Date: Sat, 10 Sep 2005 18:08:08 -0400
From: Finn Lassen <finn.lassen@verizon.net>
Subject: Re: [FlyRotary] Re: Overvoltage control (help Ed A)
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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I think the +100 volts statement relates to no battery load. I guess if 
the electrical system was designed so that a contactor could disconnect 
the battery from the load circuits and the load circuits (avionics) 
still be connected to the alternator you would have a situation where 
you could wave your avionics goodbye.

Let's say on top of that that one (or all) of the three retifiers 
shorted out too, you'd have 100 volts A/C into your avionics. Not a 
pretty picture. (I've seen Zener diodes short out regularily due to 
overload/voltage; rectifier diodes usually fail open - but not always).

Finn

Jim Sower wrote:

> <... the alternator is capable of producing over 100 volts ...>
> I don't think so ...
> ...
> Bottom line, with the regulator failed (or bypassed) to send full B+ 
> voltage to the field, the charging voltage never exceed 18V in my 
> experience.