Hi Richard and all,
>
>I checked the C terminal. Disconnecting it does eventually
>kill the charging but not very quickly, so disconnecting
>the C connection via a crowbar won't work.
>
>
In our circuit, the crow bar connects the C wire to ground, so it sees
zero volt. At the same time, it trips the alternator disconnect CB,
opening the line relay. So the alternator is totally disconnected from
the ship's circuit.
>At about 5000 rpm the C terminal was taking 0.04 A.
>Not-a-lot !
>
>Gilles - I notice you say that earthing the C terminal
>will kill the output. But your own wiring diagram shows
>that the C terminal is connected directly to a diode which
>would not allow any current to run to earth from inside
>the regulator !
>
Correct. The C terminal is a sense connection to provide a reference
voltage to the command circuit. When you ground it, the reference
voltage is zero volt.
No current is intended to flow out of it. C voltage is always greater
than or equal to zero volt.
>So I suspect your "earthing" of the C
>terminal was really just disconnecting it.
>
>
What voltage does C teminal see when it is left dangling "in the air" ?
>I replaced my original (intermittent fault) rectifier
>today and it worked. So the replacement (which flicked the
>ammeter needle between 1 - 10 amps 5 times a second over
>5000 rpm) was faulty and it will be on its way back to the
>supplier tomorrow !
>
>I actually looked at the circuit board of my original (now
>re-installed) regulator and saw three possible sites for
>dry-joints. So I applied my soldering iron. The regulator
>still works so I didn't bu**er it up; I will wait for a
>few flights before I proclaim that I have fixed the
>intermittent failure to charge !
>
>Richard with positive engineering news about the
>electrics.
>
Great news.
> So now to continue to determine why the oil
>thermostat doesn't work the way I expected.
>
>
>
Maybe I missed previous messages, but how should it work, and how does
it behave ?
We shunned the thermostat thing, and went the duct and cowl flap route,
with great satisfaction.
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
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