Help me with building power supply - materials, calculations

[cajun4417]

HELP PLEASE!!!!!!

I am trying to build a power supply that has an input voltage at 120V AC and an output voltage at 3V DC and 3 more at 6V DC, 9V DC, and 12V DC. I know i need a transformer but I'm not sure what size. I think I need a diode and resistor, but once again I not sure what size. If possible could someone help me with the materials and the calculations on how to find the right values. Thank you.

 

[memarian]

Re: HELP PLEASE!!!!!!

Dear,

The Transformer size depend on your Power Dissipation (V*I) in all voltages.

You must calculate total power dissipation of all outputs and select the transformer.

Before using a Resistor Divider,I think for better Configuration you have to use

Regulators.For Lower Power Dissipation you can use a transformer with 120 V

AC input and two (13V)& (8V) outputs.after that you can use 2 diodes and 2 capacitors

and use the output voltage of 13V section For 12V & 9V Regulators.and output

of 8V Section for 6V & a 3V Regulators.after that you must connect all outputs

grounds together.

Good Luck.