Anti-surge circuit, air conditioner power supply control system and air conditioner

Abstract

The utility model provides an anti-surge circuit, an air conditioner power supply control system and an air conditioner. In the anti-surge circuit, the change of the running current of the air conditioner is detected in real time through an acquisition unit, and when the air conditioner encounters a surge impact state and an overcurrent state, the switching of a second relay and a PTC thermistor is realized through a first comparison unit and a second comparison unit, so that the air conditioner is ensured to be in an abnormal working state of the surge impact state and the overcurrent state; the PTC thermistor can be switched in time to protect a post-stage circuit, so that normal and safe operation of the air conditioner is guaranteed, the air conditioner experience degree of a user is guaranteed, the service life of the air conditioner is prolonged, and the air conditioner has good practical value.

Description

Technical Field

[0001] The utility model relates to the technical field of surge protection, in particular to a surge protection circuit, an air-conditioning power supply control system and an air-conditioner. Background Art

[0002] Surge refers to excessive instantaneous voltage or current. If it exceeds the tolerance of electronic devices, it will cause circuit damage. Therefore, it is of great significance to control the surge of electronic devices. For air conditioners, when the frequency conversion module is equipped with surge protection function, most of the surge protection circuits use relays + PTC (Positive Temperature Coefficient) thermistors / cement resistors. When the power is turned on, the PTC thermistor / cement resistor is first connected to the main circuit to prevent excessive charging current from impacting the rectifier diode and causing damage. After the electrolytic capacitor of the main circuit is charged, the relay is attracted to short-circuit the PTC thermistor / cement resistor, thereby realizing the surge protection function.

[0003] However, the above-mentioned surge protection circuit cannot determine whether a surge impact is encountered during operation, nor can it determine the overcurrent phenomenon caused by load short circuit, failure, etc. during operation; that is, during operation, when a surge impact or overcurrent is encountered, a large impact current will flow through the relay to the subsequent circuit, causing device damage and other phenomena, thereby affecting the normal operation of the air conditioner. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide a surge protection circuit, an air conditioning power control system and an air conditioner to alleviate the above-mentioned problems and ensure that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time when it is in abnormal working conditions such as surge impact state and overcurrent state, thereby ensuring the normal and safe operation of the air conditioner and further ensuring the user's air conditioning experience.

[0005] In a first aspect, an embodiment of the utility model provides a surge protection circuit, comprising: a collection unit, a first comparison unit, a second comparison unit, a first relay, a second relay and a positive temperature coefficient PTC thermistor;

[0006] Wherein, one end of the collection unit is connected to the third contact of the first relay, the other end of the collection unit is connected to the fourth contact of the first relay, one end and the other end of the collection unit are also connected to the first comparison unit, the first contact and the second contact of the first relay are both connected to the first comparison unit, the fifth contact of the first relay is connected to the second comparison unit, the second comparison unit is also connected to the first contact of the second relay, the fourth contact of the second relay is connected between the other end of the collection unit and one end of the PTC thermistor, the third contact of the second relay and the other end of the PTC thermistor are both connected to the post-stage circuit of the air conditioner, and the second contact of the second relay is connected to the control circuit of the air conditioner;

[0007] The collecting unit is used to collect the operating current of the air conditioner under the power supply, obtain the corresponding operating voltage, and send the operating voltage to the first comparing unit; the first comparing unit is used to obtain the operating voltage and control the state of the first relay according to the operating voltage so that the operating voltage is transmitted to the second comparing unit; the second comparing unit is used to output a high level to the second relay according to the operating voltage and the preset voltage when the air conditioner is in a normal working state, so that the second relay is attracted, and the power supply is transmitted to the subsequent circuit via the second relay; and, when the air conditioner is in an abnormal working state, output a low level to the second relay according to the operating voltage and the preset voltage so that the second relay is disconnected, and the power supply is transmitted to the subsequent circuit via the PTC thermistor; wherein the abnormal working state includes: surge impact state and overcurrent state.

[0008] The above-mentioned surge protection circuit detects the operating current changes of the air conditioner in real time through the acquisition unit. When encountering a surge impact state and an overcurrent state, the first comparison unit and the second comparison unit are used to switch the second relay and the PTC thermistor, ensuring that the air conditioner can switch the PTC thermistor in time to protect the subsequent circuit under abnormal working conditions of surge impact state and overcurrent state, thereby ensuring the normal and safe operation of the air conditioner and further ensuring the user's air conditioning experience.

[0009] Preferably, the above-mentioned first comparison unit includes a first comparator and a first pull-up resistor; wherein, the first end of the first comparator is connected to the second contact of the first relay, the second end of the first comparator is connected to the other end of the acquisition unit, the third end of the first comparator is connected to one end of the acquisition unit, the fourth end of the first comparator is grounded, the fifth end of the first comparator is connected to the first working voltage, one end of the first pull-up resistor is connected between the fifth end of the first comparator and the first working voltage, the other end of the first pull-up resistor is connected between the first end of the first comparator and the second contact of the first relay, and the first contact of the first relay is connected to the fourth end of the first comparator.

[0010] Preferably, the above-mentioned second comparison unit includes a second comparator and a second pull-up resistor; wherein, the first end of the second comparator is connected to the first contact of the second relay, the second end of the second comparator is connected to the fifth contact of the first relay, the third end of the second comparator is connected to the first working voltage, the fourth end of the second comparator is grounded, the fifth end of the second comparator is connected to the first working voltage, one end of the second pull-up resistor is connected to the first working voltage, and the other end of the second pull-up resistor is connected between the first end of the second comparator and the first contact of the second relay.

[0011] Preferably, the above-mentioned second comparison unit also includes a first voltage-dividing resistor and a second voltage-dividing resistor; wherein, one end of the second voltage-dividing resistor is connected to the first working voltage, the other end of the second voltage-dividing resistor is connected to the third end of the second comparator, one end of the first voltage-dividing resistor is connected between the other end of the second voltage-dividing resistor and the third end of the second comparator, and the other end of the first voltage-dividing resistor is grounded.

[0012] In the second aspect, the embodiment of the utility model also provides an air-conditioning power supply control system, which includes: a power supply, a subsequent circuit and the surge protection circuit of the first aspect mentioned above; when the air conditioner is in normal working state, the power supply is transmitted to the subsequent circuit via the second relay of the surge protection circuit; when the air conditioner is in abnormal working state, the power supply is transmitted to the subsequent circuit via the PTC thermistor of the surge protection circuit.

[0013] Preferably, the air conditioning power control system further comprises a filtering circuit; wherein the filtering circuit comprises: an inductor, a discharge tube, a first varistor, a second varistor, a third varistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor; one end of the first varistor is connected to the first end of the power supply, the other end of the first varistor is connected to the second end of the power supply, one end of the second varistor is connected to the second end of the power supply, the other end of the second varistor is respectively connected to one end of the third varistor and one end of the discharge tube, the other end of the third varistor is connected to the first end of the power supply, the other end of the discharge tube is connected to the third end of the power supply, and the fifth capacitor is connected to the first end of the power supply. One end of the inductor is connected to the first end of the power supply, the other end of the fifth capacitor is connected to the second end of the power supply, one end of the first capacitor is connected to the second end of the power supply, the other end of the first capacitor is connected to the third end of the power supply, one end of the second capacitor is connected to the first end of the power supply, the other end of the second capacitor is connected to the third end of the power supply, the first end of the inductor is connected to the first end of the power supply, the second end of the inductor is connected to the second end of the power supply, the third end of the inductor is respectively connected to one end of the fourth capacitor and one end of the sixth capacitor, the fourth end of the inductor is respectively connected to one end of the third capacitor and the other end of the sixth capacitor, and the other end of the third capacitor and the other end of the fourth capacitor are both connected to the third end of the power supply.

[0014] Preferably, the above-mentioned air conditioner power control system also includes a control circuit; wherein the control circuit is connected to the second contact of the second relay; the control circuit is used to control the load to work normally when the air conditioner is in normal working state; and to control the load to stop working when the air conditioner is in abnormal working state.

[0015] Preferably, the above-mentioned control circuit includes: a transistor, a first resistor, a second resistor, a third resistor and a control chip; wherein, the base of the transistor is connected to the second contact of the second relay, one end of the first resistor is connected between the base of the transistor and the second contact of the second relay, the other end of the first resistor is grounded, the emitter of the transistor is connected to the other end of the first resistor, the collector of the transistor is connected to one end of the second resistor, the other end of the second resistor is connected to the second working voltage, one end of the third resistor is connected between the collector of the transistor and one end of the second resistor, and the other end of the third resistor is connected to the control chip.

[0016] Preferably, the control circuit further comprises a diode; wherein an anode of the diode is connected to the other end of the first resistor, and a cathode of the diode is connected to the first contact of the second relay.

[0017] In a third aspect, an embodiment of the utility model further provides an air conditioner, which includes the air conditioner power control system of the second aspect.

[0018] The embodiments of the present invention bring the following beneficial effects:

[0019] The embodiments of the utility model provide a surge protection circuit, an air-conditioning power supply control system and an air conditioner. In the surge protection circuit, a collection unit is used to detect the operating current change of the air conditioner in real time. When encountering a surge impact state and an overcurrent state, the first comparison unit and the second comparison unit are used to realize the switching of the second relay and the PTC thermistor, thereby ensuring that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time when the air conditioner is in an abnormal working state of a surge impact state and an overcurrent state, thereby ensuring the normal and safe operation of the air conditioner, not only ensuring the user's air-conditioning experience, but also extending the service life of the air conditioner, and having good practical value.

[0020] Other features and advantages of the utility model will be described in the following description, and partly become apparent from the description, or understood by practicing the utility model. The purpose and other advantages of the utility model are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A circuit diagram of an air-conditioning power supply control system provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] To facilitate understanding of this embodiment, the embodiment of the utility model is described in detail below.

[0026] The embodiment of the utility model provides a surge protection circuit, comprising: a collection unit, a first comparison unit, a second comparison unit, a first relay, a second relay and a positive temperature coefficient (PTC) thermistor.

[0027] Among them, one end of the collection unit is connected to the third contact of the first relay, the other end of the collection unit is connected to the fourth contact of the first relay, one end and the other end of the collection unit are also connected to the first comparison unit, the first contact and the second contact of the first relay are both connected to the first comparison unit, the fifth contact of the first relay is connected to the second comparison unit, the second comparison unit is also connected to the first contact of the second relay, the fourth contact of the second relay is connected between the other end of the collection unit and one end of the PTC thermistor, the third contact of the second relay and the other end of the PTC thermistor are both connected to the post-stage circuit of the air conditioner, and the second contact of the second relay is connected to the control circuit of the air conditioner.

[0028] Specifically, the collection unit is used to collect the operating current of the air conditioner under the power supply, obtain the corresponding operating voltage, and send the operating voltage to the first comparison unit; the first comparison unit is used to obtain the operating voltage, and control the state of the first relay according to the operating voltage, so that the operating voltage is transmitted to the second comparison unit; the second comparison unit is used to output a high level to the second relay according to the operating voltage and the preset voltage when the air conditioner is in a normal working state, so that the second relay is energized, and the power supply is transmitted to the subsequent circuit via the second relay; and, in an abnormal working state of the air conditioner, output a low level to the second relay according to the operating voltage and the preset voltage, so that the second relay is disconnected, and the power supply is transmitted to the subsequent circuit via the PTC thermistor; wherein the abnormal working state includes: surge impact state and overcurrent state.

[0029] In the above-mentioned surge protection circuit, the operating current changes of the air conditioner are detected in real time through the acquisition unit. When encountering a surge impact state and an overcurrent state, the switching of the second relay and the PTC thermistor is realized through the first comparison unit and the second comparison unit, thereby ensuring that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time when it is in an abnormal working state of a surge impact state and an overcurrent state, thereby ensuring the normal and safe operation of the air conditioner, which not only ensures the user's air conditioning experience, but also extends the service life of the air conditioner, and has good practical value.

[0030] For example, Figure 1 As shown, the surge protection circuit 10 includes: a collection unit, a first comparison unit, a second comparison unit, a first relay K1, a second relay K2 and a PTC thermistor (i.e., PTC); wherein the collection unit includes a sampling resistor R1, one end (i.e., the left end) of the sampling resistor R1 is connected to the third contact (i.e., contact 3) of the first relay K1, the other end (i.e., the right end) of the sampling resistor R1 is connected to the fourth contact (i.e., contact 4) of the first relay K1, and both ends of the sampling resistor R1 are also connected to the first comparison unit. In practical applications, the collection unit collects the operating current of the air conditioner under the power supply through the sampling resistor R1, obtains the corresponding operating voltage, and sends the operating voltage to the first comparison unit. It should be noted that the first relay K1 is a single-pole double-throw relay.

[0031] Preferably, the first comparison unit includes a first comparator IC1A and a first pull-up resistor R2; wherein, a first end of the first comparator IC1A is connected to a second contact (i.e., contact 2) of the first relay K1, a second end of the first comparator IC1A is connected to the other end of the acquisition unit (i.e., the sampling resistor R1), a third end of the first comparator IC1A is connected to one end of the acquisition unit (i.e., the sampling resistor R1), a fourth end of the first comparator IC1A is grounded, a fifth end of the first comparator IC1A is connected to a first operating voltage VCC, one end of the first pull-up resistor R2 is connected between the fifth end of the first comparator IC1A and the first operating voltage VCC, the other end of the first pull-up resistor R2 is connected between the first end of the first comparator IC1A and the second contact of the first relay K1, and the first contact (i.e., contact 1) of the first relay K1 is connected to the fourth end of the first comparator IC1A.

[0032] In addition, the fifth contact (i.e., contact 5) of the first relay K1 is also connected to the second comparison unit. The second comparison unit includes a second comparator IC1B and a second pull-up resistor R3; specifically, a first end of the second comparator IC1B is connected to a first contact (i.e., contact 1) of the second relay K2, a second end of the second comparator IC1B is connected to a fifth contact of the first relay K1, a third end of the second comparator IC1B is connected to a first operating voltage VCC, a fourth end of the second comparator IC1B is grounded, a fifth end of the second comparator IC1B is connected to the first operating voltage VCC, one end of the second pull-up resistor R3 is connected to the first operating voltage VCC, and the other end of the second pull-up resistor R3 is connected between the first end of the second comparator IC1B and the first contact of the second relay K2.

[0033] Specifically, when the air conditioner is running under the power supply, the operating current is collected through the sampling resistor R1 to obtain the corresponding operating voltage; when the power supply is in the positive half cycle, the voltage on the left side of the sampling resistor R1 is higher than the voltage on the right side. At this time, the first comparator IC1A outputs a high level, the first relay K1 is energized, and the contact 3 and contact 5 of the first relay K1 are energized (contact 4 and contact 5 are energized when not powered), and the operating voltage input to the second comparator IC1B is the voltage on the left side of the sampling resistor R1; similarly, when the power supply is in the negative half cycle, the voltage on the left side of the sampling resistor R1 is lower than the voltage on the right side. At this time, the first comparator IC1A outputs a low level, the first relay K1 is disconnected, contacts 4 and contacts 5 are energized, and the operating voltage input to the second comparator IC1B is the voltage on the right side of the sampling resistor R1.

[0034] Therefore, during the operation of the air conditioner, when the operating current is collected, no matter whether the power supply is in the positive half cycle or the negative half cycle, the collected operating voltage is the maximum voltage value (i.e., the high-voltage side voltage value) corresponding to the sampling resistor R1 under the operating current, so that the sampling resistor R1 can effectively collect the operating voltage corresponding to the power supply current in both the positive and negative half cycles of the power supply through the first comparator IC1A and the first relay K1. In addition, the collected operating voltage is transmitted to the second comparator IC1B through the first relay K1, so that the second comparator IC1B switches the second relay K2 and the PTC thermistor according to the operating voltage and the preset voltage, so as to ensure that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time in the abnormal working state of the surge impact state and the overcurrent state, so as to realize that whether it encounters surge impact and overcurrent in the positive half cycle of the power supply or surge impact and overcurrent in the negative half cycle of the power supply, the air conditioner can be protected to operate reliably, thereby ensuring the normal and safe operation of the air conditioner.

[0035] In addition, for the first comparator IC1A and the second comparator IC1B, since some comparators have no output capability or weak output capability, a first pull-up resistor R2 is added to the first comparator IC1A to ensure that the first relay K1 is reliably turned on; similarly, a second pull-up resistor R3 is added to the second comparator IC1B to ensure that the second relay K2 is reliably turned on.

[0036] Optionally, the above-mentioned second comparison unit also includes a first voltage-dividing resistor R4 and a second voltage-dividing resistor R5; wherein, one end of the second voltage-dividing resistor R5 is connected to the first working voltage VCC, the other end of the second voltage-dividing resistor R5 is connected to the third end of the second comparator IC1B, one end of the first voltage-dividing resistor R4 is connected between the other end of the second voltage-dividing resistor R5 and the third end of the second comparator IC1B, and the other end of the first voltage-dividing resistor R4 is grounded.

[0037] Specifically, the first working voltage VCC is divided by the first voltage-dividing resistor R4 and the second voltage-dividing resistor R5 to generate a preset voltage corresponding to the second comparator IC1B, and is input to the third terminal (i.e., the + terminal) of the second comparator IC1B, so as to be compared with the operating voltage inputted at the second terminal of the second comparator IC1B, and the state of the second relay K2 is controlled according to the comparison result. Wherein, in the normal working state of the air conditioner, the operating voltage is less than the preset voltage, the second comparator IC1B outputs a high level to the second relay K2, so that the second relay K2 is attracted, at this time, the power supply is transmitted to the subsequent circuit via the second relay K2; similarly, in the abnormal working state of the air conditioner, the abnormal working state includes but is not limited to the surge impact state and the overcurrent state, and also includes other high current states; at this time, the abnormal working state causes the operating voltage to be greater than the preset voltage, the second comparator IC1B outputs a low level to the second relay K2, so that the second relay K2 is disconnected, at this time, the power supply is transmitted to the subsequent circuit via the PTC thermistor.

[0038] It should be noted that in abnormal working conditions, due to excessive current, the heating of the PTC thermistor becomes more serious as the resistance increases, causing the resistance of the PTC thermistor to increase rapidly to the maximum resistance. Due to the sharp increase in resistance, the current passing through the component is greatly reduced, thereby limiting the impact of excessive current on the subsequent circuit, achieving overcurrent protection function, improving the operating reliability of the air conditioner, and reducing the failure rate of the air conditioner.

[0039] Therefore, the second comparator IC1B can realize the switching of the second relay K2 and the PTC thermistor according to the operating voltage and preset voltage corresponding to the collected operating current of the air conditioner, ensuring that the air conditioner can switch the PTC thermistor in time to protect the subsequent circuit under abnormal working conditions such as surge impact state and overcurrent state, thereby ensuring the normal and safe operation of the air conditioner.

[0040] Among them, the preset voltage is preferably 1.2 times the sampling voltage corresponding to the operating current of the normal operation of the air conditioner. For example, if the maximum operating current of the air conditioner is 10A, the preset voltage divider is the sampling voltage value corresponding to the 12A current. The specific preset voltage value can be adjusted by adjusting the values ​​of the first voltage divider resistor R4 and the second voltage divider resistor R5. The embodiment of the utility model does not limit this.

[0041] Furthermore, when the power supply returns to normal, at this time, the air conditioner is in normal working state, the collected operating voltage is less than the preset voltage, the second comparator IC1B outputs a high level to the second relay K2, the second relay K2 is energized, and the PTC thermistor is based on its own self-recovery (when the abnormal state ends, when the temperature drops below its transition temperature, the resistance of the PTC thermistor will return to the initial lower level). Therefore, the surge protection circuit can transmit the power supply to the subsequent circuit through the second relay K2 when the air conditioner is operating normally, and when encountering surge impact and overcurrent, it switches the second Relay K2 and PTC thermistor, so that the power supply is transmitted to the subsequent circuit via the PTC thermistor, so that the subsequent circuit is protected according to the PTC thermistor; and, when the air conditioner resumes normal operation, the second relay K2 and the PTC thermistor are switched again, so that the power supply is transmitted to the subsequent circuit via the second relay K2, and the above process is repeated. The surge protection circuit can realize that when the air conditioner encounters surge shock and overcurrent, it can protect the subsequent circuit from interference for multiple times by switching the second relay K2 and the PTC thermistor, thereby ensuring the normal and safe operation of the air conditioner and the user's air conditioning experience.

[0042] It should be noted that for Figure 1 The surge protection circuit 10 in the embodiment can also be provided with an amplifying unit (including but not limited to an amplifier) ​​at the input end of the first comparator IC1A and the second comparator IC1B on the basis of the above circuit structure. For example, an amplifier is provided between the first comparator IC1A and the sampling resistor R1, and the voltage values ​​on both sides of the sampling resistor R1 are amplified and then respectively input to the second end and the third end of the first comparator IC1A; similarly, an amplifier can also be provided between the second comparator IC1B and the first relay K1. As long as the surge protection circuit 10 can detect the power supply current in real time and switch the second relay K2 and the PTC thermistor in time when the current is abnormal such as surge impact and overcurrent, the subsequent circuit can be protected from interference.

[0043] Based on the above surge protection circuit, the embodiment of the utility model also provides an air conditioner power supply control system, such as Figure 1 As shown, the air conditioner power control system includes: a power supply, a post-stage circuit 20 and the above-mentioned surge protection circuit 10; wherein the power supply includes a first terminal AC-N (i.e., an AC live wire terminal), a second terminal AC-L (i.e., an AC neutral wire terminal) and a third terminal GND (i.e., a ground terminal).

[0044] Specifically, when the air conditioner is in normal working state, the power supply is transmitted to the subsequent circuit 20 via the second relay K2 of the surge protection circuit 10; when the air conditioner is in abnormal working state, the power supply is transmitted to the subsequent circuit 20 via the PTC thermistor of the surge protection circuit, so that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time when it is in abnormal working state of surge impact state and overcurrent state, thereby ensuring the normal and safe operation of the air conditioner. The specific switching process can refer to the aforementioned embodiment, and the embodiment of the utility model will not be described in detail here.

[0045] Preferably, the air conditioner power control system further includes a filter circuit; Figure 1 As shown, the filter circuit 30 includes: an inductor L, a discharge tube SA, a first varistor ZNR1, a second varistor ZNR2, a third varistor ZNR3, a first capacitor CRV1, a second capacitor CRV2, a third capacitor CRV3, a fourth capacitor CRV4, a fifth capacitor CRV5 and a sixth capacitor CRV6.

[0046] Among them, one end of the first varistor ZNR1 is connected to the first end AC-N of the power supply, the other end of the first varistor ZNR1 is connected to the second end AC-L of the power supply, one end of the second varistor ZNR2 is connected to the second end AC-L of the power supply, the other end of the second varistor ZNR2 is respectively connected to one end of the third varistor ZNR3 and one end of the discharge tube SA, the other end of the third varistor ZNR3 is connected to the first end AC-N of the power supply, the other end of the discharge tube SA is connected to the third end GND of the power supply, one end of the fifth capacitor CRV5 is connected to the first end AC-N of the power supply, the other end of the fifth capacitor CRV5 is connected to the second end AC-L of the power supply, one end of the first capacitor CRV1 is connected to the power supply The second end AC-L of the power supply is connected, the other end of the first capacitor CRV1 is connected to the third end GND of the power supply, one end of the second capacitor CRV2 is connected to the first end AC-N of the power supply, the other end of the second capacitor CRV2 is connected to the third end GND of the power supply, the first end of the inductor L is connected to the first end AC-N of the power supply, the second end of the inductor L is connected to the second end AC-L of the power supply, the third end of the inductor L is respectively connected to one end of the fourth capacitor CRV4 and one end of the sixth capacitor CRV6, the fourth end of the inductor L is respectively connected to one end of the third capacitor CRV3 and the other end of the sixth capacitor CRV6, the other end of the third capacitor CRV3 and the other end of the fourth capacitor CRV4 are both connected to the third end GND of the power supply.

[0047] Specifically, after the power supply is filtered by the filter circuit 30, the operating current of the air conditioner is generated, and the corresponding operating voltage is collected by the sampling resistor R1, so that the surge protection circuit can realize the switching of the second relay K2 and the PTC thermistor according to the operating voltage, ensuring that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time when it is in abnormal working conditions such as surge impact state and overcurrent state, thereby ensuring the normal and safe operation of the air conditioner, not only ensuring the user's air conditioning experience, but also extending the service life of the air conditioner, and has good practical value.

[0048] Preferably, if Figure 1 As shown, the above-mentioned air-conditioning power supply control system also includes a control circuit 40; wherein the control circuit 40 is connected to the second contact of the second relay K2; the control circuit 40 is used to control the load to work normally when the air conditioner is in normal working state; and to control the load to stop working when the air conditioner is in abnormal working state.

[0049] The control circuit 40 includes: a transistor Q, a first resistor R6, a second resistor R7, a third resistor R8 and a control chip 41; Figure 1 As shown, the base of the transistor Q is connected to the second contact of the second relay K2, one end of the first resistor R6 is connected between the base of the transistor Q and the second contact of the second relay K2, the other end of the first resistor R6 is grounded, the emitter of the transistor Q is connected to the other end of the first resistor R6, the collector of the transistor Q is connected to one end of the second resistor R7, the other end of the second resistor R7 is connected to the second operating voltage VDD, one end of the third resistor R8 is connected between the collector of the transistor Q and one end of the second resistor R7, and the other end of the third resistor R8 is connected to the control chip 41.

[0050] It should be noted that the second operating voltage VDD is the operating voltage of the control chip 41, and the first operating voltage VCC is the operating voltage of the comparator and the controller. The specific values ​​of the first operating voltage VCC and the second operating voltage VDD can be set according to actual conditions.

[0051] In addition, the control circuit 40 further includes a diode D, wherein the anode of the diode D is connected to the other end of the first resistor R6, and the cathode of the diode D is connected to the first contact of the second relay K2. Also, a fourth varistor ZNR4 is provided between the surge protection circuit 10 and the subsequent circuit 20.

[0052] Specifically, the control principle of the air conditioning power control system is as follows: when the air conditioner is in normal working state, the operating voltage collected by the sampling resistor R1 is less than the preset voltage, and the second comparator IC1B outputs a high level to the second relay K2 to make the second relay K2 energized. At this time, the power supply is transmitted to the subsequent circuit 20 via the second relay K2. At the same time, the transistor Q is turned on, and the pin of the control chip 41 is at a low level to control the load to work normally. Similarly, when the air conditioner is in abnormal working state such as surge impact or overcurrent, the operating voltage collected by the sampling resistor R1 is greater than the preset voltage, and the second comparator IC1B outputs a low level to the second relay K2 to disconnect the second relay K2. At this time, the power supply is transmitted to the subsequent circuit 20 via the PTC thermistor. At the same time, the transistor Q is disconnected, and the pin of the control chip 41 is at a high level to control the load to stop working.

[0053] Therefore, the control chip 41 also determines the state of the second relay K2 (such as energized or disconnected) through the transistor Q to determine whether the subsequent circuit 20 is in a protection state, thereby controlling the operating state of the load, further increasing the operating stability and reliability of the air conditioner.

[0054] In summary, the air-conditioning power supply control system provided by the embodiment of the utility model adds a surge protection circuit on the basis of the existing air-conditioner filter circuit architecture, and monitors the current change of the power supply in real time through the sampling resistor R1, the first comparator IC1A, and the first relay K1. Then, through the second comparator IC1B and the preset voltage, the switching of the second relay K2 and the PTC thermistor is realized to ensure that the air conditioner can switch the PTC thermistor to protect the subsequent circuit in time when it is in the abnormal working state of surge impact state and overcurrent state, thereby ensuring the safe and reliable operation of the air conditioner; and in the surge protection circuit, multiple protections of the subsequent circuit can also be realized according to the characteristics of the PTC thermistor itself.

[0055] Furthermore, based on the above-mentioned air-conditioning power control system, an embodiment of the utility model also provides an air conditioner, which includes the above-mentioned air-conditioning power control system. The air conditioner has the same technical features as the above-mentioned air-conditioning power control system, so it can also solve the same technical problems and achieve the same technical effects.

[0056] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and air conditioner described above can refer to the corresponding process of the surge protection circuit in the aforementioned embodiment, and will not be repeated here.

[0057] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that can be executed by a processor. Based on this understanding, the technical solution of the utility model, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the utility model. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

[0059] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0060] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the utility model, which are used to illustrate the technical solution of the utility model, rather than to limit it. The protection scope of the utility model is not limited thereto. Although the utility model is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solution recorded in the above-mentioned embodiments within the technical scope disclosed by the utility model, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the utility model, and should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A surge protection circuit, characterized in that: include: An acquisition unit, a first comparison unit, a second comparison unit, a first relay, a second relay and a positive temperature coefficient PTC thermistor; Wherein, one end of the acquisition unit is connected to the third contact of the first relay, the other end of the acquisition unit is connected to the fourth contact of the first relay, one end and the other end of the acquisition unit are also connected to the first comparison unit, the first contact and the second contact of the first relay are both connected to the first comparison unit, the fifth contact of the first relay is connected to the second comparison unit, the second comparison unit is also connected to the first contact of the second relay, the fourth contact of the second relay is connected between the other end of the acquisition unit and one end of the PTC thermistor, the third contact of the second relay and the other end of the PTC thermistor are both connected to the post-stage circuit of the air conditioner, and the second contact of the second relay is connected to the control circuit of the air conditioner; The acquisition unit is used to acquire the operating current of the air conditioner under the power supply, obtain the corresponding operating voltage, and send the operating voltage to the first comparison unit; The first comparing unit is used to obtain the operating voltage and control the state of the first relay according to the operating voltage so that the operating voltage is transmitted to the second comparing unit; The second comparison unit is used to output a high level to the second relay according to the operating voltage and the preset voltage when the air conditioner is in a normal working state, so that the second relay is energized, and the power supply is transmitted to the subsequent circuit via the second relay; and to output a low level to the second relay according to the operating voltage and the preset voltage when the air conditioner is in an abnormal working state, so that the second relay is disconnected, and the power supply is transmitted to the subsequent circuit via the PTC thermistor; wherein the abnormal working state includes: a surge impact state and an overcurrent state.

2. The surge protection circuit according to claim 1, characterized in that: The first comparison unit includes a first comparator and a first pull-up resistor; wherein, the first end of the first comparator is connected to the second contact of the first relay, the second end of the first comparator is connected to the other end of the acquisition unit, the third end of the first comparator is connected to one end of the acquisition unit, the fourth end of the first comparator is grounded, the fifth end of the first comparator is connected to a first working voltage, one end of the first pull-up resistor is connected between the fifth end of the first comparator and the first working voltage, the other end of the first pull-up resistor is connected between the first end of the first comparator and the second contact of the first relay, and the first contact of the first relay is connected to the fourth end of the first comparator.

3. The surge protection circuit according to claim 2, characterized in that: The second comparison unit includes a second comparator and a second pull-up resistor; wherein, the first end of the second comparator is connected to the first contact of the second relay, the second end of the second comparator is connected to the fifth contact of the first relay, the third end of the second comparator is connected to the first working voltage, the fourth end of the second comparator is grounded, the fifth end of the second comparator is connected to the first working voltage, one end of the second pull-up resistor is connected to the first working voltage, and the other end of the second pull-up resistor is connected between the first end of the second comparator and the first contact of the second relay.

4. The surge protection circuit according to claim 3, characterized in that: The second comparison unit also includes a first voltage-dividing resistor and a second voltage-dividing resistor; wherein, one end of the second voltage-dividing resistor is connected to the first working voltage, the other end of the second voltage-dividing resistor is connected to the third end of the second comparator, one end of the first voltage-dividing resistor is connected between the other end of the second voltage-dividing resistor and the third end of the second comparator, and the other end of the first voltage-dividing resistor is grounded.

5. An air conditioning power supply control system, characterized in that: The air conditioner power supply control system comprises: a power supply, a subsequent circuit and a surge protection circuit as described in any one of claims 1 to 4 above; When the air conditioner is in normal working state, the power supply is transmitted to the subsequent circuit via the second relay of the surge protection circuit; when the air conditioner is in abnormal working state, the power supply is transmitted to the subsequent circuit via the PTC thermistor of the surge protection circuit.

6. The air conditioning power supply control system according to claim 5, characterized in that: The air conditioner power supply control system further includes a filter circuit; wherein the filter circuit includes: an inductor, a discharge tube, a first varistor, a second varistor, a third varistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor; One end of the first varistor is connected to the first end of the power supply, the other end of the first varistor is connected to the second end of the power supply, one end of the second varistor is connected to the second end of the power supply, the other end of the second varistor is respectively connected to one end of the third varistor and one end of the discharge tube, the other end of the third varistor is connected to the first end of the power supply, the other end of the discharge tube is connected to the third end of the power supply, one end of the fifth capacitor is connected to the first end of the power supply, the other end of the fifth capacitor is connected to the second end of the power supply, one end of the first capacitor is connected to the power supply The first capacitor is connected to the second end of the power supply, the other end of the first capacitor is connected to the third end of the power supply, one end of the second capacitor is connected to the first end of the power supply, the other end of the second capacitor is connected to the third end of the power supply, the first end of the inductor is connected to the first end of the power supply, the second end of the inductor is connected to the second end of the power supply, the third end of the inductor is respectively connected to one end of the fourth capacitor and one end of the sixth capacitor, the fourth end of the inductor is respectively connected to one end of the third capacitor and the other end of the sixth capacitor, and the other end of the third capacitor and the other end of the fourth capacitor are both connected to the third end of the power supply.

7. The air conditioning power supply control system according to claim 5, characterized in that: The air conditioner power supply control system further includes a control circuit; wherein the control circuit is connected to the second contact of the second relay; The control circuit is used to control the load to work normally when the air conditioner is in a normal working state; and to control the load to stop working when the air conditioner is in an abnormal working state.

8. The air conditioning power supply control system according to claim 7, characterized in that: The control circuit comprises: a transistor, a first resistor, a second resistor, a third resistor and a control chip; Among them, the base of the transistor is connected to the second contact of the second relay, one end of the first resistor is connected between the base of the transistor and the second contact of the second relay, the other end of the first resistor is grounded, the emitter of the transistor is connected to the other end of the first resistor, the collector of the transistor is connected to one end of the second resistor, the other end of the second resistor is connected to the second working voltage, one end of the third resistor is connected between the collector of the transistor and one end of the second resistor, and the other end of the third resistor is connected to the control chip.

9. The air conditioning power supply control system according to claim 8, characterized in that: The control circuit further includes a diode; wherein an anode of the diode is connected to the other end of the first resistor, and a cathode of the diode is connected to the first contact of the second relay.

10. An air conditioner, characterized in that: The air conditioner comprises the air conditioner power control system as described in any one of claims 5 to 9 above.

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