Transformer "resetable fuse" question

Mon Jul 07, 2014 5:05 pm

Has anybody worked with a "resetable fuse" in a transformer. This particular tranny is in a solid state Ampeg BA210. I've not found a schematic for it. I've read this fuse is actually located inside the transformer and can only be accessed after removing the protective paper.

There is a black ceramic strangely shaped piece between the tranny stage connections on the PCB. Could this be the fuse? Crazy thing.

Zippy

Re: Transformer "resetable fuse" question

Wed Aug 20, 2014 10:15 pm

Hi Zippy

The fuse is most likely a thermal type. These are a one shot fuse, not resetable but it is replaceable. These fuses are mounted directly in contact with the transformer, well they should be anyway as its protecting the transformers max operating temp. It should look like a 1/8 to 3/16th inch metallic cylinder and about a 1/2 inch long with a wire coming out at each end. If you look closely you should be able to read a temperature number on it somewhere. Go to Radio Shack or somewhere like that with the fuse and ask for a replacement. You will need to solder or crimp the replacement making sure of a good connection. This fuse is placed in the mains power feed to transformer so all current flows through this device. For this reason please check the fuses current rating also.
Hope this helps
Cheers
Geoff

Re: Transformer "resetable fuse" question

Wed Aug 20, 2014 10:28 pm

I have to say though if you have no knowledge of working with transformers etc, please be very careful. Assuming you have some understanding you need to find the 2 AC supply wires going to the transformer, if you follow these wires you will find the fuse. It could be placed in either wire but typically on the active wire not the return side of the supply power..It will be insulated and you will have to remove that and of course replace it when reassembling. Remount the fuse as it is mounted originally.
Do you have a test meter of any sort, volt/ohm meter?.
Cheers
Geoff

Re: Transformer "resetable fuse" question

Wed Aug 20, 2014 10:30 pm

LMAO, i just looked at the post date, well better late than never,
still laughing
Cheers