Quote Originally Posted by Skepticist View Post
The lower the resistance, the lower the heat losses for a given current and there are high current mosfets available with Rds less than 0.001 ohm (at a cost of course) so you can get away without using a heatsink apart from the copper on the PCB. A good example is the PWM ESC modules available for RC applications.

This surface mounted one is 500 microOhms and rated for 30V, 300A
You'd need about 35 IRFZ44N's in parallel to get the total Rds that low!
Had a look at RS components for the IPT004N03LATMA1 N-Channel MOSFET, 300 A, 30 V OptiMOS, 8+Tab-Pin HSOF Infineon so HELP!!!! how do you connect that 8 pin monster to suit my simple diagram.