Voltage Doubler

There are two configurations. One makes +2*V to neutral, the other makes +V and -V. "Full wave doubler" and "Half-wave doubler."

650, theoretically, a bit less with diode and capacitor losses. 230 VRMS is 650 peak-to-peak.

Isolation.

That's too complex to do for free. Bigger caps allow more current. How much do you need?

Depends on the hazards. Might be ok if you're careful as to which line is neutral.

What's the application?

John

Reply to
John Larkin
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I have a design for which I need to generate a high DC voltage (more than

400V). My power source for this voltage is the UK mains (230Vrms @ 50Hz). The way I see it is that I have 2 options. The first option is to use a step up transformer and a bridge. The transformer would need a ratio of 1:2 (primary: 230V, secondary: 460V). As I cannot find any off the shelf transformers I would need to wind my own. My second option is to use a simple voltage doubler consisting of 2 capacitors and 2 diodes. The output of the voltage doubler would be something close to 460V DC.

Out of the 2 options the voltage doubler seems the most straightforward. Some questions I have on this setup are:

1) Does the transformer option offer any advantage over the voltage doubler? 2) How can I determine the maximum current that can be drawn from the voltage doubler? 3) Is connecting a voltage doubler directly to the mains a good idea?

If you have any opinions or advice on this subject then please share them.

Thank you.

Reply to
Jay

50Hz).
1:2

doubler?

might use an inrush current limiter to safeguard your setup if using 230Vac as input might think of fusing the output (PTC or fuse) be very carefull if using mains directly, for personal security

Reply to
peterken

Looks like you could find a suitable transformer if you hunted around at some sources that carry old tube type radio equipment. They would have 460 volt output or close transformers........also.....couldnt a person use a microwave oven transformer and strip off some of the secondary windings till he got the desired output ???

Reply to
cornytheclown

Actually, the voltage doubler could, depending on the current you draw and the size of the capacitors, give you an output of twice the peak voltage (230V is the RMS value). This could be closer to 650V.

2 * 230 * sqrt(2) = 650V

Don't forget that the capacitors could remain charged after you disconnect the mains. Be very careful.

Gareth.

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Reply to
Gareth

Theyre not built for continuous duty. You could try two in parallel.

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Reply to
Steve Evans

Either case will make the transformer saturate and catch fire.

John

Reply to
John Larkin

You might look for dual-primary transformers, designed to allow easy conversion between 120V and 240V systems. In normal use for 240V, you would put the two primaries in series. Instead, you can either use only one primary (if your load current is small compared to the transformer rating), or hook them in parallel with the proper polarity to get double the output voltage.

Just a thought.

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

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Reply to
Bob Masta

Don't run it that hard next time! ;-)

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

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Reply to
Bob Masta

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