dc motor position control using pot

[shehry]

Hi,

Can anyone give me an idea concerning position control for a dc motor. I heard that it was possible using a pot. all i have to do is to give the voltage references on the pot (0 and 5V in this case) and then assign 5V a value say 10. so we have 10/5 = 2meter/volts. so if the microcontroller ADC reads 0V initially then every time it crosses the 0V mark, it means that 10 meters have been covered

it seems ok, but is it? if it is ok, then are there any special IC's for it, or would any pot do the trick?

 

[akg]

using pot may limit the rotation speed , usage of encode/slotted disk (non-contact type) monitoring may be recommended

 

[pike]

i think what you want is a servo, they contain all the circuitry, pot, gearing all in one small unit.

You can take it apart and use the circuit to control a bigger motor setup-google around and see what you get.

 

[atferrari]

Another solution

You don't say if the motor has to rotate between two extreme positions or it could do it continuously.

If so, you can use an position encoder which gives you exactly how far is from the reference postion, whether you rotate just few degrees or many turns in a row.

Google for optical encoder / Gray code.

The pot will work if rotation is limited between two fixed points less than 360 degrees away from each other.