high voltage boost DC/DC converters (5V->250V)

[JosephKK]

Winfield [email protected] posted to sci.electronics.design:

1000:1 is a bit of a challenge for the transformer,
all kinds of painful issues, like excess winding
capacitance, etc., may come up, especially at low
power. Not to say it can't be done, or hasn't been
done, but I'd be inclined to first step up from 1V
to 5 or 10V, then go the rest of the way with a
flyback transformer.

They have some pretty tall ratios in tasers, but they might not be one
stage. Though i have heard claims that they can be made. Kettering
ignition is pretty tall too (> 1000:1).

 

[JosephKK]

Tam/WB2TT t-tammaru@c0mca$t.net posted to sci.electronics.design:

news:[email protected]...

Electronic photo flash units commonly work off 3 or 6 volts, and
deliver several hundred V DC. You should be able to find a schematic
for such, or even fix a junked flash unit; maybe from a disposable
single use camera.

Tam

I have found out that the normal single use camera is actually a
recycled / recyclable camera. It is more nearly one use per user.

 

[Winfield Hill]

Winfield [email protected] posted to sci.electronics.design:





They have some pretty tall ratios in tasers, but they might
not be one stage. Though i have heard claims that they can
be made. Kettering ignition is pretty tall too (> 1000:1).

Correct, but a Kettering ignition is NOT low
power; a car battery cannot be well compared
to a single AAA cell.

 

[David DiGiacomo]

Well, of course, modulo that. I need some 1kV/10uA, preferably from a
single AA (for an insulation tester; I'm tired of lugging around the
mains-powered one), but I'm so swamped with other things that I'll probably
never get around to it.

You could probably adapt a CCFL inverter, or at least take the transformer
out of one.

You could also start with an EL inverter out of a clock, but you'd have to
add a voltage multiplier to the output.

 

[Robert Baer]

You could probably adapt a CCFL inverter, or at least take the transformer
out of one.

You could also start with an EL inverter out of a clock, but you'd have to
add a voltage multiplier to the output.

The transformer in those is rather lossy; the square wave input drive
results in a sine wave even for a resistive load, and the power that can
be obtined at the output is rather low even if you drive the input with
a number of watts - even at "resonant" frequency.