How to create voltage of 100-200V in 1x2 inches - Page 1
Forum section: electronics / beginners

author: hemanthboddu
author_rank: Newbie
timestamp: March 18, 2020, 08:38:13 pm
content: I'm trying to create a voltage of 100v-200v and mili-amps of 3mA with the dimensions of 1x2 inches. My initial strategy is to use a small lithium-ion battery, USB killers capacitors and voltage boosters to amp up the voltage. However, I believe there could be an even more practical and streamlined approach for this. Really happy to hear different suggestions. PS: I would appreciate it if the suggestions are taken from the pure electrical engineering approach. Thanks!

author: floobydust
author_rank: Super Contributor
timestamp: March 18, 2020, 08:56:25 pm
content: How many mega-amps?

author: hemanthboddu
author_rank: Newbie
timestamp: March 18, 2020, 10:01:17 pm
content: Haha would prefer 3mA.

author: Zero999
author_rank: Super Contributor
timestamp: March 18, 2020, 10:07:40 pm
content: Does it need to be regulated?DC, AC, what frequency?If all you need is AC of a few hundred kHz, use a Royer converter. Add a rectifier and you get DC.If it's regulated DC, then a flyback converter is probably best.

author: hemanthboddu
author_rank: Newbie
timestamp: March 18, 2020, 11:08:40 pm
content: AC / Chopped DC at around 2KHz. We want to create a shock when it's touched.

author: james_s
author_rank: Super Contributor
timestamp: March 18, 2020, 11:52:03 pm
content: That's easy to do with a boost converter. I built several around the MAX771 back when I built some nixie tube clocks. I think that specific IC was discontinued but there are many others. There were several ready made modules available, some open source that were only about 1" square.

author: hemanthboddu
author_rank: Newbie
timestamp: March 19, 2020, 12:16:10 am
content: That's amazing to hear James! do you mind helping me find some of the modules that are 1'' square? It would be insanely helpful!

author: james_s
author_rank: Super Contributor
timestamp: March 19, 2020, 02:47:00 am
content: This is one of them, not the smallest I've seen but it's still quite small.https://desmith.net/NMdS/Electronics/NixiePSU.htmlI'll see if I can find the smaller ones, the design is essentially the same, just scaled down for lower current.

author: Zero999
author_rank: Super Contributor
timestamp: March 19, 2020, 09:20:58 am
content: Quote from: hemanthboddu on March 18, 2020, 11:08:40 pmThat will work but you for optimum shock vs current, a lower frequency AC is better. The downsides are it's either more bulky i.e. using a small mains transformer or complex: a DC:DC converter with an h-bridge on the output to convert it to AC.

author: hemanthboddu
author_rank: Newbie
timestamp: March 19, 2020, 08:54:19 pm
content: Quote from: james_s on March 19, 2020, 02:47:00 amThank you so much for sharing the link! Just asking this out of ignorance but now that we have this boost converter, what are the steps to take on creating the design to get it printed on circuit board?

author: Zero999
author_rank: Super Contributor
timestamp: March 19, 2020, 09:23:55 pm
content: Quote from: hemanthboddu on March 19, 2020, 08:54:19 pmThere are two ways:Buy the chemicals, etching solution and make the board yourself. This isn't quite so popular as it used to be. There are plenty oftutorials online.Get it make by a board manufacture. Choose someone local, if you're not bothered about cost, but want it quickly or go to China, if you want cheap.To do either of the above, you'll need to draw the schematic in a PCB CAD program, layout and route it. KiCad is the most common package for hobbyists, as it's free.

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 19, 2020, 11:25:05 pm
content: Quote from: hemanthboddu on March 18, 2020, 08:38:13 pmi check usb killer, it dumps its high voltage back to its input killing its supply source1) you'll need to mod it to get what you want 2) its using step up transformer, from the look of the size i doubt it can give your 0.5W that you want...https://sooriyamathy.blogspot.com/2016/11/usb-killers-explained.htmli built a pcb to use EE10 transformer corehttp://www.0759.com/cecweb/Catalog/pdf/EE.pdf(winding is from myself diy) in sort of flyback converter configuration, just to download the datasheet later and figured out its only good up to 3W where i need 15W. so i toasted the project, the board is about 1" x 1". it is a bipolar output, some leds indicator and some kind of fancy feedback from -ve rail output back to the smps controller (i was thinking attiny10 as the controller for both rails), so it got a little bit bigger in size. in theory with your 0.5W requirement and single rail output, and with suitable sot23 (6 or 5 pins) or even soic8 footprint smps controller you can cramp the pcb down to 0.5" x 1" including the bulk capacitor tank and the transformer, those two largest items will dictate your pcb size, the rest is tiny.from my observation, boost converter will have limit to maximum voltage ratio it can convert, if some design can convert 16V to 200V it doesnt mean it can convert from your 3.7V to the same 200V, PWM could cranked up to near 90% and yet it cant reach the required output. flyback transformer is much configurable in term of voltage ratio if current is not so large, ymmv.this one confirmed my observation..https://www.edn.com/power-tips-90-get-more-boost-from-your-boost-converter/https://www.eetimes.com/power-tip-61-watch-the-conversion-ratio-on-boost-converters/#