"mikem" writes:


First, Glad that you seem to have fixed your problem. Your alternator
must have had a bum diode, and my prediction was wrong.

Second, I want to point something out to you. Disconnecting the battery
while the alternator is spun-up (and maintaining field exitation) is
EXTREMELY DANGEROUS. Doing this could cause the bus voltage to spike
beyond 100+V, and destroy every piece of avionics in your panel. Rather
than trying to explain why here, do a Goggle search on the phrase
"ALTERNATOR LOAD DUMP".

What he said (WHS). Although the figure I recall wasa mere 65 volts;
that from a discussion of such in a GE-MOV applications book many
years ago. Further, the resulting spikes is not just big (V) but
fat (long persistence) and thus high total energy.


Every aircraft I have seen is wired such that turning off the battery
master simultaneously breaks the path to the alternator field, thereby
shutting down the alternator. Some aircraft accomplish this with a
mechanical interlock on the switch (Cessna split master/ALT switch), or
by the way the ALT switch is wired. The fact that your Lake is NOT
wired this way seems to be a major screw up.

WHS!!!!

Disconnecting the battery in order to diagnose an alternator is NOT an
accepted diagnostic tool.

The ONLY good news is you'll blow up only the avionics; the magnetos
will not care and even an electric fuel pump may likely survive.

Do that stunt on modern car and you shall regret it...


Third, to show the expected bus voltage under different conditions, I
did four different Spice simulations and put the results he
http://tinyurl.com/lkzt4

Hmm, zip seen here, alas....
Is it working?


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