single stage cockroft walton with 1A current? - Page 1
Forum section: electronics / beginners

author: JWoodrell
author_rank: Contributor
timestamp: December 05, 2013, 04:26:18 pm
content: So in my project right now I need to take 24v up to 40-46v (exact value not important right now) with around 1 amp of current output.In the simulator it looks like a single stage C-W can do this using a decent frequency (20-30k) and 10uF stage caps, and a 2200uF filter cap. but my question is what would this work IRL, or is it a simulator goose chase?or am I looking at it wrong, is there an easier way to do this without a complicated DC-DC prepackaged IC controller?

author: mariush
author_rank: Super Contributor
timestamp: December 05, 2013, 04:35:44 pm
content: I sincerely doubt you'd be able to do 1A with it.It's much safer to just use a boost dc-dc converter.

author: olsenn
author_rank: Frequent Contributor
timestamp: December 05, 2013, 05:13:58 pm
content: Cockroft Walton would make a badass name!

author: ThomasDK
author_rank: Regular Contributor
timestamp: December 06, 2013, 12:15:56 am
content: 24V AC or DC?If AC, have a look at this (In german, but you should still get the idea from the schematic):http://www.elv-downloads.de/service/manuals/PPS5330/PPS5330_KM_G_080303.pdf

author: Psi
author_rank: Super Contributor
timestamp: December 06, 2013, 12:19:04 am
content: Try it and see, it probably will work but there will be less voltage/current in the actual circuit vs an 'ideal simulation'

author: minime72706
author_rank: Frequent Contributor
timestamp: December 06, 2013, 04:12:59 am
content: I didn't give it a ton of thought, but I think you're barking up the wrong tree considering a CW voltage multiplier for this application.

author: minime72706
author_rank: Frequent Contributor
timestamp: December 06, 2013, 09:50:19 pm
content: I'm personally working on a basic high-voltage/low current DC power supply involving a CW multiplier. It'll get done when my depression goes into remission and I have motivationEDIT: I have a square wave of some frequency and peak voltage feeding the input of the CW; I think a reasonable value would be 20V @ 50kHz, though I'd probably tune the frequency for the best performance. On the output of the CW, I'd have some sort of adjustable over-voltage clamp to limit the voltage to a set value. I'm looking for a maximum output voltage of maybe 500VDC, but definitely less than 1kVDC and I only need tens of milliamps. I also intend to make it current-limited and the same device may end up performing both tasks. I have some 900V MOSFETS as well as some IGBTs that I would use in a shunt regulator configuration. Having a CW multiplier in a feedback loop is probably the stupidest thing I could do, so yes, it will waste power, but I don't entirely care. If I'm going to be nutty, I could manually reduce the input peak voltage to reduce the wasted power.I just thought I'd mention a similar project I am working on to give you an idea of what's "reasonable". To put it in perspective, even assuming that no power is wasted in my 16+ stage CW multiplier, an example of 600VDC output at 20mA still leads to a dissipation of 12W. I am using some known-brand (Nichicon or Rubycon, I can't remember) 47uF 100V electrolytic capacitors and I've been playing with different diodes. For 20VDC input, I'd use something with at least a 100V breakdown voltage. I tried some schottky diodes but blew one up, which was no surprise.