Lightning protection and overvoltage and undervoltage protection circuit

Abstract

The utility model relates to a lightning protection and overvoltage and undervoltage protection circuit, which comprises a live wire input interface Lin, a null line input interface Nin, a lightning protection circuit, a power taking circuit, a control circuit, an indicating circuit, a relay, a live wire output interface Lout and a null line output interface Nout, the live wire input interface Lin and the null line input interface Nin are respectively connected with a first input end and a second input end of the lightning protection circuit, a first output end of the lightning protection circuit is connected with the live wire output interface Lout through the relay, and a second output end of the lightning protection circuit is connected with the null line output interface Nout. The power taking circuit is arranged between the first output end and the second output end of the lightning protection circuit and supplies power to the control circuit and the action circuit. The control circuit collects the output voltage of the lightning protection circuit and controls the indicating circuit and the relay. The utility model has the advantages that: the lightning protection and the overvoltage and undervoltage protection are realized; compared with an independent lightning protection device and an independent overvoltage and undervoltage protection device, the occupied space is small; installation is convenient, and repeated wiring operation is not needed.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical protection, in particular to a lightning protection and over- and under-voltage protection circuit. Background Art

[0002] For outdoor electrical equipment, the power supply cables are long, the voltage fluctuates greatly and is easily affected by lightning strikes. Therefore, it is necessary to install over-voltage and under-voltage protectors and lightning protectors separately, which will undoubtedly take up a large space. In addition, the separate installation of over-voltage and under-voltage protectors and lightning protectors requires multiple wiring operations, and the installation is more cumbersome. Summary of the invention

[0003] The utility model mainly solves the above problems and provides a lightning protection and over-voltage and under-voltage protection circuit.

[0004] The technical solution adopted by the utility model to solve its technical problems is a lightning protection and over- and under-voltage protection circuit, comprising a live wire input interface Lin, a neutral wire input interface Nin, a lightning protection circuit, a power supply circuit, a control circuit, an indication circuit, a relay, a live wire output interface Lout and a neutral wire output interface Nout, wherein the live wire input interface Lin and the neutral wire input interface Nin are respectively connected to a first input end and a second input end of the lightning protection circuit, a first output end of the lightning protection circuit is connected to the live wire output interface Lout through a relay, and a second output end of the lightning protection circuit is connected to the neutral wire output interface Nout, the power supply circuit is arranged between the first output end and the second output end of the lightning protection circuit to supply power to the control circuit and the action circuit, and the control circuit collects the output voltage of the lightning protection circuit and controls the indication circuit and the relay.

[0005] As a preferred embodiment of the above scheme, the lightning protection circuit includes an overload switch TF101, a fuse F101, a fuse F102, a varistor VR101, a discharger GDT101, a light-emitting diode LED101 and a first resistor series circuit, the live wire input interface Lin is connected to the first end of the fuse F102 through the overload switch TF101, the second end of the fuse F102 is the first output end of the lightning protection circuit, the neutral wire input interface Nin is connected to the first end of the fuse F101, the second end of the fuse F101 is the second output end of the lightning protection circuit, the two ends of the varistor VR101 are respectively connected to the first end of the fuse F101 and the first end of the fuse F102, the two ends of the discharger GDT101 are respectively connected to the varistor VR101 and the ground wire PE, the first resistor series circuit and the light-emitting diode LED101 form a series circuit arranged between the first output end and the second output end of the lightning protection circuit.

[0006] As a preferred scheme of the above scheme, the power supply circuit includes a resistor R101, a capacitor CB101, a diode DS101, a voltage regulator ZS101, a polar capacitor CE101 and a second resistor series circuit. The first output end of the lightning protection circuit, the resistor R101, the capacitor CB101, the diode DS101, the polar capacitor CE101 and the second output end of the lightning protection circuit are connected in series in sequence. The second resistor series circuit is connected in parallel with the capacitor CB101. The anode of the voltage regulator ZS101 is connected to the second output end of the lightning protection circuit, the cathode of the voltage regulator ZS101 is connected to the anode of the diode DS101, and the cathode of the diode DS101 is respectively connected to the relay and the control circuit.

[0007] As a preferred scheme of the above scheme, the indication circuit includes a light-emitting diode LED101, a light-emitting diode LED102 and a resistor RS122, the anode of the light-emitting diode LED101 and the anode of the light-emitting diode LED102 are connected to different output ports of the control circuit, and the cathode of the light-emitting diode LED101 and the cathode of the light-emitting diode LED102 are connected to the second output port of the lightning protection circuit through the resistor RS122.

[0008] As a preferred embodiment of the above scheme, the control circuit includes a single-chip microcomputer, a sampling circuit, a zero-crossing detection circuit and a voltage conversion circuit. The single-chip microcomputer is respectively connected to the sampling circuit, the indication circuit, the voltage conversion circuit, the zero-crossing detection circuit and the relay, and the voltage conversion circuit is connected to the power supply circuit.

[0009] As a preferred embodiment of the above scheme, the sampling circuit includes a resistor RS112, a diode DS102, a capacitor CS104 and a third resistor series circuit, the first output end of the lightning protection circuit is connected to the first end of the third resistor series circuit, the second end of the third resistor series circuit is respectively connected to the first end of the resistor RS112 and the anode of the diode DS102, the second end of the resistor RS112 is respectively connected to the first end of the capacitor CS104 and the zero line output interface Nout, and the cathode of the diode DS102 is respectively connected to the second end of the capacitor CS104 and the single-chip microcomputer.

[0010] As a preferred embodiment of the above scheme, the zero-crossing detection circuit includes a resistor RS113, a resistor RS114, a resistor RS117, a diode DS104, a transistor QS101 and a fourth resistor series circuit, the first output end of the lightning protection circuit is respectively connected to the first end of the fourth resistor series circuit, the second end of the fourth resistor series circuit is respectively connected to the first end of the resistor RS114 and the first end of the resistor RS117, the second end of the resistor RS114 is respectively connected to the anode of the diode DS104, the emitter of the transistor QS101 and the zero line output interface Nout, the second end of the resistor RS117 is respectively connected to the cathode of the diode DS104 and the base of the transistor QS101, the collector of the transistor QD101 is respectively connected to the first end of the resistor RS113 and the single-chip computer, and the second end of the resistor RS113 is connected to the voltage conversion circuit.

[0011] As a preferred embodiment of the above scheme, the voltage conversion circuit includes a resistor RS124, a resistor RS118, a resistor RS119, a capacitor CS103, a capacitor CS105, a transistor QS104 and a voltage regulator US103, the collector of the transistor QS104 is respectively connected to the power taking circuit and the first end of the resistor RS124, the base of the transistor QS104 is respectively connected to the second end of the resistor RS124, the first end of the capacitor CS105 and the cathode of the voltage regulator US103, the emitter of the transistor QS104 is respectively connected to the first end of the resistor RS118 and the first end of the capacitor CS103, the emitter output voltage VCC of the transistor QS194 is powered by the circuit and the single-chip computer, the second end of the resistor RS118 is respectively connected to the second end of the capacitor CS105, the reference electrode of the voltage regulator US103 and the first end of the resistor RS119, and the second end of the resistor RS119 is respectively connected to the cathode of the voltage regulator US103, the second end of the capacitor CS103 and the zero line output interface Nout.

[0012] As a preferred solution of the above solution, the single chip microcomputer is connected to the relay and the indication circuit respectively.

[0013] The advantages of the utility model are: it has both lightning protection and over-voltage and under-voltage protection, and occupies less space than independent lightning protection devices and over-voltage and under-voltage protection devices; it is easy to install and does not require multiple wiring operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the lightning protection and over- and under-voltage protection circuit in the embodiment.

[0015] Figure 2 4 is a circuit diagram of a control circuit in an embodiment. DETAILED DESCRIPTION

[0016] The technical solution of the utility model is further described below through embodiments and in conjunction with the accompanying drawings.

[0017] Example:

[0018] This embodiment is a lightning protection and over-voltage and under-voltage protection circuit, such as Figure 1 As shown, it includes a live input interface Lin, a neutral input interface Nin, a lightning protection circuit, a power supply circuit, a control circuit, an indication circuit, a relay, a live output interface Lout and a neutral output interface Nout. The live input interface Lin and the neutral input interface Nin are respectively connected to the first input end and the second input end of the lightning protection circuit. The first output end of the lightning protection circuit is connected to the live output interface Lout through the relay. The second output end of the lightning protection circuit is connected to the neutral output interface Nout. The power supply circuit is arranged between the first output end and the second output end of the lightning protection circuit to supply power to the control circuit and the action circuit. The control circuit collects the output voltage of the lightning protection circuit and controls the indication circuit and the relay. The action end of the relay is respectively connected to the first output end of the lightning protection circuit and the live output interface Lout. The control end of the relay is respectively connected to the power supply circuit and the collector of the transistor QS102. The emitter of the transistor QS102 is connected to the neutral output interface Nout. The base of the transistor QS102 is connected to the control circuit. In this embodiment, the live wire input interface Lin, the neutral wire input interface Nin, the lightning protection circuit, the power supply circuit, the indication circuit, the relay, the live wire output interface Lout and the neutral wire output interface Nout are integrated on the first PCB board, the control circuit is integrated on the second PCB board, and the first PCB board and the second PCB board are connected via a pin header DB101.

[0019] The lightning protection circuit includes an overload switch TF101, a fuse F101, a fuse F102, a varistor VR101, a discharger GDT101, a light-emitting diode LED101 and a first resistor series circuit, wherein the live line input interface Lin is connected to the first end of the fuse F102 through the overload switch TF101, the second end of the fuse F102 is the first output end of the lightning protection circuit, the neutral line input interface Nin is connected to the first end of the fuse F101, the second end of the fuse F101 is the second output end of the lightning protection circuit, the two ends of the varistor VR101 are respectively connected to the first end of the fuse F101 and the first end of the fuse F102, the two ends of the discharger GDT101 are respectively connected to the varistor VR101 and the ground wire PE, the first resistor series circuit and the light-emitting diode LED101 form a series circuit arranged between the first output end and the second output end of the lightning protection circuit. The light-emitting diode LED101 is used to indicate whether the lightning protection circuit is normal. The first resistor series circuit is composed of a resistor RS101, a resistor RS101A, a resistor RS101B, and a resistor RS101C.

[0020] The power-taking circuit includes a resistor R101, a capacitor CB101, a diode DS101, a voltage-stabilizing tube ZS101, a polar capacitor CE101, and a second resistor series circuit. The first output end of the lightning protection circuit, the resistor R101, the capacitor CB101, the diode DS101, the polar capacitor CE101, and the second output end of the lightning protection circuit are sequentially connected in series. The second resistor series circuit is connected in parallel with the capacitor CB101. The anode of the voltage-stabilizing tube ZS101 is connected to the second output end of the lightning protection circuit, the cathode of the voltage-stabilizing tube ZS101 is connected to the anode of the diode DS101, and the cathode of the diode DS101 is respectively connected to the relay and the control circuit. The drive circuit provides a 27V voltage for the relay and the control circuit. The second resistor series circuit consists of a resistor RS104, a resistor RS104A, a resistor RS104B, and a resistor RS104C.

[0021] The indicating circuit includes a light emitting diode LED101, a light emitting diode LED102 and a resistor RS122, wherein the anode of the light emitting diode LED101 and the anode of the light emitting diode LED102 are connected to different output ports of the control circuit, and the cathode of the light emitting diode LED101 and the cathode of the light emitting diode LED102 are connected to the second output port of the lightning protection circuit through the resistor RS122. Among them, the light emitting diode LED101 emits green light and the light emitting diode LED102 emits red light, which is used to indicate whether there is an over-voltage or under-voltage situation.

[0022] like Figure 2 As shown, the control circuit includes a single-chip microcomputer, a sampling circuit, a zero-crossing detection circuit and a voltage conversion circuit. The single-chip microcomputer is respectively connected to the sampling circuit, the indication circuit, the voltage conversion circuit, the zero-crossing detection circuit and the relay, and the voltage conversion circuit is connected to the power supply circuit.

[0023] The sampling circuit includes a resistor RS112, a diode DS102, a capacitor CS104 and a third resistor series circuit, the first output end of the lightning protection circuit is connected to the first end of the third resistor series circuit, the second end of the third resistor series circuit is respectively connected to the first end of the resistor RS112 and the anode of the diode DS102, the second end of the resistor RS112 is respectively connected to the first end of the capacitor CS104 and the zero line output interface Nout, and the cathode of the diode DS102 is respectively connected to the second end of the capacitor CS104 and the single chip computer. The third resistor series circuit consists of a resistor RS102, a resistor RS102A, a resistor RS102B and a resistor RS102C.

[0024] The zero-crossing detection circuit includes a resistor RS113, a resistor RS114, a resistor RS117, a diode DS104, a transistor QS101 and a fourth resistor series circuit, the first output end of the lightning protection circuit is respectively connected to the first end of the fourth resistor series circuit, the second end of the fourth resistor series circuit is respectively connected to the first end of the resistor RS114 and the first end of the resistor RS117, the second end of the resistor RS114 is respectively connected to the anode of the diode DS104, the emitter of the transistor QS101 and the zero line output interface Nout, the second end of the resistor RS117 is respectively connected to the cathode of the diode DS104 and the base of the transistor QS101, the collector of the transistor QD101 is respectively connected to the first end of the resistor RS113 and the single-chip computer, and the second end of the resistor RS113 is connected to the voltage conversion circuit. The fourth resistor series circuit consists of a resistor RS103, a resistor RS103A, a resistor RS103B and a resistor RS103C. The zero-crossing detection circuit is used to detect the zero-crossing point of the input sinusoidal voltage, allowing the protected products at the back end to be connected to the power grid at the zero point of the sine wave, thereby suppressing the inrush current of the back end products.

[0025] The voltage conversion circuit includes a resistor RS124, a resistor RS118, a resistor RS119, a capacitor CS103, a capacitor CS105, a transistor QS104 and a voltage regulator US103. The collector of the transistor QS104 is respectively connected to the power-taking circuit and the first end of the resistor RS124, the base of the transistor QS104 is respectively connected to the second end of the resistor RS124, the first end of the capacitor CS105 and the cathode of the voltage regulator US103, the emitter of the transistor QS104 is respectively connected to the first end of the resistor RS118 and the first end of the capacitor CS103, the emitter output voltage VCC of the transistor QS194 is used for power supply of the circuit and the single-chip computer, the second end of the resistor RS118 is respectively connected to the second end of the capacitor CS105, the reference electrode of the voltage regulator US103 and the first end of the resistor RS119, and the second end of the resistor RS119 is respectively connected to the cathode of the voltage regulator US103, the second end of the capacitor CS103 and the zero line output interface Nout. The voltage regulator US103 model is TL431.

[0026] In this embodiment, the single-chip microcomputer model is HC89F0312, the second pin of the single-chip microcomputer is connected to the anode of the light-emitting diode LED101, the fourth pin of the single-chip microcomputer is connected to the anode of the light-emitting diode LED102, the fifth pin of the single-chip microcomputer is connected to the cathode of the diode DS102, the sixth pin of the single-chip microcomputer is connected to the collector of the transistor QS101, and the seventh pin of the single-chip microcomputer is connected to the base of the transistor QS102 through the resistor RS116.

[0027] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A lightning protection and over-voltage and under-voltage protection circuit, characterized in that: It includes a live wire input interface Lin, a neutral wire input interface Nin, a lightning protection circuit, a power supply circuit, a control circuit, an indication circuit, a relay, a live wire output interface Lout and a neutral wire output interface Nout. The live wire input interface Lin and the neutral wire input interface Nin are respectively connected to the first input end and the second input end of the lightning protection circuit. The first output end of the lightning protection circuit is connected to the live wire output interface Lout through the relay, and the second output end of the lightning protection circuit is connected to the neutral wire output interface Nout. The power supply circuit is arranged between the first output end and the second output end of the lightning protection circuit to supply power to the control circuit and the action circuit. The control circuit collects the output voltage of the lightning protection circuit and controls the indication circuit and the relay.

2. The lightning protection and over-voltage and under-voltage protection circuit according to claim 1 is characterized in that: The lightning protection circuit includes an overload switch TF101, a fuse F101, a fuse F102, a varistor VR101, a discharger GDT101, a light-emitting diode LED101 and a first resistor series circuit. The live wire input interface Lin is connected to the first end of the fuse F102 through the overload switch TF101, and the second end of the fuse F102 is the first output end of the lightning protection circuit. The neutral wire input interface Nin is connected to the first end of the fuse F101, and the second end of the fuse F101 is the second output end of the lightning protection circuit. The two ends of the varistor VR101 are respectively connected to the first end of the fuse F101 and the first end of the fuse F102. The two ends of the discharger GDT101 are respectively connected to the varistor VR101 and the ground wire PE. The first resistor series circuit and the light-emitting diode LED101 form a series circuit arranged between the first output end and the second output end of the lightning protection circuit.

3. The lightning protection and over-voltage and under-voltage protection circuit according to claim 1 is characterized in that: The power supply circuit includes a resistor R101, a capacitor CB101, a diode DS101, a voltage regulator ZS101, a polar capacitor CE101 and a second resistor series circuit. The first output end of the lightning protection circuit, the resistor R101, the capacitor CB101, the diode DS101, the polar capacitor CE101 and the second output end of the lightning protection circuit are connected in series in sequence. The second resistor series circuit is connected in parallel with the capacitor CB101. The anode of the voltage regulator ZS101 is connected to the second output end of the lightning protection circuit, the cathode of the voltage regulator ZS101 is connected to the anode of the diode DS101, and the cathode of the diode DS101 is respectively connected to the relay and the control circuit.

4. The lightning protection and over-voltage and under-voltage protection circuit according to claim 1 is characterized in that: The indication circuit includes a light-emitting diode LED101, a light-emitting diode LED102 and a resistor RS122, wherein the anode of the light-emitting diode LED101 and the anode of the light-emitting diode LED102 are connected to different output ports of the control circuit, and the cathode of the light-emitting diode LED101 and the cathode of the light-emitting diode LED102 are connected to the second output port of the lightning protection circuit through the resistor RS122.

5. The lightning protection and over-voltage and under-voltage protection circuit according to claim 1 is characterized in that: The action end of the relay is respectively connected to the first output end of the lightning protection circuit and the live wire output interface Lout, the control end of the relay is respectively connected to the power supply circuit and the collector of the transistor QS102, the emitter of the transistor QS102 is connected to the neutral wire output interface Nout, and the base of the transistor QS102 is connected to the control circuit.

6. The lightning protection and over-voltage and under-voltage protection circuit according to claim 1 is characterized in that: The control circuit includes a single chip microcomputer, a sampling circuit, a zero-crossing detection circuit and a voltage conversion circuit. The single chip microcomputer is connected to the sampling circuit, the indication circuit, the voltage conversion circuit, the zero-crossing detection circuit and the relay respectively. The voltage conversion circuit is connected to the power supply circuit.

7. The lightning protection and over-voltage and under-voltage protection circuit according to claim 6 is characterized in that: The sampling circuit includes a resistor RS112, a diode DS102, a capacitor CS104 and a third resistor series circuit. The first output end of the lightning protection circuit is connected to the first end of the third resistor series circuit, the second end of the third resistor series circuit is respectively connected to the first end of the resistor RS112 and the anode of the diode DS102, the second end of the resistor RS112 is respectively connected to the first end of the capacitor CS104 and the zero line output interface Nout, and the cathode of the diode DS102 is respectively connected to the second end of the capacitor CS104 and the single-chip microcomputer.

8. The lightning protection and over-voltage and under-voltage protection circuit according to claim 6 is characterized in that: The zero-crossing detection circuit includes a resistor RS113, a resistor RS114, a resistor RS117, a diode DS104, a transistor QS101 and a fourth resistor series circuit. The first output end of the lightning protection circuit is respectively connected to the first end of the fourth resistor series circuit, the second end of the fourth resistor series circuit is respectively connected to the first end of the resistor RS114 and the first end of the resistor RS117, the second end of the resistor RS114 is respectively connected to the anode of the diode DS104, the emitter of the transistor QS101 and the zero line output interface Nout, the second end of the resistor RS117 is respectively connected to the cathode of the diode DS104 and the base of the transistor QS101, the collector of the transistor QD101 is respectively connected to the first end of the resistor RS113 and the single-chip computer, and the second end of the resistor RS113 is connected to the voltage conversion circuit.

9. The lightning protection and over-voltage and under-voltage protection circuit according to claim 6 is characterized in that: The voltage conversion circuit includes a resistor RS124, a resistor RS118, a resistor RS119, a capacitor CS103, a capacitor CS105, a transistor QS104 and a voltage regulator US103. The collector of the transistor QS104 is respectively connected to the power taking circuit and the first end of the resistor RS124, the base of the transistor QS104 is respectively connected to the second end of the resistor RS124, the first end of the capacitor CS105 and the cathode of the voltage regulator US103, the emitter of the transistor QS104 is respectively connected to the first end of the resistor RS118 and the first end of the capacitor CS103, the emitter output voltage VCC of the transistor QS194 is powered by the circuit and the single-chip computer, the second end of the resistor RS118 is respectively connected to the second end of the capacitor CS105, the reference electrode of the voltage regulator US103 and the first end of the resistor RS119, and the second end of the resistor RS119 is respectively connected to the cathode of the voltage regulator US103, the second end of the capacitor CS103 and the zero line output interface Nout.

10. The lightning protection and over-voltage and under-voltage protection circuit according to claim 6 is characterized in that: The single chip microcomputer is connected with the relay and the indicating circuit respectively.

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