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bakka
Nov 5, 2009, 02:19 AM
HI

I am doing a project on 8051 micro controller, need to rotate the DC motor with the help of electrical on and off relays(relays get on and off signal from micro controller ). I need a DC motor of 12v in put voltage and a torque of 50 N-m. If the DC motor is available please suggest.

This is the first time I knowing about relays. Actually what the relay is?? Suggest any soft copy of relays , so that I can have some idea

Can we control the DC motor(12V) by giving pulses from the controller to the relay?

Thank u...

KISS
Nov 5, 2009, 04:15 AM
There is not a lot of info in your post. Final RPM and what kind of duty cycle is required and whether over run can be tolerated.

While I've done I microcontroller project (about when the IBM PC came out) which used 1-2 relays for each motor using NOT ENABLE and DIRECTION signals and dynamic braking, you would not be able to control speed.

That's done by applying a PWM (pulse width modulated) signal to the motor and control is usually done with an H-bridge (removes need for relays).

Relays consist of a coil (AC or DC) that moves an arm which makes one or more contacts. An isolated switch say where a small amount of current can turn on/off a large load.

The controller's output has to be conditioned to drive the relay coil.