scuba14c

Couldn't figure out what happened, thanks for reposting it. I've got a couple more questions about the pulsed DC and transformer. If it is pulsed DC, do I get DC or AC output? If it is AC, would I use an inverter to change it to DC? How much current could I expect to get from it? If it is powered with batteries, the current would have to be lower than the battery, right?

How do I get the pulsed DC, a 555 timer with low frequency? From what you have said, this seems like it would be better than the boost converter. Will any type of transformer work? I have one sitting in the basement from a dehumidifier. How do you make the comparator? I've heard of them, but couldn't find a diagram of one online.

Still have a problem, don't you need AC to use a transformer?

I was hoping to avoid the using the mains, my parents won't let me. Can't afford a variac, either.

The capacitor bank I have been using to this point is 330V 1900uF. When I charged this with a photoflash charger, it took 4 minutes. The new bank is 350V @ 56700uF or 700V @ 14400uF. I would like it to be able to charge to 700V, but keep the charge time down to about 30 seconds. The schematic for the boost converter said it would charge a smaller bank in 3 seconds.

Not sure where to find it. I actually gave up on the IGBT and am using two 400V 8A NPN transistors in parallel because they gave me a higher voltage. If you tell me where it would be, I'll give it to you. I think the switch may be the problem after trying to alter the duty cycles on the timers.

I have tried another inductor in parallel and it gave me an increase of about .5V. Is it necessary to put the circuit on the board? I am not quite at the stage of being able to put his on a board. Do you think this is causing the problems?

On the last post, the first is a pic of two inductors, the second is the diode and inductor. These two are: the whole setup, and the transistors, respectively. [attachment deleted by admin]

Ok let's try it again. [attachment deleted by admin]

L1 is an RF choke form radioshack, 100uH. I have three available. Wah tdo you mean I need another cap. Don't I just have the bank I'm trying to charge in between?

I have changed the duty cycle, but it also changed the frequency. The duty cycle is anywhere from 66.6-99.1%. Because the frequency changed, I can't tell if the duty cycle or the frequency makes the most difference. The timer that works the best is 2186Hz @ 66.66% duty. Is it better to have a larger voltage driving the chip; right now it is a 9V battery. I am also not using the 1200V 20A IGBT, it only charged to 25V or so. I have replaced it with (2) 400V 8A NPN transistors in parallel to reduce the heating of the switch. The NPNs work the best of any switch I have tried.

I have been trying to build a boost converter, but am having problems. If you aren't familiar with these, they use an inductor, diode, a semiconducting switch, and a 555 timer. The voltage builds up in the inductor, and is pumped into the capacitors. The diode prevents it from flowing out. I can get it to charge to 45V, and then it won't go any farther. With a 12V input, it does work, but should be able to charge to a much higher voltage. The load on the capacitor doesn't matter either. I have used 100uF and 3600uF banks and both stop at 45V. I have a 100uH inductor and a fast recovery diode. This is the schematic I built it off of...