RC-Monster Forums - View Single Post

BrianG · 05:34 PM

What causes wires to move? Extremely high current AC signals. The magnetic fields produced by this interact with each other. Since AC changes polarity and each phase is at a different point of the signal, the wires move. Don't forget, much of a motor's "resistance" is formed by back EMF from a moving magnet. If the rotor doesn't turn for whatever reason, there is very little back EMF and the current is MUCH higher. The FETs don't blow up right away because they can actually handle a lot more current than they are rated, for a short time. No wonder why the motor wires get warm!

If the ESC goes bad and sends a conflicting signal to the motor, the motor won't turn effectively locking it. If it doesn't turn, there is only the pure DC resistance of the windings limiting the current.

	(#7)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	11.16.2006, 05:33 PM What causes wires to move? Extremely high current AC signals. The magnetic fields produced by this interact with each other. Since AC changes polarity and each phase is at a different point of the signal, the wires move. Don't forget, much of a motor's "resistance" is formed by back EMF from a moving magnet. If the rotor doesn't turn for whatever reason, there is very little back EMF and the current is MUCH higher. The FETs don't blow up right away because they can actually handle a lot more current than they are rated, for a short time. No wonder why the motor wires get warm! If the ESC goes bad and sends a conflicting signal to the motor, the motor won't turn effectively locking it. If it doesn't turn, there is only the pure DC resistance of the windings limiting the current. Last edited by BrianG; 11.16.2006 at 05:34 PM.