This H-bridge is easy to build, without any critical components. It is based on the famous and cheap TIP122 and TIP127 power transistors. It have been used on many of our robots and proved to be very versatile and robust.
Another major advantage is that it only needs 4 wires for 12V power supply and direction control. Nevertheless, it allows bidirectional control, breaking and freewheeling.
Resistors R2, R4, R5 and R10 have to be 1 WATT rated, to support high currents, especially if a 24V power supply is used.
The wire connection W1 to W4 are the wires between this H-bridge module and the controller board that provides the 12/24V power supply and the logic signals for direction control.
The wire connection W3 can be connected to a power source from 10V to 24V, without circuit modifications.
The wire connection W1 and W2 are for connecting the H-bridge to a microcontroller or another logic device allowing the control of the motor. A truth table is given below showing the effect of every combination of the logic states of W1 and W2:
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