I'm using a bidirectional tranzorb to protect the drain of a MOSFET being used to switch an inductive load - so when the inductive flyback exceeds the breakdown voltage of the tranzorb, the pulse is conducted back to battery positive.
The device is from Vishay's range - http://www.vishay.com/docs/88301/15ke.pdf
Calculating the energy stored in the inductor is no problem, I've got 5mJ stored. Now, to calculate the heat dissipation in the tranzorb, I seem to recall reading/hearing it would be the energy stored by the inductor multiplied by the switching frequency, that is - P = E * F.
Would this be correct, if so - I'm not sure what to type into Google to read more about this, things like 'power dissipation switching frequency' seem to come up short. If correct, in my worst case situation I'm dissipating 415mW. Of course, some of the energy is dissipated in the wires, traces etc - but predominantly the tranzorb I presume.
Any thoughts? Cheers!