Of note . . .
One should determine what type alternator is being used.
OVPM for a PM (permanent magnet) alternator and a claw pole alternator will not be exactly the same. These are very different electrical machines. Bob's OVPM circuit is a crowbar for the field on a claw pole alternator design to blow the 5 amp fuse.
The crowbar circuit can be (should be) scaled up to blow the main fuse for the PM alternator if desired. It is not uncommon to do this on highly rated and expensive equipment, always to limit any catastrophic damage. Frequently exercised to protect against software glitches in development of brushless DC motor drive inverter systems. It's what fuses are for, to blow, even it it is large.
Edit: I should have looked at the drawing - using the same OVPM to blow the alternator disconnect supply will work for the PM alternator as well.
1st Flight 1-27-18
Phase II 8-3-18
Instrument Currency 12-17-18
Last edited by BillL : 08-24-2018 at 07:13 AM.