Low to High voltage converters (5KV ) basic questions (For polarisation usec) - Page 1
Forum section: electronics / projects

author: tlhsglm
author_rank: Contributor
timestamp: September 27, 2022, 11:56:33 am
content: Hi,I'm mechatronics engineer, ı'have done lot of circuits but my knowledge is not deep espicially on high voltages.I want to polarise a chemical. I have seen they are polorasing with this Electrical Safety Testers ; GoodWill GPI-826https://static.rapidonline.com/pdf/90-6239.pdfI don't have this machine. I can use it at an university lab. Polarization is done as like this;https://ibb.co/WzP00vnI'm curious about this questions;1-) I've seen devices that provide 5kv 10kv potential powered by 9 volt batteries. The names of the devices I've seen are Insulation resistance tester. Can I do that with step-up converters too?2-) As you can see at polarisation process we are making an open circuit, therefore can i do it with a simple 200v ac to 12v dc 1a wall adapter and step-up convertors?

author: moffy
author_rank: Super Contributor
timestamp: September 27, 2022, 01:36:05 pm
content: You need to specify how much current you need at 5kV for your experiment.

author: tlhsglm
author_rank: Contributor
timestamp: September 27, 2022, 02:06:17 pm
content: Quote from: moffy on September 27, 2022, 01:36:05 pmsince this is an open circuit there is no current flow i think. only leakage maybe.

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 27, 2022, 03:59:38 pm
content: The model you are pointing to is AC voltage not DC. There is a lot of difference (electrically speaking, also probably from the chemical point of view but I'm not referring to this) since steady state current for DC is going to be very low, but for AC depending on the distance between electrodes and area, will surely let more current thru.Insulation resistor testers are normally DC. You'd need something like an Hipotronics that can generate both AC and DC,https://www.isre.com/specs/hipotronics-hd100-series.pdf

author: tlhsglm
author_rank: Contributor
timestamp: September 27, 2022, 07:09:20 pm
content: Quote from: PartialDischarge on September 27, 2022, 03:59:38 pmThanks for your reply, that is my mistake, it have to be DC 5000 volts.Can i do this by adding condansator and diode to 220v ac to 12 v DC 1 a wall adaptor? Like this video(circuit diagram on 2.19)https://youtu.be/nOootePeSBo

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 27, 2022, 08:22:23 pm
content: Don’t be so cheap, that is not safe for many reasons. Find a proper 5kv adjustable power supply or module on eBay

author: james_s
author_rank: Super Contributor
timestamp: September 27, 2022, 08:28:38 pm
content: 5kV DC at very low current is fairly easy. Does it need to be regulated? Look at designs for the HV section of CRT monitors or HeNe laser power supplies. A common approach for the latter is to have a self oscillating converter with a transformer followed by a Cockroft-Walton multiplier. a CCFL inverter could be a reasonable starting point if you don't want to design the converter yourself.

author: tlhsglm
author_rank: Contributor
timestamp: September 28, 2022, 10:36:39 am
content: Quote from: PartialDischarge on September 27, 2022, 08:22:23 pmThanks it is an option too right. i want to have a little expriment at first. 100 dollars an hv adjustable power supply.Also power supply module is dangerous too and i will use both of them with lot of attanchen.@james_s and @PartialDischargeBasically i can try with that cheap circuit right?Let's say i've done the circuit. if i tie 1k resistor to my multimeter's red cable, i can safely (without burning my max 1000volt dc multimeter) measure it's voltage?

author: HighVoltage
author_rank: Super Contributor
timestamp: September 28, 2022, 11:15:31 am
content: You might want to look atelectrophoresishigh voltage power supplies, they are made for such testing and polarization of chemicals.

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: September 28, 2022, 12:47:38 pm
content: Quote from: tlhsglm on September 28, 2022, 10:36:39 amdefinitely not.if you go into HV terrain, you want to have the right tools for the job. any makedo setup is just asking for desaster.i'm using a FLUKE 80K-40 for my work on electrostatic loudspeakers, which i can recommend.https://www.fluke.com/en-us/product/accessories/probes/fluke-80k-40as this is a pretty "uncommon" tool, it's fairly easy to grab one on the bay for a decent price.

author: Terry Bites
author_rank: Super Contributor
timestamp: September 29, 2022, 06:18:27 pm
content: Buy one or get hands on help from someone with HV build experience.Its not so much about the electonics but the quality of build and HV know how.Genuine HV cable, connectors, enclosure, layout, HV safety relay.... etc.