range of lorry onboard voltage 24V & voltage spikes

Discussion in 'The Projects Forum' started by frpr666, Feb 19, 2010.

  1. frpr666

    Thread Starter Active Member

    Feb 2, 2010

    I'm designing a simple switcher.
    It will be powered from the car (lorry) on-board voltage 24V.
    It will drive solenoid of the pump of the heating.
    Solenoid consumption is about i=1A, u=24V.
    Clamping diode is connected parallel to the coil.
    The output transistor Q1 is IRLR120 (V=100V, I=7.7A).
    The driver for Q1 will be something like SA556 or PIC12...

    Now I need protect the Q1 and the driver for Q1 against voltage spikes, they
    are normally present in the car voltage.
    I have read somewhere that on-board voltage can have spikes even over 100V.

    My questions:

    1. what is the regular range of lorry on-board voltage 24V?
    2. where could I find information about it
    3. what kinds of voltage spikes can be there?
    4. How much energy they have?
    5. where could I find information about it
    Thank you very much

    edit1: thank you MikeML for the littelfuse link. I have found http://www.ee.cityu.edu.hk/~emc/20098022ppt2.pdf ,page 20, ISO 7637-2 is exactly what I need.
    Last edited: Feb 19, 2010
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009