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Voltage Suppression from 35V - 20V

  1. Mar 7, 2013 #1
    Ok i am a hobbyist and i currently building a circuit in which when i place this on an oscilloscope i am gaining a voltage spike of 38V i need to minimise this spike down to a maximum of 20V in order to protect my external circuitry. When my circuit is working under 20V i need this protective device to have no action thus the circuit as it would. The current in this circuit is a big problem so using resistors in series resulting in less current is not an option.

    I have heard that there are protective resistors that can be used or zenner diode circuits. can anybody help me with this?

    Regards Daniel Floyd.
  2. jcsd
  3. Mar 7, 2013 #2


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    Staff: Mentor

    Can you post a schematic of your circuit?
  4. Mar 7, 2013 #3
    What is the source of your voltage spike?
  5. Mar 7, 2013 #4
    Could you use a 20v voltage regulator?
  6. Mar 8, 2013 #5
    What you probably need is a TVS (Transient Voltage Suppressor).
    One way to get a data sheet on a TVS is to go to either Mouser or Digi-Key and search for TVS. When you are shown data for TVS, select a like one and then ask for a data sheet.
    It may take some searching, but you should be able to locate a TVS that will keep the transient voltage below 20 volt.

    Good Luck
  7. Mar 9, 2013 #6


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    Gold Member

    Look up P6KE24V. It is a zener type device that can REALLY take a beating. Of course it is available in other voltages, the number I gave is a 24 volt device.
  8. Mar 10, 2013 #7
    Thank you i will begin my search around a TVS from Mouser I will then post my findings.
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