> I don't think it's quite that easy. If I remember my old college
> EE courses the caps will charge to the peak voltage available
> which should be 120 volts times the square root of three (1.714).
Actually, it's the square root of two, or about 1.414. But the trick in
creating a voltage tripler is to arrange the circuit such that the first
capacitor winds up in series when the input is charging the second
capacitor, and the second capacitor winds up in series when charging the
third capacitor. In theory the output voltage (with no current drawn) winds
up being 120 * 1.414 * 3 or 509 volts, although in practice it's always
slightly less. See for example the circuit at
http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/voldoub.html
These circuits aren't suitable for producing much output current, but they
were commonly used with vacuum tube circuits when a low current, high
voltage was needed. For example, many televisions used them for the picture
tube anode voltage once high voltage solid state diodes became cheap. The
cost and weight savings over a transformer capable of producing 15-20 kV was
significant.
Randall
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