On Sat, Oct 3, 2009 at 6:41 PM, Pureteenlard <pureteenl...@hotmail.com> wrote: > > Ah, that's the point. If the POWER goes up proportionately to the > VOLTAGE then the CURRENT won't change - 180w motor at 12v would, if > the power goes up in proportion to the voltage, at 18v become a 270w > motor but the current would remain at 15a. > > I need to know because my speed controller is rated well above 15 amps > but if I overvolt my 180w motors to 18v will the current rise too or > just the power? >
Motors are weird. You can't really apply standard electronics logic to them. If the motor is stalled, the current through the motor is determined by the voltage applied and the resistance of the windings. Just like any other resistor, I = V / R. Double the voltage, you double the current. As the motor spins, it generates a voltage countering the voltage applied across the windings. As this counter-electromotive force (a voltage created within the windings of a motor is called an electromotive force, just to make things more confusing (as if that's needed)) increases, the current drawn by the motor go down. I = (V - cemf) / R. Power delivered is I * cemf. cemf and current both depend on the speed of the motor, and the speed of the motor depends on the loading and the voltage applied across the windings. This is where you start doing calculus. Like I said, motors are weird. -- -Bill Hamilton --~--~---------~--~----~------------~-------~--~----~ You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat-unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat -~----------~----~----~----~------~----~------~--~---
