CN204557118U - A kind of air conditioner and Intelligent Power Module power-on protective circuit thereof - Google Patents

Abstract

The utility model belongs to the technical field of power-on protection and provides a power-on protection circuit for an air conditioner and an intelligent power module thereof. The utility model adopts an intelligent power module power-on protection circuit including a power-on protection switch module and a diode. When power-on, the power-on protection switch module is in a high-impedance state according to the input and output ports of the microprocessor, and the power-on circuit is output through the diode. The protection signal is used to prohibit enabling the intelligent power module; and when the power-on is completed, the power-on protection switch module stops outputting the power-on protection signal through the diode according to the high level output by the input and output ports of the microprocessor, so as to enable the intelligent power module The power module enters the normal working state, so that the power-on protection of the intelligent power module can be realized to prevent it from malfunctioning, and the damage to the internal circuit caused by the malfunction of the intelligent power module can be avoided, thereby solving the existing technology that cannot The problem of realizing false operation protection for intelligent power modules during power-on.

Description

An air conditioner and its intelligent power module power-on protection circuit

technical field

The utility model belongs to the technical field of power-on protection, in particular to an power-on protection circuit of an air conditioner and an intelligent power module thereof.

Background technique

At present, in the application of intelligent power module (IPM, Intelligent Power Module), as shown in Fig. 1, in order to realize overcurrent protection for the intelligent power module, the existing technology usually connects the output terminal LO of the lower bridge arm of the intelligent power module and The over-current protection pin CP is connected to the first end of the sampling resistor Rs, and the second end of the sampling resistor Rs is grounded. The intelligent power module judges whether there is an over-current through its over-current protection pin CP. If so, it stops working immediately to achieve overcurrent protection. However, when the circuit is powered on, the voltage of the circuit is in the process of establishing from zero to the normal working voltage, and the microprocessor controlling the intelligent power module works in an uncertain state during the power-on process. The control logic disorder causes the intelligent power module to malfunction, thus causing the intelligent power module to be damaged. Therefore, there is a problem in the prior art that the intelligent power module cannot be protected from malfunctions when it is powered on.

Utility model content

The purpose of the utility model is to provide a power-on protection circuit for an intelligent power module, aiming at solving the problem in the prior art that the intelligent power module cannot be protected from malfunction when power-on.

The utility model is realized in this way, an intelligent power module power-on protection circuit is connected with the intelligent power module and the microprocessor, and the output terminal of the lower bridge arm of the intelligent power module and the overcurrent protection pin are jointly connected to the sampling resistor The first end of the sampling resistor, the second end of the sampling resistor is grounded; the input and output ports of the microprocessor are in a high-impedance state when powered on, and the input and output ports of the microprocessor output a high level after power on ;

The power-on protection circuit of the intelligent power module includes a power-on protection switch module and a diode, the controlled end of the power-on protection switch module is connected to the input and output ports of the microprocessor, and the input terminal of the power-on protection switch module and the output end are respectively connected to the DC power supply and the anode of the diode, and the cathode of the diode is connected to the overcurrent protection pin of the intelligent power module; The input and output ports of the device are in a high-impedance state, and the power-on protection signal is output through the diode to prohibit enabling the intelligent power module; when the power-on is completed, the power-on protection switch module stops passing through the The diode outputs the power-on protection signal to enable the intelligent power module to enter a working state.

The utility model also provides an air conditioner, which includes an intelligent power module, a microprocessor and the above-mentioned power-on protection circuit for the intelligent power module.

The utility model adopts an intelligent power module power-on protection circuit including a power-on protection switch module and a diode. When power-on, the power-on protection switch module is in a high-impedance state according to the input and output ports of the microprocessor, and the power-on circuit is output through the diode. The protection signal is used to prohibit enabling the intelligent power module; and when the power-on is completed, the power-on protection switch module stops outputting the power-on protection signal through the diode according to the high level output by the input and output ports of the microprocessor, so as to enable the intelligent power module The power module enters the normal working state, so that the power-on protection of the intelligent power module can be realized to prevent it from malfunctioning, and the damage to the internal circuit caused by the malfunction of the intelligent power module can be avoided, thereby solving the existing technology that cannot The problem of realizing false operation protection for intelligent power modules during power-on.

Description of drawings

FIG. 1 is a schematic diagram of an overcurrent protection circuit of an intelligent power module involved in the prior art;

Fig. 2 is a module structure diagram of the power-on protection circuit of the intelligent power module provided by the embodiment of the utility model;

Fig. 3 is an example circuit structure diagram of the power-on protection circuit of the intelligent power module provided by the embodiment of the present invention;

FIG. 4 is a schematic diagram of an application example of the power-on protection circuit of the intelligent power module shown in FIG. 3 .

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Figure 2 shows the module structure of the power-on protection circuit of the intelligent power module provided by the embodiment of the utility model. For the convenience of description, only the parts related to the embodiment of the utility model are shown, and the details are as follows:

The power-on protection circuit 100 of the intelligent power module is connected to the intelligent power module 200 and the microprocessor MCU. The output end LO of the lower bridge arm of the intelligent power module 200 and the overcurrent protection pin CP are connected to the first end of the sampling resistor Rs, and the sampling The second end of the resistor Rs is grounded; the input and output port I/O of the microprocessor MCU is in a high-impedance state when powered on, and the input and output port I/O of the microprocessor MCU outputs a high level after power on.

The power-on protection circuit 100 of the intelligent power module includes a power-on protection switch module 101 and a diode D1. The controlled end of the power-on protection switch module 101 is connected to the input and output port I/O of the microprocessor MCU, and the input The terminal and the output terminal are respectively connected to the DC power supply VCC and the anode of the diode D1, and the cathode of the diode D1 is connected to the overcurrent protection pin CP of the intelligent power module.

When powering on, the power-on protection switch module 101 outputs a power-on protection signal through the diode D1 to prohibit enabling the intelligent power module 200 according to the input and output port I/O of the microprocessor MCU is in a high-impedance state. 200 stops working due to power-on protection, and its internal circuit will not be damaged due to malfunction. When the power-on is completed, the power-on protection switch module 101 stops outputting the power-on protection signal through the diode D1 according to the high level output by the input and output port I/O of the microprocessor MCU, so as to enable the intelligent power module 200 to enter the working state .

Specifically, as shown in FIG. 3, the power-on protection switch module 101 includes:

A first resistor R1, a PNP transistor Q1 and a second resistor R2;

The common contact between the first end of the first resistor R1 and the base of the PNP transistor Q1 is the controlled end of the power-on protection switch module 101, the second end of the first resistor R1 is grounded, and the emitter of the PNP transistor Q1 is powered on. The input terminal of the protection switch module 101 and the collector of the PNP transistor Q1 are connected to the first terminal of the second resistor R2 , and the second terminal of the second resistor R2 is the output terminal of the power-on protection switch module 101 .

The power-on protection circuit 100 of the intelligent power module shown in FIG. 3 is further described below in conjunction with the working principle:

When the power is turned on, the input and output port I/O of the microprocessor MCU is in a high-impedance state, and since the base of the PNP transistor Q1 is grounded through the first resistor R1, the base of the PNP transistor Q1 is at a low level at this time , then the PNP transistor Q1 is turned on and outputs a high level (that is, the above-mentioned power-on protection signal) to the overcurrent protection pin CP of the intelligent power module 200 through the second resistor R2 and the diode D1, so as to trigger the start of the intelligent power module 200 The overcurrent protection function, so that the intelligent power module 200 is prohibited from being enabled when it is powered on, so as to achieve the purpose of power-on protection for the intelligent power module 200 . After the power-on is completed, the microprocessor MCU works normally and outputs a high level to the base of the PNP transistor Q1 through its input and output port I/O. At this time, the PNP transistor Q1 enters the cut-off state and stops outputting a high level. , then the overcurrent protection function of the intelligent power module 200 is thus released and enters a normal working state.

In addition, in the actual application process, as shown in FIG. 4, a third resistor R3 is connected in parallel between the output terminal LO of the lower bridge arm of the intelligent power module 200 and the overcurrent protection pin CP, so as to realize overcurrent protection in the intelligent power module 200. In the process of protection, it acts as a current limiter.

Based on the above-mentioned power-on protection function of the intelligent power module power-on protection circuit 100 for the intelligent power module, the embodiment of the utility model also provides an air conditioner, which includes an intelligent power module 200, a microprocessor MCU and the above-mentioned Intelligent power module power-on protection circuit 100 .

The embodiment of the utility model adopts the intelligent power module power-on protection circuit 100 including the power-on protection switch module 101 and the diode D1. In the high-impedance state, the power-on protection signal is output through the diode D1 to prohibit enabling the intelligent power module 200; and when the power-on is completed, the power-on protection switch module 101 outputs according to the input and output port I/O of the microprocessor MCU The high level stops outputting the power-on protection signal through the diode D1, so that the intelligent power module 200 can enter the normal working state, so that the power-on protection of the intelligent power module 200 can be implemented to prevent it from malfunctioning, and the intelligent power The internal circuit is damaged due to malfunction, thereby solving the problem in the prior art that the intelligent power module cannot be protected from malfunction when powered on.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (3)

1. an Intelligent Power Module power-on protective circuit, is connected with Intelligent Power Module and microprocessor, and the lower brachium pontis output terminal of described Intelligent Power Module and overcurrent protection pin are connected to the first end of sampling resistor altogether, the second end ground connection of described sampling resistor; The input/output port of described microprocessor is in high-impedance state when powering on, and the input/output port of described microprocessor exports high level after the power-up; It is characterized in that:

Described Intelligent Power Module power-on protective circuit comprises electric protective circuit breaker module and diode, the controlled end of described upper electric protective circuit breaker module connects the input/output port of described microprocessor, input end and the output terminal of described upper electric protective circuit breaker module are connected the anode of direct supply and described diode respectively, and the negative electrode of described diode connects the overcurrent protection pin of described Intelligent Power Module; When powering on, described upper electric protective circuit breaker module is in high-impedance state according to the input/output port of described microprocessor, is exported power on guard signal to forbid enable described Intelligent Power Module by described diode; When having powered on, described upper electric protective circuit breaker module has stopped, by the guard signal that powers on described in described diode output, entering duty with enable described Intelligent Power Module according to described high level.

2. Intelligent Power Module power-on protective circuit as claimed in claim 1, it is characterized in that, described upper electric protective circuit breaker module comprises:

First resistance, PNP type triode and the second resistance;

The common contact of the first end of described first resistance and the base stage of described PNP type triode is the controlled end of described upper electric protective circuit breaker module; second end ground connection of described first resistance; the input end of the very described upper electric protective circuit breaker module of transmitting of described PNP type triode; the collector of described PNP type triode connects the first end of described second resistance, and the second end of described second resistance is the output terminal of described upper electric protective circuit breaker module.

3. an air conditioner, it comprises Intelligent Power Module and microprocessor, it is characterized in that, described air conditioner also comprises Intelligent Power Module power-on protective circuit as claimed in claim 1 or 2.