Home Electronics Coin Positioning Motor
	Electronics - Coin Positioning Motor In order to have precise control over the position of the penny dropper, a stepper motor was used to move it left and right. A L293B H-bridge was used as a go-between from the C32 processor to the stepper motor. By pulsing the proper sequence of input pins on the L293B, the motor can be driven in either direction. The diodes are used to snub any voltage spikes created when the state of the motor changes. The threshold voltage for L293B is 0.9V for low and 3.15V for high, so the C32 can easily drive the H-Bridge. The resistance of the stepper motor from A to Abar and B to Bbar is 160Ω. Since the motor was driven with 13.5V the resulting current was 84mA, safely below the 1A limit of the L293B.