High Speed Switching circuit

Discussion in 'The Projects Forum' started by Rickg5106, Nov 16, 2010.

  1. Rickg5106

    Thread Starter New Member

    Mar 1, 2010
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    As a disclaimer/excuse, I am a mechanical guy and I want to do everything that way. I understand there are more cooler :cool: ways to do it, my thought default is mechanical.

    Another is I hate just buying stuff. I don't learn anything and I didn't increase my skill set by just throwing cash at something.

    Soooooooo Here is what I want to do and lets see what I can come up with.

    I have a motorcycle motor that has 2 hall effect switches that fire the cylinders in a round about way. It's an I4 and cylinders 1&3 and 2&4 are ganged so each fires twice per cycle and the gangs are 180 out of phase with each other.

    I want to be able to take the coil impulse and switch it to ground to shut the coil off as part as a RPM limit circuit but I want to be able to switch between the gangs so as not to load up one set of cylinders.

    This will happen as part of a Launch sequence so the motor will be up against this for 2 or 3 seconds at least and could be operating at up to 9000 motor rpm. So at that speed this would be switching a 18,000 cycles per second. Is that 300 Hz?

    What would they call what I am trying to build and what do I need to know to spec it out.
     
    Last edited: Nov 16, 2010
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    It's not quite as fast switching as you think.

    9,000 RPM with a 4-cylinder 4-stroke engine is 18,000 switches per minute, and 300 switches per second, each complete switch cycle taking 3.333...mS.

    This sounds like a project for a microcontroller. Do you have any experience with them?
     
  3. Rickg5106

    Thread Starter New Member

    Mar 1, 2010
    11
    0
    Other than the name, no. But that is what I am looking for.
    I think I could do it with relays but I doubt they are fast enough.
    Let me nose around a little and being as I have this thread started, I can bounce ideas around here. What Do I need to know as far as values are concerned? I can guess I need to know what I'm dealing with for volts and amps on the supply side of the coil. Let me see what I can find out on my own.
     
  4. Rickg5106

    Thread Starter New Member

    Mar 1, 2010
    11
    0
    Can you give me a hint about what kind of MC I should be looking at? Do you have one in mind? I used to know basic and have a couple of reference books on the shelf. Looks like it's time to blow the dust off them. I still have to figure out what kind of load it will be switching to spec it out. Will return.
     
  5. Rickg5106

    Thread Starter New Member

    Mar 1, 2010
    11
    0
    General consensus says the load @13 vdc is 4.6 amps
     
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