Need Help: L293D - Bipolar stepper motor problem

[Don_dody]

I followed the the circuit in the picture below:



taken from:
https://www.8051projects.net/stepper-motor-interfacing/stepper-motor-connections.php

But I don't know why every time the motors start, they disturb the other system such as my 16x2 LCD.
When they starts, LCD display is like dimming or I dont know what does it called (like lack of power).

Is there any suggestions for me?

 

[emresel]

Hi;
Porbably, sudden current increase because of the motor windings cannot be compansated by your power supplys.
Place elco caps close to L293D, and also some ceramics in parallel also. take care to place as close as to L293D device pins.
Check also power line from your power supply to motor driver, that power line on PCB should be thick enough to carry high current.
Hope helps

 

[Don_dody]

Place elco caps close to L293D, and also some ceramics in parallel also. take care to place as close as to L293D device pins.

Can you help me with image? So it will be clearer.

 

[Don_dody]

It is the problem of your power supply... reconstruct your power supply with more current rating

I did!

Check this out:


I have add that transistor to produce more current rating and prevent the regulator from overheating.

 

[emresel]

soemthing like this