Low to High voltage converters (5KV ) basic questions (For polarisation usec)

• Low to High voltage converters (5KV ) basic questions (For polarisation usec)
  Posted by tlhsglm on 27 Sep, 2022 11:56
• 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-826
  https://static.rapidonline.com/pdf/90-6239.pdf
  
  I don't have this machine. I can use it at an university lab. Polarization is done as like this;
  
  https://ibb.co/WzP00vn
  
  
   I'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?
   
• #1 Reply
  Posted by moffy on 27 Sep, 2022 13:36
• You need to specify how much current you need at 5kV for your experiment.
• #2 Reply
  Posted by tlhsglm on 27 Sep, 2022 14:06
• Quote from: moffy on 27 Sep, 2022 13:36

  You need to specify how much current you need at 5kV for your experiment.
  

  since this is an open circuit there is no current flow i think. only leakage maybe.
• #3 Reply
  Posted by PartialDischarge on 27 Sep, 2022 15:59
• 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
  
  
• #4 Reply
  Posted by tlhsglm on 27 Sep, 2022 19:09
• Quote from: PartialDischarge on 27 Sep, 2022 15:59

  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
  

  Thanks 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
• #5 Reply
  Posted by PartialDischarge on 27 Sep, 2022 20:22
• Don’t be so cheap, that is not safe for many reasons. Find a proper 5kv adjustable power supply or module on eBay
• #6 Reply
  Posted by james_s on 27 Sep, 2022 20:28
• 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.
• #7 Reply
  Posted by tlhsglm on 28 Sep, 2022 10:36
• Quote from: PartialDischarge on 27 Sep, 2022 20:22

  Don’t be so cheap, that is not safe for many reasons. Find a proper 5kv adjustable power supply or module on eBay
  

  Thanks 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 @PartialDischarge
  Basically 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?
• #8 Reply
  Posted by HighVoltage on 28 Sep, 2022 11:15
• You might want to look at electrophoresis high voltage power supplies, they are made for such testing and polarization of chemicals.
  
• #9 Reply
  Posted by Le_Bassiste on 28 Sep, 2022 12:47
• Quote from: tlhsglm on 28 Sep, 2022 10:36

  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?
  

  
  definitely 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-40
  as this is a pretty "uncommon" tool, it's fairly easy to grab one on the bay for a decent price.
  
  
• #10 Reply
  Posted by Terry Bites on 29 Sep, 2022 18:18
• 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.