So recently my doorbell button got stuck and it burnt out both the electromagnetic coil in the chime and the transformer. As I'm replacing everything I was thinking that I could add fuse to prevent a rogue button from causing so much damage again.
The transformer is 16VAC 10W and I measured the voltage as just over 20VAC. The chime consists of an electromagnetic coil that drives a pin hitting a chime (separate coils for the front and back buttons). It claims it's suitable for a 16VAC 10W or 16VAC 15W transformer.
Let's say that x amps run through the circuit when the button is depressed. Normally the button is depressed for very short periods of time (let's say <10 seconds for an enthusiastic doorbell ringer). I've read that a fuse can withstand more than its rated current for a period of time depending of how high the current is over the rated current… can I undersize a fuse such that the blow time for an x amp load would be 10–15 seconds? Would sizing the fuse be so finicky as to be not worth it?
Best Answer
Wouldn't a slow-blow fuse work? I don't think you'd want to under size it. Just understand what voltage/current ratings you need and find a slow-blow fuse that can handle 10-15 seconds of that.
Something like this. Just figure out where you need to be on the Average Time Current Curves.