Custom (very) Quark esc heatsink...

[zeropointbug]

Originally Posted by GriffinRU

Looking on all this mighty heatsinks I am thinking how much power dissipates on Quark?

Lets say 7XL draws 50A continuously, so at 0.00036Ohms at 25C power loss should be 0.9W
Next say at 100C derating factors bring us to 3 times up, so 0.00036*3=0.00108 - power loss now 2.7W

To get even 10W requires Rdon to be at 0.004Ohm which is 11.1 times higher then at 25C.

So, is the ESC efficiency so low or there is something else?

LOL, okay now I know... are you sure you know what your saying?

The physical resistance is only PART of the heat output. Most of the power loss is the design of the motor, and how well it transforms the power input to it.

What is 2.7Watt? That would be barely warm to the touch....

The esc I am guessing is somewhere between 92 - 97% efficient. Couldn't tell you, it's probably about 10 - 25 watts of heat, which is alot for these little FET's to dissipate, that's why they can get so hot because of insufficient heatsinking. With a proper heatsink, 25 watts of heat is a piece of cake to keep the temps down (~15C Delta).

Is there a misunderstanding here about motor efficiency.