skyview Panel built EAB by my wife & I.
> First Flight: 11/21/13. It's a keeper....Tom
>
>
Where does the Dynon measure battery voltage? If it's measuring the voltage
between its own B+ & ground terminals, it can't tell the difference between
a weak battery and bad connections somewhere in the power circuit. They can
be anywhere along the B+ path, or anywhere along the ground path back to
the battery.
Try monitoring the battery voltage with a separate meter connected directly
to the battery terminals (the posts, not the cable terminals on the battery
terminals). Watch the meter while cranking the engine, & see how far
voltage drops. It's hard to get the time domain resolution on a digital
meter that you see on the Dynon graph, so you might try pulling the Dynon
fuse, & power the Dynon with a wire directly to the battery B+ terminal so
it can see true battery voltage during cranking. Remember to run a ground
wire from the Dynon directly to the battery ground terminal also, if you
try this.
If you see your voltage drops going to ~9-10volts instead of 6-8volts, then
you probably have some bad connections somewhere in the circuit. If the
battery is truly dropping to 6volts during cranking, then it's either not
fully charged, or defective. (Or you've got a bad starter.)
Message 4
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Subject: | Re: Pitot Heat Ground |
IIRC the general guidance is that high current devices like pitot heat
and landing lights, nav lights do not need separate ground wire back to
grounding block, only sensitive low current electronic devices like
radios, intercoms, etc need central grounding. I haven't flown yet, but
have the Dynon heated pitot with the controller mounted within 6" of the
pitot mast. If you can't mount the combined ADAHRS in the fuselage
clear of magnetic influences. they also offer a separate, remote
magnetometer that you could mount out near a wing tip.
On 9/9/2015 4:32 AM, JDA_BTR wrote:
>
> I spoke with a knowledgeable person at Dynon and was told that the MOSFET power
transistor in the controller uses the case for a heat sink and thus is grounded
to same; so the ground to the chassis is by design and necessary. It will
also be low impedance in this configuration. In a metal airplane even if a
wire is carried back to the battery most if not all of the current will pass to
the mounting points of the controller box; so grounding the box to the airframe
locally will make as much sense as carrying a wire back to the battery.
>
> There won't be a way to make a balanced wire run for the pitot heat controller.
>
> I could mount the controller in the fuselage and run the actual pitot wires balanced
out to the heater. Will have to consider that; but I'm thinking now to
just wire it up and if the magnetometer is affected (likely) then I'll remote
it to another location, or relocate the ADAHRS/magnetometer.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=446911#446911
>
>
Message 5
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Subject: | Re: Active VOR antenna |
VOR antenna project update:
I want to extend a big THANK YOU to all that helped with this project
and tell you it was a complete success!
We have been progressing through Phase I testing and the non-standard
VOL/ILS antenna design is working splendidly. It is being used with a
Garmin 650 (internal splitter) and locks onto VOR signals from 100mi @
10,000=99 and has no problem at all with ILS capture either. It
was made from RG-58 coax and a short scrap of 22-AWG wire for the
counterpoise per the dimensions below.
We are very pleased with it=99s performance and can=99t
imagine that a standard antenna would perform any better in this
application. Testing will continue to determine if there are any blind
or degraded spots or freqs. But for now, mark it up as a successful
alternate design!
Thanks again!
-James
Berkut/Race 13
From: Robert L. Nuckolls, III
Sent: Thursday, June 04, 2015 5:26 PM
Subject: Re: AeroElectric-List: Active VOR antenna
Jim, finished one of these and was disappointed in performance.
The thing is so tiny that it's hard to troubleshoot,
assembled a second just in case.
I think the best plan-b for now is to install
a quasi-sleeve dipole . . . except that the 'sleeve'
is just a piece of wire. I forget how long you said
your antenna conduit was, hopefully considerably
more than 26".
Make the antenna from wire stiff enough to push
into the tube on the end of the coax. Wouldn't
put a connector in the counterpoise. Just thread
it to the ship's interior on installation and tape
it sort out of the way.
I've got a couple other antenna projects on the bench
but some buys waving credit cards have purchased some
keyboard/hammer-n-tongs time . . . and I've got a couple
of pots boiling for B&C. I'd like to pursue the
active antenna experiment. It would be useful to field
test the idea in close proximity to transponder and
vhf/comm transmitters!
In the mean time, let's get your airplane flying.
Bob . . .
Message 6
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Subject: | Re: Engine Starter Stalling |
The Dynon system allows the builder to place the voltage sensing lead
where ever he/she chooses. Could be where battery plus connects to the
bus, could be most anywhere. I don't know where the RV-12 plans call for
the connection, but with this aircraft built under EAB rules rather than
ELSA, he didn't have to follow the plans.
On 9/9/2015 5:44 AM, Charlie England wrote:
>
>
> On Wed, Sep 9, 2015 at 7:01 AM, todehnal <tomscub@gmail.com
> <mailto:tomscub@gmail.com>> wrote:
>
> <tomscub@gmail.com <mailto:tomscub@gmail.com>>
>
>
> Where does the Dynon measure battery voltage? If it's measuring the
> voltage between its own B+ & ground terminals, it can't tell the
> difference between a weak battery and bad connections somewhere in the
> power circuit. They can be anywhere along the B+ path, or anywhere
> along the ground path back to the battery.
>
> Try monitoring the battery voltage with a separate meter connected
> directly to the battery terminals (the posts, not the cable terminals
> on the battery terminals). Watch the meter while cranking the engine,
> & see how far voltage drops. It's hard to get the time domain
> resolution on a digital meter that you see on the Dynon graph, so you
> might try pulling the Dynon fuse, & power the Dynon with a wire
> directly to the battery B+ terminal so it can see true battery voltage
> during cranking. Remember to run a ground wire from the Dynon directly
> to the battery ground terminal also, if you try this.
>
> If you see your voltage drops going to ~9-10volts instead of 6-8volts,
> then you probably have some bad connections somewhere in the circuit.
> If the battery is truly dropping to 6volts during cranking, then it's
> either not fully charged, or defective. (Or you've got a bad starter.)
> http://www.matronics.com/contribution
Message 7
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Hi Guys
We will be using a (base) Z11 for our RV9a
Q 1 - The only CB's in use (otherwise all fuses) will be the 'ALT FIELD' CB, and
a pullable CB for the autopilot, the 'Alt Field' wire is fed with as 'fusable
link', does the autopilot feed need the fusable link too (same source, ie main
power bus feed, same run length)
Q 2 - The Z11 endurance feed, does not have any protection, yet all (I think) other
Z figures do have a fuse link feed.
Lastly, when making up the fuse links, is it OK to finish off the end covering
with 'shrink wrap' or should the covering have 'free air' circulation
Regards
John
Message 8
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Subject: | Re: Engine Starter Stalling |
I did build my RV-12 under EAB rules. Pretty sure Dynon is monitoring the voltage
at the Avionics Bus, right at the amperage shunt. As far as the starter,
I have hooked a +12 volt lead directly to it, and it functions flawlessly. I
also have removed, cleaned, and reattached every connection from the battery plus,
through the master relay, through the start relay, and starter, and back
to the battery ground post, with no change. I guess my real question should be,
is it a problem when the active starter voltage dips below 7 volts? Not sure
what I should typically be seeing here........Tom
--------
RV-12 with Skyview Panel built EAB by my wife & I.
First Flight: 11/21/13. It's a keeper....Tom
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=446927#446927
Message 9
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Subject: | Re: Engine Starter Stalling |
On 9/9/2015 11:04 AM, todehnal wrote:
>
> I did build my RV-12 under EAB rules. Pretty sure Dynon is monitoring the voltage
at the Avionics Bus, right at the amperage shunt. As far as the starter,
I have hooked a +12 volt lead directly to it, and it functions flawlessly.
I also have removed, cleaned, and reattached every connection from the battery
plus, through the master relay, through the start relay, and starter, and back
to the battery ground post, with no change. I guess my real question should
be, is it a problem when the active starter voltage dips below 7 volts? Not
sure what I should typically be seeing here........Tom
>
> --------
> RV-12 with Skyview Panel built EAB by my wife & I.
> First Flight: 11/21/13. It's a keeper....Tom
>
Does that mean that you *started the engine* by hooking a battery lead
directly to the starter? Because if you removed the starter & just spun
it up with the battery, that doesn't give you much useful info that you
didn't already know (that the windings have some continuity and the
bearings allow it to turn).
If you're monitoring voltage anywhere except at the battery terminals,
you really need to know actual battery voltage *at the battery posts*
before proceeding further. If it's staying higher than 8-10 volts while
cranking, and you're seeing 6 volts at the remote monitoring point,
you've got high resistance somewhere in the power circuit between
battery & monitoring point. Don't forget that every connection using a
terminal on a wire is really *two* connections: the transition in the
bolted joint, and the joint between the terminal and the wire itself,
whether crimped or soldered.
Voltage will typically drop to between 8 & 10 volts while under starting
load. Dropping to 6 volts can often cause electronics to drop off line,
& may cause relays to drop out, as well. Try eliminating 'stuff' that's
between the battery & starter.
Eliminate the master contactor by putting both heavy terminals on the
same post (this will obviously power up the plane even with the master
switch off). Try starting the engine & see if your symptoms change for
the better. If so, likely bad contacts in the master contactor.
No change? return to 'normal' configuration & move on.
Temporarily eliminate the wing spar interlock by jumping across it's
contacts, & try starting. If symptoms change, perhaps the interlock is
misadjusted or its contacts are flaky, causing it to be intermittent
with vibration.
The above are just examples; follow the power circuit and eliminate or
'bridge' each joint in sequence.
Message 10
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Subject: | Re: Engine Starter Stalling |
At 07:01 AM 9/9/2015, you wrote:
>
>Hi Guys, New kid on the block, and I am looking for some advice. I
>have been having starter stall on cold starts. It will stop the
>prop a couple of times, and then spin up and start fine. I have
>been chasing this for a couple of months now. By the way, this is a
>Rotax powered RV-12. I know that when this happens the starter
>solenoid chatters. I can hear it. This chatter is caused by
>another starter circuit interrupt on the RV-12 called the spar pin
>relay. This safety device ensures that the removable wings spar
>pins are fully engaged, then completed the circuit to the start
>relay. I am now analyzing the battery. I downloaded data from the
>Dynon skyview, searched the spreadsheet and came up with a chart
>that shows the battery voltage during a typical start. If someone
>could take a look at the link below and offer some thoughts about
>the battery performance, or offer other advice, I would greatly
>appreciate it. Neat chart, and you can see the compression cycles
>on the chart. Thanks.........Tom
As Charlie points out, without knowing exactly where
the Dynon gets its data, the value of that data
is weak. The plots show that the voltage doesn't drop
below 8v or so . . . normally too high for contactor
'chatter'. I suspect that the data is being gathered at
the bus . . . which may well be a voltage different than
what drives the starter and/or it's control contactor.
Is this a new condition? What size and how old the
battery. Have you load checked it? Is there a wiring diagram for
the system you can share? Just for grins, you might
try clipping a charge car battery across the ship's
battery and repeat the cold start experiment to
see if there's a marked difference in behaviors.
Bob . . .
Message 11
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Subject: | Re: Pitot Heat Ground |
At 04:55 PM 9/8/2015, you wrote:
>
>I read the faqs, and know the recommendation to just take the pitot
>ground to the chassis.
>
>But I have a specific situation in mind, and would like some
>thoughts on it. I'm building an RV14 and the pitot heat controller
>will be about 4 feet outboard of an ADAHRS in the wing with a built
>in magnetometer. I figured if I ran the 14V/Gnd pair together as
>far from the magnetometer as possible I stood a chance of not
>interfering with it when the heater is on.
>
>I've gotten a Dynon heated pitot tube with controller. In this
>controller the aluminum controller box is connected to ground as is
>the ground lead leaving the box. Dynon says to a) not use the box
>for ground, and b) run a ground wire all the way to the battery.
NOBODY should ever need to run any applicance
wire(s) ground or otherwise, directly to the
battery. Can you point us to a copy of the
system wiring diagram? Do you KNOW how much
power the pitot heater needs?
Bob . . .
Message 12
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Subject: | Re: Pitot Heat Ground |
I was going to say what Bob says here. The battery posts are for one,
and only one, purpose. That is the connect for the main supply cables
for the vehicle. No other wire should be attached at that point.
Terminal strips are for that purpose.
Wiring connected directly to the battery posts will corrode. Even large
battery cables will corrode internally. I have a ten inch cable that
ran from the battery to the starter solenoid that was green under the
insulation for its entire length. This reduces the useable conductor in
the cable and restricts its ability to carry the required current. With
smaller gauge wires that reduction is tantamount to cutting the wire.
On 9/9/2015 12:06 PM, Robert L. Nuckolls, III wrote:
> At 04:55 PM 9/8/2015, you wrote:
>> <dudley@jdatkinson.net>
>>
>> I read the faqs, and know the recommendation to just take the pitot
>> ground to the chassis.
>>
>> But I have a specific situation in mind, and would like some thoughts
>> on it. I'm building an RV14 and the pitot heat controller will be
>> about 4 feet outboard of an ADAHRS in the wing with a built in
>> magnetometer. I figured if I ran the 14V/Gnd pair together as far
>> from the magnetometer as possible I stood a chance of not interfering
>> with it when the heater is on.
>>
>> I've gotten a Dynon heated pitot tube with controller. In this
>> controller the aluminum controller box is connected to ground as is
>> the ground lead leaving the box. Dynon says to a) not use the box
>> for ground, and b) run a ground wire all the way to the battery.
>
> NOBODY should ever need to run any applicance
> wire(s) ground or otherwise, directly to the
> battery. Can you point us to a copy of the
> system wiring diagram? Do you KNOW how much
> power the pitot heater needs?
>
>
> Bob . . .
>
> http://www.matronics.com/contribution
Message 13
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Subject: | Re: Pitot Heat Ground |
I don't see anything in the dynon installation manual about connecting
directly to the battery.
http://dynonavionics.com/downloads/Install_Guides/Heated_Unheated_AOA_Pitot_Probe_Installation_Guide_-_Rev_C.pdf`
It says:
Do not connect the Black (Ground) wire to the airframe as a Ground
connection. Doing so will introduce high currents (10A) into the airframe.
This can introduce a significant voltage drop, and potentially cause engine
instrumentation, avionics, and audio system electrical problems.
Also it says the ground wire should be:
Constant connection to ground (not routed through a switch or fuse /
circuit breaker). Must be sized to conduct 10A with minimal voltage drop.
Ground connection must be constant FOR PITOT HEAT STATUS LINE (White wire)
to operate when the controller is powered Off or not functioning.
On Wed, Sep 9, 2015 at 11:21 AM Lyle Peterson <lyleap@centurylink.net>
wrote:
> I was going to say what Bob says here. The battery posts are for one, and
> only one, purpose. That is the connect for the main supply cables for the
> vehicle. No other wire should be attached at that point. Terminal strips
> are for that purpose.
>
> Wiring connected directly to the battery posts will corrode. Even large
> battery cables will corrode internally. I have a ten inch cable that ran
> from the battery to the starter solenoid that was green under the
> insulation for its entire length. This reduces the useable conductor in
> the cable and restricts its ability to carry the required current. With
> smaller gauge wires that reduction is tantamount to cutting the wire.
>
>
> On 9/9/2015 12:06 PM, Robert L. Nuckolls, III wrote:
>
> At 04:55 PM 9/8/2015, you wrote:
>
> <dudley@jdatkinson.net>
>
> I read the faqs, and know the recommendation to just take the pitot ground
> to the chassis.
>
> But I have a specific situation in mind, and would like some thoughts on
> it. I'm building an RV14 and the pitot heat controller will be about 4
> feet outboard of an ADAHRS in the wing with a built in magnetometer. I
> figured if I ran the 14V/Gnd pair together as far from the magnetometer as
> possible I stood a chance of not interfering with it when the heater is on.
>
> I've gotten a Dynon heated pitot tube with controller. In this controller
> the aluminum controller box is connected to ground as is the ground lead
> leaving the box. Dynon says to a) not use the box for ground, and b) run a
> ground wire all the way to the battery.
>
>
> NOBODY should ever need to run any applicance
> wire(s) ground or otherwise, directly to the
> battery. Can you point us to a copy of the
> system wiring diagram? Do you KNOW how much
> power the pitot heater needs?
>
>
> Bob . . .
>
>
> *
>
>
> *
>
>
Message 14
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Subject: | Re: Engine Starter Stalling |
Don't forget the ground side of the circuit, you can have high resistance anywhere.
One diagnostic method is to put a volt meter in series with the ground circuit,
ie one probe on the battery negative post and the other on the engine case.
You should see about a volt or less while cranking. Do the same on the
positive side next, battery positive post and the other on the terminal on the
starter. Anything over a volt or so and you have high resistance in the circuit,
which can then be easily found by moving the probe backwards from the starter
measuring at each terminal toward the battery.
Having said all that, your chattering solenoid is pretty typical of a weak battery.
Tim Andres
> On Sep 9, 2015, at 9:50 AM, Charlie England <ceengland7@gmail.com> wrote:
>
>
>> On 9/9/2015 11:04 AM, todehnal wrote:
>>
>> I did build my RV-12 under EAB rules. Pretty sure Dynon is monitoring the voltage
at the Avionics Bus, right at the amperage shunt. As far as the starter,
I have hooked a +12 volt lead directly to it, and it functions flawlessly.
I also have removed, cleaned, and reattached every connection from the battery
plus, through the master relay, through the start relay, and starter, and back
to the battery ground post, with no change. I guess my real question should
be, is it a problem when the active starter voltage dips below 7 volts? Not
sure what I should typically be seeing here........Tom
>>
>> --------
>> RV-12 with Skyview Panel built EAB by my wife & I.
>> First Flight: 11/21/13. It's a keeper....Tom
> Does that mean that you *started the engine* by hooking a battery lead directly
to the starter? Because if you removed the starter & just spun it up with the
battery, that doesn't give you much useful info that you didn't already know
(that the windings have some continuity and the bearings allow it to turn).
>
> If you're monitoring voltage anywhere except at the battery terminals, you really
need to know actual battery voltage *at the battery posts* before proceeding
further. If it's staying higher than 8-10 volts while cranking, and you're
seeing 6 volts at the remote monitoring point, you've got high resistance somewhere
in the power circuit between battery & monitoring point. Don't forget that
every connection using a terminal on a wire is really *two* connections: the
transition in the bolted joint, and the joint between the terminal and the
wire itself, whether crimped or soldered.
>
> Voltage will typically drop to between 8 & 10 volts while under starting load.
Dropping to 6 volts can often cause electronics to drop off line, & may cause
relays to drop out, as well. Try eliminating 'stuff' that's between the battery
& starter.
>
> Eliminate the master contactor by putting both heavy terminals on the same post
(this will obviously power up the plane even with the master switch off). Try
starting the engine & see if your symptoms change for the better. If so, likely
bad contacts in the master contactor.
>
> No change? return to 'normal' configuration & move on.
>
> Temporarily eliminate the wing spar interlock by jumping across it's contacts,
& try starting. If symptoms change, perhaps the interlock is misadjusted or
its contacts are flaky, causing it to be intermittent with vibration.
>
> The above are just examples; follow the power circuit and eliminate or 'bridge'
each joint in sequence.
>
>
>
>
>
>
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