Can anyone Identify the Missing Fuse?

[NardDog]

Good morning. I picked up this bench power supply not long ago made by Electro model PS-2. I really want to get this working but i have no idea what type of fuse is missing and if its missing something to hold down the fuse itself. If any of you who are long in the tooth could chime in with your suggestions it would be appreciated.

 

[bigdog9191999]

Best answer is a round one! Lol. Seriously should be a lot like an older cylinder style like a classic car. Should be a "cap" that holds it in. Amp or exact style is a good guess.

I would say some Google an hope to find a user book for it or similar ( usually a model or two one way or the other is quite similar) and you should find some information.

 

[89Suburban]

Yup glass fuse I am assuming.

 

[89Suburban]

Amazon.com : glass fuse holder

 

[Fless]

That fuse location is probably the input protection (AC), but you could verify that if you open up the case and see where the input wires connect. You have a variety of sizes from which to choose; see link below. You'll need to measure the physical length of the fuse socket along with the retainer cap, to get the physical length. The cap is a bayonet mount; push in and twist to lock it in place or to remove it.
Glass tube datasheets

If you have an AC clamp meter you could measure one of the AC wires from the power cord (the house current), then use a small (say, 1/2A) fuse to power up the power supply. You may need to apply some kind of DC load (auto bulb?) to it to be able to measure the max current draw on the input.

You could also open up the unit and rig up a bypass circuit for that fuse socket, but you'll want to be careful to protect the circuit with a relatively small fuse.

Note that the fuse protecting the low current circuit is a time-delay fuse (slo-blo), not that it matters for this discussion.

 

[NardDog]

thanks for all who answered there some good info here that I think I can get started with. I knew i came to the right place!

 

[Fless]

That fuse location is probably the input protection (AC), but you could verify that if you open up the case and see where the input wires connect. You have a variety of sizes from which to choose; see link below. You'll need to measure the physical length of the fuse socket along with the retainer cap, to get the physical length. The cap is a bayonet mount; push in and twist to lock it in place or to remove it.
Glass tube datasheets

If you have an AC clamp meter you could measure one of the AC wires from the power cord (the house current), then use a small (say, 1/2A) fuse to power up the power supply. You may need to apply some kind of DC load (auto bulb?) to it to be able to measure the max current draw on the input.

You could also open up the unit and rig up a bypass circuit for that fuse socket, but you'll want to be careful to protect the circuit with a relatively small fuse.

Note that the fuse protecting the low current circuit is a time-delay fuse (slo-blo), not that it matters for this discussion.

Once you've determined the max load on the fused circuit, double that for the fuse electrical size. For example, if the max current draw is 1/4A, use something like a 1/2A fuse.

 

[NardDog]

That fuse location is probably the input protection (AC), but you could verify that if you open up the case and see where the input wires connect. You have a variety of sizes from which to choose; see link below. You'll need to measure the physical length of the fuse socket along with the retainer cap, to get the physical length. The cap is a bayonet mount; push in and twist to lock it in place or to remove it.
Glass tube datasheets

If you have an AC clamp meter you could measure one of the AC wires from the power cord (the house current), then use a small (say, 1/2A) fuse to power up the power supply. You may need to apply some kind of DC load (auto bulb?) to it to be able to measure the max current draw on the input.

You could also open up the unit and rig up a bypass circuit for that fuse socket, but you'll want to be careful to protect the circuit with a relatively small fuse.

Note that the fuse protecting the low current circuit is a time-delay fuse (slo-blo), not that it matters for this discussion.

So long story short I found one for sale on Ebay. The seller sent me the details he said quote- “I couldn't find a schematic on the internet so I removed the fuse in the one we have in inventory and put it under a microscope. On one end it has 250VAC UL SA and on the other end it has BUSS ABC 5. It is a ceramic type. Hope that helps. Gene”

These seem to be readily available online.