Forumchem - Forum with AI(ALICE BOT & HAL9000) and TTS

I need to add a throttle to my bike motor to help control the speed, but I don"t know what throttle to use. Most throttles I"ve been eye-ballin" say that their a hall-effect type, with stats like "supply: 12volt" and "return 4 volts". Will this reduces the power of my motor, even at full speed? I am using a 12V DC Motor, and a 12V battery (12ah)

It wont effect your motor at full speed, because the throttle will let the current go directly to the motor. But at lower speeds the throttle will use some power up. In the older days they used a resistance wire throttle. This put a resistor that increased resistance to the motor by converting the power to heat at low speed. So you wasted all that power at low speeds and used just as much power as if there was no throttle there to begin with. The hall effect is a better solution because it regulates power to the motor by rapidly cutting the power to the motor to control speed instead of turning the battery power to heat. But any device is going to waste some power, but the hall is much beter than the sliding resistance throttle of years ago.

Im a little confused by the information here. A hall-effect sensor could measure the speed of the wheel, or it could measure current to the motor. It does not regulate power to the motor. Hall sensor are very easily added to gears, so they would be suitable for a bicycle (in fact, if you look under most car youll find something that looks like a gear attached to each wheel; this i there for the benefit of the hall sensor that activate the ABS when a wheel lock up). The sensor you are looking at probably outputs a 4V square wave that varies in frequency with rotation speed.

Another answer mentioned a PWM controller. This is probably what you want. Its just an ordinary "motor speed controller," or ESC, which you can buy online or at a hobby store. You need to match it to the voltage and current your motor will draw. Remember that current is proportional to torque, so you will want to set up some kind of overcurrent protection for situations where the motor is overloaded; otherwise youll fry your ESC.

Pulse width modulation would be your best method. Actually a 3 phase PWM controller with a 3 phase motor. 12AH battery i not going to get you very far. Start thinking about a 55AH battery. If thi bike is going to propel you look for about a 25 - 30 Amp draw. Also consider regenerative braking which will put a little power back into the battery a you brake.

A pulse-width modulation technique would be the most efficient means of controlling the delivery of power to a DC motor.