30V to 12V dc voltage regulator?

[Teshan]

Hi there, I have a 30 V dc power supply. I want to have a 12 V output from this. Can someone suggest a proper way to do this? I couldn't find a suitable voltage regulator.

 

[JohnM1]

See source

 

[lee26looammmmmm]

LM7812 good up to 1A.

 

[john]

It depends on the current you need.

Suppose you need 1 amp.

The 30V supply produces 30V 1A = 30 watts of power.

your circuit takes 12V * 1A = 12W of power. So your regulator needs to "waste" 18 watts.

A 7812 generates 5 degrees per watt = 90 degrees! so thats no good.

Honestly, it would be better and probably cheaper to get a 12V supply.