Current limiting

[wayea]

I need to design a circuit that will limit current for an ac amp. I need some type of logic circuit to limit the current to 10A @ 50Vac. Any ideas?

 

[Nigel Goodwin]

You need to give a great amount more details, your question is too vague to be of any use.

 

[wayea]

Well, the output of the amp needs to be linear to the input signal at a frequency 10Hz-30kHz. What else do you need to know?

 

[Nigel Goodwin]

What sort of amp it is?, what kind of signal?, why you want to limit it? - presumably from the frequency spec it's an audio amp?.

 

[wayea]

It is based off an audio design, but I will be using it to amplify signals from a DAQ. I want to test the effect of harmonics on different types of loads.

 

[Nigel Goodwin]

Audio amps usually have in-built overcurrent limiting, if not you should add it. However, using an amp in this way is probably going to call for making the heatsinking MUCH larger, and probably increasing the number of output devices and beefing up the PSU.

Bear in mind 10A at 50V is 500W, so you're talking very high powered amplifiers - good quality 1000W or 2000W PA amps could well do it with no changes.

 

[wayea]

That's where I'm stuck... Other than fuses and a big resistor on the output, I'm not really sure how to limit the current.