Earl,
Circuit breakers are useful but the problem is they take a while to trip. We often think a 10 A circuit breaker will "break" at 10A. Note this chart from a Mouser datasheet for a typical pushbutton type circuit breaker (when it pops, a button pops out and is reset by pushing it back in)
Looking at the chart, a 10 A circuit breaker will pop after one hour of a 14.5 A load! That's OK for a direct short circuit (lots of amps more than 10), but even for a 40A load, this 10A breaker may take between 1.6 and 4.5 seconds to "pop". Not much protection for delicate electronics.
Finding a high speed circuit breaker becomes the issue of $$$$. A cheap one may be OK for a real solid short circuit, but that's about all it's good for.
Ed
