PWM (Pulse Width Modulation) driving circuit with short-circuit protection

Abstract

The utility model discloses a PWM (Pulse Width Modulation) drive circuit with short-circuit protection, which comprises a triode amplification circuit module connected with a PWM MCU (Microprogrammed Control Unit) and a triode drive circuit module connected with the triode amplification circuit module, the circuit is characterized in that the circuit also comprises a triode short-circuit circuit module which is connected with the triode amplification circuit module and the triode drive circuit module; according to the utility model, through the arrangement of the triode short-circuit circuit module, the triode driving circuit module is controlled, then the triode amplification circuit module is driven to work and PWM signals are output, and when the triode amplification circuit module is short-circuited, the triode short-circuit circuit module opens and closes the triode amplification circuit module, so that the effect of output short-circuit protection is achieved; therefore, the circuit is protected from being damaged. And meanwhile, a circuit protection function can be realized by using a small number of triodes and resistors, so that the production cost is reduced while a short-circuit protection function is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to new energy automobile technical field, concretely is a PWM drive circuit with short circuit protection. BACKGROUND

[0002] At present, in the new energy automobile field, in order to meet the safety specification and strengthen electronic equipment protection, more and more electronic equipment needs to increase the PWM drive circuit with short circuit protection, in the existing PWM drive circuit, there is no short circuit protection function, when short circuit occurs in the PWM drive process, will not automatically close output, leads to the breakdown PWM drive circuit in component, for this, propose a kind of PWM drive circuit with short circuit protection. SUMMARY

[0003] The utility model mainly aims at providing, can effectively solve the problem in background art.

[0004] To achieve the above object, the utility model takes the technical scheme as follows: a kind of PWM drive circuit with short circuit protection, including triode amplification circuit module being connected with PWM MCU, triode drive circuit module being connected with triode amplification circuit module, it is characterized by: still include triode short circuit circuit module being connected with triode amplification circuit module and still being connected with triode drive circuit module;Still include resistance R4 being connected with PWM MCU, resistance R5 and the base of triode Q3 being connected with the other end of resistance R4, the emitter of triode Q3 and resistance R6 being connected with the other end of resistance R5, and resistance R5 other end, the emitter of triode Q3, resistance R6 ground connection, resistance R3 and resistance R2 being connected with the collector of triode Q3, power supply end 12V, capacitor C1, the emitter of triode Q1 and resistance R1 being connected with the other end of resistance R2, and capacitor C1 other end ground connection, the collector of triode Q1 and the base of triode Q2 being connected with the other end of resistance R3, the base of triode Q1 and the emitter of triode Q2 being connected with the other end of resistance R1, resistance R6 and PWM OUT being connected with the collector of triode Q2.

[0005] The utility model has following beneficial effects: through the setting of triode short circuit circuit module, control triode drive circuit module works, drive triode amplification circuit module 1 work again, output PWM signal, when triode amplification circuit module short circuit, triode short circuit circuit module opens, and triode amplification circuit module 1 is closed by drive current, reaches the effect of output short circuit protection, to protect circuit from damage;Meanwhile, using a small amount of triode and resistance, can realize circuit protection function, while realizing short circuit protection function, reduce production cost. BRIEF DESCRIPTION OF DRAWINGS

[0006] Fig. 1It is the PWM drive circuit structure schematic diagram of the utility model with short circuit protection.

[0007] Fig. 2 It is the PWM drive circuit connection diagram of the utility model with short circuit protection.

[0008] Legend: 1, triode amplification circuit module; 2, triode short circuit circuit module; 3, triode drive circuit module. DETAILED DESCRIPTION

[0009] In order to make the technical means, creation features, purposes and effects of the utility model easy to understand, the utility model is further described below in combination with specific embodiments.

[0010] As Figs. 1-2 The utility model discloses a PWM drive circuit with short circuit protection, which comprises a triode amplification circuit module 1 connected with a PWM MCU, a triode drive circuit module 3 connected with the triode amplification circuit module 1, characterized in that it further comprises a triode short circuit circuit module 2 connected with the triode amplification circuit module 1 and also connected with the triode drive circuit module 3; and it further comprises a resistance R4 connected with the PWM MCU, a resistance R5 and a base of a triode Q3 connected with the other end of the resistance R4, an emitter of the triode Q3 and a resistance R6 connected with the other end of the resistance R5, the other end of the resistance R5, the emitter of the triode Q3 and the resistance R6 being grounded, a resistance R3 and a resistance R2 connected with the collector of the triode Q3, a power supply end 12V, a capacitor C1, an emitter of a triode Q1 and a resistance R1 connected with the other end of the resistance R2, a collector of the triode Q1 and a base of a triode Q2 connected with the other end of the resistance R3, a base of the triode Q1 and an emitter of the triode Q2 connected with the other end of the resistance R1, and a resistance R6 and a PWM OUT connected with the collector of the triode Q2.

[0011] Through the arrangement of the triode short circuit circuit module 2, the triode drive circuit module 3 is controlled to work, and then the triode amplification circuit module 1 is driven to work and output PWM signals. When the triode amplification circuit module 3 is short-circuited, the triode short circuit circuit module 2 is turned on, the triode amplification circuit module 1 is closed through a driving current, and the effect of output short-circuit protection is achieved, so that the circuit is protected from damage. At the same time, the circuit protection function can be realized by using a small number of triodes and resistors, the production cost is reduced while the short-circuit protection function is realized.

[0012] The utility model discloses a working principle: through singlechip or pulse generator give PWM MCU pulse signal, resistance R4 is electrified, and divides voltage after resistance R5, voltage enters the base of triode Q3, is used for controlling the opening and closing of triode Q3, when triode Q3 draws low, resistance R3 is pulled down, controls the opening and closing of triode Q2, when PWM OUT sends short circuit, the voltage on resistance R1 can be big, when voltage reaches 0.7V on resistance R1, triode Q1 opens, after triode Q1 opens, triode Q2 base is pulled high, will make triode Q2 close, to reach the purpose of protection of PWM drive in short circuit.

[0013] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model can also have various changes and improvements, and these changes and improvements all fall within the scope of the utility model claimed. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A PWM drive circuit with short circuit protection, comprising a triode amplification circuit module (1) connected with a PWM MCU, a triode drive circuit module (3) connected with the triode amplification circuit module (1), characterized in that: It also includes a triode short circuit circuit module (2) connected with the triode amplification circuit module (1) and also connected with the triode drive circuit module (3); It also includes resistance R4 connected with PWM MCU, resistance R5 and the base of triode Q3 connected with the other end of resistance R4, the emitter of triode Q3 and resistance R6 connected with the other end of resistance R5, and the other end of resistance R5, the emitter of triode Q3, resistance R6 are grounded, resistance R3 and resistance R2 connected with the collector of triode Q3, power supply end 12V, capacitor C1, the emitter of triode Q1 connected with the other end of resistance R2, and resistance R1, and the other end of capacitor C1 is grounded, the collector of triode Q1 and the base of triode Q2 connected with the other end of resistance R3, the base of triode Q1 and the emitter of triode Q2 connected with the other end of resistance R1, resistance R6 and PWM OUT connected with the collector of triode Q2.

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