Self-protection H bridge driving circuit

Abstract

The invention provides a self-protection H bridge driving circuit. The self-protection H bridge driving circuit comprises an H bridge driving unit and an H bridge driving control unit. Four switch elements are located on diagonal lines, an upper left and lower right driving branch is formed by the switch element of an upper left arm and the switch element of a lower right arm, an upper right and lower left driving branch is formed by the switch element of an upper right arm and the switch element of a lower left arm, and the H bridge driving control unit controls the two driving branches to be connected alternately and controls the direction of a load current; in the same driving branch, one switch element controls output of the load driving current, and the other switch element controls the duty ratio of the load driving current. When one or two switch elements on one driving branch in the H bridge driving unit are connected, the H bridge driving control unit stops the two switch elements on the other driving branch from being connected, and thus the self-protection function is achieved. Because the independent switch elements are adopted by the H bridge driving unit to built the driving circuit, when different loads are driven by the circuit, the switch elements different in driving capacity can be selected according to currents required for driving the loads, and thus the self-protection H bridge driving circuit is high in flexibility.

Description

technical field [0001] The invention relates to an H bridge driving circuit. technical background [0002] The H-bridge drive circuit gets its name from "H-bridge drive circuit" because its shape resembles the letter H. The 4 switching elements form the 4 vertical legs of the H, and the load being driven is the bar in the H. The H-bridge driving circuit includes 4 switching elements and a load. To make the load work, a pair of switching elements on the diagonal must be turned on at the same time. Depending on the conduction of different switching element pairs, current may flow through the load from left to right or from right to left, thereby controlling the operating state of the load. For example, if image 3 As shown, the triodes Q1, Q2, Q3, and Q4 are used as four switching elements in the H-bridge drive circuit shown in the figure, and the load of the H-bridge drive circuit is a motor. When the Q1 tube and the Q4 tube are turned on, the current passes through the m...

AI Technical Summary

Problems solved by technology

[0004] The usual solutions are mainly implemented by using a dedicated driver chip with integrated hardware circuits or using discrete logic devices to build a control circuit, such as IR2110, L298N, TLE5209, etc. The disadvantages of these solutions are relatively high cost and flexibility. Poor, when driving high-power loads, external high-power switching elements are required, which takes up a lot of PCB area

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