I am trying to convert 24-30V input to 24V 3A regulated output. I tried using ti's 5A adjustable regulator LM338 but I faced heatsink problem which seems like impossible to keep cool while trying to supply that much. Do I have to buy a DC/DC converter or is there any other 'diy' way of doing it?
This regulator is going to be used for powering a water pump which requires 24V 3 Amps.
Heat dissipation calculation:
lm338 has a characteristic of 'Junction to Case, RθJC(top) 15.7°C/W'
The load will be dissipating 24v*3A=72 Watts of power, and the regulator will be dissipating (30v-24v)*3A = 18 Watts of power. So total is 90 Watts.
90*15.7= 1413°C seems too much isn't it?