Driving two stepper motors with a ULN2803APG

[stobbz]

Hello folks, I'm looking for some advice on the ULN2803APG. Is it possible to drive two 2-phase, unipolar/bipolar stepper motors with this particular IC?

This how I have a single motor connected in unipolar configuration to the IC:

**broken link removed**

It would have to be possible to control both motors independently from the IC inputs and both motors would have to be able to move independently of each other.

Any help appreciated,
Thanks!

 

[Sceadwian]

The configuration in the schematic you have listed already answers your question with a unipolar motors, you'r running each line in parallel with two drivers, simple use 1-2-3-4 for one stepper and 5-6-7-8 for the second with the inputs and output correspondingly re-routed. I don't believe there is any way to drive bipolar units from this chip.

You may need to be careful though as the given schematic shares the output current between two darlingtons, so the possible output power will be lower depending on the motor that it's driving. You need to detail the specifications for the motor(s) you're using.

 

[stobbz]

That's great, thanks a lot for your help. These are the motors being used:

https://uk.farnell.com/nanotec/sp2575m0206-a/stepper-motor-7-5deg/dp/4743209

2-phase, 240 mA stepper motors.