Step-Up to 100V - Page 1
Forum section: electronics / beginners

author: MAntunes
author_rank: Regular Contributor
timestamp: October 03, 2016, 11:10:35 am
content: Hi guys,I need a step-up IC that can supply 100V DC, current is not important, a few miliamps is enough.Do you know of any IC, that is not too complicated to use? Power electronics is not really my thing!I already found the LTC3813 from Linear Tech, but I don't know if it is any good.Best regards,Miguel

author: neo
author_rank: Super Contributor
timestamp: October 03, 2016, 11:19:01 am
content: What are you powering? What is the input voltage? if you want dead simplehttps://en.wikipedia.org/wiki/Cockcroft%E2%80%93Walton_generatorthan thats about as simple as it gets though it needs a pulsed input, but if you only need a few ma that could be done with a 555 timer

author: StuUK
author_rank: Frequent Contributor
timestamp: October 03, 2016, 11:23:18 am
content: ELT Wire by any chance?

author: StuUK
author_rank: Frequent Contributor
timestamp: October 03, 2016, 11:30:26 am
content: Quote from: StuUK on October 03, 2016, 11:23:18 amjust spotted DC, should have read it properly

author: MAntunes
author_rank: Regular Contributor
timestamp: October 03, 2016, 11:42:21 am
content: No, it is for my impulse generator/detector using avalanche transistors and photodiodes.I need it to be fairly small so I can fit it in a small PCB.

author: Neilm
author_rank: Super Contributor
timestamp: October 03, 2016, 07:38:09 pm
content: Pretty much any boost converter chip with an external FET can be made to do this. I have made a 150V supply from a 555 timer and a comparator. The finished circuit was reasonably stable but I had to be sure the inductor didn't saturate as it switched on. It replaced a Maxim part that was originally in the circuit but was too expensive for our device.

author: setq
author_rank: Frequent Contributor
timestamp: October 03, 2016, 08:07:09 pm
content: If it's a one shot, definitely just hack something up. Did exactly the same as Neilm with a 555 and a 311. Got 100v out of this at about 150mA from a 12v DC input. Enough to charge up some big capacitors to test leakage that I extracted from something.No schematic - I didn't do one but it's a crap zener reference, LM311, 555 oscillator, final divider to set output voltage, 1n5819 diode, IRF510 MOSFET and a 100uH inductor. Took about 30 minutes to knock up. Ugly as fuck but after destroying one, you don't do high voltage or high power on a solderless board:

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: October 03, 2016, 11:38:49 pm
content: I have built a variation of circuit on page 7 of this App Note:http://cds.linear.com/docs/en/application-note/AN118fb.pdfIt has a programmed output from 0 to 300V with 0-1V DC input. Transformer - you can take one from any CCFL power supply from old laptop or monitor that uses small CCFL tubes for backlight or from DigiKey/Mouser. Do not replace or be careful with replacing an Operational Amplifier in this circuit with another model - having small input offset etc. is important.I am using it for same purpose - APD biasing and I am happy with it, except maybe its regulation response time. Large capacitors at the output make it sluggish to react to control voltage, BUT ripple and noise are low, like REALLY low which is important for APD sensors.

author: David Hess
author_rank: Super Contributor
timestamp: October 03, 2016, 11:42:44 pm
content: Use any boost converter to drive a diode-capacitor multiplier.

author: fmaimon
author_rank: Unknown
timestamp: October 03, 2016, 11:59:38 pm
content: There is some info on doing just that with a 555 and some transistors in this site:http://www.aplomb.nl/TechStuff/Switcher/Switcher.html

author: hugo
author_rank: Regular Contributor
timestamp: October 04, 2016, 02:13:57 am
content: Take a look here :http://www.kerrywong.com/2013/05/18/avalanche-pulse-generator-build-using-2n3904/He uses LT1613 to generate the high voltage needed by the avalanche pulse generator.

author: george.b
author_rank: Frequent Contributor
timestamp: October 04, 2016, 05:09:48 am
content: I normally use a TL494 for this. Last time was for a 9 to 400V boost converter for a Geiger tube power supply.