Today's Message Index:
----------------------
1. 04:35 AM - Re: Printed circuit board question (D Fritz)
2. 07:27 AM - Re: Contact Arc Suppression (Eric M. Jones)
3. 10:52 AM - Re: Re: Contact Arc Suppression (Robert L. Nuckolls, III)
4. 03:25 PM - Ique 3600a ? (Jim Jewell)
5. 04:39 PM - Z-13A questions for Bob (John Swartout)
Message 1
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| Subject: | Re: Printed circuit board question |
--> AeroElectric-List message posted by: D Fritz <dfritzj@yahoo.com>
You might try this web-site:
http://www.mihdirect.biz/
They sell a fuse block (with rear-entry for the wires and two busses built in)
packaged up with connectors and a crimp tool.
Dan
---------------------------------
Message 2
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| Subject: | Re: Contact Arc Suppression |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
Eric M. Jones wrote:
>>I have a B&C contactor that I have disassembled. The gap is very
>>small...0.020-0.040? The contactor will protect itself due to massive
copper
>>contacts. But it won't do your instrument panel goodies much good.
Ken Wrote:
>I was afraid of that. Sufficient for 12 volts but not much more.
>A contactor with more separation should be workable for an OVP
>disconnect that only has to work once. With massive contacts like these
>and a runaway, but power limited, source it should not be difficult to
>get enough contact separation to stop the arc. This can't be near as
>difficult as interupting power flow from 36 volt batteries that have
>large amounts of current to feed the arc with. The current has to
>decrease as voltage climbs on my little runaway alternator.
I assume the current decreases as the voltage goes up, but I don't have the
details. It would be nice to see the data from failing alternators, but it
might be well-nigh impossible to get.
>Another approach would be to use a momentary duty solenoid that yanked a
>manual disconnect or knife switch to the off position. (a latching
>relay) Not elegant but I don't think transorbs will last long enough
>for me to turn it off manually.
I lean towards the Jules Verne giant knife switches and polished brass
handles and levers on a panel with snaphead rivets the size of snooker
balls. Now that's elegant.
It is important to know that there is a solution, but the alternator
contactor is not one of them. There are probably lots of circuit breakers
that pay attention to arc quenching and can be made to trip on OV used in
the power industry.
For my configuration I think an internally regulated alternator with an
ON/OFF lead is necessary. When the B+ is over 16.2 V for 200 mS, the ON/OFF
lead of the alternator gets turned OFF. There will be a Littelfuse
Midi-Fuse in the B-lead for backup.
>PS - I have played with a ESR meter used for measuring the equivalent
>series resistance of a capacitor. ..........snip....That might be a way of
instantly
>getting an idea of battery degradation and sulphation??
Start here: http://www.batteryweb.com/library.cfm The Powersonic technical
handbook is good. A microprocessor and some input data will do the job quite
well.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net
Ring the bells that still can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
- - Leonard Cohen
Message 3
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| Subject: | Re: Contact Arc Suppression |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <b.nuckolls@cox.net>
>
>
>I assume the current decreases as the voltage goes up, but I don't have the
>details. It would be nice to see the data from failing alternators, but it
>might be well-nigh impossible to get.
Why? take an alternator on a test stand, bring the field lead
out to tie to the b-lead via a switch, put just enough 'bus' power
on to excite the alternator and close the switch. From the first
time the contacts touch until you take steps to shut it down, you
have a perfectly failed alternator to study. Shut it down before it
toasts itself and you can do the test many times.
> >Another approach would be to use a momentary duty solenoid that yanked a
> >manual disconnect or knife switch to the off position. (a latching
> >relay) Not elegant but I don't think transorbs will last long enough
> >for me to turn it off manually.
>
>I lean towards the Jules Verne giant knife switches and polished brass
>handles and levers on a panel with snaphead rivets the size of snooker
>balls. Now that's elegant.
>
>It is important to know that there is a solution, but the alternator
>contactor is not one of them. There are probably lots of circuit breakers
>that pay attention to arc quenching and can be made to trip on OV used in
>the power industry.
Have you tested this?
>For my configuration I think an internally regulated alternator with an
>ON/OFF lead is necessary. When the B+ is over 16.2 V for 200 mS, the ON/OFF
>lead of the alternator gets turned OFF. There will be a Littelfuse
>Midi-Fuse in the B-lead for backup.
Absolutely. There will be no solution involving an internally
regulated alternator that is any simpler, an free of spectacular
results than to simply open the field lead on the alternator.
Bob . . .
Message 4
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--> AeroElectric-List message posted by: "Jim Jewell" <jjewell@telus.net>
A friend sent the following to Garmin
Inquiry:
> I am considering the iQue 3600a to put in my homebuilt and was wondering
> if
> the unit has the ability to drive my autopilot through some sort of
> link?Or to
> put it another way is there provisions for a signal out?
Garmin's answer indicated that the iQue 3600a is the one portable GPS that
does not output the NMEA 0183 sentences needed by some devices to drive an
autopilot.
The response also indicated that a work around has been found by "some
people".
If this is in fact true? can "some of you" describe the fixes and how you
feel about the efficacy of the outcome?
Jim in Kelowna
Message 5
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| Subject: | Z-13A questions for Bob |
--> AeroElectric-List message posted by: "John Swartout" <jgswartout@earthlink.net>
Bob, have you changed Z-13A since the end of December?
http://www.aeroelectric.com/PPS/Architecture/z13A.pdf
Any changes in the works?
On the main alternator, far right, is the "F" lead on the left side of
the alternator a field lead? I didn't think internally regulated
alternators had an external field lead.
If this is a modification as suggested in Note 11, can you point me
towards instructions on how to perform the modification?
Why are there ammeter shunts and alternator loadmeters attached? You
recently said: Voltmeters and ammeters are diagnostic tools, not flight
operations tools.
Would it be at all useful to have a diagnostic tool installed? I'm
thinking--maybe if you saw a sudden unexplained increase in load, it
might warn you that something, somewhere, had shorted and maybe you
should start turning things off to try to isolate it before you get
smoke. I realize fuses/CB's should deal with such faults, but why else
would you install a loadmeter, other than idle curiosity?
I may yet repent and splurge for an L40, but want to understand both
options as well as I can.
Thank you.
John
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