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How to determine proper capacitors for high frequency voltage doubler and pass DC current??

russwr

Dec 20, 2019
32
High frequency AC transformer output hooked to half wave DC voltage doubler. Current through is 6 amps to LOW frequency switching load. I assumed there is enough 20khz time to keep second cap charged, as ready for discharge at low frequency. First cap is hot. second is cold. using camera photo fast discharge caps 47uf as lower esr , but not type low esr capacitors. Is there something wrong with first cap, or is there misalignment with reactance 12 ohms of secondary of transformer? Other method is resonance of Xl=Xc so as maximum energy transfer with cap in series. I don't know. The formula for matching says .5UF , but the formula for a filter capacitor for 6 amps DC capable flow says 47uf. I don't want to burn out my power supply. With short time on and off of power supply,I get 6 amps , but the first capacitor is hot of the voltage doubler. Should I put .5uf as first cap + 47uf as second cap of voltage doubler??

Last edited:

Harald Kapp

Moderator
Moderator
Nov 17, 2011
13,719
Circuit diagram so we have a chance of understanding what you are talking about?

russwr

Dec 20, 2019
32
The question has to do with determining proper capacitors for HALF WAVE TYPE voltage doubler of 2 capacitors.. C Farad = I X dt / dv. speed of pulse divided by 2 times change of volts Vpeak - V average. Numerator as decimal second time , changed to frequency HTZ in denominator, as 6 A / 20000 cycles X 4v change = .000075 farad or 75uf. derived from I = C X dv/dt rearranged as above formula . dv= somewhere between V peak and v average. as 2 X Vpeak-Vav. Vpeak = Vav times square root 2. The 47uf caps used were hot , so as may need to be larger as a close 82uf.

Last edited:

Delta Prime

Jul 29, 2020
1,964
X Vpeak-Vav. Vpeak = Vav times square root 2. The 47uf caps used were hot , so as may need to be larger as a close 82uf
The language of electronics is schematics. "The 47uF caps used were hot".How hot were they?... (Rhetorical question).Schematic Please.

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