Low-power-consumption power supply circuit and air conditioner

Abstract

The utility model provides a low-power-consumption power supply circuit and an air conditioner, and relates to the technical field of power supply. Comprising a power supply module, a voltage conversion module, an MCU and a feedback module, the feedback module comprises a first feedback branch and a second feedback branch, the power supply module is electrically connected with the voltage conversion module and the feedback module, the voltage conversion module is further electrically connected with the MCU, and the MCU is electrically connected with the first feedback branch. The working current when the first feedback branch is conducted is greater than the working current when the second feedback branch is conducted; wherein in a normal working state, the first feedback branch is switched off, the second feedback branch is switched on, and the power supply module outputs a first voltage to the voltage conversion module; in a standby state, the first feedback branch is switched on, the second feedback branch is switched off, and the power supply module outputs a second voltage to the voltage conversion module; the second voltage is smaller than the first voltage, and the second voltage is larger than the working voltage of the MCU. The utility model has the advantage of lower standby power consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply, in particular to a low-power supply circuit and an air conditioner. BACKGROUND

[0002] When a user uses an air conditioner, a general total power plug is always connected to a socket. In this standby state, the indoor unit and the outdoor unit control board of the air conditioner system are powered on, which causes the standby power consumption of the air conditioner to be large and consume a lot of power.

[0003] For example, assuming that the indoor unit control board power consumption is 2W and the outdoor unit control board power consumption is 4W, the air conditioner system consumes 4.3 degrees of power in a standby state for one month. It can be seen that this wasted power will increase the economic cost of the user. Therefore, reducing the standby power consumption of the air conditioner system is one of the design goals that needs to be considered in the design of the air conditioner control board.

[0004] In summary, the prior art has the problem of high standby power consumption of the air conditioner. CONTENT OF THE INVENTION

[0005] The purpose of the present application is to provide a low-power supply circuit and an air conditioner to solve the problem of high standby power consumption of the air conditioner in the prior art.

[0006] To solve the above problem, on the one hand, the present application provides a low-power supply circuit, which comprises a power supply module, a voltage conversion module, an MCU and a feedback module. The feedback module comprises a first feedback branch and a second feedback branch. The power supply module is electrically connected to the voltage conversion module and the feedback module. The voltage conversion module is electrically connected to the MCU. The MCU is electrically connected to the first feedback branch. The working current of the first feedback branch when it is turned on is greater than the working current of the second feedback branch when it is turned on. Wherein,

[0007] When in a normal working state, the first feedback branch is turned off, the second feedback branch is turned on, and the power supply module outputs a first voltage to the voltage conversion module.

[0008] When in a standby state, the first feedback branch is turned on, the second feedback branch is turned off, and the power supply module outputs a second voltage to the voltage conversion module. The second voltage is less than the first voltage, and the second voltage is greater than the working voltage of the MCU.

[0009] Due to the low-power supply circuit provided in the application, different feedback branches can be turned on when in normal working state and in standby state, and the working current of the first feedback branch turned on in standby state is large, so that the power supply module can reduce its output after receiving the feedback, so that the output second voltage is small, and the standby power consumption can be greatly reduced.

[0010] Optionally, the feedback module comprises a feedback unit, a first voltage stabilizing tube, a second voltage stabilizing tube and a switching unit, the feedback unit is electrically connected with the voltage output end and the feedback end of the power supply module respectively, the feedback unit is also electrically connected with the first voltage stabilizing tube and the second voltage stabilizing tube respectively, and the switching unit is electrically connected with the first voltage stabilizing tube and the MCU respectively; wherein,

[0011] The feedback unit, the first voltage stabilizing tube and the switching unit constitute a first feedback branch;

[0012] The feedback unit and the second voltage stabilizing tube constitute a second feedback branch, and the voltage stabilizing value of the second voltage stabilizing tube is greater than that of the first voltage stabilizing tube.

[0013] By the feedback module provided in the application, on the basis of the prior art, only the first voltage stabilizing tube and the switching unit need to be added, so that the purpose of reducing standby power consumption can be achieved, and therefore the cost is low.

[0014] Optionally, the feedback unit comprises a first resistor and an optical coupler, the optical coupler comprises a light-emitting diode and a light-receiving triode, one end of the first resistor is electrically connected with the voltage output end of the power supply module, the other end is electrically connected with the anode of the light-emitting diode, the cathode of the light-emitting diode is electrically connected with the first voltage stabilizing tube and the second voltage stabilizing tube respectively, the collector of the light-receiving triode is electrically connected with the feedback end of the power supply module, and the emitter of the light-receiving triode is grounded.

[0015] Optionally, the switching unit comprises a first switch tube, a second resistor and a third resistor, the cathode of the first voltage stabilizing tube is electrically connected with the feedback unit, the anode is electrically connected with the first end of the first switch tube, the control end of the first switch tube is electrically connected with one end of the second resistor and the third resistor respectively, the other end of the second resistor and the second end of the first switch tube are both grounded, and the other end of the third resistor is electrically connected with the MCU; wherein,

[0016] When in normal working state, the MCU outputs low level to control the first switch tube to be turned off;

[0017] When in standby state, the MCU outputs high level to control the first switch tube to be turned on.

[0018] Optionally, the first voltage stabilizer has a voltage stabilization value of 5.6V, and the second voltage stabilizer has a voltage stabilization value of 11V.

[0019] Optionally, the power supply module comprises a switching power supply chip and a power supply main circuit, the power supply main circuit is electrically connected with the switching power supply chip, an output end of the power supply main circuit is electrically connected with the voltage conversion module and the feedback module, and the switching power supply chip is also electrically connected with the feedback module; wherein,

[0020] When in the standby state, the switching power supply chip is used to reduce the output voltage of the power supply main circuit until the working current of the first feedback branch equals the working current when the second feedback branch is turned on, according to the working current when the first feedback branch is turned on.

[0021] Optionally, the voltage conversion module comprises an electrolytic capacitor, a second switch tube, a fourth resistor and a third voltage stabilizer, one end of the electrolytic capacitor is electrically connected with the output end of the power supply module, the other end is grounded, the first end of the second switch tube and the fourth resistor are both electrically connected with the output end of the power supply module, the second end of the second switch tube is electrically connected with the MCU, the control end of the second switch tube and the other end of the fourth resistor are both electrically connected with the cathode of the third voltage stabilizer, and the anode of the third voltage stabilizer is grounded.

[0022] Optionally, the third voltage stabilizer has a voltage stabilization value of 5.6V, and the working voltage of the MCU is 5V.

[0023] Optionally, the voltage conversion module further comprises a filter capacitor, one end of the filter capacitor is electrically connected with the second end of the second switch tube, and the other end of the filter capacitor is grounded.

[0024] On the other hand, the embodiment of the present application also provides an air conditioner, which comprises a load and the low-power consumption power supply circuit described above, and the low-power consumption power supply circuit is electrically connected with the load. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a power supply circuit schematic diagram of the air conditioner provided in the prior art.

[0026] Figure 2 It is another power supply circuit schematic diagram of the air conditioner provided in the prior art.

[0027] Figure 3 It is a module schematic diagram of the low-power consumption power supply circuit provided by the embodiment of the present application.

[0028] Figure 4 It is a circuit schematic diagram of the low-power consumption power supply circuit provided by the embodiment of the present application.

[0029] MARKED DESCRIPTION:

[0030] 110 - Power supply module; 111 - Main power supply circuit; 112 - Switching power supply chip; 120 - Voltage conversion module; 130 - MCU; 140 - Feedback module; 141 - First feedback branch; 142 - Second feedback branch; 143 - Feedback unit; 144 - Switching unit; ZD1 - First Zener diode; ZD2 - Second Zener diode; ZD3 - Third Zener diode; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; R4 - Fourth resistor; Q1 - First switching transistor; Q2 - Second switching transistor; Q3 - Optocoupler; C1 - Electrolytic capacitor; C2 - Filter capacitor. Detailed Implementation

[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0032] As described in the background section, air conditioners generally consume a large amount of power during standby, so reducing the standby power consumption of air conditioners is a key concern for those skilled in the art.

[0033] To reduce the standby power consumption of air conditioners, the following two methods are generally used:

[0034] For the first option, please refer to [the original text]. Figure 1 A relay that can control the power supply to the outdoor unit can be added to the indoor unit board. When the air conditioner is in standby mode, the indoor unit controls the relay not to supply power to the outdoor unit, thereby reducing the standby power consumption of the outdoor unit.

[0035] While this solution can effectively reduce the standby power consumption of air conditioners, if... Figure 1 As shown, an additional power cord is required when setting up the circuit. Figure 1 (5) In addition, if the power of the outdoor unit board is very large, the indoor unit board needs to use relays / contactors with a large current carrying capacity, which increases the cost of building the conduction system.

[0036] The second option, please refer to Figure 2 An MCU with a low-power mode can be used on the indoor and outdoor unit boards. When the air conditioner is in standby mode, the indoor and outdoor unit controller MCU enters a low-power mode to reduce standby power consumption.

[0037] However, when the internal and external circuit boards are in standby mode, the MCU is not the only power-consuming component on the board, such as... Figure 2As shown, the +5V power supply for the MCU is generated by the +12V through a voltage stabilizer, and the conversion rate of +12V power to +5V power is only 41.7%, and most of the power is wasted. The parasitic resistance on the capacitor is consuming power at all times, and the power consumption is positively correlated with the output voltage; the leakage current on various loads is also consuming power at all times, and the power consumption is also positively correlated with the output voltage; the switching power supply itself needs to consume power, and the larger the load, the more power is consumed, further increasing the standby power consumption.

[0038] In other words, the load required for the air conditioner to work normally includes a water pump, a relay, an electronic expansion valve, a stepper motor, etc., and therefore the switching power supply needs to output +12V power (or +15V power) to supply power to these load devices, and needs to output +5V power (or +3.3V power) to supply power to the MCU main control system. In the standby state, although these 12V loads have been turned off, the +12V power still exists, and inevitably forms a leakage current on the capacitor and resistor, resulting in additional loss; if the +5V power uses a linear power supply scheme, +5V output is generated by connecting a voltage stabilizing block to +12V, and 7V power is wasted, and the standby loss is higher.

[0039] Therefore, in order to solve the above problems, the low-power power supply circuit is provided.

[0040] The low-power power supply circuit provided by the application will be described below:

[0041] As an implementation manner, please refer to Figure 3 The low-power power supply circuit includes a power supply module 110, a voltage conversion module 120, an MCU 130, and a feedback module 140, the feedback module 140 includes a first feedback branch 141 and a second feedback branch 142, the power supply module 110 is electrically connected with the voltage conversion module 120 and the feedback module 140, the voltage conversion module 120 is also electrically connected with the MCU 130, the MCU 130 is electrically connected with the first feedback branch 141, and the working current of the first feedback branch 141 when turned on is greater than the working current of the second feedback branch 142 when turned on; wherein, when in a normal working state, the first feedback branch 141 is turned off, the second feedback branch 142 is turned on, and the power supply module 110 outputs a first voltage to the voltage conversion module 120; when in a standby state, the first feedback branch 141 is turned on, the second feedback branch 142 is turned off, and the power supply module 110 outputs a second voltage to the voltage conversion module 120; the second voltage is less than the first voltage, and the second voltage is greater than the working voltage of the MCU 130.

[0042] Since the low-power supply circuit provided in the application, different feedback branches can be turned on when in normal working state and in standby state, and the working current of the first feedback branch 141 turned on in standby state is large, so that the power supply module 110 can reduce its output after receiving the feedback. Finally, the output second voltage is small, which can greatly reduce the standby power consumption.

[0043] As an implementation manner, please refer to Figure 4 The power supply module 110 includes a switching power supply chip 112 and a power supply main circuit 111, the power supply main circuit 111 is electrically connected with the switching power supply chip 112, the output end of the power supply main circuit 111 is electrically connected with the voltage conversion module 120 and the feedback module 140, and the switching power supply chip 112 is also electrically connected with the feedback module 140; wherein, when in standby state, the switching power supply chip 112 is used to reduce the output voltage of the power supply main circuit 111 according to the working current when the first feedback branch 141 is turned on, until the working current of the first feedback branch 141 is equal to the working current when the second feedback branch 142 is turned on.

[0044] Generally, the power supply includes rectifier bridge, transformer and the like, the input end of the rectifier bridge can be connected with power supply, for example, connected with mains, and converts alternating current into 310V direct current, at the same time, the transformer can convert 310V direct current into the required output voltage, which can generally be converted into 15V voltage or 12V voltage and the like.

[0045] At the same time, the switching power supply chip 112 is connected with the transformer, and by controlling the PWM duty cycle, the voltage converted by the transformer can be controlled.

[0046] On this basis, the voltage output end of the power supply module 110 refers to the output of the transformer secondary side; the feedback end of the power supply module 110 refers to the feedback port of the switching power supply chip 112. In actual application, the switching power supply chip 112 can adjust the output voltage of the transformer based on the signal of the feedback port. For example, when overcurrent occurs, the switching power supply chip 112 can control the voltage of the transformer secondary side to be reduced, so that the voltage of the voltage output end of the power supply module 110 is reduced.

[0047] As an implementation manner, the feedback module 140 comprises a feedback unit 143, a first voltage stabilizing tube ZD1, a second voltage stabilizing tube ZD2, and a switching unit 144, the feedback unit 143 is electrically connected with the voltage output end and the feedback end of the power supply module 110 respectively, the feedback unit 143 is further electrically connected with the first voltage stabilizing tube ZD1 and the second voltage stabilizing tube ZD2 respectively, and the switching unit 144 is electrically connected with the first voltage stabilizing tube ZD1 and the MCU 130 respectively; wherein the feedback unit 143, the first voltage stabilizing tube ZD1, and the switching unit 144 form a first feedback branch 141; the feedback unit 143 and the second voltage stabilizing tube ZD2 form a second feedback branch 142; and the voltage stabilizing value of the second voltage stabilizing tube ZD2 is greater than the voltage stabilizing value of the first voltage stabilizing tube ZD1.

[0048] The feedback unit 143 is configured to transmit a feedback signal to the switching power supply chip 112, and the feedback signal transmitted by the feedback unit 143 to the switching power supply chip 112 is different when different feedback branches are turned on.

[0049] Specifically, the feedback unit 143 comprises a first resistor R1 and an optical coupler Q3, the optical coupler Q3 comprises a light-emitting diode and a light-receiving triode, one end of the first resistor R1 is electrically connected with the voltage output end of the power supply module 110, the other end is electrically connected with the anode of the light-emitting diode, the cathode of the light-emitting diode is electrically connected with the first voltage stabilizing tube ZD1 and the second voltage stabilizing tube ZD2 respectively, the collector of the light-receiving triode is electrically connected with the feedback end of the power supply module 110, and the emitter of the light-receiving triode is grounded.

[0050] The switching unit 144 comprises a first switching tube Q1, a second resistor R2, and a third resistor R3, the cathode of the first voltage stabilizing tube ZD1 is electrically connected with the feedback unit 143, the anode is electrically connected with the first end of the first switching tube Q1, the control end of the first switching tube Q1 is electrically connected with one end of the second resistor R2 and the third resistor R3 respectively, the other end of the second resistor R2 and the second end of the first switching tube Q1 are both grounded, and the other end of the third resistor R3 is electrically connected with the MCU 130; wherein the MCU 130 outputs a low level to control the first switching tube Q1 to be turned off when in a normal working state, and the MCU 130 outputs a high level to control the first switching tube Q1 to be turned on when in a standby state.

[0051] The feedback module 140 provided in the present application can make the MCU 130 control the first feedback branch 141 to be turned off when the circuit is in a normal working state, and the MCU 130 can control the first feedback branch 141 to be turned on when the circuit is in a standby state. When different feedback branches are turned on, the feedback unit 143 can transmit different feedback signals to the switching power supply chip 112. When the circuit is in a standby state, the current of the feedback signal is greater, and the switching power supply chip 112 will determine that an overvoltage condition occurs at this time, and then control the voltage of the voltage output end of the power supply module 110 to decrease.

[0052] When the working voltage of the MCU 130 is 5V and the voltage output end of the power supply module 110 outputs a voltage of 12V, the voltage stabilizing value of the first voltage stabilizing tube ZD1 is 5.6V and the voltage stabilizing value of the second voltage stabilizing tube ZD2 is 11V. Of course, the voltage stabilizing values of the first voltage stabilizing tube ZD1 and the second voltage stabilizing tube ZD2 can be adjusted according to actual needs, and then the voltage output by the voltage output end can be adjusted. For example, when the voltage output by the voltage output end needs to be 15V, the voltage stabilizing values of the first voltage stabilizing tube and the second voltage stabilizing tube ZD2 can be appropriately increased.

[0053] As an implementation manner, the voltage conversion module 120 comprises an electrolytic capacitor C1, a second switch tube Q2, a fourth resistor R4 and a third voltage stabilizing tube ZD3. One end of the electrolytic capacitor C1 is electrically connected with the output end of the power supply module 110, and the other end is grounded. The first end of the second switch tube Q2 and the fourth resistor R4 are both electrically connected with the output end of the power supply module 110. The second end of the second switch tube Q2 is electrically connected with the MCU 130. The control end of the second switch tube Q2 and the other end of the fourth resistor R4 are both electrically connected with the cathode of the third voltage stabilizing tube ZD3. The anode of the third voltage stabilizing tube ZD3 is grounded.

[0054] Among them, the first switch tube Q1 and the second switch tube Q2 described in the present application can both adopt NPN triode. Of course, other switch tubes can also be used, for example, MOS tube, which is not limited here.

[0055] Exemplarily, the voltage stabilizing value of the third voltage stabilizing tube ZD3 is 5.6V, and the working voltage of the MCU 130 is 5V.

[0056] In addition, the voltage conversion module 120 further comprises a filter capacitor C2. One end of the filter capacitor C2 is electrically connected with the second end of the second switch tube Q2, and the other end of the filter capacitor C2 is grounded.

[0057] The working principle of the low-power supply circuit provided in the present application will be described in detail below. Figure 4 The working principle of the low-power supply circuit provided in the present application will be described in detail below.

[0058] In the normal working state, for example, the air conditioner is in cooling, heating or ventilation mode, the MCU 130 master control GPIOx control port output low (0V), the first switch tube Q1 and the first voltage regulator ZD1 are not turned on, the electrolytic capacitor C1 both ends voltage reaches 12V, the second voltage regulator ZD2 is turned on, the light coupling Q3 primary and secondary flow through the appropriate current i1 (need to debug the first resistor R1, the current is adjusted in the linear region of the light coupling Q3, the switch power supply chip 112 and the light coupling Q3 selection is related) the voltage signal at this time is fed back to the switch power supply chip 112. The switch power supply chip 112 controls the power supply main road 111 to be stable and no longer rise. And, when the electrolytic capacitor C1 both ends voltage is greater than 5.6V, the third voltage regulator ZD3 is turned on, the second switch tube Q2 is turned on, the emitter voltage of the second switch tube Q2 follows the base voltage, that is, the voltage of the third voltage regulator ZD3, +5V voltage is generated, the required load voltage is complete, the MCU 130 controls the water pump, motor and other load to start, the system works normally.

[0059] In standby state, the MCU 130 master control GPIOx control port output high (5V), the first switch tube Q1 is turned on, the second voltage regulator ZD2 both ends breakdown voltage 11V is greater than the first voltage regulator ZD1 breakdown voltage 5.6V, the first voltage regulator ZD1 is turned on, the second voltage regulator ZD2 both ends voltage is clamped at about 5.6V, the first resistor R1 voltage division increases rapidly, the current flowing through also increases rapidly, the light coupling Q3 primary current i2 of the same loop will increase rapidly, the current of the light coupling Q3 secondary will increase in proportion. On this basis, the switch power supply chip 112 receives the instantaneous increase of current signal, judges as output overvoltage, the output +12V voltage will gradually decrease, until the light coupling Q3 secondary current i2 is equal to i1, the switch power supply chip 112 receives the same feedback signal as the current i1 to stop adjusting the output voltage, the output voltage is about 6.6V and keeps stable; The second switch tube Q2 and the third voltage regulator ZD3 are normally turned on, the +5V voltage is normally output, the MCU 130 master control works normally, the rest of the load is off, until the standby state is cancelled.

[0060] It can be seen that, taking the example that the power supply module 110 outputs a 12V voltage, when in a normal working state, the first feedback branch 141 is turned off, and the second feedback branch 142 is turned on, at this time, the switch power supply chip 112 controls the power supply main circuit 111 to output a 12V voltage. When in a standby state, the MCU 130 controls the first switch tube Q1 to be turned on, at this time, the feedback end current of the switch power supply chip 112 increases, the switch power supply chip 112 identifies the overvoltage at this time, and thus controls the output voltage of the power supply main circuit 111 to be reduced until it is reduced to about 6.6V. This voltage can guarantee the normal power supply requirement of the MCU 130, and compared with the prior art, in the prior art, the power supply main circuit 111 also needs to output a 12V voltage when in a standby state, while the present application only needs to output a 6.6V voltage, so the power consumption can be reduced by about 45%.

[0061] In addition, compared with the existing power supply circuit, the present application only needs to additionally increase two devices, i.e., the second resistor R2, the third resistor R3, the first switch tube Q1 and the first voltage stabilizing tube ZD1, so the circuit building cost is relatively low. At the same time, by adjusting the voltage stabilizing values of the first voltage stabilizing tube ZD1, the second voltage stabilizing tube ZD2 and the third voltage stabilizing tube ZD3, the present application can be applied to different power supply systems, for example, can also be applied to a 15V power supply system, and the application scene is more flexible.

[0062] Based on the above implementation mode, the present application embodiment further provides an air conditioner, which comprises a load and the low-power-consumption power supply circuit described above, and the low-power-consumption power supply circuit is electrically connected with the load.

[0063] In summary, the present application embodiment provides a low-power-consumption power supply circuit and an air conditioner, the low-power-consumption power supply circuit comprises a power supply module, a voltage conversion module, an MCU and a feedback module, the feedback module comprises a first feedback branch and a second feedback branch, the power supply module is electrically connected with the voltage conversion module and the feedback module, the voltage conversion module is further electrically connected with the MCU, the MCU is electrically connected with the first feedback branch, and the working current of the first feedback branch when turned on is greater than the working current of the second feedback branch when turned on; wherein, when in a normal working state, the first feedback branch is turned off, the second feedback branch is turned on, and the power supply module outputs a first voltage to the voltage conversion module; when in a standby state, the first feedback branch is turned on, the second feedback branch is turned off, and the power supply module outputs a second voltage to the voltage conversion module; the second voltage is less than the first voltage, and the second voltage is greater than the working voltage of the MCU. Since the low-power-consumption power supply circuit provided by the present application can turn on different feedback branches when in a normal working state and a standby state, and the working current of the first feedback branch turned on in the standby state is relatively large, the power supply module can reduce its output after receiving the feedback, so that the output second voltage is relatively small, and the standby power consumption can be greatly reduced.

[0064] Although the present application has been disclosed with reference to above examples, the present application is not limited to the above examples. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, and therefore the scope of protection of the present application should be defined by the scope of claims.

Claims

1. A low power supply circuit, characterized by comprising: The low-power supply circuit comprises a power supply module (110), a voltage conversion module (120), an MCU (130) and a feedback module (140), the feedback module (140) comprises a first feedback branch (141) and a second feedback branch (142), the power supply module (110) is electrically connected with the voltage conversion module (120) and the feedback module (140) respectively, the voltage conversion module (120) is electrically connected with the MCU (130), the MCU (130) is electrically connected with the first feedback branch (141), and the working current of the first feedback branch (141) when turned on is greater than the working current of the second feedback branch (142) when turned on; wherein, When in a normal working state, the first feedback branch (141) is turned off, the second feedback branch (142) is turned on, and the power supply module (110) outputs a first voltage to the voltage conversion module (120); When in a standby state, the first feedback branch (141) is turned on, the second feedback branch (142) is turned off, and the power supply module (110) outputs a second voltage to the voltage conversion module (120); the second voltage is less than the first voltage, and the second voltage is greater than the working voltage of the MCU (130).

2. The low power supply circuit according to claim 1, wherein The feedback module (140) comprises a feedback unit (143), a first voltage stabilizing tube (ZD1), a second voltage stabilizing tube (ZD2) and a switching unit (144), the feedback unit (143) is electrically connected with the voltage output end and the feedback end of the power supply module (110) respectively, the feedback unit (143) is also electrically connected with the first voltage stabilizing tube (ZD1) and the second voltage stabilizing tube (ZD2) respectively, and the switching unit (144) is electrically connected with the first voltage stabilizing tube (ZD1) and the MCU (130) respectively; wherein, The feedback unit (143), the first voltage stabilizing tube (ZD1) and the switching unit (144) constitute the first feedback branch (141); The feedback unit (143), the second voltage stabilizing tube (ZD2) constitute the second feedback branch (142); and the voltage stabilizing value of the second voltage stabilizing tube (ZD2) is greater than the voltage stabilizing value of the first voltage stabilizing tube (ZD1).

3. The low power supply circuit according to claim 2, wherein The feedback unit comprises a first resistor (R1) and an optical coupler (Q3), the optical coupler (Q3) comprises a light-emitting diode and a light-receiving triode, one end of the first resistor (R1) is electrically connected with the voltage output end of the power supply module (110), the other end is electrically connected with the anode of the light-emitting diode, the cathode of the light-emitting diode is electrically connected with the first voltage stabilizing tube (ZD1) and the second voltage stabilizing tube (ZD2) respectively, the collector of the light-receiving triode is electrically connected with the feedback end of the power supply module (110), and the emitter of the light-receiving triode is grounded.

4. The low power supply circuit according to claim 2, wherein The switch unit (144) comprises a first switch tube (Q1), a second resistor (R2) and a third resistor (R3), the cathode of the first voltage stabilizing tube (ZD1) is electrically connected with the feedback unit (143), the anode is electrically connected with the first end of the first switch tube (Q1), the control end of the first switch tube (Q1) is electrically connected with one end of the second resistor (R2) and the third resistor (R3) respectively, the other end of the second resistor (R2) and the second end of the first switch tube (Q1) are grounded, the other end of the third resistor (R3) is electrically connected with the MCU (130); wherein, When in the normal working state, the MCU (130) outputs low level to control the first switch tube (Q1) to be off; When in the standby state, the MCU (130) outputs high level to control the first switch tube (Q1) to be on.

5. The low power supply circuit according to claim 2, wherein The voltage stabilizing value of the first voltage stabilizing tube (ZD1) is 5.6V, and the voltage stabilizing value of the second voltage stabilizing tube (ZD2) is 11V.

6. The low power supply circuit according to claim 1, wherein The power supply module (110) comprises a switching power supply chip (112) and a power supply main circuit (111), the power supply main circuit (111) is electrically connected with the switching power supply chip (112), the output end of the power supply main circuit (111) is electrically connected with the voltage conversion module (120) and the feedback module (140), and the switching power supply chip (112) is also electrically connected with the feedback module (140); wherein, When in the standby state, the switching power supply chip (112) is used for reducing the output voltage of the power supply main circuit (111) according to the working current when the first feedback branch (141) is on, until the working current of the first feedback branch (141) is equal to the working current when the second feedback branch (142) is on.

7. The low power supply circuit according to claim 1, wherein The voltage conversion module (120) comprises an electrolytic capacitor (C1), a second switch tube (Q2), a fourth resistor (R4) and a third voltage stabilizing tube (ZD3), one end of the electrolytic capacitor (C1) is electrically connected with the output end of the power supply module (110), the other end is grounded, the first end of the second switch tube (Q2) and the fourth resistor (R4) are both electrically connected with the output end of the power supply module (110), the second end of the second switch tube (Q2) is electrically connected with the MCU (130), the control end of the second switch tube (Q2) and the other end of the fourth resistor (R4) are both electrically connected with the cathode of the third voltage stabilizing tube (ZD3), and the anode of the third voltage stabilizing tube (ZD3) is grounded.

8. The low power supply circuit according to claim 7, wherein The voltage stabilizing value of the third voltage stabilizing tube (ZD3) is 5.6V, and the working voltage of the MCU (130) is 5V.

9. The low power supply circuit according to claim 7, wherein The voltage conversion module (120) further comprises a filter capacitor (C2), one end of the filter capacitor (C2) is electrically connected with the second end of the second switch tube (Q2), and the other end of the filter capacitor (C2) is grounded.

10. An air conditioner characterized by comprising: The air conditioner comprises a load and the low-power consumption power supply circuit according to any one of claims 1 to 9, and the low-power consumption power supply circuit is electrically connected with the load.

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