Stepper problem

[ecid]

Hallo!
Once again, need some advices...

As you can see on the picture i attached, it's a six wires motor stepper (an unipolar one, as far as i know), with a gear box. It's written on it = 12VDC Hz 4,5 W ; marked HURST ; RPM MODEL ABS ; P/N SP-3165 ; RED 250 5/88

Question:

1. I want to control it with a microcontroller (Atmel89C51), is a driver required? If it is, why and how? Because, a friend told me that it wouldn't need a driver, but with such stepper specification, i become hesitate. Is a ULN2003 would be enough?

2. How is it to determine which wires is COM and which wires is COIL?
Wires colors : blue ; white ; white – bluestriped ; white – blackstriped ; black ; red

3. Based on what written on it, which one to determine the RPM or phase of the stepper?

4. How to test if a stepper work or not?

That's all... Thanks very much.... is there anything that i should know about stepper, please inform me....

[bibinjohn]

if it is of 6 wire then you can use it as unipolar as well as bipolar, read this then u will understand
http://booksbybibin.14.forumer.com/viewtopic.php?t=42

Bibin john
www.bibinjohn.tk

[MP]

Yes, in some cases, you can run a stepper directly from the micro. However, your micro port pins are limited on current and if the stepper all of a sudden draws more current, poof! goes the micro.
The ULN2003 is good insurance.

MP

[MP]

Forgot your second question....
You can find out which windings are connected by using an ohm meter. The windings will read like two resistors connected in series and the center tap is half the resistance of the ends of the coil.
Hope that helps.

MP