DC motor Control

In principle, depending on the motor type and loading, it might. Possible issues are noisy mechanical operation of the motor, particularly at low speed, and interference pushed back up the power lines. Being an inductive load, for which the dimmer is not designed, it may fail to work completely, even though the motor is ' isolated ' by the bridge. Would have thought that a better alternative would be to build or buy a proper motor controller ...

Arfa

"Goldenshuttle" bravely wrote to "All" (10 Jan 06 22:19:03) --- on the heady topic of "DC motor Control"

Go> From: "Goldenshuttle" Go> Xref: core-easynews sci.electronics.repair:354800

Go> Hi Guys Go> If we add a bridge rectifier to the output of light Dimmer to make a Go> DC motor control.....would it work ? did any of U pals try it ???

Should work fine but use some type of filtering to keep the rfi hash down. If you use a filter cap the motor will see only a constant DC that you can vary. The control will feel rubbery however.

For example when the motor is stopped the control will have to be turned up a lot before the motor starts to rotate and then the motor will speed up far more than expected so the control has to be turned back down a lot.

One way around this is to make the control dependant on motor current. For instance an optical feedback of motor current. This way the position of the control will become almost equal to motor speed. In other words the circuit automatically applies a greater voltage to get the motor started and then the motor current turns back the voltage. It does however require more circuitry than just a simple dimmer.

A*s*i*m*o*v

What's the voltage and current of the motor involved?

It might work, but it's certainly far less than ideal. You'd be much better off to control power to the motor with a mosfet switched by a 555 configured as a variable duty cycle oscillator.