I'm making a DIY air purifier and among other things I want to put in a negative ion generator. I disassembled some Chinese product that had it in, its specs are: input voltage 12VDC, output voltage -4.5kV - -5.0kV. I figured it could cause problems so I enclosed it in the case that I got from one of my power supplies (MEANWELL power supplies).

Ionizer has 2 power supply cables and one cable that has small broom at the end of it where the negative ions should be transmited from. I tried and moved ionizer as far as I can from my other components and enclosed it into the metal case, but still when I turn the power on, device malfunctions and when I measure voltage across sensor and other components, it gives some sparks on their metal parts.

When I disconnected the cable from the outlet and tried to remove the cables of ionizer from power supply, I got zapped, even though I waited till the LED in the power supply went off as I presumed the capacitors in it were then discharged.

I removed the ionizer from the module and tried it, and everything works fine, there are no more sparks and other components are working fine.

The components are:

  • Meanwell 230-12vdc power supply enclosed
  • Meanwell 230-5vdc power supply enclosed between which I connected their grounds for a common ground
  • Arduino pro micro
  • sensor that works on 5vdc and gives 2 digital outputs
  • programmable LED strip that signals the state of air pollution that works on 5vdc
  • 2 vents that work on 12vdc and are connected on l298n motor driver

My question is: Can some changes be made on the input of ion generator, such as putting some Zener there or something to help this problem? Not sure what to do to eliminate these issues I have when I connect the generator (it is connected directly to 12vdc meanwell power supply). I'll try and move the broom of generator as far as possible from the sensor and see if that helps. Any other ideas?


1 Answer 1


Here are some suggestions.

All metal parts in the air purifier module are to be earthed. This includes the metal housing of the ionizer circuit board.

In case of need to work on the ionizer circuit, it must be powered off and the HV pins shorted to common (-ve of 12V= PSU) to discharge the unit completely and avoid unpleasant HV shocks.

  • 1
    \$\begingroup\$ The problem is here ewspecially in old buildings there is no earting of installations preformed so even if I connect the device with the cable that has earthing wire it will make no difference at all since it has nowhere to go. Im thinking of building some kind of case around the sensitive parts to protect them from charging especially the ones that are close to ionizer broom. \$\endgroup\$
    – tuadru
    May 22, 2020 at 6:40

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