AC power supply for testing

[shed_dweller]

Hi

I'm new in here and will have lots of silly question to ask.
(nodoubt)

At present i need a variable AC power supply to supply units under test. The normal working range is from 20 to about 300 volts AC. Current is very low. Normally the unit is supplied by two coils connected together within a generator and each of the ends of the coil go to a rectifier within unit.

Searching for AC bench supplies didn't turn up much, except for some very expensive items.

So what I thought I'd use is an isolating tranformer hooked up to a variac and mount these in a nice metal case to form a contained safe unit, run off standard 220 mains. How could I limit the current flow?

Anything I should be aware of or good reason why not to use this? What other alternatives would you suggest for a low current variable ac supply?

This is the circuit I want to test, I have a signal generator to drive the SCR gate.

**broken link removed**


thanks in advance

 

[shed_dweller]

I've decided to use a 1 amp variac to vary the supply voltage between 0 and 112% of the mains supply with the output from that feed into an isolating transformer with a 100VA rating to give a maximum current of approx .50 amp. I have access to sheet ally and a cutting machine so I will make a case to mount the transformers in and create a nice bench unit. Thanks for all your input.

 

[arunb]

what input....???