pulsing HV

Discussion in 'General Electronics Chat' started by umd1989, Aug 2, 2012.

  1. umd1989

    Thread Starter New Member

    Aug 1, 2012
    1
    0
    Hi,

    I am an engineering student working on an electro active polymer actuator but I only have basic background when it comes to electronics.

    I have a high voltage DC-DC converter that I use to obtain 2500 VDC(max voltage for actuator) from a low DC voltage power supply. Now, I want to investigate the dynamic response of my actuator by sending it 2500 V pulses at different frequencies (1kHz max).

    I was thinking a high voltage relay connected to the DC amplifier and sending on/off signals to the relay at the desired frequency. Would this work?

    The load resistance of the actuator is very high >>20MΩ hence the power drawn is low.


    Thanks for your help!
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,056
    3,245
    You may be able to use a high voltage, solid-state relay such as one of these.
     
  3. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,395
    1,607
    High voltage relays are $$$. And relays have a finite life. One manufacturer I was brainstorming with was discussing his very high quality military spec relay that is rated for 50,000 operations. At 1KHz you will burn thru the useful life of that device in under one minute.

    Transistors are cheap and reliable, but 2500 volts is huge, I could not find a device that would withstand that much.

    Could you just switch the power to the DC-DC converter to turn it on and off? (Probably not, I would expect the turn on and turn off times to be very large).

    If you find a solution please post it, I have a need for an 800 volt fast switch I have yet not filled. :)
     
  4. JMac3108

    Active Member

    Aug 16, 2010
    349
    66
    MOSFETs and IGBTs are available for high voltages in the $20-30 range. I only had a few minutes so I went to Digikey and searched on IGBT then on MOSFET. In both cases I found devices with the voltage rating you need from IXYS.

    The IGBT was rated at 3000V, and the MOSFET at 4000V.

    Be sure to select a part with a rating higher than your 2500V to account for spikes and overshoot when you switch the high voltage.
     
  5. #12

    Expert

    Nov 30, 2010
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  6. JMac3108

    Active Member

    Aug 16, 2010
    349
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    The other post was for 40KV. Thats outside my realm :cool:
     
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