Quote:
Originally Posted by JohnnieB
The output of a controller is chopped DC. An array of a dozen or so MOSFETs (Metal Oxide Field Effect Transistor) connected in parallel is located between the battery pack and the motor and the MOSFETs are switched from completely OFF to completely ON about 18,000 times per second. The ratio of ON time vs Off time determines how much power is forwarded to the motor. The technical name for the process is called PWM (Pulse Width Modulation) and the duty cycle varies from 0% with throttle up to 100% with throttle wide open.
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That makes sense. I've always wondered how a controller saves battery over a "risistor" cart. People have told me a resistor cart is running at full bore all the time. Just that the coil eats up the extra power making you go slow.
Quote:
Originally Posted by JohnnieB
On the other hand, there are a few members of this loony bin that have used solenoids to bypass a stock controller and add an addition battery or two to the pack when the pedal is on the metal.
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Did they do this with good results? I'm not sure I understand. Are you saying they somehow inserted the 6 or 12 volts in the line? I'm thinking they would have to have a selinoid cut the 36v and then add the new batteries in and reconnect. I would assume this would have to be done after the controller or maybe "around" the controller. This doesn't sound so good to me because of sepreate charging requirements.
Just to clarify for my feeble brain.
A given motor will spin at a set speed at a set voltage. (No load) it doesn't matter how many batteries you have as long as it's a set voltage.
It will draw very low amps unless it is artificly held to a lower speed. (Load) Then it will draw a certain amp amount based on the rpm its held to. Again, it doesn't matter how many batteries you have as long as it's at a set voltage.