Presented by: Sarah Krystelle P. CauanCourse/Yr/Section: BSECE 41A1

Presented to: Engr. Jan Berden D. Bermejo

Date: October 17, 2011

BIPOLAR STEPPER MOTOR DRIVER CIRCUIT

AbstractStepper motors are used in any application

which requires a discrete rotational movement. The performance of stepper motor is strongly dependent on the driver circuit. There are two basic winding arrangements in two phase stepper motor, the unipolar and the bipolar.

This project contains the discussion and features of simple bipolar stepper motor driver. It provides the forward and reverse control function. The concept of this project got from a simple running lights circuit.

AbstractThe circuit contains three different IC which

are the LM555, 94LS194, and the L293D. The stepping rate of the stepper motor is controlled by the 1 Megaohm potentiometer while the switch determined the direction of the motor.

The LM555 astable oscillator produces clock pulses that are directed to PIN 11 of the 74194 shift register. Each time the output of the LM555 timer goes high, the high state at the pins 12, 13, 14, and 15 of 74194 is shifted either up or down by one place.

AbstractThe output shift determines the direction of

the rotation of motor. Switch S1 and S2, which are connected to the switch control the direction. When the S1 is active, the motor will rotate clockwise, on the other hand, when S2 is active, the motor will rotate counter-clockwise. The four outputs of the 74194 are fed to one of the driver segments of a LS293D - H Bridge driver IC (IC 3). The output will be dependent on the input on LS293D segment.

Circuit Design Components1 MΩ PotentiometerThe potentiometer controls the rate of the

bipolar stepper motor.

Switch The switch determines how pin 12 to 15

shifted.

Circuit Design ComponentsNE555N

Circuit Design Components1 MΩ PotentiometerThe potentiometer controls the rate of the

bipolar stepper motor.

Circuit Design Components

0.01µF Ceramic Capacitor – this capacitor is used to lessen the electrical noise with the pin 5 connected to ground.

1 pc. SN754410NE (OR L293/L293D will do if no stock) – this integrated circuit is used as a driver, or commonly known as Quadruple Half-H Drivers, from which this can be used to operate or drive Bipolar Stepper Motor

1 pc. Toggle Switch – used here to be able to have an option of directions for bipolar stepper motor

Circuit Design Components1 pc. 4.7µF / 50V – is an electrolytic capacitor

used to lessen the noise experiencing from the input of the voltage regulator in this circuit.

1 pc. 470µF / 35V - is also an electrolytic capacitor used to lessen the electrical noise experiencing from the output of the voltage regulator in this circuit.

1 pc. LM7805 ( +5V Regulator) – used to provide the necessary +5V under the integrated circuit of NE555 Timer and 74LS194.

PIN CONFIG 555 TIMER

PIN CONFIG OF 74LS194

PIN CONFIG OF L293/SN754410NE

Circuit Diagram