Posted for "Ian & Irene Beadle" <beadles@webace.com.au>:

A VDR (voltage dependant resistor) and a circuit breaker does the job. Best
is to protect all electical devices with their own VDR and breaker or fuse.
If the alternator did go to full output ,which is magnet saturation, the
diodes do not fry as they are rated for full output. I have tried it. A car
alternator with the reg. bypassed makes a good welder.
Ian.