Question about sm0vpo PSU/Battery Charger

Thanks Ivan,

I found on the internet this nice software that helped me to understand the behaviour and play with the values of the caps and the load and see the changes in output voltage and current.

PSU Disegner II by Duncan Munro
http://www.duncanamps.com/psud2/

Regards

Hi Bernie,
generally, the voltage rating of capacitors must be more than the peak (not effective !) voltage in the case of a rectifier, twice the peak value in the case of voltage doubler. If I suppose a 12 V (eff) transformer, you need at least 12*1,5*2 = 36 V capacitors, 40V is OK for safety.
The capacitance affects the ripple at the output and the internal resistance of the voltage doubler. 

BR from Ivan

I am about to start building that project.

I have a 230v - 12v transformer rated 1A.
So I would go to the voltage doubler option (the middle option in the schematic)

However the capacitors rating is given in the schematic (40V) but the value is not given.

At first I thought they would be same as the filtering capacitor (4700uF), but I am not sure.
And also I do not have that many 40V-4700uF caps.

But I have several lower value or lower rating (mainly 16V from 12V PC power supplies)

Can someone advise if lower rating or capacitance can be used?

Regards.