A grounding state detection circuit and method

Abstract

The present application discloses a grounding status detection circuit and method, belonging to the technical field of grounding protection circuits; the circuit includes a signal circuit, a grounding detection circuit and an EMC coordination circuit. The present application provides a grounding status detection circuit and method, which realizes product safety, coexistence of EMC and detection circuits, simple structure, standby current and its tiny, low-cost grounding protection, and reminds users to ensure accurate and reliable grounding before using the equipment, thereby improving the safety of the equipment; during the use of the equipment, if no grounding or poor grounding is detected, the system will immediately cut off the power or issue a warning.

Description

Technical Field

[0001] The present application belongs to the technical field of ground protection circuits, and in particular, relates to a ground status detection circuit and method. Background Art

[0002] In the power system, grounding protection is essential to maintain the stability of the system, prevent equipment damage, and avoid power supply interruptions. It ensures the safety of personnel and equipment by quickly directing the current to the ground in the event of a fault. However, since many users lack the correct knowledge of grounding, it often leads to improper grounding, which creates safety hazards. When equipment fails, some users mistakenly attribute it to circuit problems without realizing the importance of grounding, which not only increases the pressure on manufacturers' after-sales service, but also affects the user experience.

[0003] At present, grounding protection usually adopts a simple method of directly connecting the equipment casing to the ground. This method cannot distinguish whether the equipment is not grounded during installation or grounded after operation, which makes it difficult to quickly determine the cause of the problem when a fault occurs, thereby delaying maintenance work. In addition, the existing grounding protection circuit lacks an automated grounding status detection function and mainly relies on manual detection, which is not only inefficient but also easily interfered by human factors, increasing the risk of error.

[0004] Therefore, developing a grounding protection circuit that can automatically detect the grounding status is of great significance to improving the safety and reliability of the power system. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present application provides a grounding status detection circuit and method, which can automatically detect the grounding status and remind customers to accurately and reliably ground before use to ensure the safe use of the equipment.

[0006] The technical solution is as follows:

[0007] On the one hand, a grounding state detection circuit is provided, including a signal circuit 1, a grounding detection circuit 2 and an EMC coordination circuit 3, wherein the signal circuit 1 includes a second resistor R2, a first capacitor C1 and an input / output port of a single chip computer; the grounding detection circuit 2 includes a transistor U1, a first resistor R1, a second diode D2 and a second capacitor CY2, and the EMC coordination circuit 3 includes a first diode D1;

[0008] The base of the transistor U1 of the ground detection circuit 2 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the first diode D1 of the EMC coordination circuit 3 and is connected to one end of the second capacitor CY2, the other end of the second capacitor CY2 is grounded, the anode of the first diode D1 is connected to the reference ground, the emitter of the transistor U1 is connected to the working voltage, the collector of the transistor U1 of the ground detection circuit 2 is respectively connected to one end of the second resistor R2 of the signal circuit 1 and one end of the first capacitor C1 and is connected to the input / output port of the single-chip computer, and the other end of the second resistor R2 is connected to the other end of the first capacitor C1 and is grounded.

[0009] Optionally, the second capacitor CY2 is a Y capacitor.

[0010] Optionally, the second capacitor CY2 is connected to the third capacitor CA1 in the EMC coordination circuit.

[0011] Optionally, the third capacitor CA1 is a Y capacitor, and the fifth capacitor CA3 is an X capacitor.

[0012] Optionally, the fifth capacitor CA3 is connected to the alternating current through the inductor L1.

[0013] On the other hand, a grounding state detection method is provided. The grounding state detection circuit is applied, and the detection method includes:

[0014] In the grounding state, the second capacitor CY2 of the grounding state detection circuit 2 is grounded, and the transistor U1 of the grounding detection circuit 2 obtains a bias voltage from the working voltage, and the transistor U1 is turned on to form a signal loop and output a grounding signal;

[0015] In the ungrounded state, the second capacitor CY2 of the grounding state detection circuit 2 is not grounded, the transistor U1 is not turned on, and the output is a low level, and the single chip fails to be grounded.

[0016] The beneficial effects of the technical solution provided by this application include at least:

[0017] If the grounding is not correct, the circuit cannot operate. Remind customers to accurately and reliably ground before use to ensure the safe use of the equipment. During operation, if the grounding is poor, timely issue a poor grounding warning or make a power outage action to ensure safe use of electricity and prevent electric shock accidents during use.

[0018] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0020] Figure 1 A schematic diagram of a circuit structure of an exemplary embodiment of the present application;

[0021] Figure 2 This is a schematic diagram of current flow when the circuit of an exemplary embodiment of the present application is correctly grounded. DETAILED DESCRIPTION

[0022] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0023] like Figure 1 The circuit structure diagram of an exemplary embodiment of the present application is shown, a grounding state detection circuit includes a signal circuit 1, a grounding detection circuit 2 and an EMC coordination circuit 3. The signal circuit 1 includes a second resistor R2, a first capacitor C1 and an input / output I / O port of a single-chip computer; the grounding detection circuit 2 includes a transistor U1, a first resistor R1, a second diode D2 and a second capacitor CY2, and the EMC coordination circuit 3 includes a first diode D1.

[0024] The base of the transistor U1 of the ground detection circuit 2 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the first diode D1 of the EMC coordination circuit 3 and is grounded through the second capacitor CY2, and the anode of the first diode D1 is connected to the reference ground. The emitter of the transistor U1 of the ground detection circuit 2 is connected to the working voltage 5v, the collector of the transistor U1 is respectively connected to one end of the second resistor R2 of the signal circuit 1, one end of the first capacitor C1 and the input / output I / O port of the single-chip computer, and the other end of the second resistor R2 is connected to the other end of the first capacitor C1 and grounded; when the second capacitor CY2 is grounded, the base (B pole) of the transistor U1 obtains a bias voltage from the +5V voltage, the transistor U1 is turned on, the current of the transistor U1 flows out, passes through the first resistor R1 and enters the second diode D2, at this time, the second diode D2 is turned on and flows into the second capacitor CY2, the second capacitor CY2 is grounded, the signal loop is formed, and the input / output port of the single-chip computer obtains a high level, and outputs a ground signal. The grounding end flows to the N phase of the power generation system through the loop of the earth, and the loop ends.

[0025] In order to synchronously implement the EMC interference loop, the embodiment of the present application places a first diode D1 to return the original N-phase interference to the N-phase through the reference point of GND, replacing the function of the original Y capacitor in the N-phase.

[0026] EMC circuit 4: The current enters from the live wire L of the AC power supply, passes through the first connector J1, passes through the fuse FL1, and continues to flow to the inductor L1. The inductor L1 and the capacitors CA1, CA2, and CA3 form a filter network for suppressing electromagnetic interference. After the current passes through the filter network, it is converted into DC through the rectifier bridge G1. The rectified DC is further filtered and stored through the sixth capacitor C6, and flows into the anode of the first diode D1 through the EMC reference ground. When the second capacitor CY2 is grounded, the first diode D1 is turned on, and the current flows into the second capacitor CY2. The current passes through the reference point of GND, and flows into the neutral line N of the AC power supply after rectification through the rectifier bridge G1, and a signal loop is formed.

[0027] Optionally, in the embodiment of the present application, the second capacitor CY2 and the third capacitor CA1 are Y capacitors, and the fifth capacitor CA3 is an X capacitor.

[0028] Circuit working principle:

[0029] like Figure 2 As shown, when grounded correctly, the base (B pole) of the PNP transistor U1 obtains a bias voltage from the +5V voltage, the transistor U1 is turned on, the emitter of the transistor U1 flows to the collector, and the working voltage 5V is grounded through the current of the second capacitor CY2 of the ground detection circuit 2, forming a complete current loop. The base (B pole) of the transistor U1 obtains a bias voltage from the +5V voltage, the transistor U1 is turned on, the current of the transistor U1 flows out, passes through the first resistor R1 and enters the second diode D2. At this time, the second diode D2 is turned on and flows into the second capacitor CY2, the second capacitor CY2 is grounded, and the signal loop is formed. At the same time, the input / output port of the single-chip microcomputer obtains a high level and outputs a ground signal.

[0030] The grounded terminal flows through the earth's loop to the N phase of the power generation system, and the loop ends.

[0031] If the grounding is not correct, the working voltage 5V is not grounded through the second capacitor CY2 circuit of the grounding detection circuit 2, the transistor U1 cannot be turned on, the current cannot flow out, the transistor bias current cannot form a complete loop, and the input / output port of the microcontroller outputs a low level, reporting that the microcontroller grounding failure.

[0032] During operation, if poor grounding occurs, a poor grounding warning will be given in time or the power will be disconnected to ensure safe use of electricity and prevent electric shock accidents during use.

[0033] An exemplary embodiment of the present application provides a grounding state detection method, which is applied to the above-mentioned grounding state detection circuit. The detection method includes:

[0034] In the grounding state, the second capacitor CY2 of the grounding detection circuit 2 is grounded, and the transistor U1 of the grounding detection circuit 2 obtains a bias voltage from the working voltage, and the transistor U1 is turned on to form a signal loop and output a grounding signal;

[0035] In the ungrounded state, the second capacitor CY2 of the ground detection circuit 2 is not grounded, the transistor U1 is not turned on, the input / output port of the microcontroller outputs a low level, and the microcontroller fails to be grounded.

[0036] In summary, the technical effects achieved by the entire circuit are as follows:

[0037] 1. Equipment safety:

[0038] a. Safety during use: If no grounding or poor grounding is detected during use, the system will immediately cut off power or issue an alarm.

[0039] b. Whether the premise of use is safe: Determine whether it is grounded before use.

[0040] 2. Forcibly prevent customers from using equipment without complete grounding, so that customers must communicate with suppliers for correct installation and control safety accidents from the source.

[0041] 3. EMC circuits and detection circuits coexist.

[0042] 4. The detection circuit structure is simple.

[0043] 5. The standby current is extremely small.

[0044] 6. Low cost.

[0045] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application herein applied. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that the present application does not apply for. The specification and embodiments are considered to be exemplary only, and the true scope and spirit of the present application are indicated by the appended claims.

[0046] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A grounding state detection circuit, characterized in that: The invention comprises a signal circuit (1), a ground detection circuit (2) and an EMC matching circuit (3), wherein the signal circuit (1) comprises a second resistor (R2), a first capacitor (C1) and an input / output port of a single chip computer; the ground detection circuit (2) comprises a triode (U1), a first resistor (R1), a second diode (D2) and a second capacitor (CY2), and the EMC matching circuit (3) comprises a first diode (D1); The base of the transistor (U1) of the ground detection circuit (2) is connected to one end of the first resistor (R1), the other end of the first resistor (R1) is connected to the anode of the second diode (D2), the cathode of the second diode (D2) is connected to the cathode of the first diode (D1) of the EMC matching circuit (3) and is connected to one end of the second capacitor (CY2), the other end of the second capacitor (CY2) is grounded, the anode of the first diode (D1) is connected to the reference ground, the emitter of the transistor (U1) is connected to the working voltage, the collector of the transistor (U1) of the ground detection circuit (2) is respectively connected to one end of the second resistor (R2) of the signal circuit (1), one end of the first capacitor (C1) and is connected to the input / output port of the single chip computer, and the other end of the second resistor (R2) is connected to the other end of the first capacitor (C1) and is grounded.

2. The grounding state detection circuit according to claim 1, characterized in that: The second capacitor (CY2) is a Y capacitor.

3. The grounding state detection circuit according to claim 1, characterized in that: The second capacitor (CY2) is connected to the third capacitor (CA1) in the EMC coordination circuit.

4. The grounding state detection circuit according to claim 3, characterized in that: The third capacitor (CA1) is a Y capacitor, and the fifth capacitor (CA3) is an X capacitor.

5. The grounding state detection circuit according to claim 4, characterized in that: The fifth capacitor (CA3) is connected to the alternating current through the inductor (L1).

6. A grounding state detection method, applied to the grounding state detection circuit according to any one of claims 1 to 5, characterized in that: include: When in the grounding state, the second capacitor (CY2) of the grounding detection circuit (2) is grounded, the transistor (U1) of the grounding detection circuit (2) obtains a bias voltage from the working voltage, the transistor (U1) is turned on, a signal loop is formed, and a grounding signal is output; In the ungrounded state, the second capacitor (CY2) of the ground detection circuit (2) is not grounded, the transistor (U1) is not conducting, the output is a low level, and the single chip fails to be grounded.

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