problem in stepper motor driver

[air-man001]

My dear friends,
i have done the famous circuit for drive one stepper motor (on a breadboard)


**broken link removed**



the issue :

the motor not stable (Vibrate strongly AND random turn left and right )
but when touch any Non-insulated wire by my hand , the motor Works regularly!!!

please, what is the problem?????

i used:

* 24 volt , 500mA (printer power supply) .
* unipolar (5 wires) stepper (NMB PM55L-048-HPG9) .
* zener 8.2 volt .
* diods 1N4007 .
* MOSFET 6N60A .
* Capacitor 220 µF 35 V.
* Mach3 program.

 

[Angry Badger]

Hi,

One or more of your 0V connections is disconnected or loose. When you touch the wire the circuit is connected to 0V through your body. Check the 0V connections to the IC's.

 

[air-man001]

Thank you , "Angry Badger"

I have checked all the 0v Connection, All connected well !!!

 

[air-man001]

i add reputation for you "Angry Badger"

 

[cr0sh]

Do you have decoupling capacitors on the ICs? They need to be around 0.1 uF (this can be played with - you may need higher or lower), non-polarized - placed as close to the IC as possible, between the VCC and GND pins on the IC...

I think what is happening is that you are acting (in a way) as the decoupling capacitor when you touch the circuit; there might possibly be other reasons as well, but I would try putting in those capacitors on each IC first.

 

[air-man001]

thank you cr0sh (reputation for you)


I will try.