Interfacing stepper motor with pic using uln203a

[laxmid]

Hi,

I am Interfacing stepper motor with pic using uln203a.

n i am giving supply to stepper motor as 12v.

but uln2003a is heating . what is the problem kindly help

Thanks

 

[ericgibbs]

Hi,

I am Interfacing stepper motor with pic using uln203a.

n i am giving supply to stepper motor as 12v.

but uln2003a is heating . what is the problem kindly help

Thanks

hi,
How much current is flowing in the motor and ULN2003.?

 

[laxmid]

Thanks for ur kind reply
current flowing betn stepper motor n uln 0.7mA..

 

[ericgibbs]

Thanks for ur kind reply
current flowing betn stepper motor n uln 0.7mA..

Have you tried connecting 2 or more ULN outputs together in parallel.
A value of 700mA for one ULN driver output exceeds the recommended rating.

Look at this image.

 

[Dragon Tamer]

The ULN2003 is a Darlington array correct? If that's the case then some heating should be expected, however ericgibbs is right. 700mA does exceed the maximum current of 500mA. Connect 2 in parallel and you should be okay.

 

[AlainB]

ULN2803 would be a better choice for using with a small stepper motor. There is 8 darlingtons instead of 7 for the ULN2003. But at 700 mA, even paralelled, it is asking too much from this chip. Sooner or later, it will smoke specially if you try to run the motor full step for better torque, that being 2 phases energized at the same time. ULN2803 is pretty good for small motors rated at 150-200 mA per phase.

YouTube - 3 axis CNC for PCB drilling

I would go with TIP120 Darlingtons transistors as power stage for your motor. At least you would have a lot of headroom.

Alain

 

[AlainB]

Thanks for ur kind reply
current flowing betn stepper motor n uln 0.7mA..

Did you spilled coffee or something else all over your keyboard?

 

[laxmid]

Thanks Sir.
I will check with uln2803.