CN117310553A - Equipment safety grounding detection circuit and detection method thereof - Google Patents
Equipment safety grounding detection circuit and detection method thereof Download PDFInfo
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- CN117310553A CN117310553A CN202311329799.4A CN202311329799A CN117310553A CN 117310553 A CN117310553 A CN 117310553A CN 202311329799 A CN202311329799 A CN 202311329799A CN 117310553 A CN117310553 A CN 117310553A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Abstract
The application provides a device safety grounding detection circuit and a detection method thereof. The circuit comprises an interface circuit, a control module and a charging and discharging module; the interface circuit comprises a live wire interface, a zero wire interface, a first grounding end and a second grounding end which are respectively connected with a live wire, a zero wire, a grounding end and an ESD ground wire of a power supply port of equipment to be detected; the control module is used for outputting a charging signal when receiving a start detection signal and outputting a discharging signal when detecting zero crossing interruption of a power supply port of the equipment to be detected after the charging is completed; the charging and discharging module is used for charging and storing energy when receiving a charging signal; discharging to the ground and starting to accumulate discharge time when receiving the discharge signal; and when the accumulated discharge time is greater than or equal to the discharge threshold value, the control module outputs a grounding abnormal alarm signal. The risk of direct and mains supply direct connection has been avoided to this application, has reduced the interference, has also improved equipment safety ground's detection precision and reliability.
Description
Technical Field
The invention relates to the technical field of grounding safety, in particular to a device safety grounding detection circuit and a detection method thereof.
Background
With the development of scientific technology, the electric safety requirement of electric equipment is higher and higher. The powered device typically has three contacts for connection to the hot, neutral and ground wires of a power source (e.g., 220V ac power source), respectively. The ground wire is short for a grounding device, and is a wire which is grounded, grounded to a shell or grounded to a reference potential of zero in a power system or electronic equipment. The grounding wire generally plays a role in safety, and is used for leading current into the ground, so that the grounding wire plays roles in preventing human body electric shock and lightning leakage, protecting electric appliances and guaranteeing normal operation of machines.
In the production assembly process of the electric equipment, sometimes the ground wire of the electric equipment is misplaced, namely, the ground wire connected with the shell of the electric equipment is misplaced to a live wire interface or a neutral wire interface of the electric equipment, so that the shell is electrified when the electric equipment is electrified, and safety threat is brought to a user. The grounding wire connects the electrically conductive exposed part with the ground to form an equipotential, and if the electric appliance shell leaks electricity, current can flow to the ground through the grounding wire, so that the electric shock of a human body is prevented. Traditional ground connection detection circuit or check out test set often need be connected with the commercial power line in the testing process, and is higher to operating personnel's requirement, and the operation is wrong will constitute the threat to operating personnel's life safety and equipment security, and the commercial power line wiring condition is complicated, easily produces the interference to the testing result.
Meanwhile, with miniaturization of electric and electronic equipment and modularization and high integration of circuit boards, electrostatic protection (ESD: electrostatic discharge, abbreviated as ESD event) cannot be ignored in the circuit production and assembly process. The static electricity can generate a large amount of charges in the discharging process, if the electric appliance does not have corresponding obstruction, the electric appliance and human body can be injured, and the ground wire discharges the charges to the ground, so that the electric appliance is protected.
Therefore, how to ensure the ground line and the ESD ground of the electric equipment to be simultaneously and safely grounded is a problem to be solved.
Disclosure of Invention
The invention provides a device safety grounding detection circuit and a detection method thereof, which are used for solving the technical problems that the traditional grounding detection method has high operation requirement and low accuracy and cannot detect ESD events at the same time.
In a first aspect, in one embodiment, an apparatus safety ground detection circuit is provided, including an interface circuit, a control module, and a charge-discharge module;
the interface circuit comprises a live wire interface, a zero wire interface, a first grounding end and a second grounding end; the live wire interface of the interface circuit is connected with the live wire of the power supply port of the equipment to be detected, the zero wire interface of the interface circuit is connected with the zero wire of the power supply port of the equipment to be detected, the first grounding end of the interface circuit is connected with the grounding end of the power supply port of the equipment to be detected, and the second grounding end of the interface circuit is connected with the ESD ground wire;
the control module is used for outputting a charging signal when receiving a start detection signal and outputting a discharging signal when detecting zero crossing interruption of a power supply port of the equipment to be detected after the charging is completed;
the charging and discharging module is used for starting charging and storing energy through an external first input power supply when receiving the charging signal; when the discharge signal is received, the first grounding end and/or the second grounding end discharge to the ground, and the accumulated discharge time is started;
and when the accumulated discharge time is greater than or equal to a discharge threshold value, the control module outputs a grounding abnormal alarm signal.
In a second aspect, an embodiment provides a device security ground detection method, which is applied to the device security ground detection circuit of the above embodiment; the equipment safety grounding detection circuit is used for being connected with a live wire, a zero wire, a grounding end and an ESD ground wire of equipment to be detected;
the detection method comprises the steps of,
when receiving a start detection signal, the equipment safety ground detection circuit starts charging;
acquiring a zero-crossing interrupt signal of a power supply port of equipment to be detected;
when a zero-crossing interrupt signal is received from a power supply port of equipment to be detected, the equipment is safely grounded, the detection circuit discharges to the ground, and the accumulated discharge time is started;
and when the accumulated discharge time is greater than or equal to a discharge threshold value, judging that the equipment to be detected is abnormal in grounding.
The equipment safety grounding detection circuit and the detection method thereof provided by the embodiment of the application comprise an interface circuit, a control module and a charging and discharging module, wherein the interface circuit, the control module and the charging and discharging module are respectively connected with a live wire, a zero wire, a grounding wire and an ESD (electro-static discharge) ground wire of equipment to be detected, the control module controls the charging and discharging module to charge and discharge the earth, the discharging time is accumulated in the process of discharging the earth, and when the discharging time is greater than or equal to a discharging threshold value, a grounding abnormal alarm is output. The interface circuit is connected with the equipment to be detected, so that the risk of direct connection with a mains supply line is avoided, and the interference of the mains supply line is reduced; in the detection process, the discharge time to the ground is accurately quantized, and the detection precision of the equipment safety grounding is improved; meanwhile, the detection circuit is simple in structure, convenient to assemble and low in cost.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.
Fig. 1 is a block diagram of a device safety ground detection circuit according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a device safety ground detection circuit according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a device safety ground detection circuit according to another embodiment of the present application;
FIG. 4 is a block diagram of a device safety ground detection circuit according to another embodiment of the present application;
fig. 5 is a functional block diagram of a device safety ground detection circuit according to an embodiment of the present application;
fig. 6 is a flowchart of a method for detecting a device security ground according to an embodiment of the present application.
Specific embodiments thereof have been shown by way of example in the drawings and will herein be described in more detail. These drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments.
Detailed Description
The invention will be described in further detail below with reference to the drawings by means of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, some operations associated with the present application have not been shown or described in the specification to avoid obscuring the core portions of the present application, and may not be necessary for a person skilled in the art to describe in detail the relevant operations based on the description herein and the general knowledge of one skilled in the art.
Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.
The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The terms "coupled" and "connected," as used herein, are intended to encompass both direct and indirect coupling (coupling), unless otherwise indicated.
For the current safety grounding detection circuit, device or method, the live wire, the zero line and the grounding wire are always required to be connected in the detection process, namely, the detection circuit is directly connected with the mains supply wire, the requirement on operators is high, and once the operators have misoperation or the grounding wire is accidentally disconnected, the voltage on the detection circuit is very high, and threatens to the life safety and equipment safety of the operators. Furthermore, as the line length of the commercial power line is up to kilometers under the normal condition and the wiring condition is complex, the line is interfered by the power frequency male mode, and the detection result is easy to interfere, so that the accuracy of the detection result is questionable.
With miniaturization of electronic devices and modularization and high integration of circuit boards, the problem of damage to ESD events in circuit assembly is more remarkable, and a large amount of static charges are accumulated, so that not only can misoperation occur to adsorb dust, but also MOSFETs and integrated circuits on a PCB (printed Circuit Board) can be damaged, the circuit functions are permanently damaged, and electronic equipment can be seriously damaged by uncontrolled discharge. The prior main measures for eliminating the ESD are grounding, humidification, ion wind elimination method and the like, wherein the grounding method is the simplest and is widely used, and the grounding reliability directly influences the quality of products. Grounding herein refers to safe and ESD grounding.
The existing ESD event detection structure is separate, so a reliable circuit or device (method) capable of detecting the safe ground of both the ground line and the ESD ground in real time is needed, and an alarm is sent when the ground is abnormal to prompt a technician to find and repair the ground fault in time.
The application proposes a device safety grounding detection circuit and a detection method thereof, wherein the device safety grounding detection circuit is characterized in that through an interface circuit, a control module and a charging and discharging module which are respectively connected with a live wire, a zero wire, a grounding wire and an ESD (electro-static discharge) ground wire of a device to be detected, the connection condition of safety ground and ESD ground is detected by detecting and quantifying the time of discharging the ground, a safety discharging time threshold value is set, and when the time of discharging the ground exceeds a preset threshold value, the device is regarded as abnormal grounding and alarm processing is carried out.
The application provides a device safety grounding detection circuit and a detection method thereof, which aim to solve the technical problems in the prior art.
The following describes the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems in detail with specific embodiments. The following embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. Embodiments of the present application will be described below with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a device safety ground detection circuit according to an embodiment of the present application. Referring to fig. 1, the device safety ground detection circuit includes an interface circuit 100, a control module 200, and a charge-discharge module 300.
The interface circuit 100 includes a live wire interface, a neutral wire interface, a first grounding end and a second grounding end, the live wire interface of the interface circuit 100 is connected with a live wire of a power supply port of the device to be detected, the neutral wire interface of the interface circuit 100 is connected with a neutral wire of the power supply port of the device to be detected, the first grounding end of the interface circuit 100 is connected with the grounding end of the power supply port of the device to be detected, namely, is connected with a shell of the device to be detected, and the second grounding end of the interface circuit 100 is connected with an ESD ground wire.
In some embodiments, the interface circuit 100 is a plug receptacle P14 of model PJ3041, having 4 terminals, which are a hot wire interface, a neutral wire interface, a first ground, and a second ground of the interface circuit 100, respectively.
The control module 200 is configured to receive a start detection signal after the device to be detected is turned on, and output a charging signal to the charging and discharging module 300. After the charging of the charging and discharging module 300 is completed, when detecting that the power supply port of the equipment to be detected is subjected to zero crossing interruption, a discharging signal is output to the charging and discharging module 300, and the charging and discharging module 300 is controlled to start discharging to the ground.
The charge-discharge module 300 is configured to start self-charging and energy storage by externally connecting a first input power supply when receiving a charging signal output by the control module 200; when receiving the discharge signal output by the control module 200, the charge/discharge module 300 discharges to the ground through the first ground terminal and/or the second ground terminal of the interface circuit 100, and starts accumulating the discharge time.
When the accumulated discharge time is greater than or equal to the discharge threshold, the control module 200 outputs a ground fault alert signal. For example, when the accumulated discharge time exceeds 30 seconds, the control module 200 outputs an alarm signal regarding the ground fault.
In some embodiments, the control module 200 includes a timer that sends a timing signal to the control module 200 to begin accumulating the discharge time after the charging module 300 begins discharging to ground.
The equipment safety grounding detection circuit provided by the embodiment of the application comprises an interface circuit, a control module and a charging and discharging module, wherein the interface circuit, the control module and the charging and discharging module are respectively connected with a live wire, a zero wire, a grounding wire and an ESD (electro-static discharge) ground wire of equipment to be detected, the control module controls the charging and discharging module to charge and discharge the earth, accumulated discharging time is accumulated in the process of discharging the earth, and when the discharging time is greater than or equal to a discharging threshold value, an abnormal grounding alarm is output. The interface circuit is connected with the equipment to be detected, so that the risk of direct connection with a mains supply line is avoided, and the interference of the mains supply line is reduced; in the detection process, the discharge time to the ground is accurately quantized, and the detection precision of the equipment safety grounding is improved; meanwhile, the detection circuit is simple in structure, convenient to assemble and low in cost.
Fig. 2 is a schematic diagram of a device safety ground detection circuit according to an embodiment of the present application. In some embodiments, referring to fig. 2, a charge-discharge module 300 of the device safety ground detection circuit includes a control circuit 301, a charging circuit 302, a clamp protection circuit 303, and a load circuit 304.
The control circuit 301 includes a first end and a second end, where the first end of the control circuit 301 is configured to turn on the first end and the second end of the control circuit 301 after receiving the charging signal output by the control module 200, and output a driving signal to the charging circuit 302 through the second end of the control circuit.
In some embodiments, referring to fig. 2, the control circuit 301 includes a resistor R26, a resistor R27, a switch Q6, a resistor R25, a resistor R24, a switch Q8, and a resistor R29.
The resistor R26 includes a first end and a second end, and the first end of the resistor R26 is connected to the first end of the control circuit 301, i.e. is configured to receive the charging signal output by the control module 200. The resistor R27 comprises a first end and a second end, the first end of the resistor R27 is connected with the second end of the resistor R26, and the second end of the resistor R27 is grounded. The switching tube Q6 comprises a first end, a second end and a control end, the control end of the switching tube Q6 is connected with the second end of the resistor R26, and the first end of the switching tube Q6 is grounded. Resistor R25 includes a first terminal and a second terminal, and the first terminal of resistor R25 is connected to the second terminal of switching tube Q6. Resistor R24 includes a first end and a second end, and the first end of resistor R24 is connected to the second end of resistor R25. The switching tube Q8 comprises a first end, a second end and a control end, the control end of the switching tube Q8 is connected with the first end of the resistor R24, and the first end of the switching tube Q8 is connected with the second end of the resistor R24. The resistor R29 includes a first end and a second end, the first end of the resistor R29 is connected to the second end of the switching tube Q8, the second end of the resistor R29 is connected to the first end of the charging circuit 302, and a driving signal is output to the charging circuit.
The charging circuit 302 includes a first end and a second end, the first end of the charging circuit 302 is connected to the second end of the control circuit 301, and the second end of the charging circuit 302 is grounded; the charging circuit 302 starts self-charging energy storage through the externally connected first input power supply in response to the driving signal output from the control circuit 301.
In some embodiments, the charging circuit includes a capacitor C41, a capacitor C42, and a resistor R38.
The capacitor C41 includes a first end and a second end, the first end of the capacitor C41 is connected to the first end of the charging circuit 302, that is, the first end of the capacitor C41 is connected to the second end of the resistor R29, and the second end of the capacitor C41 is grounded; the capacitor C42 includes a first end and a second end, the first end of the capacitor C42 is connected to the first end of the charging circuit 302, that is, the first end of the capacitor C41 is connected to the second end of the resistor R29, and the second end of the capacitor C42 is grounded; resistor R38 includes a first end and a second end, resistor R38 is connected across capacitor C41 and capacitor C42, i.e., the first end of resistor R38 is connected to the first end of capacitor C41 and the second end of resistor R38 is connected to the first end of capacitor C42. Upon receiving the drive signal output from the control circuit 301, the capacitor C41 and the capacitor C42 charge and store energy.
The clamp protection circuit 303 includes a first end, a second end and a power end, the first end of the clamp protection circuit 303 is connected to the first end of the charging circuit 302, the second end of the clamp protection circuit 303 is grounded, and the power end of the clamp protection circuit 303 is connected to an external first input power source.
In some embodiments, clamp protection circuit 303 includes diode D5. The diode D5 includes a first terminal, a second terminal and a third terminal, the first terminal of the diode D5 is connected to the external first input power source and the first terminal of the charging circuit 302, i.e. to the first terminal of the capacitor C41, the second terminal of the diode D5 is grounded, and the third terminal of the diode D5 is connected to the first terminal of the load circuit 304.
The load circuit 304 includes a first end and a second end, the first end of the load circuit 304 is connected to the first end of the charging circuit 302, the second end of the load circuit 304 is connected to the first ground and/or the second ground of the interface circuit 100, and the load circuit 304 is configured to increase impedance and reduce a current value discharged to ground.
In some embodiments, the load circuit 304 includes an inductor L2, a resistor R30, a resistor R31, a resistor R32, a resistor R33, and a resistor R35 sequentially connected in series, one end of the inductor L2 is connected to the first ground and/or the second ground of the interface circuit 100, and the other end of the resistor R35 is connected to the first end of the capacitor C41 and the third end of the diode D5.
The device safe ground detection circuit of the above-described embodiments can be simplified if the detection result does not need to be responded quickly or is used for standby in some fields during the process of detecting whether the device is safe grounded.
Fig. 3 is a schematic diagram of a device safety ground detection circuit according to another embodiment of the present application. Referring to fig. 3, in the present embodiment, the control circuit 301 in the above embodiment is simplified, where the same or similar concepts or processes may exist in some embodiments, and will not be described herein.
The control circuit 301 includes a diode D2 and a resistor R29. The diode D2 includes an anode and a cathode, the cathode of the diode D2 is connected to the first end of the charging circuit 302, that is, to the first end of the capacitor C41, the anode of the diode D2 is connected to the first end of the resistor R29, and the second end of the resistor R29 is connected to the control module 200, for receiving the charging signal output by the control module 200.
When the control module 200 outputs the charging signal, the diode D2 is turned on, and outputs a driving signal to drive the charging circuit 302 to start charging and storing energy.
In some embodiments, the charge-discharge module 300 further includes a discharge detection circuit 305. The discharge detection circuit 305 includes a first end and a second end, the first end of the discharge detection circuit 305 is connected to the first end of the charging circuit 302, that is, to the first end of the capacitor C42, and the second end of the discharge detection circuit 305 is connected to the control module 200 through the first end of the control circuit 301 or directly. When the interface of the control module 200 is deficient, the second end of the discharging circuit 305 may be connected to the first end of the control circuit 301, and share the interface of the control module 200 with the first end of the control circuit 301; when the interfaces of the control module 200 are redundant, the second end of the discharging circuit 305 can also be directly connected with another interface on the control module 200, which is connected with the first end of the control circuit 301. The discharge detection circuit 305 is configured to send a discharge timing signal to the control module 200 when the charging circuit 302 starts discharging to the ground.
In some embodiments, discharge detection circuit 305 includes resistor R28, switch Q9, switch Q10, resistor R19, resistor R48, and capacitor C43.
The resistor R28 comprises a first end and a second end, and the first end of the resistor R28 is connected with a second input power supply; the switching tube Q9 comprises a first end, a second end and a control end, the first end of the switching tube Q9 is grounded, the second end of the switching tube Q9 is connected with the second end of the resistor R28, and the control end of the switching tube Q9 is connected with the first end of the discharge detection circuit 305, namely the first end of the charging circuit 302, namely the first end of the capacitor C42; the switching tube Q10 comprises a first end, a second end and a control end, the first end of the switching tube Q10 is connected with a second input power supply, and the control end of the switching tube Q10 is connected with the second end of the switching tube Q9; the resistor R19 comprises a first end and a second end, the first end of the resistor R19 is connected with the second end of the switch tube Q10, and the second end of the resistor R19 is grounded; the resistor R48 includes a first end and a second end, the first end of the resistor R48 is connected to the second end of the switching tube Q10, and the second end of the resistor R48 is connected to the second end of the discharge detection circuit 305, i.e. through the first end of the control circuit 301 or directly connected to the control module 200; the capacitor C43 includes a first end and a second end, the first end of the capacitor C43 is connected to the second end of the resistor R48, and the second end of the capacitor C42 is grounded.
In some embodiments, as shown in fig. 3, the discharge detection circuit 305 may also include only the resistor R48 and the capacitor C43.
The resistor R48 includes a first end and a second end, the first end of the resistor R48 is connected to the first end of the discharge detection circuit 305, i.e. to the first end of the charging circuit 302, i.e. to the first end of the capacitor C42, and the second end of the resistor R48 is connected to the second end of the discharge detection circuit 305, i.e. to the first end of the control circuit 301 or directly to the control module 200; the capacitor C43 includes a first end and a second end, the first end of the capacitor C43 is connected to the second end of the resistor R48, and the second end of the capacitor C42 is grounded.
The equipment safety grounding detection circuit provided by the embodiment has the advantages of simple structure, convenience in assembly and low cost.
Fig. 4 is a block diagram of a device security ground detection circuit according to another embodiment of the present application. In some embodiments, the device security ground detection circuit further includes an alarm circuit 400, and concepts or processes similar to or identical to those of the above embodiments may be omitted in some embodiments.
The alarm circuit 400, upon receiving the abnormal ground alarm signal output from the control module 200, issues an alarm to prompt a technician to discover and repair a ground fault in time.
Referring to fig. 2 and 3, the alarm circuit 400 includes a resistor R20, a resistor R21, a switching tube Q7, and a buzzer BUZ1.
The resistor R20 includes a first end and a second end, the first end of the resistor R20 is configured to receive the abnormal grounding alarm signal output by the control module 200, and the second end of the resistor R20 is connected to the control end of the switch tube Q7. The resistor R21 comprises a first end and a second end, the first end of the resistor R21 is connected with the second end of the resistor R20, and the second end of the resistor R21 is grounded. The switching tube Q7 comprises a first end, a second end and a control end, the first end of the switching tube Q7 is grounded, and the control end of the switching tube Q7 is connected with the second end of the resistor R20. The buzzer BUZ1 comprises a first end and a second end, the first end of the buzzer BUZ1 is connected with a third input power supply, and the second end of the buzzer BUZ1 is connected with the second end of the switching tube Q7.
When the control module 200 outputs an abnormal grounding alarm signal, the switching tube Q7 and the buzzer BUZ1 are conducted, and the buzzer BUZ1 sounds a beep to prompt a technician to find and repair a grounding fault in time.
Fig. 5 is a functional block diagram of a device safety ground detection circuit according to an embodiment of the present application. Referring to fig. 5, based on the embodiment shown in fig. 2, the working principle of the device safety ground detection circuit provided in the embodiment of the present application is as follows:
before starting detection, the interface of the interface circuit 100 is respectively connected with a live wire of a power supply port, a zero wire of the power supply port, a grounding end connection of the power supply port and an ESD ground wire of the equipment to be detected.
And (3) charging: after the device to be detected is started, the control module 200 receives a start detection signal, and the ESD CkDr signal output through the P3.3 port of the control module is at a high level, that is, a charging signal, and the switching tubes Q6 and Q8 in the control circuit 301 are turned on, so that the capacitor C41 and the capacitor C42 in the charging circuit 302 are charged and stored by the first input power source with a voltage value of 5V.
The discharging process comprises the following steps: after the charging is completed, when the control module 200 receives that the power supply port of the device to be detected is subjected to zero crossing interruption, the ESD CkDr signal output through the P3.3 port of the control module is at a low level, namely a discharging signal, the switching tubes Q6 and Q8 in the control circuit 301 are turned off, and the charging circuit 302 is not charged. At this time, when the voltage of the capacitor C42 reaches the on voltage (1V to 4.7V) of the switching transistor Q9 in the discharge detection circuit 305, the switching transistor Q9 is turned on, and after filtering, the ESD Check signal output from the discharge detection circuit 305 is sent to the P3.2 port of the control module 200, and at this time, the ESD Check signal is at a high level. The control module 200 begins counting by its internal timer in response to the ESD Check signal.
At the same time, the charging circuit 302 starts to discharge the capacitor C41 and the capacitor C42 to the ground in response to the discharge signal, the voltage at the second end of the capacitor C42 decreases, and when the voltage decreases to the on voltage (1V-4.7V) of the switching transistor Q9, the switching transistor Q9 and/or the switching transistor Q10 are turned off, the ESD Check signal changes from high level to low level, and the timer in the control module 200 stops counting. The time when the ESD Check signal is continuously high is the accumulated discharge time.
If the device to be detected is grounded normally, the charging circuit 302 discharges the ESD through the load circuit 304 to form two discharge loops of P14-ESD ground impedance-user EARTH-DGND and P14-ESD ground impedance-mains EARTH-user EARTH ground impedance-user EARTH-DGND. After the discharge is continued for a period of time, when the voltage at the second end of the capacitor C42 in the charging circuit 302 drops to the on voltage (1V-4.7V) of the switching tube Q9, the switching tube Q9 and/or the switching tube Q10 is turned off, the ESD Check signal is turned from high level to low level, the timer in the control module 200 stops counting, and the accumulated discharge time of the timer does not exceed the preset discharge threshold, so that the state of the ground wire and the ESD ground of the device to be detected is safe ground.
If the device to be detected is abnormal in grounding, at this time, the user EARTH grounding impedance or the ESD grounding impedance in the discharging circuit becomes large or is opened, so that the discharging of the capacitor C41 and the capacitor C42 in the charging circuit 302 is blocked, the voltage at the second end of the capacitor C42 is not reduced, the conduction voltage (1V-4.7V) of the switching tube Q9 in the discharging detection circuit 305 can be always reached, the switching tube Q9 and/or the switching tube Q10 are turned on, the ESD Check signal is continuously high, the timer in the control module 200 continuously accumulates the discharging time, at this time, the accumulated discharging time of the timer exceeds the preset discharging threshold or the timer overflows, the state of the grounding wire and/or the ESD grounding to be detected can be considered abnormal, and an alarm signal can be output to the alarm circuit 400 through the P3.0 port of the control module 200, so as to prompt a technician to find and repair the grounding fault in time.
Fig. 6 is a flowchart of a method for detecting a device security ground according to an embodiment of the present application. Referring to fig. 6, based on the above-mentioned device safety ground detection circuit and the working principle thereof, the embodiment of the present application provides a device safety ground detection method, which specifically includes the following steps after connecting the device safety ground detection circuit with a live wire, a neutral wire, a ground terminal and an ESD ground wire of a device to be detected:
in step S100, upon receiving the start detection signal, the device safety ground detection circuit starts charging.
The control module 200 is configured to receive a start detection signal after the device to be detected is turned on, and output a charging signal to the charging and discharging module 300.
Whether the equipment safety grounding detection circuit is charged or not is judged, and the method specifically comprises the following steps:
step 101, acquiring charging time;
step 102, determining that the device safety ground detection circuit is charged when the charging time is greater than or equal to the charging threshold.
Specifically, according to the capacitance values of the capacitor C41 and the capacitor C42 in the charging circuit 302 and the voltage value of the external first input power source, the charging threshold values of the capacitor C41 and the capacitor C42 are set, for example, 100ms, and after charging starts, if the obtained charging time is greater than or equal to the charging threshold value (100 ms), the completion of charging of the device safety ground detection circuit can be determined.
In some embodiments, a flag bit is further provided in the control module, and when the charging time is greater than or equal to the charging threshold, the ESD CkDr signal is disabled, and the charging circuit 302 is controlled to stop charging, and at the same time, the measurement flag bit is set, and the discharge timer is cleared, so as to prepare for starting to count by the discharge timer.
Step S200, acquiring a zero-crossing interrupt signal of a power supply port of equipment to be detected.
After the charging of the charging and discharging module 300 is completed, when detecting that the power supply port of the equipment to be detected is subjected to zero crossing interruption, a discharging signal is output to the charging and discharging module 300, and the charging and discharging module 300 is controlled to start discharging to the ground.
In some embodiments, after the step S200 of obtaining the zero-crossing interrupt signal of the power supply port of the device to be detected, the method further includes detecting the measurement flag bit after the charging circuit 302 is charged in the step S102. For example, after the charging circuit 302 is charged, the flag bit is configured to be "1", after the zero-crossing interrupt signal of the power supply port of the detection device is obtained, whether the measurement flag bit is "1" is detected first, if the measurement flag bit is "1", the next step is performed, and if the measurement flag bit is not "1", the charging step is returned to.
Step S300, when a zero-crossing interrupt signal is received from a power supply port of the equipment to be detected, the equipment safety grounding detection circuit discharges to the ground, and the accumulated discharge time is started.
Step S400, when the accumulated discharge time is greater than or equal to the discharge threshold value, the grounding abnormality of the equipment to be detected is judged.
In some embodiments, when the accumulated discharge time is greater than or equal to the discharge threshold, determining that the device to be detected is in an abnormal state, and recording the number of times of the abnormal state of the device in the grounding state, configuring the number of times of the abnormal state of the device in the grounding state +1 when the accumulated discharge time is greater than or equal to the discharge threshold once, and configuring the abnormal state of the device in the grounding state as the number of times threshold when the number of times of the abnormal state is greater than or equal to the number of times threshold, for example, 3 times, and sending out an abnormal alarm at the moment; when the abnormal state is smaller than the frequency threshold, the measurement zone bit and the charging time timer are cleared, namely, when the zero-crossing interrupt signal of the power supply port of the equipment to be detected is acquired next time, the charging step is carried out.
In some embodiments, when the abnormal state is less than the time threshold, continuously detecting whether the device is safely grounded, if the accumulated discharge time is less than the discharge threshold, configuring the number of times of the device grounding abnormal state-1, and when the grounding abnormal state is 0, clearing the grounding abnormal state, and clearing the measurement flag bit and the charging time timer.
And S500, judging that the equipment to be detected is abnormal in grounding when the timer overflows over time in the process of accumulating the discharge time.
Therefore, according to the equipment safety grounding detection method, the equipment safety grounding detection circuit is respectively connected with the live wire, the zero wire, the grounding wire and the ESD (electro-static discharge) ground wire of the equipment to be detected, after the equipment to be detected is started, when a detection starting signal is received, the equipment safety grounding detection circuit starts charging and storing energy, when zero crossing interruption of a power supply port of the equipment to be detected is detected, the equipment starts discharging to the ground, meanwhile, the discharging time is accumulated, the discharging time to the ground is accurately quantized, whether the equipment is safely grounded or not is detected, and the detection precision and reliability of equipment safety grounding are improved.
Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.
The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those of ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are also within the protection of the present application.
Claims (10)
1. The equipment safety grounding detection circuit is characterized by comprising an interface circuit, a control module and a charging and discharging module;
the interface circuit comprises a live wire interface, a zero wire interface, a first grounding end and a second grounding end; the live wire interface of the interface circuit is connected with the live wire of the power supply port of the equipment to be detected, the zero wire interface of the interface circuit is connected with the zero wire of the power supply port of the equipment to be detected, the first grounding end of the interface circuit is connected with the grounding end of the power supply port of the equipment to be detected, and the second grounding end of the interface circuit is connected with the ESD ground wire;
the control module is used for outputting a charging signal when receiving a start detection signal and outputting a discharging signal when detecting zero crossing interruption of a power supply port of the equipment to be detected after the charging is completed;
the charging and discharging module is used for starting charging and storing energy through an external first input power supply when receiving the charging signal; when the discharge signal is received, the first grounding end and/or the second grounding end discharge to the ground, and the accumulated discharge time is started;
and when the accumulated discharge time is greater than or equal to a discharge threshold value, the control module outputs a grounding abnormal alarm signal.
2. The device safety ground detection circuit of claim 1, wherein the charge-discharge module comprises a control circuit, a charging circuit, a clamp protection circuit, and a load circuit;
the control circuit comprises a first end and a second end, wherein the first end of the control circuit is used for conducting the first end and the second end of the control circuit when receiving the charging signal and outputting a driving signal through the second end of the control circuit;
the charging circuit comprises a first end and a second end, the first end of the charging circuit is connected with the second end of the control circuit, and the second end of the charging circuit is grounded; the charging circuit is used for starting charging and storing energy through the first input power supply when receiving the driving signal;
the clamping protection circuit comprises a first end, a second end and a power end, wherein the first end of the clamping protection circuit is connected with the first end of the charging circuit, the second end of the clamping protection circuit is grounded, and the power end of the clamping protection circuit is connected with the first input power supply;
the load circuit comprises a first end and a second end, the first end of the load circuit is connected with the first end of the charging circuit, and the second end of the load circuit is connected with the interface circuit.
3. The device safety ground detection circuit of claim 2, wherein the control circuit comprises a diode D2; the diode D2 comprises a first end and a second end, the first end of the diode D2 is connected with the first end of the control circuit, and the second end of the diode D2 is connected with the second end of the control circuit;
or,
the control circuit comprises a resistor R26, a resistor R27, a switching tube Q6, a resistor R25, a resistor R24, a switching tube Q8 and a resistor R29; the resistor R26 comprises a first end and a second end, and the first end of the resistor R26 is connected with the first end of the control circuit; the resistor R27 comprises a first end and a second end, the first end of the resistor R27 is connected with the second end of the resistor R26, and the second end of the resistor R27 is grounded; the switching tube Q6 comprises a first end, a second end and a control end, the control end of the switching tube Q6 is connected with the second end of the resistor R26, and the first end of the switching tube Q6 is grounded; the resistor R25 comprises a first end and a second end, and the first end of the resistor R25 is connected with the second end of the switching tube Q6; the resistor R24 comprises a first end and a second end, and the first end of the resistor R24 is connected with the second end of the resistor R25; the switching tube Q8 comprises a first end, a second end and a control end, the control end of the switching tube Q8 is connected with the first end of the resistor R24, and the first end of the switching tube Q8 is connected with the second end of the resistor R24; the resistor R29 comprises a first end and a second end, the first end of the resistor R29 is connected with the second end of the switch tube Q8, and the second end of the resistor R29 is connected with the second end of the control circuit.
4. The device safety ground detection circuit of claim 2, wherein the charging circuit comprises a capacitor C41, a capacitor C42, and a resistor R38; the capacitor C41 comprises a first end and a second end, the first end of the capacitor C41 is connected with the first end of the charging circuit, and the second end of the capacitor C41 is connected with the second end of the charging circuit; the capacitor C42 comprises a first end and a second end, the first end of the capacitor C42 is connected with the first end of the charging circuit, and the second end of the capacitor C42 is connected with the second end of the charging circuit; the resistor R38 comprises a first end and a second end, the first end of the resistor R38 is connected with the first end of the capacitor C41, and the second end of the resistor R38 is connected with the first end of the capacitor C42;
the clamping protection circuit comprises a diode D5; the diode D5 comprises a first end, a second end and a third end, the first end of the diode D5 is connected with the power end of the clamp protection circuit, the second end of the diode D5 is connected with the second end of the clamp protection circuit, and the third end of the diode D5 is connected with the first end of the clamp protection circuit;
the load circuit comprises an inductor L2, a resistor R30, a resistor R31, a resistor R32, a resistor R33 and a resistor R35 which are sequentially connected in series, wherein one end of the inductor L2 is connected with the second end of the load circuit, and the other end of the resistor R35 is connected with the first end of the load circuit.
5. The device safety ground detection circuit of claim 2, wherein the charge-discharge module further comprises a discharge detection circuit;
the discharge detection circuit comprises a first end and a second end; the first end of the discharge detection circuit is connected with the first end of the charging circuit, and the second end of the discharge detection circuit is connected with the control module through the first end of the control circuit module or directly; the discharge detection circuit is used for sending a discharge timing signal to the control module when the charging circuit starts discharging to the ground.
6. The device safety ground detection circuit of claim 5, wherein the discharge detection circuit comprises a resistor R28, a switching tube Q9, a switching tube Q10, a resistor R19, a resistor R48, and a capacitor C43;
the resistor R28 comprises a first end and a second end, and the first end of the resistor R28 is connected with a second input power supply; the switching tube Q9 comprises a first end, a second end and a control end, the first end of the switching tube Q9 is grounded, the second end of the switching tube Q9 is connected with the second end of the resistor R28, and the control end of the switching tube Q9 is connected with the first end of the discharge detection circuit; the switching tube Q10 comprises a first end, a second end and a control end, the first end of the switching tube Q10 is connected with the second input power supply, and the control end of the switching tube Q10 is connected with the second end of the switching tube Q9; the resistor R19 comprises a first end and a second end, the first end of the resistor R19 is connected with the second end of the switch tube Q10, and the second end of the resistor R19 is grounded; the resistor R48 comprises a first end and a second end, the first end of the resistor R48 is connected with the second end of the switch tube Q10, and the second end of the resistor R48 is connected with the second end of the discharge detection circuit; the capacitor C43 includes a first end and a second end, the first end of the capacitor C43 is connected to the second end of the discharge detection circuit, and the second end of the capacitor C42 is grounded.
7. The device safety ground detection circuit of claim 1, further comprising an alarm circuit; the alarm circuit is used for responding to the grounding abnormal alarm signal and sending out an alarm;
preferably, the alarm circuit comprises a resistor R20, a resistor R21, a switching tube Q7 and a buzzer BUZ1;
the resistor R20 comprises a first end and a second end, and the first end of the resistor R20 is used for receiving the grounding abnormality alarm signal; the resistor R21 comprises a first end and a second end, the first end of the resistor R21 is connected with the second end of the resistor R20, and the second end of the resistor R21 is grounded; the switching tube Q7 comprises a first end, a second end and a control end, the first end of the switching tube Q7 is grounded, and the control end of the switching tube Q7 is connected with the second end of the resistor R20; the buzzer BUZ1 comprises a first end and a second end, the first end of the buzzer BUZ1 is connected with a third input power supply, and the second end of the buzzer BUZ1 is connected with the second end of the switching tube Q7.
8. A device safety ground detection method, characterized by being applied to the device safety ground detection circuit according to any one of claims 1 to 7; the equipment safety grounding detection circuit is used for being connected with a live wire, a zero wire, a grounding end and an ESD ground wire of equipment to be detected;
the detection method comprises the following steps:
when receiving a start detection signal, the equipment safety ground detection circuit starts charging;
acquiring a zero-crossing interrupt signal of a power supply port of equipment to be detected;
when a zero-crossing interrupt signal is received from a power supply port of equipment to be detected, the equipment is safely grounded, the detection circuit discharges to the ground, and the accumulated discharge time is started;
and when the accumulated discharge time is greater than or equal to a discharge threshold value, judging that the equipment to be detected is abnormal in grounding.
9. The apparatus safety ground detection method according to claim 8, further comprising, after the apparatus safety ground detection circuit starts charging:
acquiring charging time;
and under the condition that the charging time is greater than or equal to a charging threshold value, determining that the equipment safety grounding detection circuit is charged.
10. The apparatus safety ground detection method according to claim 8, further comprising determining that the apparatus to be detected is abnormal in ground when a timer expires during the accumulated discharge time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311329799.4A CN117310553A (en) | 2023-10-12 | 2023-10-12 | Equipment safety grounding detection circuit and detection method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311329799.4A CN117310553A (en) | 2023-10-12 | 2023-10-12 | Equipment safety grounding detection circuit and detection method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117310553A true CN117310553A (en) | 2023-12-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311329799.4A Pending CN117310553A (en) | 2023-10-12 | 2023-10-12 | Equipment safety grounding detection circuit and detection method thereof |
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| Country | Link |
|---|---|
| CN (1) | CN117310553A (en) |
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2023
- 2023-10-12 CN CN202311329799.4A patent/CN117310553A/en active Pending
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