# Transformer output voltage equations?

I'm looking for equations on how to calculate output voltage of a simple power supply made of a step down transformer with Rs secondary resistance, a bridge rectifier and a capacitor with different loads.

• Do you know what RMS voltage is coming from the transformer? If so are you able to calculate the peak voltage coming from the transformer? If so then the DC voltage under light loads from the diode bridge is peak ac input minus about 1 or 2 volts (depending on the diodes). There will be ripple - do you know what your output cap and equivalent load resistance is? If yes you can calculate how much ripple you'll get. – Andy aka Jun 30 '13 at 16:33 The ripple is not a result of the load resistor but in fact is a result of the capacitor discharging into the load resistor which causes a smoother wave, the larger the capacitor the more negligible the ripple factor but it can be hazardous if too large a capacitor is used if you're looking to build an amplifier 