STEPPER MOTOR INTERFACE PROBLEM

[wolverine123]

STEPPER MOTOR PROBLEM

Hey guys i'm trying to interface a unipolar stepper motor with a 89s52 and the program runs fine in proteus, now the problem i'm facing is that when the pin is high from the controller this should invert the signal and move the stepper motor but my problem is in hardware, when i check the controller through DMM i see i'm getting 3 to 5V from the output pin of the controller but when i connect a jumper to the uln2003A the voltage goes down to 1V or 1.7V and doesnt work. Without connecting the inverter its fine, can anyone please tell me why is this?? and i have used the following fig to just connect the stepper motor
**broken link removed**

 

[nandhu015]

STEPPER MOTOR PROBLEM

uln2003 consumes more current than 89s52 can sink.
Use a resistor more than 10k from 89s52 to uln

 

[dimas_lilik]

I have been using the ULN2003A, but I always pin 10 open.
What a difference 10 ULN2003A pin in the open and let the connecting pin 10 with vcc
Such series I have ever tried, but the motor is not strong, My STEPPER motor 0.45A. after I replace it with L297, until now a good motor

 

[hameeds01]

hey u r driving ur stepper motor via 7805 thatz not fair, use a saperate 6v supply to drive ur stepper motor

 

[anandpv2009]

Tips..

Use 8 to 12v supply for stepper motor, not from 7805. The maximum current that can flow through 7805 is 1A.

Use same supply for motor and ULN2003 (Max 15v)

 

[wolverine123]

i didnt use the 7805 i just used the stepper motor connections, anyway thanks nandhu, the resistors worked