TTL IC based step motor controller with translator for rpm display

This paper presents a transistor-transistor logic circuit that will drive a stepper motor in both clockwise and counterclockwise directions. The prototype can also control the speed of the stepper motor. The designed circuit has two controllers: it will provide motor control and can also change the motors direction; and it will determine the speed of the motor using coin switches and display the data in a numeric value in revolution per minute format using a 7-segment display. There is also a driver which uses H-bridge circuit that acts as a current amplifier to supply high current for the motor. The output rpm according to the frequency ranges of 200 to 800 Hz are from 6 to 21 rpm.