Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Making a Spark with MOSFET

  1. Jun 10, 2012 #1
    I need to make a large voltage, possibly to make a spark across a 0.05mm gap or at least to make a very large voltage across a resistor. I need this to be triggered digitally by a micro-controller.

    I was thinking of setting up an inductor and a power MOSFET, but I don't know if this will work. Can anyone help sketch a circuit that would accomplish what I described?

  2. jcsd
  3. Jun 13, 2012 #2


    User Avatar

    Staff: Mentor

    From our PMs, it sounds like you just need a spark plug circuit. Can you just use a spark plug ignition circuit off of a lawn mower or similar?
  4. Jun 13, 2012 #3
    My thoughts exactly, a simple ignition circuit is all you will need. In regards to triggering it by a micro-controller will definitely require a bit of modification.
  5. Jun 13, 2012 #4
    Not too sure what you're exactly trying to do so it's hard to say.

    http://img502.imageshack.us/img502/5589/10322599.jpg [Broken]

    There's an example.

    Needless to say, if you're going to be trying to get sparks, that's kV running from the coil to the plug, so use insulated wiring, preferably BOSCH or something similar from auto shops.

    As to triggering it from a micro-controller, how about triggering the battery with a simple switch breaking contact with the rest of the circuit when you don't want it turned on?

    *Image taken from Fundamentals of Electric Circuits (4th Ed) - Alexander, Sadiku p.353
    Last edited by a moderator: May 6, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook