Thursday, May 29, 2008

Driving stepper motor using ULN2003

The simplest way to drive stepper motor having lower current rating is using ULN2003. The ULN2003 contains seven darlington transistors. The ULN2003 can pass upto 500mA per channel and has an internal voltage drop of about 1V when on. It also contains internal clamp diodes to dissipate voltage spikes when driving inductive loads. The circuit for driving stepper motor using ULN2003 is shown below.

For higher current torque motors, you can use TIP120. The advantage is that the TIP120 can pass more current along with heat sink. The disadvantages are that the more wiring is required and four TIP120 is used to control the motor.


R. Firdaus said...

Dear Ganesh, How do I send signals from my computer via the serial port? Which pin corresponds to what? Does hyperterminal work?

Ankit Jain said...

hey hi ! can you tell me what is the voltage and power rating of the zener diode you are using ??
its important... plz reply !!!!

Pranay said...
This comment has been removed by the author.
Pranay said...

Nice and informative post.....I was not aware of the TIP120 IC's until i read abt them at ur blog.


curlytops said...

i'm using a uln2003 to drive my stepper motor but i need more torque. If I used the tip120, would it help?

asreghb said...

You could also just "piggyback" two uln2003a for 1 amp. Just solder one on top of the other.

Jarpo82 said...

I have a step motor that works with 2.1AMP / 2.5V.
My question is... could I piggyback FOUR (4) uln2003A to work with this motor?
Thanks regards from Argentina.


I have been using the same circuit as described in the figure above. But the motor does not seem to run, it is just vibrating.
Unipolar Stepper Motor USM-28BJY48-12VDC
Stepper Motor driving IC= ULN2003A
I'm not using pull resistor in the driving circuit.
I connected LED to the input of the ULN2003A the input is in proper sequence
I'm applying 12 v [The power supply is made by using 12v Transformer, 500mA, voltage regulator L7812CV]
can any one tell me where i'm going wrong in driving the motor.

PT said...

how to interface a stepper motor to8051 using uln2003driver ic?what does the use of 9th pin in in uln2003

dearmaths said...

Dear Ganesh Please tell me some circuit to run a 3 phase brushless motor and hardisk motor.
D.Vasu Raj,

Unknown said...

hi ganesh , do you have any solution for connecting motor shield with grbl