I knew that no ham could resist bringing up the subject of a reactive load..
-Adam AJ9D On Sat, Dec 31, 2011 at 5:02 AM, John Rehwinkel <[email protected]> wrote: > > I built a simple voltage multiplier as suggested out of two diodes and > two capacitors and plugged in a 12VAC as input. I got out around 36 volts > DC based on the caps I used (I am assuming that is the reason it was not > closer to 24volts. > > It's not your cap choice, it's how these doublers and multipliers work. > With little or no load, they charge to the peak > input voltage. Since AC varies, spending part of its time at low > voltages, to deliver the same power* as a DC voltage, > it also has to spend part of its time at higher than the equivalent DC > voltage. So 12VAC is generally really 12VAC RMS, delivered as a sine wave. > The peak voltage of a sine wave is 1.41 (the square root of 2) times the > RMS voltage, or > about 17 volts. The peak to peak (negative peak to positive peak) is > twice this, or about 34 volts - which is what you'd > expect from a doubler supply like yours. > > I hope I've shed more light than confusion on the issue! > > - John > > * into a resistive load - it gets more fun when reactance comes into play > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To post to this group, send an email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/neonixie-l?hl=en-GB. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
