Question about a potentiometer

[lbz5mc12]

I bought a controller to use with my Currie 24V 450W chain driven bike motor. It's not a Currie controller but so far it works fine. The controller is this one http://tncscooters.com/index.php?route=product/product&path=41_74&product_id=498. I had to run the lock connector wire in line with the positive connection because I don't have a key switch for it; I twisted the lock and positive connections together and ran them into a butt splice to the connector I used to connect to the battery pack.

All that aside, the controller has a connection on it for a speed limiting potentiometer which I believe just lowers and raises the amount of voltage that I send to the motor when I use the throttle. I was wondering if I were to get a potentiometer, could I hook up a 48V battery pack to the controller and use the potentiometer to step the voltage down closer to 36V or does it limit the Amps?

On a side note if anyone is interested, this controller works pretty well and unlike the Currie controllers, it doesn't have that stupidly annoying cut off feature that's "supposed" to protect the battery. It is only a 500W controller and the motor does go a little bit slower with it but I believe it's an even trade off as opposed to turning the the power off then back on mid ride due to the Currie cut off feature.

 

[John in CR]

It doesn't lower the actual voltage, it lowers what the motor "see" is the voltage by narrowing the width of the ON pulses in PWM (Pulse Width Modulation), which is how the controller limits speed and current. Since it turns an ON pulse if you just connected the motor directly to the battery, into rapid ON/OFF pulses using it's width of the ON as the means of control, the controller varies the average voltage to the motor. All this pot really does is limit the maximum voltage of your throttle signal, thereby lowering the top speed of the bike, which is most commonly done to meet local regulations.

 

[lbz5mc12]

Thank you for the description. Is there any other device I can run in line between the battery and the controller to step the voltage down to about 42V so it'll work with the controller? Would a dc to dc inverter work or is what I'm using to high of a voltage for one?