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cywinstanley · Mar 10, 2009, 04:10 AM

Hi there,

I need to purchase a new power supply for the transmitter of an in-ear monitoring system.

The unit says it requires a 12V AC adapter supplying 250mA, however all I can find to buy on the internet are 12V AC adapters supplying 500mA.

Is it bad to exceed the current? I remember something from school electronics saying that so long as the voltage is correct, the current can be more then required and the unit will only take what it needs.

Thanks!

Perito · Mar 10, 2009, 04:29 AM

The 12 V AC is the critical part. If you don't match the voltage, you can burn out the electronics. The 250 mA or 500 mA simply means that the power supply can provide *up to* 250 mA or 500 mA, respectively. It doesn't mean that it will force that much current on the system.

Basically, Ohms law governs the amount of current that will be drawn.

A 12V AC @ 500 mA power supply will work fine.

cywinstanley · Mar 10, 2009, 04:36 AM

Originally Posted by Perito

The 12 V AC is the critical part. If you don't match the voltage, you can burn out the electronics. The 250 mA or 500 mA simply means that the power supply can provide *up to* 250 mA or 500 mA, respectively. It doesn't mean that it will force that much current on the system.

Basically, Ohms law governs the amount of current that will be drawn.

A 12V AC @ 500 mA power supply will work fine.

What an excellent answer! Thank you so much Perito!!