Current detection circuit, ac load device control system, and detection system

Abstract

The application discloses a current detection circuit, an alternating current load device control system and a detection system. The circuit comprises a first optoelectronic coupler, a diode bridge circuit and a diode series circuit. The first port of the first optoelectronic coupler is connected with the first port of the diode series circuit, and the second port of the first optoelectronic coupler is connected with the second port of the diode series circuit. The first port of the diode bridge circuit is connected with the first port of the diode series circuit, and the second port of the diode bridge circuit is connected with the second port of the diode series circuit. The diode bridge circuit is used for realizing bidirectional flow of alternating current. The diode series circuit is used for collecting the voltage of a device to be detected. The application solves the technical problem that the load working state is only judged by detecting the output end voltage in the prior art, and thus the detection is inaccurate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hardware terminal, in particular to a current detection circuit, an alternating current load device control system and a detection system. BACKGROUND

[0002] Current detection in an alternating current circuit has always been an important technology for load line monitoring. Conventional device working state detection is performed by detecting the voltage value at both ends of the load. If there is a voltage difference at the load detection point, it is considered that the load is working. However, the voltage value can only indicate that the power supply circuit has supplied power to the load, and it is not clear whether the load is truly working. The current common current detection method is to detect through a mutual inductor and a related power metering chip. The circuit structure is complex and the cost is relatively high.

[0003] At present, no effective solution has been proposed for the above problems. SUMMARY

[0004] The embodiments of the present application provide a current detection circuit, an alternating current load device control system and a detection system to at least solve the technical problem that the working state of the load is determined only by detecting the output end voltage in the prior art, resulting in inaccurate detection.

[0005] According to an aspect of an embodiment of the present application, a current detection circuit is provided, comprising: a first optoelectronic coupler, a diode bridge circuit and a diode series circuit, wherein the first port of the first optoelectronic coupler is connected to the first port of the diode series circuit, and the second port of the first optoelectronic coupler is connected to the second port of the diode series circuit; the first port of the diode bridge circuit is connected to the first port of the diode series circuit, and the second port of the diode bridge circuit is connected to the second port of the diode series circuit, and the diode bridge circuit is used to realize bidirectional flow of alternating current; and the diode series circuit is used to collect the voltage of a device to be detected.

[0006] Optionally, the number of diodes required by the diode series circuit is determined by the forward voltage drop of the diode conduction and the voltage difference on both sides of the diode series circuit.

[0007] Optionally, a first current limiting circuit is arranged between the second port of the first optoelectronic coupler and the second port of the diode series circuit, the resistance value of the resistor in the first current limiting circuit is determined by the forward voltage drop of the diode conduction, the number of diodes required by the diode series circuit and the rated conduction current of the first optoelectronic coupler, and the first current limiting circuit is used to limit the current passing through the first optoelectronic coupler.

[0008] Optionally, the third port of the diode bridge circuit is connected with the first port of the thyristor circuit, the first port of the thyristor circuit is used for outputting current, the second port of the thyristor circuit is used for receiving input current, and the third port of the thyristor circuit is used for controlling opening or closing of the thyristor circuit.

[0009] Optionally, the thyristor circuit is connected with the control circuit, and the control circuit at least comprises a second optoelectronic coupler, the second optoelectronic coupler being used for controlling opening or closing of the control circuit.

[0010] Optionally, the control circuit further comprises a first light-emitting circuit and a second current-limiting circuit, the first light-emitting circuit being connected with the second current-limiting circuit in series, the first light-emitting circuit being used for indicating a state of an input voltage signal of the control circuit, a light-emitting device in the first light-emitting circuit emitting light when there is a voltage difference on both sides of the first light-emitting circuit, and the light-emitting device in the first light-emitting circuit not emitting light when there is no voltage difference on both sides of the first light-emitting circuit, and the second current-limiting circuit being used for limiting current passing through the first light-emitting circuit.

[0011] Optionally, the third port of the first optoelectronic coupler is connected with a signal detection circuit, and the signal detection circuit at least comprises a third current-limiting circuit, a pull-down circuit, a signal output device and a second light-emitting circuit, the third current-limiting circuit being used for limiting current of the signal detection circuit, the pull-down circuit at least being used for providing a low-level signal when the first optoelectronic coupler is not turned on, the signal output device being used for outputting a voltage signal, and the second light-emitting circuit being used for indicating a state of an output voltage signal of the first optoelectronic coupler.

[0012] Optionally, the third current-limiting circuit is connected with the second light-emitting circuit in series, and the third current-limiting circuit is connected with the pull-down circuit in parallel.

[0013] According to another aspect of the embodiments of the present application, an alternating current load device control system is further provided, and the alternating current load device control system at least comprises the current detection circuit.

[0014] According to still another aspect of the embodiments of the present application, an alternating current load detection system is further provided, and the alternating current load detection system at least comprises the current detection circuit.

[0015] In the embodiments of the present application, the diode bridge circuit and the diode series circuit are used to form a detection circuit which can directly sample an alternating current load circuit, and the detection circuit is protected by being connected with the first optoelectronic coupler, so that the circuit structure is simplified, the cost is reduced, the technical effect of reducing consumption of the load circuit is achieved, and the technical problem of inaccurate detection caused by judging the working state of the load only by the output end voltage in the prior art is solved. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0017] Figure 1 is a partial structural diagram of a current detection circuit according to an embodiment of the application;

[0018] Figure 2 is a structural diagram of a current detection circuit according to an embodiment of the application;

[0019] Figure 3 is a schematic diagram of an alternating current detection circuit according to an embodiment of the application;

[0020] Figure 4 is a block diagram of a current detection circuit according to an embodiment of the application;

[0021] Figure 5 is a flow chart of a circuit design method according to an embodiment of the application. DETAILED DESCRIPTION

[0022] In order to enable persons skilled in the art to better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the scope of protection of the present application.

[0023] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] In the related art, some researchers detect the current on the load circuit by adding an AC transformer or a multimeter with a transformer on the load line, but this method can only be used for line testing and cannot be productized. Some researchers use a method of stringing a relay on the output load to detect whether the load circuit is working normally, but the relay itself is an inductive load and adds consumption to the load circuit, and the upper limit of the current of the load circuit is restricted by the relay coil, which can only be used in small loads and is not sensitive to inductive loads.

[0025] To solve the above problems, the embodiments of the present application provide a current detection circuit which can quickly access the modular circuit design of AC and control signals, and can be integrated in conventional electronic devices to detect whether there is current in the load circuit, thereby accurately obtaining whether the load is actually working. The following will be described in detail.

[0026] Figure 1 is a partial structure diagram of a current detection circuit according to an embodiment of the present application, as shown in Figure 1 , the circuit includes a first optocoupler 102, a diode bridge circuit 104 and a diode series circuit 106, wherein the first port of the first optocoupler is connected with the first port of the diode series circuit, and the second port of the first optocoupler is connected with the second port of the diode series circuit; the first port of the diode bridge circuit is connected with the first port of the diode series circuit, and the second port of the diode bridge circuit is connected with the second port of the diode series circuit, and the diode bridge circuit is used to realize the bidirectional flow of AC current; the diode series circuit is used to collect the voltage of the device to be detected.

[0027] Figure 2 is a structure diagram of a current detection circuit according to an embodiment of the present application, Figure 2 is an extension based on Figure 1 , as shown in Figure 2 , the diode bridge circuit 104 in the embodiments of the present application can realize the bidirectional flow of current and ensure the normal flow of AC current, and the diode series circuit 106 in the embodiments of the present application can ensure the unidirectional flow of AC circuit, thereby ensuring the unidirectional flow of sampling current.

[0028] Optionally, the diode series circuit 106 and the diode bridge circuit 104 in this embodiment constitute a voltage sampling detection circuit. This detection circuit can be flexibly adjusted, and different diode configuration schemes can be configured according to the actual sampling voltage requirements to flexibly realize voltage acquisition. For example, the diode series circuit in this application can use seven diodes D2 to D8 for sampling, but it is not limited to this number. In principle, two or more diode voltage tapping circuits combined with a diode bridge circuit can constitute a detection circuit.

[0029] In the aforementioned current detection circuit, the number of diodes required in the diode series circuit 106 is determined by the forward voltage drop of the diodes and the voltage difference across the diode series circuit. The formula for calculating the number of diodes n required in the diode series circuit is as follows:

[0030] n = (V a -V b ) / U D

[0031] In the above formula, V a -V b This can be understood as the voltage difference across a diode in series circuit, U D The forward voltage drop of the diode is the starting voltage. The number of diodes required for a diode series circuit can be calculated using the formula above. Generally, a diode bridge circuit requires four diodes. Based on the calculation of the number of diodes (n) required for a diode series circuit, the total number of diodes required for the detection circuit composed of the diode series circuit and the diode bridge circuit can be determined.

[0032] In this embodiment, a silicon diode is used for circuit construction, and the forward voltage drop U of the single PN junction is... D The voltage drop is approximately 0.7V, and the final sampling voltage is calculated using this voltage drop value.

[0033] Optionally, the current capability of the load circuit in this embodiment is determined by the maximum forward rated rectified current value I of the diode used. F The influence of the silicon diodes used in the embodiments of this application on I F =1A, but the embodiments of this application are not limited to this type of diode. In principle, all diodes are applicable to the current detection circuit in the embodiments of this application.

[0034] In the current detection circuit, the first current limiting circuit 103 is arranged between the second port of the first optoelectronic coupler 102 and the second port of the diode series circuit 106, and the resistance value of the resistor in the first current limiting circuit 103 is determined by the forward voltage drop of the diode, the number of diodes required by the diode series circuit, and the rated conduction current of the first optoelectronic coupler, and the first current limiting circuit is used to limit the current passing through the first optoelectronic coupler.

[0035] Optionally, the first optoelectronic coupler in the embodiment of the present application is used to safely isolate the detection circuit from the signal detection circuit, for example, the model of the first optoelectronic coupler in the embodiment of the present application can be TLP291, but is not limited to this model and the optoelectronic coupler; in principle, the first optoelectronic coupler here can be an optoelectronic coupler, a relay device, a voltage sampling circuit, etc.

[0036] Optionally, the first current limiting circuit in the embodiment of the present application can be a current limiting resistor, and the resistance value of the current limiting resistor can be adjusted according to actual conditions, and the principle followed is that the forward current between the first port and the second port of the first optoelectronic coupler can meet the normal conduction of the optoelectronic coupler, and the calculation formula of the resistance value of the current limiting resistor in the first current limiting circuit is as follows:

[0037] R = [(U D × n) / I F ] × 1000

[0038] In the above formula, U D is the forward voltage drop of the diode, n is the number of diodes required by the diode series circuit, and I F is the rated conduction current of the optoelectronic coupler. The resistance value of the current limiting resistor in the first current limiting circuit can be calculated by the above formula.

[0039] In the current detection circuit, the third port of the diode bridge circuit 104 is connected with the first port of the thyristor circuit 105, the first port of the thyristor circuit is used to output current, the second port of the thyristor circuit is used to receive input current, and the third port of the thyristor circuit is used to control the opening or closing of the thyristor circuit.

[0040] In the current detection circuit, the thyristor circuit 105 is connected with the control circuit 107, and the control circuit at least includes a second optoelectronic coupler 108, and the second optoelectronic coupler is used to control the opening or closing of the control circuit.

[0041] Optionally, the optoelectronic coupler with a zero-crossing phase optoelectronic bidirectional thyristor device is used in the control circuit in the embodiment of the present application to trigger the bidirectional thyristor device, and the on-off characteristics of the bidirectional thyristor are used to realize the switching function of the alternating current circuit.

[0042] Optionally, the control level in the embodiment of the application is low level trigger, a pull-up circuit is arranged in the control circuit, which is used for preventing the mis-trigger of the photoelectric coupler caused by the uncontrolled pin of the single-chip microcomputer at the power-on moment; in another optional embodiment, the control level can also be adjusted to high level trigger, and the circuit in the control circuit is arranged as a pull-down circuit.

[0043] In the current detection circuit, the control circuit 107 further comprises a first light-emitting circuit 109 and a second current-limiting circuit 110, the first light-emitting circuit 109 is connected in series with the second current-limiting circuit 110, the first light-emitting circuit is used for indicating the state of the input voltage signal of the control circuit, when there is a voltage difference on both sides of the first light-emitting circuit, the light-emitting device in the first light-emitting circuit emits light, when there is no voltage difference on both sides of the first light-emitting circuit, the light-emitting device in the first light-emitting circuit does not emit light, and the second current-limiting circuit is used for limiting the current passing through the first light-emitting circuit.

[0044] In the current detection circuit, the third port of the first photoelectric coupler 102 is connected with a signal detection circuit 111, the signal detection circuit 111 at least comprises a third current-limiting circuit 112, a pull-down circuit 113, a signal output device 114 and a second light-emitting circuit 115, the third current-limiting circuit 112 is used for limiting the current of the signal detection circuit, the pull-down circuit 113 is at least used for providing a low level signal when the first photoelectric coupler is not turned on, and providing a high level signal when the first photoelectric coupler is turned on, the signal output device 114 is used for outputting a voltage signal, and the second light-emitting circuit 115 is used for indicating the state of the output voltage signal of the first photoelectric coupler.

[0045] Optionally, a light-emitting diode can be arranged in the second light-emitting circuit 115 in the embodiment of the application, the light-emitting diode is used for indicating the state of the output signal of the first photoelectric coupler, the level on both sides of the pull-down circuit in the signal detection circuit is taken and compared, and according to the acquired voltage state, whether there is current in the alternating current circuit can be acquired in real time.

[0046] In the current detection circuit, the third current-limiting circuit 112 is connected in series with the second light-emitting circuit 115, and the third current-limiting circuit 112 is connected in parallel with the pull-down circuit 113.

[0047] The current detection circuit provided by the embodiment of the present application can conveniently detect whether the current of the AC load circuit is in a state, and the current detection circuit in the embodiment of the present application provides a thyristor circuit controllable by a low-voltage level signal to control the turn-on and turn-off of the load circuit, and uses photoelectric isolation technology to safely isolate the low-voltage control circuit from the load circuit and to safely isolate the detection sampling circuit from the signal detection circuit, so as to achieve the purposes of simplifying the circuit structure and reducing the cost, thereby realizing the technical effect of reducing the consumption of the load circuit, and further solving the technical problem in the prior art that the load working state is only judged by detecting the output voltage, resulting in inaccurate detection.

[0048] The embodiment of the present application realizes the current state detection of the AC load circuit without using large-scale integrated devices, greatly reduces the complexity of the circuit, improves the stability of the circuit, and meanwhile, the current detection circuit provided by the embodiment of the present application can be used as a basis to add more application functions and realize more flexible current detection circuits.

[0049] The embodiment of the present application provides a current detection circuit that can directly sample in the AC load circuit, solves the inaccuracy of judging the load working state by simply detecting the output voltage, and also provides a convenient and easy-to-build detection circuit for device state detection. The circuit in the embodiment of the present application has strong compatibility and can be conveniently integrated into any circuit that needs to detect AC current. The control circuit and the signal detection circuit of the current detection circuit in the embodiment of the present application can be different voltage levels (such as one DC 3.3V and one 5V). The sampling voltage of the current detection circuit in the embodiment of the present application can be flexibly configured, and the diode circuit parameters can be configured according to the voltage demand of the back end.

[0050] The embodiment of the present application provides an AC load device control system, which at least includes Figure 1 or Figure 2 the current detection circuit shown in the drawings, and can realize the principle of the above-mentioned current detection circuit, so as to judge the state of the AC load device.

[0051] Based on the above-mentioned AC load device control system, the embodiment of the present application further provides a light control system, such as a physical network-based light control system. The Internet of Things light control device is an Internet of Things device that often needs to be remotely controlled. The working state of the controlled device (LED lamp) is usually judged by detecting whether the voltage is present or not. When there is an LED fault, the working state cannot be correctly judged. By integrating the current detection circuit in the embodiment of the present application into the light control system, the working state of the controlled device can be monitored, and the working condition of the controlled device can be judged according to different states of the controlled device, for example:

[0052] ① Control end gives open light instruction, but current detection circuit does not monitor current existence, LED lamp strip working abnormal failure (such as: equipment burnout causes open circuit condition, no installation LED lamp strip etc.) can be judged;

[0053] ② Control end gives off light instruction, but current detection circuit monitors current existence, device short circuit failure (control circuit is not controlled, output end short circuit etc.) can be judged;

[0054] ③ Control end gives open light instruction, current detection circuit monitors current existence, LED lamp working opening normal state can be judged;

[0055] ④ Control instruction gives off light instruction, current detection circuit does not monitor current existence, LED lamp working in the normal state of closing can be judged.

[0056] The embodiment of the application further provides an AC load detection system, which at least comprises the current detection circuit shown in Figure 1 Or Figure 2 The principle of the above-mentioned current detection circuit can be realized, so as to detect the state of the AC load device.

[0057] Based on the above-mentioned AC load detection system, the embodiment of the application further provides a plugboard detection system, which at least comprises the current detection circuit shown in Figure 1 Or Figure 2 The principle of the above-mentioned current detection circuit can be realized, so as to judge the working state of the plugboard, which will not be described here.

[0058] Based on the above-mentioned AC load detection system, the embodiment of the application further provides a binding device detection system, which at least comprises the current detection circuit shown in Figure 1 Or Figure 2 The principle of the above-mentioned current detection circuit can be realized, so as to judge whether the working state of each motor on the binding machine is normal, thereby playing the role of protecting the motor, improving the stability of the device and reducing the failure rate.

[0059] Figure 3 It is a schematic diagram of an AC current detection circuit according to the embodiment of the application, as shown in Figure 3As shown, diodes D1, D9-11 constitute a diode bridge circuit, diodes D2-D8 constitute a diode series circuit, U6 corresponds to a first optocoupler, the 1 port of U6 is connected with the first port of the diode series circuit, the 2 port of U6 is connected with the second port of the diode series circuit, a current limiting resistor R3 is arranged between the 2 port of U6 and the second port of the diode series circuit, the 3 port of U6 is connected with a signal detection circuit, the signal detection circuit comprises: a signal outputter Signout, a third current limiting circuit (composed of a current limiting resistor R1), a pull-down circuit (composed of a pull-down resistor R2) and a second light emitting circuit (composed of LED2), R1 is connected in series with LED2, and then R1 and LED2 are connected in parallel with R2, one end of the parallel circuit is connected with the ground, that is, connected with GND, the other end of the parallel circuit is connected with the 2 port of Signout, the 3 port of Signout is connected with GND, the 1 port of Signout is connected with a voltage level VCC2; the 4 port of U6 is connected with the voltage level VCC2, and the voltages on both sides of the diode series circuit are V a and V b .

[0060] The third port of the diode bridge circuit is connected with the first port of the silicon controlled circuit Qv1, that is, the AC BTIN (that is, the alternating current output) signal of the diode bridge circuit is output from the 1 port of Qv1, the 2 port of Qv1 is connected with the L line of the alternating current input end (AC220IN), the L line is the live wire, the 3 port of Qv1 is the control port, which is used for controlling the conduction or turn-off of the circuit, the resistor Rv3 is a current limiting resistor, which is used for limiting the current passing through the silicon controlled circuit Qv1, the resistor Rv4 is a resistor with a given resistance value, which is used for providing a control voltage for the silicon controlled circuit Qv1, the resistor Rv5 and the capacitor CV1 constitute a resistance-capacitance absorption circuit, which is connected in parallel with the silicon controlled circuit, the transient consistent diode Dv1 is connected in parallel with the silicon controlled circuit, which is used for protecting the circuit when the voltage value in the circuit exceeds the preset threshold.

[0061] U3 is a second optocoupler, which is used for controlling the conduction or turn-off of the control circuit, the control circuit comprises an alternating current controller ACControl, a pull-up resistor Rv1, a current limiting resistor Rv2, a first light emitting circuit, a second current limiting circuit and the second optocoupler U3, wherein the pull-up resistor Rv1 is used for preventing the U3 from being triggered by the uncontrolled single-chip microcomputer pin during power-on, the current limiting resistor Rv2 is used for limiting the current passing through the second optocoupler U3, the ACControl is used for outputting a control signal, the first light emitting circuit is connected with the 1 port of U3, the second current limiting circuit is connected with the 2 port of U3, and the 3 port of U3 is connected with the 4 port of U6. Figure 2The current limiting circuit can be a current limiting resistor Rd1 for limiting the current through the light emitting diode LED1, wherein the 1th port of the ACControl, the current limiting resistor Rd1 and the pull-up resistor Rv1 are connected with the control circuit voltage VCC1, the 3th port of the ACControl is connected with the GND, the 1th and 2th ports of the U3 are control ports, and the 4th and 6th ports are output ports.

[0062] The 3th ports of the AC220IN and the AC220OUT are N lines, which are zero lines, and the 1th port of the AC220OUT is used for outputting the AC signal AC BTOUT through the detection circuit port.

[0063] It should be noted that, Figure 3 the schematic diagram of the AC current detection circuit shown in Figure 2 is the same as the principle of the current detection circuit shown in Figure 2 Therefore, the related explanations and descriptions of the current detection circuit in Figure 3 are also applicable to the AC current detection circuit shown in This will not be described here.

[0064] Figure 4 is a constituent block diagram of a current detection circuit according to an embodiment of the present application, as shown in Figure 4 The block diagram includes a low-voltage control interface circuit 401, a control input end optoelectronic isolation protection circuit 402, a signal detection end optoelectronic isolation protection circuit 403, a detection result output interface circuit 404, an AC input interface circuit 405, a bidirectional thyristor control circuit 406, a diode bridge detection circuit 407 and an AC output interface circuit 408.

[0065] Figure 4 The low-voltage control interface circuit in Figure 2 corresponds to the control circuit 107 shown in Figure 2 The control input end optoelectronic isolation protection circuit 402 corresponds to the second optoelectronic coupler 108 shown in Figure 2 The signal detection end optoelectronic isolation protection circuit 403 corresponds to the first optoelectronic coupler 102 shown in Figure 2 The detection result output interface circuit 404 corresponds to the signal detection circuit 111 shown in Figure 3 The AC input interface circuit 405 corresponds to the AC220IN shown in Figure 2 The bidirectional thyristor control circuit 406 corresponds to the thyristor circuit 105 shown in Figure 2 The diode bridge detection circuit 407 corresponds to the diode bridge circuit 104 and the diode series circuit 106 shown in Figure 3 The AC output interface circuit 408 corresponds to the AC220OUT shown in

[0066] It should be noted that, Figure 4 The working principle of the composition block diagram of the current detection circuit shown in Figure 2 The working principle of the current detection circuit shown in Figure 2 The relevant explanation of the current detection circuit in Figure 4 will not be repeated here.

[0067] Figure 5 The flow chart of a circuit design method according to an embodiment of the present application is shown in Figure 5 Step 501: determine the control circuit voltage VCC1, step 502: determine whether the control level uses high level to trigger the second optocoupler U3 to turn on, when the control level uses high level, step 503 is used to configure the pull-down resistor to prevent false triggering, when the control level uses low level, step 504 is used to configure the pull-up resistor to prevent false triggering, step 505 is used to determine the voltage difference V a -V b of the two ends of the diode series circuit in the detection circuit, according to the type of the selected diode, the forward voltage drop U D of the diode is determined, step 506 is used to calculate the number of diodes n required by the diode series circuit in the detection circuit, wherein n=(V a -V b ) / U D , step 507 is used to calculate the resistance R of the current limiting resistor arranged between the first optocoupler and the diode series circuit, wherein R=[(U D ×n) / I F ]×1000, step 508 is used to adjust the value of diode n and the resistance of current limiting resistor R to obtain the most stable circuit configuration.

[0068] It should be noted that, Figure 5 The circuit design method shown in Figure 2 can be applied to the current detection circuit shown in Figure 2 , and the relevant explanation of the current detection circuit in Figure 5 The circuit design method shown in will not be repeated here.

[0069] The above-mentioned serial numbers of the embodiments of the present application only serve for description, and do not represent the advantages and disadvantages of the embodiments.

[0070] In the above-mentioned embodiments of the present application, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0071] In several embodiments provided in the present application, it should be understood that the disclosed technology can be implemented by other ways. Among them, the above-described device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, units or modules, and can be electrical or other forms.

[0072] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place or distributed to multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0073] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0074] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and various program codes that can be stored in the medium.

[0075] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A current detection circuit, characterized by, The application relates to a control circuit for an alternating current (AC) load device, and belongs to the technical field of electrical control. The control circuit comprises a first optoelectronic coupler, a diode bridge circuit and a diode series circuit, wherein, a first port of the first optoelectronic coupler is connected with a first port of the diode series circuit, and a second port of the first optoelectronic coupler is connected with a second port of the diode series circuit; a first port of the diode bridge circuit is connected with the first port of the diode series circuit, and a second port of the diode bridge circuit is connected with the second port of the diode series circuit, and the diode bridge circuit is used for realizing bidirectional flow of alternating current; the diode series circuit is used for collecting voltage of a device to be detected; a third port of the diode bridge circuit is connected with a first port of a thyristor circuit, the thyristor circuit is connected with a control circuit, the control circuit uses an optoelectronic coupler with a zero-crossing phase photoelectric bidirectional thyristor device to trigger a bidirectional thyristor device, and the bidirectional thyristor device realizes switching function of an alternating current circuit through the fast on-off characteristic of the bidirectional thyristor device; an up pull circuit is arranged in the control circuit, and the up pull circuit is used for preventing the optoelectronic coupler from being triggered by mistake due to uncontrolled pins of a single-chip microcomputer at the moment of power-on; a third port of the first optoelectronic coupler is connected with a signal detection circuit, the signal detection circuit at least comprises a down pull circuit, the signal detection circuit acquires voltage levels on both sides of the down pull circuit, compares the voltage levels on both sides, thereby acquiring a voltage state, and in real time acquires whether current exists in the alternating current circuit according to the voltage state; whether the alternating current load device is normal is judged according to whether the current exists, wherein, in the case that the control end is opened and the current detection circuit does not monitor the existence of the current, it is judged that the alternating current load device has a fault, and in the case that the control end is closed and the current detection circuit monitors the existence of the current, it is judged that the alternating current load device has a fault.

2. The circuit of claim 1, wherein, The number of diodes required by the diode series circuit is determined by a forward voltage drop of diode conduction and a voltage difference on both sides of the diode series circuit.

3. The circuit of claim 2, wherein, A first current limiting circuit is arranged between the second port of the first optoelectronic coupler and the second port of the diode series circuit, a resistance value of a resistor in the first current limiting circuit is determined by the forward voltage drop of diode conduction, the number of diodes required by the diode series circuit and a rated conduction current of the first optoelectronic coupler, and the first current limiting circuit is used for limiting current passing through the first optoelectronic coupler.

4. The circuit of claim 1, wherein The first port of the thyristor circuit is used for outputting current, the second port of the thyristor circuit is used for receiving input current, and the third port of the thyristor circuit is used for controlling opening or closing of the thyristor circuit.

5. The circuit of claim 4, wherein, The control circuit at least comprises a second optoelectronic coupler, and the second optoelectronic coupler is used for controlling opening or closing of the control circuit.

6. The circuit of claim 5, wherein, The control circuit further comprises a first light-emitting circuit and a second current-limiting circuit, the first light-emitting circuit and the second current-limiting circuit are connected in series, the first light-emitting circuit is used for indicating the state of the input voltage signal of the control circuit, when there is a voltage difference on both sides of the first light-emitting circuit, the light-emitting device in the first light-emitting circuit emits light, when there is no voltage difference on both sides of the first light-emitting circuit, the light-emitting device in the first light-emitting circuit does not emit light, and the second current-limiting circuit is used for limiting the current passing through the first light-emitting circuit.

7. The circuit of claim 1, wherein The signal detection circuit at least comprises a third current-limiting circuit signal output device and a second light-emitting circuit, the third current-limiting circuit is used for limiting the current of the signal detection circuit, the pull-down circuit is at least used for providing a low-level signal when the first optocoupler is not turned on, the signal output device is used for outputting a voltage signal, and the second light-emitting circuit is used for indicating the state of the output voltage signal of the first optocoupler.

8. The circuit of claim 7, wherein, The third current-limiting circuit and the second light-emitting circuit are connected in series, and the third current-limiting circuit and the pull-down circuit are connected in parallel.

9. An alternating current load device control system characterized by, The AC load device control system at least comprises the current detection circuit of any one of claims 1-8.

10. An alternating current load detection system characterized by, The AC load detection system at least comprises the current detection circuit of any one of claims 1-8.

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