But i've been trying to do some theoretical calculations for a half wave rectifier... the circuit is a 12V-0V-12V AC power supply at 50hz, a 1N4001 diode with 680ohm resistor as the load, then a 1000uF capacitor in parallel with the resistor providing some smoothing.

I'm trying to find the voltage peak to peak of the ripple that results, but i think i need the average dc current of the ripple? once i have that, i was planning to use the formula; changeinVoltage = current(dc) / frequency x capacitance, so up to now i've got;

changeinVoltage = I(dc) / 50hz x 1000uF, so it's just the current i'm missing.

If anyone can point me in the right direction on how to work this out that would be great, i've been searching the internet for ages, and don't seem to be getting anywhere.

PS i'm new to electronics and the maths behind it, so please go easy on me.