Presented
here is a simple circuit that can drive two motors for a small robot,
allowing the robot to negotiate an obstacle course. Two light-dependent
resistors (LDRs) are used to detect the obstacle and the motors are
driven correspondingly to avoid the obstacles automatically. Two
H-bridge motor circuits are used that can drive each motor forward or
backward, or stop it, independently.
Circuit and working
Fig. 1
shows the circuit of dual motor control. The circuit is built around
four-channel multiplexer CD4052 (IC1), light-dependent resistors (LDR1
and LDR2), four BC547 npn transistors (T1 through T4), four BC338
transistors (T7, T8, T11 and T12), four BC327 pnp transistors (T5, T6,
T9 and T10) and a few other components.
Fig. 1: Circuit of the dual motor control
As mentioned earlier, there are two H-bridge circuits to drive the two motors. Motor M1 drives the left side, while motor M2 drives the right side. Each H-bridge circuit is built around a pair of npn and pnp transistors as shown in Fig. 1. Each driving transistor has a diode connected between
