Current detection circuit and air conditioner

Abstract

The utility model discloses a current detection circuit and an air conditioner, and the current detection circuit comprises a coil which is wound on a live wire and is used for carrying out the induction with the live wire and outputting an induction current; the detection module is connected with the coil, and the detection module is used for rectifying the induction current and then outputting detection current; and the control module is respectively connected with the detection module and the live wire, and the control module is used for controlling the working state of the motor according to the detection current. Compared with a current transformer used in the prior art, a current detection device does not need to be additionally arranged, the coil is arranged on the live wire, the occupied space of the current detection device can be reduced, cost is reduced, and the space utilization rate of the air conditioner is increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to air conditioner technical field especially relates to a current detection circuit and air conditioner. BACKGROUND

[0002] With the rapid development of air conditioning industry, the load demand of air conditioner is more and more, and the stability requirement of load to power supply and the influence to system are bigger in use process, so current monitoring needs to be carried out to load to ensure that the load can run stably. At present, current detection is usually carried out through current transformer to detect the current of load or loop, and the current detection device occupies larger space due to the larger size of current transformer. UTILITY MODEL CONTENTS

[0003] The utility model discloses a current detection circuit and air conditioner, and aims at reducing the space occupied by current detection device.

[0004] In order to realize the above-mentioned purpose, the current detection circuit provided by the utility model is applied to a motor, and the power supply end of the motor is connected to a live wire.

[0005] A coil is arranged around the live wire, and the coil is used to induct the live wire and output an induction current.

[0006] A detection module is connected to the coil, and the detection module is used to rectify the induction current and output a detection current.

[0007] A control module is connected to the detection module and the live wire respectively, and the control module is used to control the working state of the motor according to the detection current.

[0008] In some embodiments, the detection module comprises:

[0009] A detection unit is electrically connected to the coil, and the detection unit is used to rectify and convert the induction current connected to the coil and output a corresponding voltage signal.

[0010] An amplification unit is connected to the detection unit, and the amplification unit is used to amplify the voltage signal and output the detection current.

[0011] In some embodiments, the detection unit comprises:

[0012] A first resistor has one end connected to one end of the coil and the other end connected to the other end of the coil.

[0013] A diode has a positive electrode connected to one end of the coil.

[0014] a second resistor, one end of the second resistor being connected to the negative electrode of the diode, the other end of the second resistor being connected to the amplification unit.

[0015] In some embodiments, the amplification unit comprises:

[0016] an operational amplifier, the non-inverting input terminal of the operational amplifier being connected to the other end of the second resistor, the inverting input terminal of the operational amplifier being connected to the other end of the first resistor, the output terminal of the operational amplifier being connected to the control module.

[0017] In some embodiments, the amplification unit further comprises:

[0018] a third resistor, one end of the third resistor being connected to the other end of the second resistor, the other end of the third resistor being connected to the non-inverting input terminal of the operational amplifier;

[0019] a fourth resistor, one end of the fourth resistor being connected to the other end of the first resistor, the other end of the fourth resistor being connected to the inverting input terminal of the operational amplifier;

[0020] a fifth resistor, one end of the fifth resistor being connected to the inverting input terminal of the operational amplifier, the other end of the fifth resistor being connected to a power supply;

[0021] a sixth resistor, one end of the sixth resistor being connected to the non-inverting input terminal of the operational amplifier, the other end of the sixth resistor being connected to the output terminal of the operational amplifier.

[0022] In some embodiments, the control module comprises:

[0023] a controller, connected to the detection module, the controller being configured to output a control signal according to the detection current;

[0024] a driver, one input pin of the driver being connected to the control terminal of the controller, one output pin of the driver being connected to the motor through the live wire, the driver being configured to control the working state of the motor according to the control signal.

[0025] In some embodiments, the control module further comprises:

[0026] a relay, the first coil end of the relay being connected to one output pin of the driver, the second coil end of the relay being connected to a power supply, the first contact end and the second contact end of the relay being connected to the live wire respectively, the relay being configured to control the power supply on-off of the motor according to the control signal.

[0027] In some embodiments, the current detection circuit further comprises:

[0028] A protection module is connected to the live wire, and the protection module is configured to disconnect the live wire when a current signal on the live wire exceeds a current threshold.

[0029] In some embodiments, the protection module comprises:

[0030] A thermistor is connected to one end of the live wire, and the other end of the thermistor is connected to the first contact end of the relay.

[0031] The utility model also provides a kind of air conditioner, including the current detection circuit as any one of the above.

[0032] The current detection circuit and the air conditioner of the utility model, the coil is wound on the live wire to induct the current on the live wire, the motor current is detected by detection module, and the motor working state is controlled by control module, to reduce the influence of current anomaly on motor;Compared with the current transformer in the prior art, the coil is arranged on the live wire without additional current detection device, which can reduce the occupied space of current detection device, reduce cost, improve the space utilization rate of air conditioner. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced as follows, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained from the structure shown in these drawings without creative labor.

[0034] Figure 1 It is the first structure schematic view of the current detection circuit of the utility model;

[0035] Figure 2 It is the second structure schematic view of the current detection circuit of the utility model;

[0036] Figure 3 It is the third structure schematic view of the current detection circuit of the utility model;

[0037] Figure 4 It is the fourth structure schematic view of the current detection circuit of the utility model;

[0038] Figure 5 It is the fifth structure schematic view of the current detection circuit of the utility model;

[0039] Figure 6 It is the sixth structure schematic view of the current detection circuit of the utility model.

[0040] EXPLANATION OF DRAWINGS:

[0041]

[0042]

[0043] The purposes, functional features and advantages of the utility model will be further described with reference to the drawings in combination with embodiments. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0045] In addition, the description such as "first", "second" and the like in the utility model is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one feature. In addition, the technical solutions of the various embodiments can be combined with each other, but must be based on the fact that those skilled in the art can realize it. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0046] The application provides a current detection circuit.

[0047] Reference Figure 1 , Figure 1 It is a first structure schematic view of the current detection circuit of the utility model. In an embodiment, the current detection circuit 100 is applied to the motor 200, that is, the current of the motor 200 is detected; the power supply end of the motor 200 is connected to the live wire 210. The current detection circuit 100 comprises a coil 110, a detection module 120 and a control module 130.

[0048] The coil 110 is a winding coil, and the coil 110 is wound on the live wire 210. The coil 110 is used for inducting the live wire 210 and outputting an induced current. It can be understood that the coil is wound on the live wire 210, and since the live wire 210 has a current passing therethrough, according to the law of induction, the coil 110 will generate a varying current. By detecting this current and converting and analyzing it, the control of the motor 200 can be made more intelligent, the motor 200 and the compressor can be protected in time, and damage caused by the motor not being turned on and the compressor current being too large can be avoided.

[0049] The detection module 120 is connected to the coil 110. The detection module 120 is used to rectify the induced current and output a detection current for analysis and judgment by the control module 130. It can be understood that the detection module 120 is not only used for detecting the current signal, but also for processing the current signal to obtain a signal format usable by the control module 130, so as to facilitate the subsequent control actions of the control module 130.

[0050] The control module 130 is the control center of the current detection circuit 100. The control module 130 is used to control the working state of the motor 200 based on the detected current. For example, when the current is low or there is no current, the control module 130 can determine that a circuit fault has occurred, and in order to prevent damage to the motor 200, it can control the motor 200 to stop working.

[0051] The current detection circuit 100 provided in this application embodiment uses a coil 110 wound on the live wire 210 to sense the current on the live wire 210. The detection module 120 detects the current of the motor 200, and the control module 130 controls the working state of the motor 200 to reduce the impact of abnormal current on the motor 200. Compared with the use of current transformers in the prior art, this application does not require additional current detection devices. By placing the coil 110 on the live wire 210, the space occupied by the current detection devices can be reduced, the cost can be reduced, and the space utilization of the air conditioner can be improved.

[0052] See Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of a second structure of the current detection circuit of this utility model. Figure 3 This is a schematic diagram of a third structure of the current detection circuit of this utility model. In some embodiments, the detection module 120 includes a detection unit 122 and an amplification unit 124.

[0053] The detection unit 122 is connected to the coil 110. The detection unit 122 is used to rectify and convert the incoming induced current and output the corresponding voltage signal.

[0054] For example, the detection unit 122 includes a first resistor R1, a diode D1, and a second resistor R2. One end of the first resistor R1 is connected to one end of the coil 110, and the other end of the first resistor R1 is connected to the other end of the coil 110. The anode of the diode D1 is connected to one end of the coil 110. One end of the second resistor R2 is connected to the cathode of the diode D1, and the other end of the second resistor R2 is connected to the amplification unit 124.

[0055] It should be noted that the induced current of coil 110 can be converted into an AC voltage signal through the first resistor R1, and then rectified by diode D1 to convert the AC voltage signal into a DC voltage signal.

[0056] For example, the detection unit 122 further includes a second capacitor C2, which can be an electrolytic capacitor. One end of the second capacitor C2 is connected to the other end of the second resistor, and the other end of the second capacitor C2 is connected to the other end of the first resistor R1. In other words, the second capacitor C2 is connected in parallel with the first resistor R1. The second capacitor C2 is used to filter the voltage signal; that is, the induced current of the coil 110 is converted into an AC voltage signal by the first resistor R1, then rectified by the diode D1, and filtered by the second capacitor C2, converting the AC voltage signal into a DC voltage signal.

[0057] For example, the amplification unit 124 includes an operational amplifier U1. The non-inverting input of the operational amplifier U1 is connected to the other end of the second resistor R2, the inverting input of the operational amplifier U1 is connected to the other end of the first resistor R1, and the output of the operational amplifier U1 is connected to the control module 130. The operational amplifier U1 is used to amplify the voltage signal.

[0058] For example, the amplification unit 124 further includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6. One end of the third resistor R3 is connected to the other end of the second resistor R2, and the other end of the third resistor R3 is connected to the non-inverting input terminal of the operational amplifier U1. One end of the fourth resistor R4 is connected to the other end of the first resistor R1, and the other end of the fourth resistor R4 is connected to the inverting input terminal of the operational amplifier U1. One end of the fifth resistor R5 is connected to the inverting input terminal of the operational amplifier U1, and the other end of the fifth resistor R5 is connected to a power supply, which can be 5V. One end of the sixth resistor R6 is connected to the non-inverting input terminal of the operational amplifier U1, and the other end of the sixth resistor R6 is connected to the output terminal of the operational amplifier U1.

[0059] It should be noted that the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are resistors used to adjust the amplification factor of operational amplifier U1. Specifically, the third resistor R3 and the fourth resistor R4 are connected to the two ends of the second capacitor C2 respectively for voltage acquisition. Based on the virtual short and virtual open principle of operational amplifier U1, the amplified voltage value can be obtained. Based on the voltage value and the amplification factor, the induced operating current of motor 200 can be calculated.

[0060] In some embodiments, the detection module 120 further includes a filtering unit 126, which is used to filter the detection current output by the amplification unit 124 to improve the reliability of the detection current.

[0061] For example, the filter unit 126 includes a seventh resistor R7 and a first capacitor C1. One end of the seventh resistor R7 is connected to the output terminal of the operational amplifier U1, and the other end of the seventh resistor R7 is connected to the control module 130. One end of the first capacitor C1 is connected to the control module 130, and the other end of the first capacitor C1 is grounded. It can be understood that the seventh resistor R7 and the first capacitor C1 form an RC circuit, which can play a certain role in anti-interference.

[0062] The current detection circuit 100 provided in this embodiment detects whether the motor 200 is operating normally by winding a coil around the live wire 210 of the motor 200. Specifically, the current signal from the coil 110 is converted into an AC voltage signal by the first resistor R1, then rectified by the diode D1 and filtered by the second capacitor C2, converting the AC voltage into a DC voltage. The third resistor R3, fourth resistor R4, fifth resistor R5, and sixth resistor R6 are resistors for adjusting the amplification factor of the operational amplifier U1; the seventh resistor R7 and the first capacitor C1 form an RC circuit that provides some anti-interference. The third resistor R3 and fourth resistor R4 are connected to the two ends of the second capacitor C2 for voltage acquisition. Based on the virtual short and virtual open principle of the operational amplifier U1, the voltage value at the acquisition port after operational amplification can be obtained, which is also the voltage value sent to the control module 130. The induced operating current of the motor 200 can be obtained based on the voltage value and the amplification factor.

[0063] The control module 130 controls the operating status of the motor 200 based on the sensed operating current. For example, when the current in the live wire 210 is low or there is no current, it can be determined that the motor 200 is operating abnormally, and the control module 130 can control the motor 200 to stop working to avoid causing greater damage to the motor 200.

[0064] Please see Figure 4 , Figure 4 This is a schematic diagram of a fourth structure of the current detection circuit of this utility model. In some embodiments, the control module 130 includes a controller 132 and a driver 134.

[0065] The controller 132 is connected to the detection module 120, and is used to output a control signal based on the detected current. For example, the controller 132 can be the main chip of the current detection circuit 100. For instance, the current detection circuit 100 can be used in an air conditioner, and the controller 132 can be the main chip of the air conditioner, i.e., the logic processing center of the air conditioner.

[0066] One input pin, or controlled pin, of driver 134 can be connected to the control pin of controller 132, and one output pin of driver 134 is connected to motor 200 via live wire 210. Driver 134 is used to control the operating state of motor 200 according to control signals. It can be understood that driver 134 can also be called a driver chip, such as IC72003.

[0067] To facilitate the control of the motor 200's on / off state, the control module 130 also includes a relay K5. Relay K5 has a first coil terminal, a second coil terminal, a first contact terminal, and a second contact terminal. The first coil terminal is connected to an output pin of the driver 134, and the second coil terminal is connected to a power supply, which can be 12V. The first and second contact terminals are respectively connected to the live wire 210. Relay K5 acts as a switch, controlling the on / off state of the live wire 210 to control the power supply to the motor 200.

[0068] For example, the control module 130 also includes a rectifier RC1, one end of which is connected to the first contact terminal of the relay K5, and the other end of which is connected to the neutral wire. It is understood that the rectifier RC1 is used to absorb the inrush current when the relay K5 switches, thereby reducing the impact on the relay K5.

[0069] Please see Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the fifth structure of the current detection circuit of this utility model. Figure 6 This is a schematic diagram of the sixth structure of the current detection circuit of this utility model. In some embodiments, the current detection circuit 100 further includes a protection module 140, which is connected to the live wire 210 and is used to disconnect the live wire 210 when the current on the live wire 210 exceeds a current threshold.

[0070] For example, the protection module 140 includes a thermistor PTC, one end of which is connected to the live wire 210, and the other end of which is connected to an output pin of the driver 134. It should be noted that both the thermistor PTC and the capacitor RC1 are connected to the first contact terminal of the relay K5, and both the thermistor PTC and the capacitor RC1 are connected to an output pin of the driver 134 through the first coil terminal of the relay K5.

[0071] It should be noted that the controller 132 sends a control signal and drives the relay K5 through the driver 134 to control the operation of the AC motor 200. When the current of the live wire 210 of the motor 200 is large, the thermistor PTC will activate, disconnect the live wire, and the motor 200 will stop running. This can prevent the large current from burning out the motor coil, thus effectively protecting the motor 200.

[0072] This application also provides an air conditioner, which includes a motor and the aforementioned current detection circuit. Since this air conditioner adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0073] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A current detection circuit, applied to a motor, wherein the power supply terminal of the motor is connected to a live wire; characterized in that, include: A coil is wound around the live wire, and the coil is used to induce current with the live wire. A detection module is connected to the coil, and the detection module is used to rectify the induced current and output a detection current; The control module is connected to both the detection module and the live wire, and is used to control the operating state of the motor based on the detected current.

2. The current detection circuit according to claim 1, characterized in that, The detection module includes: The detection unit is electrically connected to the coil. The detection unit is used to rectify and convert the incoming induced current and output a corresponding voltage signal. An amplification unit is connected to the detection unit. The amplification unit is used to amplify the voltage signal and output the detection current.

3. The current detection circuit according to claim 2, characterized in that, The detection unit includes: A first resistor, one end of which is connected to one end of the coil, and the other end of which is connected to the other end of the coil; A diode, wherein the positive terminal of the diode is connected to one end of the coil; The second resistor has one end connected to the negative terminal of the diode and the other end connected to the amplification unit.

4. The current detection circuit according to claim 3, characterized in that, The amplification unit includes: An operational amplifier, wherein the non-inverting input terminal of the operational amplifier is connected to the other end of the second resistor, the inverting input terminal of the operational amplifier is connected to the other end of the first resistor, and the output terminal of the operational amplifier is connected to the control module.

5. The current detection circuit according to claim 4, characterized in that, The amplification unit further includes: A third resistor, one end of which is connected to the other end of the second resistor, and the other end of which is connected to the non-inverting input terminal of the operational amplifier; A fourth resistor, one end of which is connected to the other end of the first resistor, and the other end of which is connected to the inverting input terminal of the operational amplifier; The fifth resistor has one end connected to the inverting input terminal of the operational amplifier and the other end connected to the power supply. The sixth resistor has one end connected to the non-inverting input terminal of the operational amplifier and the other end connected to the output terminal of the operational amplifier.

6. The current detection circuit according to any one of claims 1 to 5, characterized in that, The control module includes: A controller is connected to the detection module, and the controller is used to output a control signal according to the detected current; The driver has an input pin connected to the control terminal of the controller and an output pin connected to the motor via the live wire. The driver is used to control the operating state of the motor according to the control signal.

7. The current detection circuit according to claim 6, characterized in that, The control module also includes: A relay, wherein the first coil terminal of the relay is connected to an output pin of the driver, the second coil terminal of the relay is connected to a power source, and the first and second contact terminals of the relay are respectively connected to the live wire, the relay being used to control the power supply to the motor according to the control signal.

8. The current detection circuit according to claim 7, characterized in that, The current detection circuit also includes: A protection module is connected to the live wire, and the protection module is used to disconnect the live wire when the current signal on the live wire exceeds a current threshold.

9. The current detection circuit according to claim 8, characterized in that, The protection module includes: A thermistor, one end of which is connected to the live wire, and the other end of which is connected to the first contact terminal of the relay.

10. An air conditioner, characterized in that, Includes the current detection circuit as described in any one of claims 1 to 9.

Images