A low-power load detection circuit, method, and meter

Abstract

This invention relates to a low-power load detection circuit, method, and meter, comprising: a switching module, a detection module connected to the switching module, and a control module connected to both the switching module and the detection module; the switching module cuts off the load power supply and activates the detection module based on a switching signal output by the control module; the detection module performs load detection and outputs a load detection signal; when the input signal is abnormal, the control module controls the switching module to cut off the load power supply and activates the detection module through the switching module; the control module also determines whether the closing conditions are met based on the load detection signal, and controls the switching module to conduct when the meter meets the closing conditions. This invention detects the load through the detection module and controls the on / off of the load power supply through the switching module when the meter malfunctions, achieving not only metering but also local power on / off functionality, ensuring electrical safety at low cost and avoiding problems caused by unstable wireless signals.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric meter, more particularly, to a low-power consumption load detection circuit, method and electric meter. BACKGROUND

[0002] The wireless electric meter cannot be truly popularized due to its high cost, and the grid voltage is unstable, which easily leads to overvoltage, undervoltage and other events, and most of the household appliances used are unqualified or aging, which easily leads to over-power events. In order to protect the safety of electricity, the electric meter determines over-power or overvoltage and undervoltage, and then makes a breaker protection, but it is troublesome to close the breaker, and only RS485 or infrared communication can be used for local closing.

[0003] In order to realize the breaker protection, there are two common schemes in the market at present:

[0004] I. The mode of master station + wireless electric meter:

[0005] In this mode, when the wireless electric meter of the customer detects events such as overload, overvoltage, undervoltage and the like, the master station is reported first, the operator of the master station and the customer make safety confirmation, and after confirming that the event is over, remote closing is carried out.

[0006] II. The mode of using metering electric meter:

[0007] In this mode, the electric meter only carries out metering, cannot carry out relay closing, and cannot guarantee the safety of electricity.

[0008] For the first mode, although remote control closing can be realized, the wireless electric meter is high in cost and the wireless signal is unstable, and there is a problem that closing cannot be realized due to unstable signal. For the second mode, although the cost is low, relay closing cannot be realized, and the safety of electricity cannot be guaranteed. SUMMARY

[0009] The technical problem to be solved by the present application is to provide a low-power consumption load detection circuit, method and electric meter.

[0010] The technical solution adopted by the present application to solve the technical problem is that a low-power consumption load detection circuit is constructed, which comprises a switching module, a detection module connected with the switching module, and a control module connected with the switching module and the detection module;

[0011] The switching module cuts off the power supply of the load according to the switching signal output by the control module, and starts the detection module when cutting off the power supply of the load;

[0012] The detection module starts load detection and outputs a load detection signal according to the control of the switching module;

[0013] The control module detects an input signal, and when the input signal is abnormal, controls the switch module to cut off power supply of a load and starts the detection module through the switch module; the control module is also used for judging whether a closing condition is met according to the load detection signal when the detection module is started, and controlling the switch module to be turned on when the closing condition is met.

[0014] In the low-power-consumption load detection circuit, the closing condition is that:

[0015] After the detection module is started, the control module detects that there is a load according to the load detection signal, and after detecting that there is a load, the control module continues to collect the load detection signal and judges according to the load detection signal; if it is detected that there is no load at present according to the load detection signal, load detection is continued and the judgment is made according to the load detection signal; if it is detected again that there is a load at present according to the load detection signal, it is determined that the closing condition is met.

[0016] In the low-power-consumption load detection circuit, the switch module comprises a switch unit connected with the control module and a controllable switch connected with the switch unit.

[0017] The switch unit controls the on-off of the controllable switch according to the switch signal output by the control module.

[0018] The controllable switch is in a normally closed state when the input signal is normal, and cuts off the power supply of the load and starts the detection module according to the switch signal when the input signal is abnormal.

[0019] In the low-power-consumption load detection circuit, the controllable switch comprises a relay.

[0020] When the input signal is normal, the relay is in a normally closed state, and when the input signal is abnormal, the relay is disconnected.

[0021] In the low-power-consumption load detection circuit, the switch unit comprises a second diode and a first triode.

[0022] The cathode of the second diode is connected with a power supply voltage and a second pin of the relay, the anode of the second diode is connected with a collector of the first triode and a first pin of the relay, the emitter of the first triode is grounded, and the base of the first triode is connected with the control module.

[0023] The third pin of the relay is connected with a live wire input end, the fourth pin of the relay is connected with an air switch, and the fifth pin of the relay is connected to the detection module.

[0024] The detection module comprises a first isolation unit, a second isolation unit and a load detection unit.

[0025] The first isolation unit and the second isolation unit are connected with the switch module respectively, and the load detection unit is connected with the first isolation unit, the second isolation unit and the control module respectively.

[0026] When the switch module is turned on, the first isolation unit, the second isolation unit and the load detection unit are all cut off, and when the switch module is turned off, the first isolation unit, the second isolation unit and the load detection unit are turned on.

[0027] The first isolation unit comprises a third diode, a first resistor, an eighth resistor, a first photoelectric coupler, a fourth resistor and a first diode.

[0028] The anode of the third diode is connected with the switch module, the cathode of the third diode is connected with the first end of the first resistor, the second end of the first resistor is connected with the first end of the eighth resistor and the first end of the first photoelectric coupler, and the second end of the eighth resistor is connected with the third end of the first photoelectric coupler and a zero line input end.

[0029] The sixth end of the first photoelectric coupler is connected with the cathode of the first diode through the fourth resistor, the anode of the first diode is connected with a live line input end, and the fourth end of the first photoelectric coupler is connected with the load detection unit.

[0030] The load detection unit comprises a second resistor, a seventh resistor, a second photoelectric coupler and a fifth resistor.

[0031] The first end of the second resistor is connected with a power supply voltage, the second end of the second resistor is connected with the sixth end of the second photoelectric coupler, the fourth end of the second photoelectric coupler outputs the load detection signal, and the fourth end of the second photoelectric coupler is also connected with the ground through the seventh resistor.

[0032] The first end of the second photoelectric coupler is connected with the fourth end of the first photoelectric coupler, the third end of the second photoelectric coupler is connected with the second isolation unit, the fifth resistor is connected between the first end and the third end of the second photoelectric coupler, and the first end of the second photoelectric coupler is connected with the first end of an air switch.

[0033] The second isolation unit comprises a fourth diode, a tenth resistor, an eleventh resistor and a third photoelectric coupler.

[0034] Anode of the fourth diode is connected with the switch module, cathode of the fourth diode is connected with the first end of the tenth resistor, the second end of the tenth resistor is connected with the first end of the eleventh resistor and the first end of the third optocoupler, the second end of the eleventh resistor is connected with the third end of the third optocoupler, the third end of the third optocoupler is connected with the zero line input end, the sixth end of the third optocoupler is connected with the third end of the second optocoupler, and the fourth end of the third optocoupler is connected with the fourth end of the air switch.

[0035] The application further provides an electric meter comprising the low-power-consumption load detection circuit.

[0036] The application further provides a low-power-consumption load detection method comprising the following steps:

[0037] The control module detects the input signal in real time;

[0038] The control module judges whether the input signal is abnormal or not;

[0039] If yes, the control module outputs a switch signal;

[0040] The switch module cuts off the power supply of the load and starts the detection module according to the switch signal;

[0041] The control module collects the load detection signal generated by the detection module;

[0042] The control module judges whether the electric meter meets the closing condition according to the load detection signal;

[0043] If the closing condition is met, the control module controls the switch module to be turned on.

[0044] In the low-power-consumption load detection method, the closing condition is that:

[0045] After the detection module is started, the control module detects that there is a load according to the load detection signal, and after detecting that there is a load, the control module continues to collect the load detection signal and judges according to the load detection signal; if it is detected that there is no load at present according to the load detection signal, the load detection is continued and the judgment is made according to the load detection signal; if it is detected again that there is a load at present according to the load detection signal, it is determined that the closing condition is met.

[0046] In the low-power-consumption load detection method, the load detection signal comprises a high-level signal or a low-level signal.

[0047] The control module judges whether the closing condition is met according to the load detection signal.

[0048] After the detection module is started, if the load detection signal is low, the control module determines that the load is detected.

[0049] After the load is detected, the control module continues to collect the load detection signal.

[0050] If the load detection signal is high, the control module determines that the current load is not detected.

[0051] The detection module continues to detect the load.

[0052] The control module continues to judge whether the load is detected according to the load detection signal.

[0053] If the load detection signal is low, the control module determines that the current load is detected.

[0054] The control module controls the switch module to be turned on.

[0055] The low-power load detection circuit, method and electric meter have the following beneficial effects: the low-power load detection circuit, method and electric meter comprise a switch module, a detection module connected with the switch module and a control module connected with the switch module and the detection module; the switch module cuts off the power supply of the load according to the switch signal output by the control module and starts the detection module; the detection module detects the load and outputs a load detection signal; the control module controls the switch module to cut off the power supply of the load when the input signal is abnormal and starts the detection module through the switch module; the control module further judges whether the closing condition is met according to the load detection signal and controls the switch module to be turned on when the electric meter meets the closing condition. The low-power load detection circuit, method and electric meter detect the load through the detection module when the electric meter fails and control the on-off of the power supply of the load through the switch module, which not only realizes the metering function but also realizes the local closing and opening function, ensures the safety of electricity use in a low-cost way and avoids the problem caused by unstable wireless signals. BRIEF DESCRIPTION OF DRAWINGS

[0056] The application will be further described below in combination with the drawings and examples, and the drawings are as follows:

[0057] Figure 1 is a principle block diagram of the low-power load detection circuit provided by the embodiment of the application;

[0058] Figure 2 is a circuit diagram of the switch module provided by the embodiment of the application;

[0059] Figure 3is a circuit diagram of the detection module provided by the embodiment of the present application;

[0060] Figure 4 is a flowchart of the low-power load detection method provided by the embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the drawings.

[0062] Reference Figure 1 The present application provides a low-power load detection circuit, which is a high-voltage isolation-based low-power load detection circuit and can be applied to an electric meter such as a smart electric meter, a smart water meter, a smart electric meter, etc.

[0063] In a preferred embodiment, as shown in Figure 1 The low-power load detection circuit comprises a switch module 10, a detection module 20 connected with the switch module 10, and a control module 30 connected with the switch module 10 and the detection module 20. The low-power load detection circuit can be arranged in an electric meter.

[0064] In the embodiment of the present application, the switch module 10 cuts off the power supply of the load according to the switch signal output by the control module 30, and starts the detection module 20 when the power supply of the load is cut off. Specifically, when working normally, the switch module 10 is in an on state, at this time, the electric energy passes through the switch module 10 and then passes through the air switch to supply power to the load; when the control module 30 detects an abnormal input signal, the switch module 10 cuts off the power supply of the load according to the switch signal output by the control module 30, and starts the detection module 20 when the power supply of the load is cut off, and detects the load through the detection module 20.

[0065] Optionally, in the embodiment of the present application, the switch module 10 comprises a switch unit connected with the control module 30 and a controllable switch connected with the switch unit.

[0066] The switch unit controls the on-off of the controllable switch according to the switch signal output by the control module 30. The controllable switch is in a normally closed state when the input signal is normal, and cuts off the power supply of the load and starts the detection module 20 according to the switch signal when the input signal is abnormal. When the controllable switch is in a normally closed state, the switch module 10 is in an on state.

[0067] Optionally, in the embodiment of the present application, the controllable switch comprises a relay; when the input signal is normal, the relay is in a normally closed state, and when the input signal is abnormal, the relay is disconnected. Specifically, when the input signal is normal, the relay is in a normally closed state (i.e., the switch module 10 is in a conducting state), at this time, the electric energy is supplied to the load through the relay and then through the air switch; when the input signal is abnormal, the control module 30 controls the relay to be disconnected (i.e., the breaker is pulled) through the switch unit, at this time, the electric energy supplied to the load is cut off, thereby achieving the purpose of ensuring the safety of electricity use.

[0068] The detection module 20 starts the load detection and outputs the load detection signal according to the control of the switch module 10. Optionally, in the embodiment of the present application, the load detection signal comprises a high-level signal or a low-level signal. Specifically, when the load detection signal is a low-level signal, it indicates that there is currently a load; when the load detection signal is a high-level signal, it indicates that there is currently no load. In the embodiment of the present application, when the input signal is normal, the detection module 20 is in a cut-off state, i.e., the detection module 20 does not work; when the input signal is abnormal, the detection module 20 starts to work. Therefore, through this setting, the power consumption can be reduced.

[0069] In some embodiments, as shown in FIG. 2, the detection module 20 comprises a first isolation unit, a second isolation unit, and a load detection unit. Figure 1

[0070] The first isolation unit and the second isolation unit are respectively connected with the switch module 10, and the load detection unit is respectively connected with the first isolation unit, the second isolation unit, and the control module 30; when the switch module 10 is conducting, the first isolation unit, the second isolation unit, and the load detection unit are all cut off, and when the switch module 10 is disconnected, the first isolation unit, the second isolation unit, and the load detection unit are conducting.

[0071] The control module 30 detects the input signal, controls the switch module 10 to cut off the power supply of the load and starts the detection module 20 through the switch module 10 when the input signal is abnormal, and is further used for judging whether the closing condition is met according to the load detection signal when the detection module 20 is started, and controlling the switch module 10 to be conducting when the closing condition is met.

[0072] Optionally, in the embodiment of the present application, the closing condition is that: after the detection module 20 is started, the control module 30 detects that there is a load according to the load detection signal, and after detecting that there is a load, the control module 30 continues to collect the load detection signal and judges according to the load detection signal; if it is detected according to the load detection signal that there is currently no load, the load detection is continued and the judgment is made according to the load detection signal; if it is detected again according to the load detection signal that there is currently a load, it is determined that the closing condition is met.

[0073] ​Specifically, when the input signal is abnormal, the control module 30 outputs a switch signal to control the switch module 10 to be turned off to cut off the power supply of the load, and at the same time, the detection module 20 is started through the switch module 10, and after the detection module 20 is started, the detection module 20 detects the load, and the control module 30 detects the load after the air switch through the load detection signal. At this time, the control module 30 can detect that there is a load at present. In addition, after the power supply of the load is cut off, the user checks the overload load and timely removes the overload appliance, and checks whether the voltage displayed by the electric meter is abnormal. If the voltage displayed by the electric meter is normal and the overload appliance has been removed, the user pulls down the air switch (i.e., controls the air switch to be turned off). At this time, it can be detected through the detection module 20 that there is no load at present. When the user turns on the air switch again, it can be detected through the detection module 20 that there is a load at present. At this time, the control module 30 determines that the closing condition is met, and controls the switch module 10 to be turned on again when it is determined that the condition is met.

[0074] The electric meter with a relay is used for power protection in the application, the circuit power consumption is low, and the high-voltage isolation scheme is also relatively safe. The closing is performed after the load is detected according to the air switch state, the reliability and safety of the closing are improved, and it is also relatively safe for the user to perform safety inspection after power failure and then operate the air switch. In addition, the application closes only when the air switch state and the load state are both in the safe state, which absolutely ensures the safety of power consumption.

[0075] Further, in the embodiment of the application, the control module 30 realizes the monitoring and fault diagnosis of the input signal according to the voltage and current collected by the metering sampling circuit inside the electric meter. Optionally, in the embodiment of the application, the input signal includes a sampling voltage and a sampling current, wherein the sampling voltage is the sampling of the voltage input to the load, and the sampling current is the sampling of the current input to the load. Specifically, the control module 30 can determine whether overvoltage or undervoltage occurs by comparing the sampling voltage with the overvoltage threshold and the undervoltage threshold. Specifically, when the sampling voltage is greater than or equal to the overvoltage threshold (120%U), it is determined that overvoltage occurs; and when the sampling voltage is less than or equal to the undervoltage threshold (80%), it is determined that undervoltage occurs. The control module 30 calculates the power according to the sampling voltage and the sampling current, and compares the power with the overload threshold to determine whether overload occurs. For example, when the power is greater than the overload threshold (120%P), it is determined that overload occurs.

[0076] Reference Figure 2 and Figure 3 The application provides a circuit diagram of a preferred embodiment of the switch module 10 and the detection module 20.

[0077] Specifically, as Figure 2As shown, the switching unit includes a second diode D2 and a first transistor Q1.

[0078] The cathode of the second diode D2 is connected to the power supply voltage and the second pin of the relay LS1. The anode of the second diode D2 is connected to the collector of the first transistor Q1 and the first pin of the relay LS1. The emitter of the first transistor Q1 is grounded, and the base of the first transistor Q1 is connected to the control module 30 (i.e., SW1 in the figure). The third pin of the relay LS1 is connected to the live wire input terminal, the fourth pin of the relay LS1 is connected to the air switch S1, and the fifth pin of the relay LS1 is connected to the detection module 20.

[0079] like Figure 3 As shown, the first isolation unit includes: a third diode D3, a first resistor R1, an eighth resistor R8, a first optocoupler U1, a fourth resistor R4, and a first diode D1.

[0080] The anode of the third diode D3 is connected to the switch module 10 (i.e., the anode of the third diode D3 is connected to the fifth pin of the relay LS1), the cathode of the third diode D3 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the first end of the eighth resistor R8 and the first end of the first optocoupler U1, the second end of the eighth resistor R8 is connected to the third end of the first optocoupler U1 and the neutral input terminal; the sixth end of the first optocoupler U1 is connected to the cathode of the first diode D1 through the fourth resistor R4, the anode of the first diode D1 is connected to the live wire input terminal, and the fourth end of the first optocoupler U1 is connected to the load detection unit.

[0081] like Figure 3 As shown, the load detection unit includes: a second resistor R2, a seventh resistor R7, a second optocoupler U2, and a fifth resistor R5.

[0082] The first end of the second resistor R2 is connected to the supply voltage (VDD), the second end of the second resistor R2 is connected to the sixth end of the second optocoupler U2, the fourth end of the second optocoupler U2 outputs the load detection signal (i.e., the SW2 signal in the figure), and the fourth end of the second optocoupler U2 is also grounded through the seventh resistor R7; the first end of the second optocoupler U2 is connected to the fourth end of the first optocoupler U1, the third end of the second optocoupler U2 is connected to the second isolation unit, the fifth resistor R5 is connected between the first end and the third end of the second optocoupler U2, and the first end of the second optocoupler U2 is connected to the first end of the air switch S1.

[0083] like Figure 3 The second isolation unit shown includes: a fourth diode D4, a tenth resistor R10, an eleventh resistor R11, and a third optocoupler U3.

[0084] Anode of the fourth diode D4 is connected with the switch module 10 (i.e. the anode of the fourth diode D4 is connected with the fifth pin of the relay LS1), the cathode of the fourth diode D4 is connected with the first end of the tenth resistor R10, the second end of the tenth resistor R10 is connected with the first end of the eleventh resistor R11 and the first end of the third optocoupler U3, the second end of the eleventh resistor R11 is connected with the third end of the third optocoupler U3, the third end of the third optocoupler U3 is connected with the zero line input end, the sixth end of the third optocoupler U3 is connected with the third end of the second optocoupler U2, and the fourth end of the third optocoupler U3 is connected with the fourth end of the air switch S1.

[0085] Specifically, as shown in Figure 2 and Figure 3 When the control module 30 detects overvoltage, undervoltage or overload, the control module 30 outputs a high level signal through SW1, at this time, the first triode Q1 is turned on, and the third pin and the fifth pin of the relay LS1 are turned on (i.e. L and L2 are communicated), after L2 is powered on, the first optocoupler U1 and the fourth end and the sixth end of the third optocoupler U3 are turned on, at this time, the detection module 20 is started, and the control module 30 can determine whether there is a load by detecting the signal of SW2.

[0086] As shown in Figure 3As shown, after the detection module 20 is started, the signal of SW2 can be used to detect the air switch S1 and the load RL; when the air switch S1 is disconnected, SW2 is high level, at this time, the control module 30 can determine that there is no load currently; when the air switch S1 is turned on, the first end of the second optocoupler U2 is pulled low, SW2 is low level, at this time, the control module 30 can determine that there is a load currently. Therefore, when the control module 30 detects that the power meter has overvoltage, undervoltage or overload failure, a high level signal is first output through SW1 to make the first triode Q1 conduct, and then the third pin and the fourth pin of the relay LS1 are disconnected (L and L1 are disconnected, the relay LS1 is pulled out of the gate), the load power supply is cut off, at the same time, the third pin and the fifth pin of the relay LS1 are connected (L and L2 are connected), after L2 is powered on, the first optocoupler U1 and the third optocoupler U3 are turned on, the detection module 20 is started, and the current user has not yet acted, the air switch S1 is in a closed state, therefore, SW2 is low level, and the control module 30 can determine that there is a load currently through the signal of SW2; when the user finds that the power is cut off, the air switch S1 is disconnected, SW2 is high level, at this time, the control module 30 can determine that there is no load currently through the signal of SW2; when the user checks the over-current protector and confirms that the power meter is normal and the over-current protector is removed, the air switch S1 is closed again (i.e. the air switch S1 is closed), at this time, the first end of the second optocoupler U2 is pulled low, SW2 is low level, the control module 30 detects that there is a load currently again, and then determines that the air switch S1 is closed again, thereby determining that the closing condition is met, the control module 30 outputs a low level signal through SW1 to make the first triode Q1 cut off, at this time, the third pin and the fourth pin of the relay LS1 are connected (i.e. L and L1 are connected again), after L2 is disconnected, the fourth end and the sixth end of the first optocoupler U1 and the third optocoupler U3 are disconnected, at this time, the detection module 20 is closed, and since L and L1 are connected again, the load is powered on again.

[0087] The application realizes the automatic start-stop control of the detection module 20 by controlling the opening and closing of the relay, and when the power consumption is normal, the detection module 20 is closed to significantly reduce the power consumption, and when the relay state is detected, the air switch state is detected and the load state is detected, the high-voltage isolation detection is used, and the relay is controlled to close only when the air switch and the load are in a safe state, thereby ensuring the safety of power consumption.

[0088] The application also provides a power meter, which can include the low-power consumption load detection circuit disclosed in the embodiments of the application.

[0089] Reference Figure 4The application provides a low-power load detection method, which can be realized by the low-power load detection circuit disclosed by the application.

[0090] Specifically, as shown in the figure, Figure 4 The low-power load detection method comprises the following steps:

[0091] In step S401, the control module 30 detects the input signal in real time.

[0092] In step S402, the control module 30 judges whether the input signal is abnormal.

[0093] In step S403, if the input signal is abnormal, the control module 30 outputs a switch signal. When the input signal is abnormal, the switch signal is a high-level signal; when the input signal is normal, the switch signal remains a low-level signal.

[0094] In step S404, the switch module 10 cuts off the power supply of the load and starts the detection module 20 according to the switch signal.

[0095] In step S405, the control module 30 collects the load detection signal generated by the detection module 20.

[0096] Optionally, in the application, the load detection signal comprises a high-level signal or a low-level signal.

[0097] In the application, the control module 30 judges whether the closing condition is met according to the load detection signal, which comprises the following steps: after the detection module 20 is started, if the load detection signal is a low-level signal, the control module 30 determines that the load is detected; after the load is detected, the control module 30 continues to collect the load detection signal; if the load detection signal is a high-level signal, the control module 30 determines that the current load is not detected; the load detection is continued by the detection module 20; the control module 30 continues to judge whether the load is detected according to the load detection signal; if the load detection signal is a low-level signal, the control module determines that the current load is detected; and the control module 30 controls the switch module 10 to be turned on.

[0098] In step S406, the control module 30 judges whether the closing condition is met according to the load detection signal.

[0099] In step S407, if the closing condition is met, the control module 30 controls the switch module 10 to be turned on.

[0100] Optionally, in the embodiment of the present application, the closing condition is that after the detection module 20 is started, the control module 30 detects the load according to the load detection signal, and after detecting the load, the control module 30 continues to collect the load detection signal and judges according to the load detection signal. If no load is detected according to the load detection signal, the load detection is continued and the judgment is made according to the load detection signal. If the current load is detected again according to the load detection signal, it is determined that the closing condition is met.

[0101] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0102] The skilled person can further realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed in the present text can be realized in electronic hardware, computer software or combination of both. In order to clearly show the interchangeability of hardware and software, the composition and steps of the examples have been described in general in the above description. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0103] The steps of the method or algorithm described in combination with the embodiments disclosed in the present text can be directly implemented by hardware, software module executed by a processor, or combination of both. The software module can be placed in random access memory (RAM), memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0104] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it accordingly, and cannot limit the protection scope of the present application. Any equivalent changes and modifications made within the scope of the claims of the present application shall be within the scope of the claims of the present application.

Claims

1. A low power consumption load detection circuit, characterized by, The application relates to a switch module, a detection module connected with the switch module and a control module connected with the switch module and the detection module. The switch module cuts off power supply of a load according to a switch signal output by the control module and starts the detection module when cutting off the power supply of the load. The detection module starts load detection according to control of the switch module and outputs a load detection signal; the load detection signal comprises a high-level signal and a low-level signal; when the load detection signal is a low-level signal, there is a load at present; when the load detection signal is a high-level signal, there is no load at present. The control module detects an input signal and controls the switch module to cut off the power supply of the load and starts the detection module through the switch module when the input signal is abnormal; the control module is also used for judging whether a closing condition is met according to the load detection signal when the detection module is started and controlling the switch module to be turned on when the closing condition is met. The closing condition is that the control module detects a load according to the load detection signal after the detection module is started and continues to collect the load detection signal and judges according to the load detection signal after detecting the load; if the control module detects that there is no load at present according to the load detection signal, the control module continues to detect the load and judges according to the load detection signal; if the control module detects that there is a load at present again according to the load detection signal, it is judged that the closing condition is met. The switch module comprises a switch unit connected with the control module and a controllable switch connected with the switch unit.

2. The low power consumption load detection circuit according to claim 1, characterized by, The switch unit controls the on-off of the controllable switch according to the switch signal output by the control module. The controllable switch is in a normally closed state when the input signal is normal and cuts off the power supply of the load and starts the detection module according to the switch signal when the input signal is abnormal. The controllable switch comprises a relay.

3. The low power consumption load detection circuit according to claim 2, characterized by, When the input signal is normal, the relay is in a normally closed state; when the input signal is abnormal, the relay is disconnected. The switch unit comprises a second diode and a first triode.

4. The low power consumption load detection circuit according to claim 3, characterized by, The cathode of the second diode is connected with a power supply voltage and a second pin of the relay, the anode of the second diode is connected with a collector of the first triode and a first pin of the relay, the emitter of the first triode is grounded, and the base of the first triode is connected with the control module. A third pin of the relay is connected with a firewire input end, a fourth pin of the relay is connected with an air switch, and a fifth pin of the relay is connected with the detection module. The detection module comprises a first isolation unit, a second isolation unit and a load detection unit.

5. The low power consumption load detection circuit according to claim 1, wherein The first isolation unit and the second isolation unit are respectively connected with the switch module, and the load detection unit is respectively connected with the first isolation unit, the second isolation unit and the control module. ​ The first isolation unit, the second isolation unit and the load detection unit are cut off when the switch module is turned on, and the first isolation unit, the second isolation unit and the load detection unit are turned on when the switch module is turned off.

6. The low power consumption load detection circuit according to claim 5, wherein The first isolation unit comprises a third diode, a first resistor, an eighth resistor, a first optocoupler, a fourth resistor and a first diode. The anode of the third diode is connected with the switch module, the cathode of the third diode is connected with the first end of the first resistor, the second end of the first resistor is connected with the first end of the eighth resistor and the first end of the first optocoupler, and the second end of the eighth resistor is connected with the third end of the first optocoupler and the zero line input end. The sixth end of the first optocoupler is connected with the cathode of the first diode through the fourth resistor, the anode of the first diode is connected with the live line input end, and the fourth end of the first optocoupler is connected with the load detection unit.

7. The low power consumption load detection circuit according to claim 6, characterized by The load detection unit comprises a second resistor, a seventh resistor, a second optocoupler and a fifth resistor. The first end of the second resistor is connected with the power supply voltage, the second end of the second resistor is connected with the sixth end of the second optocoupler, the fourth end of the second optocoupler outputs the load detection signal, and the fourth end of the second optocoupler is also connected with the ground through the seventh resistor. The first end of the second optocoupler is connected with the fourth end of the first optocoupler, the third end of the second optocoupler is connected with the second isolation unit, the fifth resistor is connected between the first end and the third end of the second optocoupler, and the first end of the second optocoupler is connected with the first end of the air switch.

8. The low power consumption load detection circuit according to claim 7, characterized by, The second isolation unit comprises a fourth diode, a tenth resistor, an eleventh resistor and a third optocoupler. The anode of the fourth diode is connected with the switch module, the cathode of the fourth diode is connected with the first end of the tenth resistor, the second end of the tenth resistor is connected with the first end of the eleventh resistor and the first end of the third optocoupler, the second end of the eleventh resistor is connected with the third end of the third optocoupler, the third end of the third optocoupler is connected with the zero line input end, the sixth end of the third optocoupler is connected with the third end of the second optocoupler, and the fourth end of the third optocoupler is connected with the fourth end of the air switch.

9. An electricity meter characterized by The low-power consumption load detection circuit of any one of claims 1-8. The low-power consumption load detection circuit comprises the following steps:

10. A low power consumption load detection method characterized by, The control module detects the input signal in real time; The control module determines whether the input signal is abnormal; If yes, the control module outputs a switch signal; The switch module cuts off the power supply of the load according to the switch signal and starts the detection module; The control module collects the load detection signal generated by the detection module, the load detection signal comprises a high-level signal and a low-level signal, the load detection signal is a low-level signal when there is a load at present, and the load detection signal is a high-level signal when there is no load at present; The control module determines whether the closing condition is met according to the load detection signal. ​ If the closing condition is met, the control module controls the switch module to be turned on. The closing condition is: After the detection module is started, the control module detects that there is a load according to the load detection signal, and after detecting that there is a load, the control module continues to collect the load detection signal and judges according to the load detection signal. If it is detected that there is no load at present according to the load detection signal, the load detection is continued and the judgment is made according to the load detection signal. If it is detected again that there is a load at present according to the load detection signal, it is determined that the closing condition is met.

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