Found this stepper motor on the website

Discussion in 'General Electronics Chat' started by mrel, Jul 30, 2013.

  1. mrel

    Thread Starter Active Member

    Jan 20, 2009
    97
    1
    Hello
    Found this stepper motor circuit from a website.
    I have question about this circuit maybe someone have the answer.
    The writing about this circuit say to turn the stepper motor is TO Pulsed the motor,How do i pulse the motor.
    Do i ground point that say step in the circuit to turn the motor?
    How to build Stepper Motor Controller

    December 9, 2010 - category: PWM and power control
    Description

    I found this circuit in my files. I don't know where it came from, but it looks like I photocopied it from somewhere years ago. I have been told that it came from "The Robot Builder's Bonanza", by Gordan McComb. Anyway, I thought that it should be fairly useful, so I decided to post it here. The circuit is very simple and inexpensive. This is good thing because most commercial stepper motor controller ICs are quite expensive. This circuit is built from standard components and can easily be adapted to be controlled by a computer. If you use cheap surplus transistors and stepper motor, the price of the circuit can be kept to under $10.
    Circuit diagram

    [​IMG]
    Parts

    • R1, R2 ,R3, R4 1K 1/4W Resistor
    • D1, D2, D3, D4 1N4002 Silicon Diode
    • Q1, Q2, Q3, Q4 TIP31 NPN Transistor (See Notes) or TIP41, 2N3055
    • U1 4070 CMOS XOR Integrated Circuit
    • U2 4027 CMOS Flip-Flop
    • S1 SPDT Switch
    • MISC Case, Board, Wire, Stepper Motor
    Notes

    • You should be able to substitute any standard (2N3055, etc.) power transistor for Q1-Q4.
    • Every time the STEP line is pulsed, the motor moves one step.
    Thank help mrel
     
    Last edited: Jul 30, 2013
  2. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    The switch on the left (S1) is to control the direction that the motor turns. The input STEP is connected to the clock of the flip flips so a pulse will move the motor one step. You just need to ensure that the connections to the motor are correct.
     
  3. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    The signal labeled STEP is the clock input. This is meant to be driven by a CLOCK signal such as the output of a 555 timer, an oscillator or output of a microcontroller.

    Since the circuit uses CMOS gates powered by +12V, you need a signal that goes from 0V to +12V and back to 0V.

    One way to do this manually is to connect a 1k to 10kΩ resistor from STEP to GND and connect a push button between STEP and +12V. Be warned that such a switch has "bounce" and the motor will make a random number of steps instead of single steps every time the pushbutton is pressed.
     
  4. mrel

    Thread Starter Active Member

    Jan 20, 2009
    97
    1
    LDC3
    The inut step is connected to clock of the flip-flop (4027) which pin do i connect to turn the motor on the fiip-flop (pin).
    mrel
     
  5. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    When you power up the circuit, 2 of the windings on the motor are active and hold the motor in position. You will notice that when the motor has no power, it turns easily. When you apply power, it is very difficult to turn the motor.
     
  6. mrel

    Thread Starter Active Member

    Jan 20, 2009
    97
    1
    MrChips

    Are you saying there two way to turn this stepper motor (1) is to build a clock input using a 555 chip?
    (2) second way is use a 1k to 10k resistor?
    Where would i find this right circuit for 555 chip to hook to this circuit?
    So are you saying without this circuit with 555 chip the stepper motor turn more than one step at a time using a resistor.
    mrel
     
  7. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    If you want to simply test this motor driver circuit, build a 555 timer circuit to give a low frequency output such as 1Hz.

    http://www.sentex.ca/~mec1995/circ/555test.htm

    Feed the output from the 555 (pin-3) to the STEP input of the motor driver circuit.

    Use the same supply voltage for both circuits.
     
  8. Potato Pudding

    Well-Known Member

    Jun 11, 2010
    684
    92
    The Stepper would need to be a unipolar 2 phase stepper. It will have 5, 6, or possibly 8 wires.

    You need to meter (ohms) for connections and find the center taps. One center tap for the five wire, likely to be a larger gauge wire. 2 center taps for the 6 wire versions and pulling those taps together will let you use them the same as the single center tap of the 5 wire.

    The 8 wire stepper doesn't make any center tap connections internally. Not sure I want to bother explaining how you work out the wiring for those except to say that you should look for a datasheet or hope it has the wiring description printed on a label attached to the motor.

    4 wires means your stepper needs a full bridge for a bipolar connection. Bipolar full bridge connection is also an option for unipolar motors. Just ignore the center taps.
     
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