It used to be that in houses all the electrical systems were wired through a fusebox.
But now they’re all circuit breakers, which are easy to reset and don’t require buying and installing a new fuse. They’re also safer, because with fuseboxes people sometimes wedged a coin into a burned-out fuse “temporarily” and caused a house fire.
So I guess I have two questions here:
When did fuseboxes give over to circuit breakers?
and
Why don’t modern cars have circuit breakers now?
My only guess as to the latter is that cars bounce around more than most houses, so circuit breakers could trip accidentally. But that just seems like a design feature that would be easy to work around.
1. When did fuseboxes give over to circuit breakers?
Sometime around WWII.
2. Why don’t modern cars have circuit breakers now?
The loads on home circuits are changed whenever anyone plugs in a new load. With a 1500 Watt hairdryer drawing almost fifteen amps, it is easy for a homeowner to plug enough stuff into a circuit to overload it. The loads on most auto circuits do not change after the car leaves the factory, and the fuses can be sized for a specific load.
When a breaker trips in your home, it’s because you plugged too many things in to one circuit. You then unplug or turn off something, then reset the breaker - much more convienent than getting a new fuse.
When a fuse blows in a car, it’s because something in the car’s electrical system is shorting out. In that case you don’t want the power to be re-applied to the load until the car has been checked out and repaired. So having circuit breakers wouldn’t be much use, since you’re looking at repair work anyway.
>> When did fuseboxes give over to circuit breakers?
>> Sometime around WWII.
Really? I doubt it. I think circuit breakers have become widespread much more recently.
At any rate, circuit breakers are bulkier and more expensive than fuses. For reasons already said, in a car fuses very rarely blow and when they do it usually means a trip to the garage anyway.
But they have circuit breakers on aircraft (well, aircraft made after about 1980 in my limited personal experience).
I think sailor nailed it; circuit breakers are more expensive. Given the number of cars produced, car manufacturers are loathe to increase the cost of a car by even a small amount per car, because it really mounts up.
On the other hand, (as the owner of an '88 Caddy), I still don’t know why car manufacturers make the fusebox so damned hard to get at.
My house (#1) built in the 50’s had fuses so maybe CB’s were available around WW2 but they weren’t standard.
My parents house was built in 72 and had CB’s.
Bottom line is this: There is absolutely no advantage to using circuit breakers in a car. When compared to a fuse, a thermal or magnetic circuit breaker is:
Larger
Heavier
More expensive
Less reliable
Less accurate
Slower actuation time
Sure, a circuit breaker is more convenient, but this is not factor on an automobile (unlike your home).
While a blown automobile fuse can mean a problem in the circuit, this is not always the case. They occasionally fail from apparent “old age,” in which case replacing the fuse is all that is needed. Many cars provide a spare fuse of each size (amp rating) in the fusebox for this purpose.
car voltages arent constant so the amps must not be either
old type fuses are insensitive and take a while to blow …millisecond wise
cb’s are very sensitive and could blow everytime a bulb went leaving you completely in the dark
this is what happens in my house if a bulb blows
easy to pop down stairs and flick the switch back up
but a bit disconcerting on a fast bend in the dark if a tail light goes
imo only
As Desmostylus pointed out, circuit breakers are used in cars, but only in a few applications. Every car has an array of fuses, some cars have a few CB’s (typically 1-3). Power window and A/C circuits seem to be the most common place for them.
Every automotive CB I’ve seen is self-resetting. They are available in different amperages and can be installed in place of fuses, though I don’t recommend that as a matter of course. One situation where it could be helpful, though, is with an intermittent short circuit that occasionally pops the fuse but then functions OK for a number of weeks or months. Until it’s feasible to find and fix the short, a CB is a lot more convenient than fuses. Don’t use one if the short recurs in a brief time period, there’s a risk of causing damage.