I'm looking to convert the ac power input of a thermostat to 5v DC power.
I want to convert 24v AC to 12v DC. please give me the circuit diagram& component values.. so please help me.. Many Thanks

 

Hello,

You just hijacked an existing thread:
http://forum.allaboutcircuits.com/showthread.php?t=46706

I opened a new thread for you, so you can continue here.

Bertus

 

I'm looking to convert the ac power input of a thermostat to 5v DC power.
I want to convert 24v AC to 12v DC. please give me the circuit diagram& component values.. so please help me.. Many Thanks

What do you want to power?

If you don't need much current (more than ~0.5A), and don't care too much about efficiency, take a look at a full-wave rectifier (to make DC) with a 7812 voltage regulator (to give you a constant 12v) circuit on the output.