Load dump protection in an automobile

Discussion in 'General Electronics Chat' started by nickw1881, Jan 19, 2010.

  1. nickw1881

    Thread Starter Member

    Dec 25, 2009
    I made my own regulator for an automotive alternator, and I now need a way to absorb the current when I switch off a heavy electrical load.

    There will not be a lead acid battery connected to the alternator to absorb voltage spikes, which is why they are a problem. Can I simply use a bunch of TVS diodes in parallel?
  2. peranders

    AAC Fanatic!

    May 21, 2007
    The generator has probably built-in load dump protection but if you want to protect your electronics you can do it in two ways:
    Design the cicuits to withstand 70-80 V continuously or use a 5 kW tranzil. Less than 5 kW will break.
  3. Darren Holdstock

    Active Member

    Feb 10, 2009
    Normally the battery is the load dump, and running an alternator without a battery connected can blow the regulator, and anything else connected to the line. But I'm sure you anticipated this in your new regulator design.

    The ideal solution depends on the spec. What's the operating voltage/load current/anticipated back-emf?