I am building a HV experimental setup for energy harvesting, where I have some HV capacitors in series. I need to put diodes between the caps to act as switches. The maximum reverse voltage they need to withstand is about 5kV. They need to have as low forward voltage as possible. Their switching speed is not too important.

Anyone got suggestions on what diodes to use?

(I am a physicist/mechanical engineer, so please excuse my ignorance about electrical engineering).

  • 5
    \$\begingroup\$ What source are you "harvesting" where you expect up to 5kV, but still have to worry about the forward voltage (usually 1V or less?) \$\endgroup\$
    – JRE
    Apr 19, 2021 at 9:30
  • \$\begingroup\$ I am working at high voltages, but per cycle I will only get a voltage change on the order of 100 V. (If you are interested, I doing something similar to dielectric elastomer generators.) \$\endgroup\$ Apr 20, 2021 at 11:01

1 Answer 1


These parts from VMI are typical of what is available, assuming we are talking about low power dissipation: https://www.voltagemultipliers.com/products/diodes/axial-lead-glass-body-diodes/ At 5 kV reverse voltage, it is not possible to avoid a few volts of forward drop when using semiconductor diodes. If you are interested in very low frequencies, then it is possible to use HV relays along with sensing electronics to control when they switch.

  • \$\begingroup\$ Great, thanks! That is exactly what I was looking for. I had looked at that website earlier, but wanted to get someone else's input before buying them. I want to keep the circuit as simple as possible, and I am happy to live with a few volts forward drop. \$\endgroup\$ Apr 20, 2021 at 10:49

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