Current draw question, using eagle tree....

[BrianG]

Oh boy. This can get really technical, but here is a simple explanation:

FETs are Field Effect Transistors, and there are many of them paralleled in an ESC. There will always be a multiple of 6 (one for the + rail, one for the - rail, for each phase). The on/off cycles refer to the pulse-width modulation signals fed to the ESC. Longer on pulses results in the motor seeing more average voltage, shorter pulses results in less average voltage getting to the motor.

ESCs smoke from over voltage, being forced to pass excessive current (like when overgeared), or excessive current ripple is present (from low quality batteries), and several other reasons.