Full-function dual-path H-bridge

Full-function dual H-bridge

Perhaps the simplest reversible drive circuit is the H-bridge. Some BEAM robots use H-bridge motor drivers; many more use some variant of the H-bridge. Here is a simple conceptual diagram: [Image of a basic H-bridge with 4 switches, relays, transistors, or other circuitry to drive the motors]. In the diagram above, the switches are labeled A1, A2, B1, and B2. Since each of the four switches can be either open or closed, there are 2^4 = 16 possible switch settings. Many are useless; in fact, several should be avoided as they would short-circuit the power supply (e.g., A1 and B2 closed simultaneously). Four combinations are useful: