Mecanica

Stepper Motor Controller
Connection Diagrams | |The wires from the Logic PCB connector to the stepper motor in a TM100 Disk Drive are as follows
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This means that, to use the steppingsequences as is, the Green and Brown wires are the wrong way round. There is no need to alter the wires at the connector, of course - it can be done in the cable from the PC parallel port or microcontroller.If you have a stepper motor with different wiring, look here.
| Four-Wire Connection|

The ULN2003 / MC1413 is a 7-bit 50V 500mA TTL-input NPN darlington driver. This is more than adequate to control a four phase unipolar stepper motor such as theKP4M4-001.
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It is recommended to connect a 12v zener diode between the power supply and VDD (Pin 9) on the chip, to absorb reverse (or "back") EMF from the magnetic field collapsing when motor coilsare switched off. (See Douglas W. Jones' rather more sophisticated example)
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Here's one I made earlier
I recycled the power and motor lead connectors from the TM100 Logic PCB. A convenientsource of 12v and 5v is an old IBM-PC power supply unit. The 9-way D-type connector is appropriate for the number of (parallel) control lines needed in the cable.
Here's some example software for thissetup
• One of my student groups used an enhanced version of this circuit for their Remote Control WebCam project.
• One of my individual students produced a microcontroller-driven version forhis SMACK project. Read his report for more details.
| Data Sheets|

Allegro MicroSystems has a PDF datasheet for its 2003 thru 2024 high-voltage high-current Darlington arrays.
Texas Instruments supplies the SN75468, which is a higher-voltage...