Unipolar stepper with ULN 2003

[Ajit Barve]

:?:
Hello guys.
I have bought a 4 wire unipolar stepper motor.
I want to drive it with microcontroller 89C52. I am using ULN 2003.
What should I connect to free wheeling diode terminal (pin 9). Obviously I am asking becoz it didn't work with that pin unconnected.
Do i need any additional circuits except 2003 to drive motor? Motor doesnn't have any common suply terminal.
Ajit

 

[Nigel Goodwin]

I don't think you can drive a bipolar motor from a ULN2003, bipolar motors require an H-Bridge to drive them. If you do a google search for 'stepper tutorial' you will find plenty of helpful sites.

 

[uaefame]

Bipolar doesn't have any common supply termenial.
Simple 4 wire = bipolar
5wire till 8wire can be used both bipolar + unipolar motor. I assume you have bipolar then.

Simple way to connect bipolar is to buy a driver for it.

If u want simple stuff i am not sure.