How to use H-bridge circuit to drive a brush DC motor

From this article, we will introduce how to use the H-bridge circuit to drive the brush DC motor. This paper introduces the principle of the H-bridge circuit before the specific use of the H-bridge circuit drives the driving method of the brush DC motor. What is H-bridge circuit? Basically, the brush DC motor has two power supply terminals and drives the motor by applying a voltage on both terminals. The two terminals have the following four connection combinations (these four only): 1 The two terminals are not connected anywhere. (When another connection is not connected, it also applies it) 2 Connect the (+) of the DC power supply to one terminal, (-) to the other terminal. 3 Connect the DC power to the electrical machine according to the opposite polarity of 2. 4 Connect between the two terminals. These four states can be implemented by using four switches using four switches. Since the shape of the circuit is similar to the letter "H", it is called "H-bridge circuit" (also known as "full bridge circuit"). 1 The power terminal is not connected to any place, and can be implemented by all OFF all OFF. 2 is connected to one terminal, (-) to another terminal, need to turn SW1 and SW4 to open SW2 and SW3 (OFF). This way the motor will rotate in some direction. 3 The next method is opposite to 2. Turn SW1 and SW4 (OFF), turn SW2 and SW3 (ON). This way the motor will rotate in the opposite direction. 4 is the connection between the power terminals. When SW1 and SW3 are turned off (OFF) and SW2 and SW4 are turned on (ON), the state is connected to each other between the terminals. Example of a circuit actual H-bridge circuit with a brush DC motor change connection In the above figure, the switch is used in order to facilitate understanding of the connection, but in the actual electronic circuit, four switches use a semiconductor power transistor. The configuration shown below is the actual H-bridge circuit. In this circuit, the (+) side transistor (Q1, Q3) of the power source is used in the P-channel MOSFET, (-) side transistor (Q2, Q4) is N-channel MOSFET. Real drive circuit configuration example To change the speed of the brush DC motor, it is necessary to change the voltage applied to the brush DC motor. To this end, a voltage control circuit is inserted between the power supply and the brush DC motor, and the voltage applied to the brush DC motor is applied directly or indirectly. There are two control methods, one is to directly connect the brush DC motor on the (-) side, and the other is the insertion control circuit to simultaneously control (-) side. The actual drive circuit is composed of an H-bridge circuit and voltage control circuit that can change the connection state. Key points: • The H-bridge circuit is used to change the circuit with a brush DC motor. • Switching of 4 connection states of brush DC motor using 4 switches (transistors). · The actual drive circuit with brush DC motor is composed of H-bridge circuit and voltage control circuitry. Edit: hfy, read full text