CN211830192U

CN211830192U - Power supply control circuit and air conditioner

Info

Publication number: CN211830192U
Application number: CN202020718255.2U
Authority: CN
Inventors: 王志亮; 习涛; 黄育夫
Original assignee: TCL Air Conditioner Zhongshan Co Ltd
Current assignee: TCL Air Conditioner Zhongshan Co Ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2020-10-30
Anticipated expiration: 2030-04-30

Abstract

The utility model provides a power supply control circuit and an air conditioner, wherein the power supply control circuit comprises a direct current power supply positive input end, a direct current power supply negative input end, a voltage division circuit, a switch circuit and a switch power supply chip; the input end of the voltage division circuit is connected with the positive electrode input end of the direct-current power supply, and the output end of the voltage division circuit is connected with the controlled end of the switch circuit; the first connecting end of the switch circuit is connected with the feedback end of the switch power supply chip, and the second connecting end of the switch circuit is connected with the negative electrode input end of the direct-current power supply. The technical scheme of the utility model, aim at avoiding leading to switching power supply chip to be damaged because grid voltage is too high.

Description

Power supply control circuit and air conditioner

Technical Field

The utility model relates to the field of electronic technology, in particular to power control circuit and air conditioner.

Background

At present, a flyback switching power supply scheme is widely applied to a direct-current variable-frequency air conditioner due to the advantages of high power supply efficiency, small size, wide voltage application range and the like.

The working principle of the flyback switching power supply scheme is as follows: the alternating current power supply is converted into direct current voltage through filtering rectification. The direct current voltage flows into a switching power supply chip through a primary winding of the switching transformer, and the switching power supply chip controls the on and off of a switching tube inside the switching power supply chip to enable a secondary winding of the switching transformer to generate induced voltage and then outputs the required voltage through rectification.

However, the flyback switching power supply scheme has the defect that the switching power supply chip does not have a voltage detection function inside, and when the voltage of a power grid is too high, the switching power supply chip cannot effectively stop working, so that the switching power supply chip is damaged due to overvoltage.

SUMMERY OF THE UTILITY MODEL

The utility model provides a power control circuit and air conditioner aims at avoiding leading to switching power supply chip to be damaged because grid voltage is too high.

In order to achieve the above object, the present invention provides a power control circuit, which includes a dc power positive input terminal, a dc power negative input terminal, a voltage dividing circuit, a switching circuit and a switching power chip;

the input end of the voltage division circuit is connected with the positive electrode input end of the direct-current power supply, and the output end of the voltage division circuit is connected with the controlled end of the switch circuit; the first connecting end of the switch circuit is connected with the feedback end of the switch power supply chip, and the second connecting end of the switch circuit is connected with the negative electrode input end of the direct-current power supply.

Optionally, the voltage dividing circuit includes a first resistor, a second resistor, a third resistor, and a first zener diode;

the first end of the first resistor is connected with the positive input end of the direct-current power supply; the second end of the first resistor is connected with the first end of the second resistor and the negative electrode of the first voltage stabilizing diode; the anode of the first voltage stabilizing diode is connected with the controlled end of the switch circuit and the first end of the third resistor; and the second end of the second resistor and the second end of the third resistor are connected with the negative input end of the direct-current power supply.

Optionally, the switch circuit includes a first electron tube, a first end of the first electron tube is a controlled end of the switch circuit, a second end of the first electron tube is a first connection end of the switch circuit, and a third end of the first electron tube is a second connection end of the switch circuit.

Optionally, the first electron tube is an NPN triode, a base of the NPN triode is a first end of the first electron tube, a collector of the NPN triode is a second end of the first electron tube, and an emitter of the NPN triode is a third end of the first electron tube.

Optionally, the power control circuit further includes a voltage transformation rectifying circuit and a feedback circuit;

the controlled end of the voltage transformation rectifying circuit is connected with the signal output end of the switching power supply chip; the input end of the voltage transformation rectifying circuit is connected with the positive input end of the direct-current power supply, and the output end of the voltage transformation rectifying circuit is connected with the input end of the feedback circuit; and the output end of the feedback circuit is connected with the feedback end of the switching power supply chip.

Optionally, the voltage transformation and rectification circuit includes a first diode, a second diode, a third diode, a first capacitor, a second capacitor, a third capacitor, a fourth resistor, a fifth resistor, a first electrolytic capacitor, a second electrolytic capacitor, and a transformer;

the signal output end of the switching power supply chip is connected with the anode of the first diode and the third end of the primary coil of the transformer; the negative electrode of the first diode is connected with the first end of the first capacitor and the first end of the fourth resistor; the second end of the first capacitor and the second end of the fourth resistor are connected with the positive input end of the direct-current power supply; the positive input end of the direct-current power supply is connected with the first end of the primary coil of the transformer;

a power supply end of the switching power supply chip is connected with a first end of the second capacitor, a first end of the first electrolytic capacitor and a negative electrode of the second diode; the second end of the second capacitor and the second end of the first electrolytic capacitor are connected with the negative electrode input end of the direct-current power supply; the anode of the second diode is connected with the fourth end of the primary coil of the transformer; the fifth end of the primary coil of the transformer is connected with the negative electrode input end of the direct-current power supply;

one end of the secondary coil of the transformer is connected with the first end of the third capacitor and the anode of the third diode; the second end of the third capacitor is connected with the first end of the fifth resistor; the second end of the fifth resistor, the cathode of the third diode, the first end of the fourth capacitor and the first end of the second electrolytic capacitor are connected with the input end of the feedback circuit; and the second end of the fourth capacitor, the second end of the second electrolytic capacitor and the other end of the secondary coil of the transformer are connected with the system ground.

Optionally, the feedback circuit includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a second zener diode, and an optical coupler;

the first end of the sixth resistor and the first end of the eighth resistor are connected with the output end of the voltage transformation rectifying circuit; the second end of the sixth resistor, the first end of the tenth resistor, the first end of the seventh resistor and the anode of the second zener diode are connected with the system ground; and a second end of the seventh resistor is connected with the system ground;

a second end of the tenth resistor is connected with a first end of the fifth capacitor; a second end of the fifth capacitor, a cathode of the second zener diode, and a second end of the ninth resistor are connected to a second end of the optocoupler; a second end of the eighth resistor and a first end of the ninth resistor are connected with a first end of the optical coupler;

the third end of the optical coupler is connected with the feedback end of the switching power supply chip through the eleventh resistor; the third end of the optical coupler is connected with the first end of the seventh capacitor and the first end of the twelfth resistor; the second end of the seventh capacitor is connected with the negative electrode input end of the direct-current power supply; a second end of the twelfth resistor is connected with the negative electrode input end of the direct-current power supply through the sixth capacitor; and the fourth end of the optical coupler is connected with the negative electrode input end of the direct-current power supply.

Optionally, the power control circuit further includes a rectifying and filtering circuit;

the input end of the rectification filter circuit is connected with an alternating current live wire, and the output end of the rectification filter circuit is connected with the input end of the voltage transformation rectification circuit; and the output end of the rectification filter circuit is connected with the input end of the voltage division circuit.

Optionally, the rectification filter circuit includes a fuse, a voltage dependent resistor, a thermistor, an eighth capacitor, a ninth capacitor, a common mode inductor, a rectifier, and a third electrolytic capacitor;

the alternating current live wire is connected with the first end of the voltage dependent resistor, the first end of the eighth capacitor and the first end of the first coil of the common mode inductor through the fuse; the second end of the first coil of the common mode inductor is connected with the first end of the ninth capacitor and the first end of the thermistor; the second end of the thermistor is connected with the first input end of the rectifier;

the alternating current zero line is connected with the second end of the piezoresistor, the second end of the eighth capacitor and the first end of the second coil of the common-mode inductor; a second end of the second coil of the common mode inductor is connected with a second end of the ninth capacitor and a second input end of the rectifier;

the first output end of the rectifier is the positive input end of the direct-current power supply and is connected with the first end of the third electrolytic capacitor; and the second output end of the rectifier is the negative input end of the direct-current power supply and is connected with the second end of the third electrolytic capacitor.

In order to achieve the above object, the present invention provides an air conditioner, which includes the power control circuit as described above.

The technical scheme of the utility model, through setting up bleeder circuit and detecting the electric wire netting voltage of input, when electric wire netting voltage is too big, bleeder circuit control switch circuit switches on for the level of switching power supply chip's feedback end is the low level, thereby triggers switching power supply chip stop work, so sets up, can avoid because the electric wire netting voltage of input is too big and lead to switching power supply chip to be damaged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a block diagram of an embodiment of a power control circuit of the present invention;

fig. 2 is a schematic circuit diagram of an embodiment of the power control circuit of the present invention;

fig. 3 is a block diagram of another embodiment of the power control circuit of the present invention;

fig. 4 is a schematic circuit diagram of another embodiment of the power control circuit of the present invention;

fig. 5 is a block diagram of another embodiment of the power control circuit of the present invention;

fig. 6 is a schematic circuit diagram of an embodiment of the rectifying and filtering circuit in fig. 5.

The reference numbers illustrate:

the objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, if directional indications (such as upper, lower, left, right, front and rear … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

Fig. 1 is a schematic circuit diagram of an embodiment of the power control circuit of the present invention.

Referring to fig. 1, the power control circuit includes a DC power positive input terminal DC +, a DC power negative input terminal DC-, a voltage divider circuit 10, a switch circuit 20, and a switch power chip 30;

the input end of the voltage dividing circuit 20 is connected with the positive input end DC + of the DC power supply, and the output end of the voltage dividing circuit 10 is connected with the controlled end of the switch circuit 20; the first connection terminal of the switch circuit 20 is connected to the feedback terminal of the switch power supply chip 30, and the second connection terminal of the switch circuit 20 is DC-connected to the negative input terminal of the DC power supply.

The voltage divider circuit 10 may be implemented by a circuit in which a plurality of resistors are connected in series.

The switching circuit 20 may be implemented by a circuit composed of a single transistor or a plurality of transistors, such as a triode, a MOS transistor, and the like.

The switching power supply chip 30 is internally provided with a switching tube, and the switching power supply chip 30 controls the size of the induced voltage generated by the switching transformer in the power supply control circuit by controlling the on and off of the switching tube therein, so as to realize voltage stabilization output.

In this embodiment, the power control circuit may be a flyback switching power control circuit, and further includes a rectifying and filtering circuit 60, a voltage transformation and rectifying circuit 40, and a feedback circuit 50; wherein, the input end of the rectifying filter circuit 60 is connected with the alternating current live wire L to receive the input alternating current power supply, the output end of the rectifying filter circuit 60 is connected with the input end of the voltage transformation rectifying circuit 40, the output end of the voltage transformation rectifying circuit 40 is connected with the input end of the feedback circuit 50, and the output end of the feedback circuit 50 is connected with the feedback end of the switching power supply chip 30; and the signal output end of the switching power supply chip 30 is connected with the controlled end of the voltage transformation and rectification circuit 40.

The specific working principle is as follows: the rectifying and smoothing circuit 60 receives an ac power supply, converts the ac power supply into a dc voltage through rectifying and smoothing processing, and outputs the dc voltage to the transformer and rectifying circuit 40. The dc voltage is rectified and transformed by the transformer and rectifier circuit 40 and then output. Meanwhile, the feedback circuit 50 feeds back the voltage output by the transformer and rectifier circuit 40 to the switching power supply chip 30. The switching power supply chip 30 adjusts the on-time of its internal switching tube according to the received feedback voltage, i.e. changes the duty ratio of the PWM pulse modulation signal output to its internal switching tube to control the transformer rectifier circuit 40 to output stable voltage.

Meanwhile, the voltage divider circuit 10 is provided to detect the dc voltage output from the rectifying/smoothing circuit 60 in real time. It can be understood that when the grid voltage is normal, the dc voltage output by the rectifying and filtering circuit 60 is also normal. The normal dc voltage is input to the voltage divider circuit 10, so that the voltage divider circuit 10 can generate a turn-off signal and output the turn-off signal to the controlled terminal of the switch circuit 20, so as to trigger the switch circuit 20 to turn off. When the switching circuit 20 is turned off, the voltage at the feedback end of the switching power supply chip 30 is the voltage output by the feedback circuit 50, and the switching power supply chip 30 normally operates according to the voltage output by the feedback circuit 50.

When the grid voltage is too high, the dc voltage output by the rectifying and filtering circuit 60 will also be too high. The excessively high dc voltage is input to the voltage divider circuit 10, so that the voltage divider circuit 20 generates a conducting signal and outputs the conducting signal to the controlled terminal of the switch circuit 20, so as to trigger the switch circuit 20 to switch from the off state to the on state. When the switching circuit 20 is turned on, the feedback terminal of the switching power supply chip 30 is DC-connected to the negative input terminal of the DC voltage via the turned-on switching circuit 20. The level of the feedback terminal of the switching power supply chip 30 is a low level, that is, 0V, and the switching power supply chip 30 stops working. So set up, can avoid because the electric wire netting voltage is too high and lead to switching power supply chip 30 to be damaged, effectual protection switching power supply chip 30, ensured air conditioner normal operating.

The technical scheme of this embodiment, detect the electric wire netting voltage of input through setting up bleeder circuit 10, when electric wire netting voltage is too high, control switch circuit 20 through the produced signal that switches on of bleeder circuit 10 and switch on for the level of switching power supply chip 30's feedback end is the low level, thereby trigger switching power supply chip 30 stop work, so set up, can avoid leading to switching power supply chip 30 to be damaged because the electric wire netting voltage of input is too big, ensured the normal operating of air conditioner.

Optionally, referring to fig. 2, in an embodiment, the voltage dividing circuit 10 includes a first resistor R1, a second resistor R2, a third resistor R3, and a first zener diode T1;

a first end of the first resistor R1 is connected to the DC power supply positive input terminal DC +, and a second end of the first resistor R1 is connected to a first end of the second resistor R2 and a negative electrode of the first zener diode T1; the anode of the first zener diode T1 is connected to the controlled terminal of the switch circuit 20 and the first terminal of the third resistor R3; the second end of the second resistor R1 and the second end of the third resistor R3 are both DC-connected with the negative input end of the direct current power supply.

The specific working principle is as follows: the first resistor R1 and the second resistor R2 divide the DC voltage input from the positive input terminal DC + of the DC power supply, and if the voltage signal divided by the first resistor R1 and the second resistor R2 is less than the on-state voltage of the first zener diode T1, the first zener diode T1 is turned off. At this time, under the pull-down action of the third resistor R3, the controlled terminal of the switch circuit 20 receives the off signal, which is an electrical signal with a low level, the switch circuit 20 is turned off, the level of the feedback terminal of the switching power supply chip 30 is equal to the level output by the feedback circuit 50, and the switching power supply chip 30 operates normally.

If the voltage signal divided by the first resistor R1 and the second resistor R2 is greater than the turn-on voltage of the first zener diode T1, the first zener diode T1 is turned on. At this time, the level of the controlled terminal of the switch circuit 20 is high, and the switch circuit 20 is turned on. When the switching circuit 20 is turned on, the feedback end of the switching power supply chip 30 is electrically connected to the DC-input terminal of the DC power supply, the feedback end of the switching power supply chip 30 is at a low level, that is, the level is 0V, and the switching power supply chip 30 stops working.

Alternatively, referring to fig. 2, in an embodiment, the switching circuit 20 includes a first transistor Q, a first terminal of the first transistor Q is a controlled terminal of the switching circuit 20, a second terminal of the first transistor Q is a first connection terminal of the switching circuit 20, and a third terminal of the first transistor Q is a second connection terminal of the switching circuit 20.

In this embodiment, the first electronic tube Q may be a high-level conducting electronic tube, such as an NPN transistor, and a base of the NPN transistor is a first end of the first electronic tube Q, a collector of the NPN transistor is a second end of the first electronic tube Q, and an emitter of the NPN transistor is a third end of the first electronic tube Q.

In this embodiment, when the voltage dividing circuit 10 outputs the turn-off signal, that is, when the voltage dividing circuit 10 outputs the low-level electrical signal, it indicates that the input grid voltage is normal at this time, the first electronic tube Q is turned off, the level of the feedback end of the switching power supply chip 30 is equal to the level output by the feedback circuit 50, and the switching power supply chip 30 operates normally.

When the voltage dividing circuit 10 outputs a conducting signal, that is, when the voltage dividing circuit 10 outputs an electrical signal with a high level, it indicates that the input grid voltage is too high at this time and the switching power supply chip 30 may be damaged, the first electron tube Q is turned on, the feedback end of the switching power supply chip 30 is electrically connected to the DC-negative input end of the direct current power supply, the feedback end of the switching power supply chip 30 is at a low level, that is, the level is 0V, and the switching power supply chip 30 stops working.

Optionally, referring to fig. 3, in an embodiment, the power control circuit further includes a transformer rectifier circuit 40 and a feedback circuit 50;

the controlled end of the transformer rectifier circuit 40 is connected with the signal output end of the switch power supply chip 30, the input end of the transformer rectifier circuit 40 is connected with the positive input end DC + of the direct current power supply, the output end of the transformer rectifier circuit 40 is connected with the input end of the feedback circuit 50, and the output end of the feedback circuit 50 is connected with the feedback end of the switch power supply chip 30.

Specifically, the DC voltage input from the positive input terminal DC + of the DC power supply flows into the switching power supply chip 30 through the primary coil of the transformer in the transformer rectification circuit 40, and supplies power to the switching power supply chip 30. The switching power supply chip 30 controls the on/off of the internal switching tube thereof to enable the secondary coil of the switching transformer to generate an induced voltage, and then the induced voltage is rectified by the rectifying component in the transformer rectifying circuit 40 and then fed back to the switching power supply chip 30 through the feedback circuit 50, and the switching power supply chip 30 adjusts the on-time of the internal switching tube thereof according to the received feedback voltage, that is, the duty ratio of the PWM pulse modulation signal output to the internal switching tube thereof is changed to enable the transformer rectifying circuit 40 to output a stable voltage.

Optionally, referring to fig. 4, in an embodiment, the transformer rectifier circuit 40 includes a first diode D1, a second diode D2, a third diode D3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fourth resistor R4, a fifth resistor R5, a first electrolytic capacitor E1, a second electrolytic capacitor E2, and a transformer TR; wherein

A signal output end D of the switching power supply chip U1 is connected with an anode of a first diode D1 and a third end 3 of a primary coil of the transformer TR, and a cathode of a first diode D1 is connected with a first end of a first capacitor C1 and a first end of a fourth resistor R4; a second end of the first capacitor C1 and a second end of the fourth resistor R4 are both connected with a positive input end DC + of the direct-current power supply, and the positive input end DC + of the direct-current power supply is connected with a first end 1 of a primary coil of the transformer TR;

the power supply end of the switching power supply chip U1 is connected with the first end of the second capacitor C2, the first end of the first electrolytic capacitor E1 and the cathode of the second diode D2; the second end of the second capacitor C2 and the second end of the first electrolytic capacitor E1 are both DC-connected with the negative input end of the direct-current power supply; the anode of the second diode D2 is connected to the fourth terminal 4 of the primary winding of the transformer TR; a fifth end 5 of a primary coil of the transformer TR is DC-connected with a negative electrode input end of the direct-current power supply;

one end 6 of the secondary coil of the transformer TR is connected to the first end of the third capacitor C3 and the anode of the third diode D3; a second end of the third capacitor C3 is connected with a first end of a fifth resistor R5; the second end of the fifth resistor R5, the cathode of the third diode D3, the first end of the fourth capacitor C4 and the first end of the second electrolytic capacitor E2 are all connected with the input end of the feedback circuit 50; the second terminal of the fourth capacitor C4, the second terminal of the second electrolytic capacitor E2, and the other terminal of the secondary winding of the transformer TR are connected to the system ground GND.

The power supply terminal of the switching power chip U1 IS connected to the system ground through a tenth capacitor C10, and the control terminal IS of the switching power chip U1 IS connected to the system ground through a thirteenth resistor R13.

Specifically, the transformer TR receives a DC voltage input from the positive input terminal DC + of the DC power supply, and triggers the secondary winding to generate an induced voltage through the first terminal 1 and the third terminal 3 of the primary winding. The induced voltage flows to the second end 7 of the secondary coil through the first end 6 of the secondary coil, the third diode D3, the fourth capacitor C4 and the second electrolytic capacitor E2, and forms a rectified output voltage through the third capacitor and the fifth resistor, and the rectified output voltage is output to the feedback circuit 50. And the fourth and fifth terminals of the primary coil of the transformer TR are used to supply power to the switching power supply chip 30.

Optionally, referring to fig. 4, in an embodiment, the feedback circuit 50 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, a second zener diode T2, and an optocoupler IC 1;

the first end of the sixth resistor R6 and the first end of the eighth resistor R8 are connected with the output end of the transformer rectifying circuit 40; a second end of the sixth resistor R6, a first end of the tenth resistor R10, a first end of the seventh resistor R7, and an anode of the second zener diode T2 are connected to the system ground GND; and a second end of the seventh resistor R7 is connected to system ground;

a second terminal of the tenth resistor R10 is connected to a first terminal of the fifth capacitor C5; a second end of the fifth capacitor C5, a cathode of the second zener diode T2, and a second end of the ninth resistor R9 are all connected to the second end b of the optocoupler IC 1; a second end of the eighth resistor R8 and a first end of the ninth resistor R9 are both connected to the first end a of the optocoupler IC 1;

the third terminal c of the optical coupler IC1 is connected with the feedback terminal of the switching power supply chip 30 through an eleventh resistor R11; and the third terminal C of the optocoupler IC1 is connected with the first terminal of the seventh capacitor C7 and the first terminal of the twelfth resistor R12; the second end of the seventh capacitor C7 is DC-connected with the negative input end of the direct current power supply; the second end of the twelfth resistor R12 is DC-connected with the negative input end of the direct current power supply through a sixth capacitor C6; the fourth terminal d of the optocoupler IC1 is DC-connected to the negative input terminal of the direct current supply.

Specifically, the sixth resistor R6 and the seventh resistor R7 divide the voltage output by the transformer rectifier circuit 40, so as to provide a reference voltage for the anode of the second zener diode T2, and trigger the second zener diode T2 to be turned on. When the second zener diode T2 is turned on, the voltage output from the transformer rectifier circuit 40 flows to the system ground through the eighth resistor R8, the light emitting diode of the optocoupler IC1, and the second zener diode T2, and the light emitting diode of the optocoupler IC1 emits light. When the light emitting diode of the photo coupler IC1 emits light, the third terminal c and the fourth terminal d of the photo coupler IC1 generate current, the generated current is fed back to the switching power supply chip 30 through the eleventh resistor R11, and the switching power supply chip 30 adjusts the conduction time of the internal switching tube thereof according to the received voltage, so that the transformer rectification circuit 40 outputs a stable voltage.

Optionally, referring to fig. 5, in an embodiment, the power control circuit further includes a rectifying and filtering circuit 60;

the input end of the rectifying and filtering circuit 60 is connected with an alternating current live wire L, and the output end of the rectifying and filtering circuit 60 is connected with the input end of the voltage transformation rectifying circuit 40; and the output end of the rectifying and filtering circuit 40 is connected with the input end of the voltage division circuit 10.

The rectifying and smoothing circuit 60 is configured to receive an externally input ac power, convert the ac power into a dc voltage, and input the dc voltage to the transformer and rectifying circuit 50.

Optionally, referring to fig. 6, in an embodiment, the rectifying and filtering circuit 60 includes a fuse PUSE1, a voltage dependent resistor ZR1, a thermistor NTC1, an eighth capacitor C8, a ninth capacitor C9, a common mode inductor L1, a rectifier BR1, and a third electrolytic capacitor E3;

the alternating current live wire L is connected with the first end of the piezoresistor ZR1, the first end of the eighth capacitor C8 and the first end of the first coil of the common-mode inductor L1 through the fuse PUSE 1; the second end of the first coil of the common-mode inductor L1 is connected with the first end of the ninth capacitor C9 and the first end of the thermistor NTC 1; a second end of the thermistor NTC1 is connected with a first input end of a rectifier BR 1;

the alternating current zero line N is connected with the second end of the piezoresistor ZR1, the second end of the eighth capacitor C8 and the first end of the second coil of the common-mode inductor L1; a second end of the second coil of the common mode inductor L1 is connected to a second end of the ninth capacitor C9 and a second input terminal of the rectifier BR 1;

a first output end of the rectifier BR1 is a direct-current power supply positive input end DC +, and is connected with a first end of a third electrolytic capacitor E3; a second output end of the rectifier BR1 is a negative input end DC-of the direct current power supply and is connected with a second end of the third electrolytic capacitor E3.

Specifically, an ac power supply flows into the rectifier BR1 through the fuse PUSE1, the common mode inductor L1, and the thermistor NTC1, and the rectifier BR1 full-wave rectifies the ac power supply and converts the full-wave rectified ac power supply into a dc voltage, which is output to the transformer rectifier circuit 40. Meanwhile, the voltage divider circuit 10 detects the dc voltage output by the rectifier BR1 in real time, and when the dc voltage output by the rectifier BR1 is too high, the voltage divider circuit 10 generates a turn-on signal and outputs the turn-on signal to the controlled terminal of the switch circuit 20 to trigger the switch circuit 20 to turn on. When the switching circuit 20 is turned on, the feedback terminal of the switching power supply chip 30 is DC-connected to the negative input terminal of the DC voltage via the turned-on switching circuit 20. The level of the feedback terminal of the switching power supply chip 30 is low level, i.e., 0V, and the switching power supply chip 30 stops working. By such an arrangement, the switching power supply chip 30 can be prevented from being damaged due to the excessively high grid voltage.

The utility model also provides an air conditioner, this air conditioner includes as above power control circuit. The detailed structure of the power control circuit can refer to the above embodiments, and is not described herein; it can be understood that, because the utility model discloses an above-mentioned power control circuit has been used in the air conditioner, consequently, the utility model discloses the embodiment of air conditioner includes all technical scheme of the whole embodiments of above-mentioned power control circuit, and the technical effect who reaches is also identical, no longer gives details here.

The above is only the optional embodiment of the present invention, and not the scope of the present invention is limited thereby, all the equivalent structure changes made by the contents of the specification and the drawings are utilized under the inventive concept of the present invention, or the direct/indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A power supply control circuit is characterized by comprising a direct-current power supply positive electrode input end, a direct-current power supply negative electrode input end, a voltage division circuit, a switching circuit and a switching power supply chip;

2. The power control circuit of claim 1, wherein the voltage divider circuit comprises a first resistor, a second resistor, a third resistor, and a first zener diode;

3. The power control circuit as claimed in claim 1, wherein the switching circuit includes a first lamp, a first terminal of the first lamp is a controlled terminal of the switching circuit, a second terminal of the first lamp is a first connection terminal of the switching circuit, and a third terminal of the first lamp is a second connection terminal of the switching circuit.

4. The power control circuit of claim 3, wherein the first valve is an NPN transistor, a base of the NPN transistor is a first end of the first valve, a collector of the NPN transistor is a second end of the first valve, and an emitter of the NPN transistor is a third end of the first valve.

5. The power supply control circuit according to any one of claims 1 to 3, wherein the power supply control circuit further comprises a voltage transformation rectifying circuit and a feedback circuit;

6. The power control circuit according to claim 5, wherein the transformer rectifier circuit comprises a first diode, a second diode, a third diode, a first capacitor, a second capacitor, a third capacitor, a fourth resistor, a fifth resistor, a first electrolytic capacitor, a second electrolytic capacitor, and a transformer;

7. The power control circuit of claim 5, wherein the feedback circuit comprises a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a second zener diode, and an optocoupler;

8. The power control circuit of claim 5, further comprising a rectifier filter circuit;

9. The power control circuit of claim 8, wherein the rectifying and filtering circuit comprises a fuse, a voltage dependent resistor, a thermistor, an eighth capacitor, a ninth capacitor, a common mode inductor, a rectifier, and a third electrolytic capacitor;

10. An air conditioner characterized in that it comprises a power supply control circuit as claimed in any one of claims 1 to 9.