Can anyone recommend a China Special high voltage boost converter module? I'm looking for perhaps 12 volts in, ~300 volts out at around 100 mA. So I'm guessing it's going to be flyback. Isolation not important.
-150/ +150 would actually be ideal. If they're cheap I guess I can just get two.
The "DC-DC 600W 10-60V to 12-80V Boost Converter" selling for $11 + $1.50 shipping can be modified for up to 300 volts.
BTW, the 600W rating is totally bogus.
The mod requires replacing the MOSFET, the output rectifier and caps, some passive components, and maybe adding some turns to the coil.
I reverse-engineered the PCB, see on dropbox:
Boost to +150V is better, only 12.5 times. Then you can add a simple second winding, diode & cap for the negative voltage.
On Tue, 29 Dec 2015 11:19:28 -0500 (EST), bitrex Gave us:
You 100mA output is not a reasonable figure. At least not in a compact form factor..
and that size would likely have to be custom, not off the shelf.
Look at these.
DecadentLinuxUserNumeroUno Wrote in message:
A 30 watt flyback isn't reasonable and can't be put in a compact form factor?
On Tue, 29 Dec 2015 12:23:24 -0500 (EST), bitrex Gave us:
Did you even look at the link? Those were about 3 cubic inch modules.
HV supplies at ten watts per cubic inch are not easy. At least not at that form factor.
Getting into hundreds of watts, maybe a bit easier per cubic inch, but not at the PCB mount DC to DC convertor level.
a cap and two diodes might do
-Lasse
Indeed, nice to avoid an extra winding.
One issue with either scheme: Since Vout + rides on top of the +12 input, you get 12V less than you might expect on the negative side.
Waited 5 min and still "loading"...
dropbox isn't working for you!??!!
The regulator supplying the IC seems bit complicated. Does the UC3843 need all that?
-RS
It doesn't need any of that if Vin < 28 volts. But if Vin can be as high as say 75 volts, and if you must be able to supply more than 12V at 50mA for switching drivers, etc, then some form of a serious HV power regulator is required. The designer also selected very low-cost parts.
Normally, an aux winding is used, with a ~100k pullup for startup current. For intermediate input voltages, a regulator can be worthwhile.
Tim
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