I have got an old transformer with multiple secondary taps with the ratings shown in the following figure:
I plan to put the transformer in a suitable case and connect the secondary taps to binding posts. This apparatus would be used for conducting some experimentation with AC currents, so it would be susceptible to some degree of abuse. Therefore I'd like to protect the transformer from short circuits and gross overloads.
Of course on the primary side I'll put a switch and a fuse, to avoid catastrophic failures. However I'd like to have a more lenient form of protection on the secondary side: replacing a fuse any time a secondary tap is shorted (or overloaded) would be a real hassle in a lab context.
What kind of simple and cheap protection measures can I adopt in this case? I thought of putting a suitable rated polyswitch (i.e. resettable fuse) like these in series with each secondary tap, but I never used them and I cannot say what kind of problems they could present and what parameters to consider in the design.
Is my idea a sensible one (for example, do polyswitches reset themselves reasonably quickly after an overload event -- I'd like to be able to recover in a couple of minutes, at most)? Are there alternatives which are comparably cheap and simple to implement?
To sum up my requirements:
individual protection of secondary taps: if a tap is overloaded, once the cause is removed the other taps should keep on working, even if the overloaded tap is "recovering" from the fault for some time.
simple and cheap to implement (not much more complex or expensive than adding a fuse in series with each tap).
the overloaded tap should have a recovery time that is reasonably short (a couple of minutes max).
the overloaded tap should recover automatically (preferably) or the recovery system should be hassle free (say, press a button).