Phil, This is a issue with a lot of electronics, and there are "Standard" designs for protecting the desired items. Check out http://www.radio-electronics.com/info/circuits/scr_overvoltage_crowbar/scr_over_voltage_crowbar.php
There is usually a fuse or circuit breaker "upstream" of the circuit that blows when the "Crowbar" trips. For safety reasons, I'd have a way to isolate the Voltage suppy (Generator ,alternator, dynamo) from the battery. And a a reset on the protection element (like if your using fuses, a spare fuse). Bill Higdon > yes over voltage can cook other stuff too > radio > trans pon > some ign systems > i am just figuring a good way to protect my stuff > p
