How to Stop a DC motor

[ajeya]

I searched some places and saw that stepper motor is ideal way to have precis stopping of dc motor.
But in my case. I find a DC motor which perfectly couples with the equipment I need to rotate. The equipment needs three full rounds of rotation for full open/close.

Currently I use a timer to control the motor on and off time. Is there an option to stop the dc motor by cutting off the supply (electrically) and then continue from that position when power comes back.
Pl. note this is to be automated by microcontroller, so manual switches would defeat the purpose.
Transistors could be used. But how to find the right one?

DC motor is 12 V 1 A.

 

[Issak Sdu]

take a look here, you will find the necessary information

http://iitd.vlab.co.in/?sub=67&brch=185&sim=470&cnt=1

 

[barry]

If you don't want to use a stepper, which is the absolute perfect solution to your problem. you could use a servo motor. But that requires some feedback mechanism. If you just cut off the supply to a simple DC motor, it's going to coast a bit, depending on the mechanics of your system; it is definitely not going to be precise. You could use an electrical break circuit. There are several methods; for example: switch the power leads of the motor to a load; apply a reverse voltage.

A lot of this depends on the actual accuracy requirements of your system.