The 2A rating referrs to the secondary winding.

Yes, but how seriously do I have to take it?
Does it mean the melting point of the insulation? of the wire?
...or is that a dumb question?

Peter

 

You should be able to operate continusly at 2A, @ 3A-maybe 1/2 hr. @ 4A, maybe 5 min. When the transformer is too hot to hold- time to shut down. Note: maybes do not come with guarantees.

 

You should be able to operate continusly at 2A, @ 3A-maybe 1/2 hr. @ 4A, maybe 5 min. When the transformer is too hot to hold- time to shut down. Note: maybes do not come with guarantees.

Okay, thanks Bernard.

Peter

 

You should be able to operate continusly at 2A, @ 3A-maybe 1/2 hr. @ 4A, maybe 5 min. When the transformer is too hot to hold- time to shut down. Note: maybes do not come with guarantees.

So what do you think would happen if I shorted out the secondary outputs?

 

You would cook your transformer, start a fire, and hopefully blow a breaker. If you have a 20A breaker, you will burn it up before the breaker trips.

 

You would cook your transformer, start a fire, and hopefully blow a breaker. If you have a 20A breaker, you will burn it up before the breaker trips.

But wouldn't the smell of burning insulation give me time to break the short?

 

usually by the time you smell it, it would have already shorted the windings in the transformer....

B. Morse

 

usually by the time you smell it, it would have already shorted the windings in the transformer....

B. Morse

That's why I plan to keep the pwr supply in an open box as close to me as possible.

I'm not planning to blow my house fuse by doing anything crazy -- that's why I got on here in the first place (as i recall), I wanted to add a fuse to a published circuit where it didn't exist. Now I'm finding that the circuit is garbage, but as I've built it I'm going to use it, but cautiously.

Peter

 

If you take a look at this circuit here, you can see that the secondary on this transformer is rated at 2 amps, but they only have a 1 amp on the primary side...

http://www.nsrca.org/technical/tip_tricks/foam_cutter/foam_cutting_power_supply.htm

And apparently this guy has done the research and come up with a "safe" and almost foolproof way of powering his foam cutter.....

which is the same circuit I will be using once I get around to finishing my CNC foam cutting machine....

so by placing a 1 amp slow blow fuse on the primary may just work for you, or use a 2 amp fast blow....

B. Morse

 

I'm not saying that's a bad design, it's just that I've spent way too much time on my current build -- and cutting foam is only a side event of my current project, and I hope never to have to cut foam again!

 

I'm not saying that's a bad design, it's just that I've spent way too much time on my current build -- and cutting foam is only a side event of my current project, and I hope never to have to cut foam again!

no, I am not saying to build the circuit, but use it as an example on where to place the proper fuse in your current setup.....

B. Morse

 

no, I am not saying to build the circuit, but use it as an example on where to place the proper fuse in your current setup.....

B. Morse

I don't know enough about electricity to see how that triac circuit will help me.

 

I want to make small foam blank size cutter electrically operated with toropot as regulator.
I hv 24v, 5A(120VA) transformer as well as 12V, 5A transformer with 2 ohm, 50 watt toropot as regulator for foam / thermocolr cutter & using 23gauge/24 gauge nichrome 80/20 hot wire about 12" long. Can I use above set up for cutting 4" thick foam/thermocole blank size cutting? Plz provide ckt drwg 7 valuable information.