Voltage regulator contacts

Dan Thomas wrote:

In most airplanes the alternator switch controls only a relay in the
regulator, not the field current itself. The relay connects the
voltage regulator relay to the "A" line, which runs to the alternator
output which in turn is connected to the aircraft's electrical system.
The small current required to run the relay might not be enough to
keep the master/field switch contacts burned clean, and the relay
contacts themselves can get worn.
The voltage regulator contacts can burn and start cutting out or
sticking shut intermittently, too.



Not Piper. Piper's field circuit goes from the master bus, through the field breaker,
through the master switch, thru the OV relay, thru the regulator to the alternator field.
A relay would have been a better design in that the master switch doesn't wear well with
the 12v several amp DC current. Many if not most Pipers have solid state regulators, so
there are no regulator contacts to burn.

--

--Ray Andraka, P.E.
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