rhlee
Hi physics forum,

I'm going to use a transformer to step down 240V AC mains to 24V AC.

I remember my physics teacher telling me about matching the load between the power supply and the load.

Regards,

Richard

No.

The transformer will have some internal resistance which will limit the current that can be supplied to any load you put on the transformer.

Manufacturers make this easy by telling you how much current the transformer can supply without overheating.

So, if it is a 2 amp transformer and supplies 24 volts, then the maximum load you can take from the transformer is 2 amps and this would be drawn by a load of 12 ohms.
This is Ohm's Law. Resistance = 24 volts / 2 amps = 12 ohms.

Any less resistance than this for more than a short time may result in the transformer overheating and possibly being destroyed. If you don't know what your load is going to be, you can include a fuse in series with the output to avoid overheating problems with the transformer.

rhlee
Thansk for the info and safety advice.