I'm testing a circuit for creating am unregulated "HV"DC source. The circuit is like this:
The example I'm using uses a Variac with 120V. I'm limited to the mains supply in Europe of 230V. The description in the example uses 1500uF caps, I'm using 220uF caps since I don't have any higher.
Using the 120VAC of the transformer, the example circuit outputs 370VDC. Me, using 230VAC get 330VDC from my circuit between 1 and 2.
A couple of things are still unclear to me.
What is causing the difference between the outputs of both circuits? Is it merely the difference between capacitors? I would expect 240VDC and 500VDC respectively (minus some voltage drop) as output. Strangely, the polarity is also reversed as I expected. I would expect line 1 to be positive, 2 to be negative, but I have to use my meters positive probe on 2 and negative probe on 1 to read a positive voltage.
Secondly, is it required to connect the AC neutral between the caps? My knowledge of AC is limited and I'm trying to learn it, but although with AC the voltage is alternating, I would expect the neutral carrying the near-earth potential to be negative for cap 1 and positive for cap 2, and reversing this polarity to make the caps puff or in the worst case explode.