Unipolar Stepper Motor Driver Circuit
This page presents a circuit for driving high-power unipolar stepper motors. Here you will find all the information needed to make your own. This circuit allows step-level control and can be easily modified for other modes of operation.
What you need
- +5v (low power)
- +12v (high power)
- Discrete Components
- (4x) 2N6045 NPN Darlington Transistor
- (8x) 1N4001 Diodes
- (2x) 3.3kOhm Resistors
- PC104 or High-Level Controller
- 12v Unipolar Stepper Motor
Circuit Schematic and Photo
The L297 has several inputs that can be generated by a PC/104 stack or other controller. This circuit allows you to control each step, in full-step mode. Meaning: You can tell it to move one step in either direction (of course you can make it move fast and it will continuously rotate). The two inputs are a direction and a pulse. In the next section you will find a program to control this using xPC.
Here is the CircuitMaker file: media:unipolar stepper driver circuit.ckt