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How do i slow down a toy car motor without using gears? i wanna know a simple way!!! Answered

I'am having a to car motor and i'am planning to make a robotic arm, but i don't know how to slow it down? so how do i slow it down without using gears or any microprocessor


thnx guys i really appreciate all your hints, i will try one of them slowly and slowly and then maybe i will gradually get the point..

Gears are the best way. You don't just want this to be slower, you need some torque too. If you can't do gears, belt-drives and pulleys may be an easier alternative?


An easy way to control the speed is to use PWM. You will need an oscillator for a signal, and then to control the motor. You should not run the motor from the oscillator.

This oscillator is a relaxation oscillator, and the potentiometer is used to vary the mark/space ratio of the output. The frequency will be given by f = 1/ {ln(3)RC}.

On the output, you will need to put a potential divider to the ground, and triggering the base of a transistor.

The ground wire between the motor and the ground should be cut, and the collector of the transistor connected to the motor side of the cut wire, and the emitter to the ground. You will also need to place a diode in reverse polarity to protect the transistor from back EMF.

If you are using a single rail power supply, you will need to make another potential divider from two 1k resistors over the power supply, with the mid-point connected to the 0v in the oscillator, but do not connect the motor to here as a ground.


8 years ago

You could use some gorilla glue and put it on the main axle, that might mot work so well, but it would slow the gears down...

Using a variable resistor maybe