The problem as I see it with over-volting motors is the heat. Some motors can be over volted safely, other can't. The motors that cannot be over volted is due to the fact that brushes will overheat, melt, or disintegrate. The motors that can be over volted have better brushes in them that can handle the additional heat. The www.robotmarketplace.com site has some limited information about motors that can be over volted (like Magmotors). They sell enhanced brush kits for the 24V Dewalt motors to allow them to run at 36V. It states that if you run the stock brushes at 36V that they will melt. With some motors, the only way to tell if they can handle being over volted is to do it. Of course you run the risk of ruining the motor. EV Warriors are supposed to self destruct if used as 36V drive motors. Although, I have heard of people using them at 36V for weapon motors.
Derek T065 On Sat, Oct 3, 2009 at 7:08 PM, Bill Hamilton <[email protected]> wrote: > > On Sat, Oct 3, 2009 at 6:41 PM, Pureteenlard <[email protected]> > 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 [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -~----------~----~----~----~------~----~------~--~---
