ULN2003 bridge!

Brand new circuit that you will fin nowhere on the internet.. he he cos i found this out. Well runnig DC motors for a robot you can very happily use this low cost circuit that using a L293D for Rs175!! in this circuit i have put a H-Bridge circuit with u ULN 2003 Ic that costs just 12 bucks


okie now i assume the circuit is very easy to understand.. A" and B" are the two control signals.. givin a high to any one of them wil make the motor move in one direction while a signal to the other will mover it in opposite direction.The main asvantage of this circuit being that you can adjust the voltage applied to the motor by cahgig the sypply at collector of the BC107.(sorry people for not puttin " >" at the emitter. assume it to be down!!) i almost got my recor torn by my techer for not putyting the arrow at the emitter in my secon semester of college!!!

This sircuit will come very handy. Use it and give me feedbacks!!


36 thoughts on “ULN2003 bridge!

  1. Hello,
    I’m trying to implement this circuit to drive a floppe drive stepper motor (4-wires, bipolar). I’m confused on how to connect the wires to the outputs. What are the blue and red lines (wires) for?
    Thank you

  2. I implemented your cicuit but the output that I get at the emitter (namely A and B) isn’t the voltage I put in at the collector (not 10V) but the input at the base (but 5V).

  3. Sorry james , just do these changes to the ckt to get what u want.
    1)just ground the base
    2)Connect the points A and B to the Collector itself.
    3)You’l get 10v then but with a negative logic.

    Try it out and comment back for any help k.

  4. I think pin9 should go to positive of power rail to clamp the collectors from high voltage spikes generated by the motor inductance on turn off.

  5. hey, i must tell u that a new Ic is available in the market to be used in place of h bridge..that also help to save
    bridge from burning up due to software faults…

  6. @Karan
    Well thanks for that. But the whole purpose of this ckt was ,
    1) Cheaper
    2) Run motor at any voltage level
    3) Increase the current rating by piggy back’in ULNIC

    And a better IC than L293D would be L298 to support higher ratings.

  7. hi,
    im new to stepper motors and pic 16f877, im doing a project using two stepper motors connected to one pic, can you plz guide me, can u plz send me the ciruit using uln 2003 or l298 for the interfacing part for stepper motor… plz send me the circuit plz guide me

  8. hi,
    i am making project on directing robot/motor using matlab by capturing the images through webcam. i have read ur article regarding it, but i was unable to see its pics. please send all info about it.
    thank u 4 everything u provided, it is a good effort.

  9. Where is the circuit???? Pls some one atleast tell me how the connections are or where i can get the circuit


  10. Hi
    I am doing a project of interfacing three stepper motors,which are presently controlled by switches through its driver circuits(quite old) to a computer.could u plz provide me with the circuit diagram.

  11. acctually i have 4wire stepper motor to inteface with ULN 2003 .i dont know how it connect and i have controll the IC by using IR transmitter and receiver

  12. Hey there, I’m a fresh blogger and I really enjoy reading this blog,
    so I figured maybe I could get your suggestions about something.
    Do you put up everyone’s responses? Even people that criticize and annoky you?
    Iam not sure what to do.

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