220v AC TO 12v dc POWER SUPPLY?

[mImoto]

Hello I would like to design a power supply for a wireless transmiter (4W max output power with Vin=12V). I don´t know much about power supplies and I would like to design a reliable and more or less small one. I would appreciate any sch. or link.

thanks a lot anyway,

mimoto

 

[barrybear]

I would use a fixed voltage regulator 12v 1 amp type, a transformer with a 12v ac secondry decouple with 2 - .1 micFarads capacitors eather side of the regulator and a 2000 uf resivour capacitor and 1amp rectifiers.
Its a prity much a bog standard circuit that you would find in the regulator data sheet.

Barrybear

 

[j_o_n_i]

I agree with barrybear, this is the most simple solution, just put that in paper. Forgot to put a capacitor at the output for stability, 100uF will do
joni

 

[coppervaporlaser]

If youre going to power a RF circuit, you MUST add small (low inductance) caps as close as possible to your preamplifier (SMD's will be the best choice). Also split the Filter cap into 3 parallel ones (e.g 22p||100p||1n) and place one 3-pack on each supply pin of your RF-IC !!