Surge protection device with surge counting function

Abstract

The utility model relates to the technical field of electrical protection devices, in particular to a surge protection device with a surge counting function, which comprises a pulse counting circuit, a magnetic ring coil and a leakage current detection circuit. The leakage current detection circuit is connected in parallel with the magnetic ring coil, the pulse counting circuit is connected in series with the leakage current detection circuit, and the leakage current detection circuit and the pulse counting circuit share the magnetic ring coil; wherein the high voltage duration time of the magnetic ring coil when the surge current appears is microsecond, and the high voltage duration time of the magnetic ring coil when the leakage current appears is millisecond. By means of the arrangement, the surge protection device achieves the dual functions of detecting leakage current and detecting surge counting through the shared magnetic ring coil sensor.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrical protection device technical field, especially a kind of surge protection device with surge counting function. BACKGROUND

[0002] Surge protection device (SPD), also called lightning protection device, is an electronic device for providing safety protection for various electronic devices, instruments, communication lines. When the electrical circuit or communication line suddenly generates peak current or voltage due to external interference, surge protection device can conduct and shunt in a very short time, thereby avoiding the damage of surge to other devices in the circuit. SPD is an indispensable device in lightning protection of electronic equipment, which limits the instantaneous overvoltage flowing into power line or signal transmission line within the voltage range that the device or system can withstand, or discharges the powerful lightning current into the ground to protect the protected device or system from impact.

[0003] At present, the existing surge counting circuit detects surge signal by using hollow coil, magnetic ring coil, reed switch, Hall element and other sensor devices, and then generates counting pulse after processing and shaping circuit, and sends it to micro control processor for surge counting. Similarly, the leakage current detection of SPD also needs to use magnetic ring coil or Hall element as sensor device to detect leakage current signal, and then sends it to micro control processor for processing after circuit processing. If both parameters need to be detected at the same time, the existing technical solution needs two sets of devices and circuits, which is high in cost, large in PCB area occupation and causes large product size.

[0004] It should be noted that the information disclosed in this background section is only intended to increase the understanding of the overall background of the utility model, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. CONTENT OF UTILITY MODEL

[0005] The utility model provides a kind of surge protection device with surge counting function, it includes pulse counting circuit, magnetic ring coil and leakage current detection circuit;Leakage current detection circuit is connected in parallel with magnetic ring coil, pulse counting circuit is connected in series with leakage current detection circuit, leakage current detection circuit and pulse counting circuit share magnetic ring coil;Wherein, the high voltage duration of magnetic ring coil when surge current appears is microsecond level, and the high voltage duration of magnetic ring coil when leakage current appears is millisecond level.

[0006] Further, the leakage current detection circuit comprises a resistor R1, a resistor R2, a rectifier, a voltage stabilizing component and a capacitor C1, the magnetic ring coil, the resistor R1, the rectifier are connected in parallel, the voltage stabilizing component and the capacitor C1 are connected in parallel, the first end of the rectifier is connected with the first end of the resistor R2, the second end of the resistor R2 is connected with the second end of the voltage stabilizing component.

[0007] Further, the capacitor C1 is a porcelain capacitor.

[0008] Further, the rectifier is a bridge stack, and the bridge stack can be a full bridge.

[0009] Further, the pulse counting circuit comprises a capacitor C26, a field effect transistor Q2 and a resistor R21, the first end of the capacitor C26 is coupled to the gate of the field effect transistor Q2, the second end of the capacitor C26 is connected with the second end of the voltage stabilizing component, the source of the field effect transistor Q2 is grounded, and the drain of the field effect transistor Q2 is coupled to the resistor R21.

[0010] Further, when a surge occurs, the magnetic ring coil generates a pulse induction voltage, the pulse voltage is obtained at the two ends of the resistor R1, is rectified by the rectifier, is current-limited by the resistor R2 and is voltage-limited by the voltage stabilizing component, and then is coupled to the gate of the field effect transistor Q2 through the capacitor C26, so that the field effect transistor Q2 is turned on to generate a falling edge pulse for surge counting.

[0011] Further, the voltage stabilizing component is one of a voltage stabilizing tube, an electrostatic protection diode and a TVS tube.

[0012] The surge protector with the surge counting function has the advantages that the leakage current detection circuit and the pulse counting circuit are connected through a common magnetic ring coil sensor, the different voltage duration of the magnetic ring coil for the surge current and the leakage current is utilized, and the dual functions of detecting the leakage current and detecting the surge counting are realized.

[0013] Other features and advantages of the present application will be illustrated in the following description, and some technical features and advantages can be obtained from the description, or can be understood by implementing the present application. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, some of the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0015] Figure 1 is a circuit schematic diagram of a surge protector provided by an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments but not all the embodiments of the present application; as long as there is no conflict, the technical features designed in the different implementation manners of the present application described below can be combined with each other; based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0017] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "transverse", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or component referred to must have a particular orientation, or be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more. In addition, the term "comprising" and any variation thereof means "at least including".

[0018] Please refer to Figure 1 , Figure 1 is a circuit schematic diagram of a surge protector provided by an embodiment of the present application. In order to achieve at least one of the above advantages or other advantages, an embodiment of the present application provides a surge protector. The surge protector has the dual functions of surge counting and leakage current detection. The leakage current detection circuit enters the capacitor of the pulse counting circuit after rectification, the leakage current signal and the pulse signal are recognized by the capacitor of the pulse counting circuit, and the capacitor sends the pulse signal to the counting port for processing after screening. Through this process, the functions of detecting leakage current and surge counting are realized at the same time. As shown in the figure, the surge protector includes a pulse counting circuit, a magnetic ring coil L1 and a leakage current detection circuit.

[0019] The leakage current detection circuit is connected in parallel with the magnetic ring coil L1, and the pulse counting circuit is connected in series with the leakage current detection circuit, and the leakage current detection circuit and the pulse counting circuit share the magnetic ring coil L1. The high voltage duration of the magnetic ring coil L1 is in the order of microseconds when the inrush current occurs, and the high voltage duration of the magnetic ring coil L1 is in the order of milliseconds when the leakage current occurs. Specifically, when no surge occurs, the magnetic ring coil L1 detects the voltage signal generated by the leakage current of the surge protector, and the voltage signal is characterized by small fluctuations and stability. If the surge protector deteriorates, the leakage current increases, and the voltage signal output by the coil also increases. When the surge occurs, the magnetic ring coil L1 generates a suddenly jumping voltage signal, and the duration of the voltage signal is short. The inrush current with a high voltage duration of uS level generates an inrush count; the leakage current with a high voltage duration of mS level can be distinguished by detecting the duration of the two signals, that is, the leakage current signal and the surge signal, so as to realize the dual function of the magnetic ring sensor which can detect the leakage current and the inrush count.

[0020] Further, the leakage current detection circuit comprises a resistor R1, a resistor R2, a rectifier DB2, a voltage stabilizing component Z1 and a capacitor C1. The magnetic ring coil L1, the resistor R1 and the rectifier DB2 are connected in parallel, the voltage stabilizing component Z1 and the capacitor C1 are connected in parallel, the first end of the resistor R2 is connected to the first end of the rectifier DB2, the second end of the rectifier DB2 is connected to the first end of the voltage stabilizing component Z1, and the second end of the resistor R2 is connected to the second end of the voltage stabilizing component Z1. The magnetic ring coil L1 is sleeved in the connection between the surge protector and the power supply line. When the surge protector deteriorates and generates a leakage current, a corresponding induced voltage is generated in the magnetic ring coil L1, a stable sinusoidal induced voltage is obtained at both ends of R1, the voltage is rectified by DB2, then limited by R2 and Z1, and filtered by C1, and then sent to the ADC of the micro-control processing, and the corresponding leakage current value is obtained after processing.

[0021] Further, the capacitor C1 is a porcelain capacitor, which mainly plays a role in filtering and eliminating interference. The porcelain capacitor is a capacitor using ceramic material as dielectric, coating a layer of metal film on the surface of the ceramic, and then sintering as an electrode after high temperature, which can be used in high-stability oscillation loop as loop, bypass capacitor and cushion capacitor.

[0022] Further, the rectifier DB2 can be a bridge stack. The bridge stack can be a full bridge, and each two diodes form connection points 1, 2, 3 and 4. The connection point 3 is the output "positive" terminal, connected with the resistor R2; the connection point 4 is the output "negative" terminal, connected with the resistor voltage stabilizing component Z1 and the capacitor C1.

[0023] Further, the voltage stabilizing component Z1 can be one of a voltage stabilizing tube, an electrostatic protection diode and a TVS tube.

[0024] Further, the pulse counting circuit comprises a capacitor C26, a field effect transistor Q2 and a resistor R21, a first end of the capacitor C26 is coupled to a gate of the field effect transistor Q2, a second end of the capacitor C26 is connected to a second end of the voltage stabilizing component Z1, a source of the field effect transistor Q2 is grounded, and a drain of the field effect transistor Q2 is coupled to the resistor R21. When the surge occurs, the magnetic ring coil L1 generates a pulse induction voltage, the pulse voltage is obtained at both ends of the resistor R1, is rectified by the rectifier DB2, is current-limited by the resistor R2, is voltage-limited by the voltage stabilizing component Z1, and is coupled to the gate of the field effect transistor Q2 through the capacitor C26, so that the field effect transistor Q2 is turned on to generate a falling edge pulse for surge counting. The voltage stabilizing component Z1 mainly plays a role of overvoltage protection to protect the single-chip microcomputer port. The capacitor C26 plays a role of direct current isolation and alternating current (pulse signal) transmission. Since the leakage current is a low-frequency signal and is converted into direct current after rectification, it is difficult to pass through the capacitor C26, while the pulse signal is still a high-frequency signal after rectification and can be transmitted to the counting port through the capacitor C26 for processing, thereby completing the surge counting. Further, when the signal is a pulse signal, it can be transmitted to the counting pin through the capacitor C26, and vice versa, if it is a power frequency leakage current, it cannot pass through the capacitor C26. In addition, the pulse signal is detected in width, if the detected signal width is in the order of uS, it is a pulse signal, and if the signal width is in the order of mS, it is discarded and not counted.

[0025] In summary, the surge protector with surge counting function provided by the utility model realizes the double functions of detecting leakage current and counting surge by using the magnetic ring coil L1 to detect the different voltage duration of the leakage current and the surge current.

[0026] In addition, those skilled in the art should understand that, although there are many problems in the prior art, each embodiment or technical solution of the utility model can only be improved in one or several aspects, and it is not necessary to solve all the technical problems listed in the prior art or background art at the same time. Those skilled in the art should understand that the content not mentioned in a claim should not be regarded as a limitation of the claim.

[0027] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A surge protector having a surge count function, characterized by: The surge protector comprises a pulse counting circuit, a magnetic ring coil and a leakage current detection circuit; The leakage current detection circuit is connected in parallel with the magnetic ring coil, and the pulse counting circuit is connected in series with the leakage current detection circuit, and the leakage current detection circuit and the pulse counting circuit share the magnetic ring coil; The high voltage duration of the magnetic ring coil when a surge current occurs is in the order of microseconds, and the high voltage duration of the magnetic ring coil when the leakage current occurs is in the order of milliseconds.

2. The surge protector with surge counting function according to claim 1, wherein: The leakage current detection circuit comprises a resistor R1, a resistor R2, a rectifier, a voltage stabilizing component and a capacitor C1, the magnetic ring coil, the resistor R1 and the rectifier are connected in parallel, the voltage stabilizing component and the capacitor C1 are connected in parallel, a first end of the rectifier is connected to a first end of the resistor R2, a second end of the rectifier is connected to a first end of the voltage stabilizing component, and a second end of the resistor R2 is connected to a second end of the voltage stabilizing component.

3. The surge protector with surge counting function according to claim 2, wherein: The capacitor C1 is a ceramic capacitor.

4. The surge protector with surge counting function according to claim 2, wherein: The rectifier is a bridge stack.

5. The surge protector with surge counting function according to claim 4, wherein: The bridge stack is a full bridge.

6. The surge protector with surge counting function according to claim 2, wherein: The pulse counting circuit comprises a capacitor C26, a field effect transistor Q2 and a resistor R21, a first end of the capacitor C26 is coupled to a gate of the field effect transistor Q2, a second end of the capacitor C26 is connected to the second end of the voltage stabilizing component, a source of the field effect transistor Q2 is grounded, and a drain of the field effect transistor Q2 is coupled to the resistor R21.

7. The surge protector with surge counting function according to claim 2, wherein: The voltage stabilizing component is one of a voltage stabilizing tube, an electrostatic protection diode and a TVS tube.

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