Which transistor?

Discussion in 'The Projects Forum' started by electro01, Mar 11, 2013.

  1. Markd77

    Senior Member

    Sep 7, 2009
    Voltage across transistor is current * resistance
    Power = current * voltage
    Power = current squared * resistance
    The OP has only mentioned the frequency and not the duty cycle, but if it is nearly 100% on then the 6 and 36W would be the power that needs to be dissipated by the transistors.
  2. takao21203

    AAC Fanatic!

    Apr 28, 2012
    OK I see. Isn't it weird the large MOSFET is going to heat up much more than the smaller one.

    for 10 mOhm, you also need thick cables to take advantage of that. PCB traces are not going to work for that.
  3. takao21203

    AAC Fanatic!

    Apr 28, 2012
    Messed this up a bit as it looks, I have examined the graphs in the datasheets. 20A is a lot of current.

    Can this be switched at the primary side somehow or do you need to switch at the low voltage side?

    From a battery perhaps?