CN112260248A - Overvoltage protection circuit and electronic equipment - Google Patents

Overvoltage protection circuit and electronic equipment Download PDF

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Publication number
CN112260248A
CN112260248A CN202011194095.7A CN202011194095A CN112260248A CN 112260248 A CN112260248 A CN 112260248A CN 202011194095 A CN202011194095 A CN 202011194095A CN 112260248 A CN112260248 A CN 112260248A
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China
Prior art keywords
circuit
overvoltage protection
electrically connected
protection circuit
limiting device
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CN202011194095.7A
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Chinese (zh)
Inventor
冉先发
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Maanshan Penang Electronics Co ltd
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Maanshan Penang Electronics Co ltd
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Priority to CN202011194095.7A priority Critical patent/CN112260248A/en
Publication of CN112260248A publication Critical patent/CN112260248A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/18—Status alarms
    • G08B21/185—Electrical failure alarms
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B7/00—Signalling systems according to more than one of groups G08B3/00 - G08B6/00; Personal calling systems according to more than one of groups G08B3/00 - G08B6/00
    • G08B7/06—Signalling systems according to more than one of groups G08B3/00 - G08B6/00; Personal calling systems according to more than one of groups G08B3/00 - G08B6/00 using electric transmission, e.g. involving audible and visible signalling through the use of sound and light sources
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The embodiment of the invention discloses an overvoltage protection circuit and electronic equipment. Wherein, this overvoltage protection circuit includes: at least two of the first module, the second module and the third module, and an alarm circuit; wherein the first module comprises: the output end of the first rectifying circuit is electrically connected with the alarm circuit; the second module includes: the output end of the second rectifying circuit is electrically connected with the alarm circuit; the third module includes: a third voltage limiting device, a third switching device and a third rectifier circuit; the output end of the third rectifying circuit is electrically connected with the warning circuit. The technical scheme provided by the embodiment of the invention can realize the monitoring and alarming of the leakage current of a plurality of voltage limiting devices through one alarm circuit and achieve the aim of preventing reverse connection of the live wire and the zero wire.

Description

Overvoltage protection circuit and electronic equipment
Technical Field
The invention relates to the technical field of overvoltage protection, in particular to an overvoltage protection circuit and electronic equipment.
Background
An overvoltage protection circuit, also called a surge protector or lightning protection device, comprises at least one surge protection device. The surge protector is an electronic device for providing safety protection for various electronic equipment, instruments and meters and communication lines. When the peak current or the voltage is suddenly generated in the electric loop or the communication line due to the external interference, the surge protector can conduct and shunt in a very short time, so that the damage of the surge to other equipment in the loop is avoided.
Common surge protection devices include: voltage limiting devices, switching devices, etc. However, the voltage limiting device has a problem of increased leakage current after long-term use.
Disclosure of Invention
The embodiment of the invention provides an overvoltage protection circuit and electronic equipment, which are used for monitoring and alarming leakage currents of a plurality of voltage limiting devices through one alarm circuit and achieving the purpose of preventing reverse connection of a live wire and a zero wire.
In a first aspect, an embodiment of the present invention provides an overvoltage protection circuit, including: at least two of the first module, the second module and the third module, and an alarm circuit;
wherein the first module comprises:
the first end of the first voltage limiting device is electrically connected with the first end of the overvoltage protection circuit;
the second end of the first voltage limiting device is electrically connected with the second end of the overvoltage protection circuit through the first switching device;
the first input end of the first rectifying circuit is electrically connected with the second end of the first voltage limiting device; the second input end of the first rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the first rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the first rectifying circuit is electrically connected with the second end of the warning circuit;
the second module includes:
the first end of the second voltage limiting device is electrically connected with the first end of the overvoltage protection circuit;
the second end of the second voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through the second switching device;
the first input end of the second rectifying circuit is electrically connected with the second end of the second voltage limiting device; the second input end of the second rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the second rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the second rectifying circuit is electrically connected with the second end of the warning circuit;
the third module includes:
a third voltage limiting device, wherein the first end of the third voltage limiting device is electrically connected with the second end of the overvoltage protection circuit;
the second end of the third voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through the third switching device;
the first input end of the third rectifying circuit is electrically connected with the second end of the third voltage limiting device; the second input end of the third rectifying circuit is electrically connected with the first end of the overvoltage protection circuit; the positive output end of the third rectifying circuit is electrically connected with the first end of the warning circuit; and the negative electrode output end of the third rectifying circuit is electrically connected with the second end of the warning circuit.
Further, the alarm circuit includes a first current limiting unit and a first alarm device,
the first current limiting unit is connected with the first warning device in series, and two ends of the first current limiting unit after being connected with the first warning device in series are respectively and electrically connected with the first end and the second end of the warning circuit.
Further, the alarm circuit further comprises a first shunt device, and the first shunt device is connected with the first alarm device in parallel.
Furthermore, the first current limiting unit comprises a first resistor and a voltage stabilizing diode, the first resistor, the voltage stabilizing diode and the first warning device are connected in series, and two ends of the first resistor, the voltage stabilizing diode and the first warning device after being connected in series are respectively and electrically connected with a first end and a second end of the warning circuit;
the first warning device includes at least one of: a light emitting diode and a buzzer.
Further, the overvoltage protection circuit further includes: a second warning device and a second current limiting device; the second warning device and the second current limiting device are connected in series, and two ends of the second warning device and the second current limiting device after being connected in series are respectively and electrically connected with the first end and the second end of the overvoltage protection circuit.
Further, the second alarm device includes a first light emitting diode, and the overvoltage protection circuit further includes: and the first diode, the second warning device and the second current limiting device are connected in series, two ends of the first diode, the second warning device and the second current limiting device after being connected in series are respectively and electrically connected with the first end and the second end of the overvoltage protection circuit, and the first light emitting diode and the first diode are connected in series in the same direction.
Further, the first rectifying circuit comprises a rectifying bridge consisting of four diodes; the second rectifying circuit comprises a rectifying bridge consisting of four diodes; the third rectifying circuit comprises a rectifying bridge consisting of four diodes; the first voltage limiting device comprises at least one of: a varistor and a transient suppression diode; the first switching device comprises at least one of: a gas discharge tube and a semiconductor discharge tube; the second voltage limiting device comprises at least one of: a varistor and a transient suppression diode; the second switching device comprises at least one of: a gas discharge tube and a semiconductor discharge tube; the third voltage limiting device comprises at least one of: a varistor and a transient suppression diode; the third switching device comprises at least one of: a gas discharge tube and a semiconductor discharge tube;
the overvoltage protection circuit also includes a first overcurrent protection device,
the first end of the overvoltage protection circuit is electrically connected with the first end of the first overcurrent protection device;
when the overvoltage protection circuit comprises the first module, the first end of the first voltage limiting device is electrically connected with the second end of the first overcurrent protection device;
when the overvoltage protection circuit comprises the second module, the first end of the second voltage limiting device is electrically connected with the second end of the first overcurrent protection device;
when the overvoltage protection circuit includes the third module, the second input terminal of the third rectification circuit is electrically connected to the second terminal of the first overcurrent protection device.
Further, when the overvoltage protection circuit comprises the first module, the overvoltage protection circuit further comprises a third current limiting device, the second input end of the first rectification circuit is electrically connected with the second end of the overvoltage protection circuit through the third current limiting device, or the first input end of the first rectification circuit is electrically connected with the second end of the first voltage limiting device through the third current limiting device;
when the overvoltage protection circuit comprises a second module, the overvoltage protection circuit also comprises a fourth current limiting device, and a second input end of the second rectifying circuit is electrically connected with a second end of the overvoltage protection circuit through the fourth current limiting device, or a first input end of the second rectifying circuit is electrically connected with a second end of the second voltage limiting device through the fourth current limiting device;
when the overvoltage protection circuit comprises a third module, the overvoltage protection circuit further comprises a fifth current limiting device, and the second input end of the third rectifying circuit is electrically connected with the first end of the overvoltage protection circuit through the fifth current limiting device, or the first input end of the third rectifying circuit is electrically connected with the second end of the third voltage limiting device through the fifth current limiting device.
Further, when the overvoltage protection circuit includes the second module, the second switching device includes an open failure type gas discharge tube, and the overvoltage protection circuit further includes a first voltage divider connected in parallel with the second switching device;
when the overvoltage protection circuit includes the third module, the third switching device includes an open failure type gas discharge tube, and the overvoltage protection circuit further includes a second voltage dividing device connected in parallel with the third switching device.
In a second aspect, embodiments of the present invention further provide an electronic device, including a circuit to be protected and an overvoltage protection circuit provided in any of the embodiments of the present invention,
the third end of the overvoltage protection circuit is grounded; the first end and the second end of the overvoltage protection circuit are respectively and electrically connected with the live wire and the zero line;
the circuit to be protected is electrically connected to the first and second terminals of the overvoltage protection circuit.
The overvoltage protection circuit provided by the embodiment of the invention comprises: at least two of the first module, the second module and the third module, and an alarm circuit; wherein the first module comprises: the overvoltage protection circuit comprises a first voltage limiting device, a first switching device and a first rectifying circuit, wherein the first end of the first voltage limiting device is electrically connected with the first end of the overvoltage protection circuit; the second end of the first voltage limiting device is electrically connected with the second end of the overvoltage protection circuit through the first switching device; the first input end of the first rectifying circuit is electrically connected with the second end of the first voltage limiting device; the second input end of the first rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the first rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the first rectifying circuit is electrically connected with the second end of the warning circuit; the second module includes: the first end of the second voltage limiting device is electrically connected with the first end of the overvoltage protection circuit; the second end of the second voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through a second switching device; the first input end of the second rectifying circuit is electrically connected with the second end of the second voltage limiting device; the second input end of the second rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the second rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the second rectifying circuit is electrically connected with the second end of the warning circuit; the third module includes: the first end of the third voltage limiting device is electrically connected with the second end of the overvoltage protection circuit; the second end of the third voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through a third switching device; the first input end of the third rectifying circuit is electrically connected with the second end of the third voltage limiting device; the second input end of the third rectifying circuit is electrically connected with the first end of the overvoltage protection circuit; the positive output end of the third rectifying circuit is electrically connected with the first end of the warning circuit; and the negative electrode output end of the third rectifying circuit is electrically connected with the second end of the warning circuit. On the basis of realizing overvoltage protection, the monitoring and alarming of leakage currents of at least two of the first voltage limiting device, the second voltage limiting device and the third voltage limiting device can be realized through one alarming circuit, and the aim of preventing reverse connection of a live wire and a zero wire is fulfilled.
Drawings
Fig. 1 is a schematic structural diagram of an overvoltage protection circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention;
fig. 8 is an assembly structural diagram of a light-condensing element, a first alarm device, and a second alarm device according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
The embodiment of the invention provides an overvoltage protection circuit. Fig. 1 is a schematic structural diagram of an overvoltage protection circuit according to an embodiment of the present invention. The overvoltage protection circuit 100 includes: a first module 1, a second module 2 and an alarm circuit 4.
Wherein the first module 1 comprises: a first voltage limiting device 10, a first switching device 20 and a first rectifying circuit 30.
Wherein, the first terminal of the first voltage limiting device 10 is electrically connected to the first terminal V1 of the overvoltage protection circuit 100; the second terminal of the first voltage limiting device 10 is electrically connected to the second terminal V2 of the overvoltage protection circuit 100 via the first switching device 20; the first input terminal In1 of the first rectifying circuit 30 is electrically connected to the second terminal of the first voltage limiting device 10; the second input terminal In2 of the first rectification circuit 30 is electrically connected with the second terminal V2 of the overvoltage protection circuit 100; the positive output end V + of the first rectifying circuit 30 is electrically connected with the first end of the warning circuit 4; and a negative electrode output end V-of the first rectifying circuit 30 is electrically connected with a second end of the alarm circuit 4.
Wherein the second module 2 comprises: a second voltage limiting device 40, a second switching device 50 and a second rectifying circuit 60.
Wherein the first terminal of the second voltage limiting device 40 is electrically connected to the first terminal V1 of the overvoltage protection circuit 100; the second terminal of the second voltage limiting device 40 is electrically connected to the third terminal V3 of the overvoltage protection circuit 100 via the second switching device 50; the first input terminal In1 of the second rectifying circuit 60 is electrically connected to the second terminal of the second voltage limiting device 40; a second input terminal In2 of the second rectification circuit 60 is electrically connected to the second terminal V2 of the overvoltage protection circuit 100; the positive output end V + of the second rectifying circuit 60 is electrically connected with the first end of the warning circuit 4; and the negative output end V-of the second rectifying circuit 60 is electrically connected with the second end of the alarm circuit 4.
The voltage limiting device presents high impedance when no surge occurs, but the impedance of the voltage limiting device is continuously reduced along with the increase of surge current and voltage, and certain voltage is presented when the surge current passes through the voltage limiting device, and the voltage is called residual voltage or clamping voltage. The switching device presents high impedance when no surge, and suddenly changes into low impedance when voltage surge occurs, so that overvoltage can be reduced to be close to zero value, and the switching device has larger through-current capacity. Optionally, the first voltage limiting device 10 comprises at least one of: a varistor and a transient suppression diode. Optionally, the first switching device 20 comprises at least one of: gas discharge tubes and semiconductor discharge tubes. Optionally, the second voltage limiting device 40 comprises at least one of: a varistor and a transient suppression diode. Optionally, the second switching device 50 comprises at least one of: gas discharge tubes and semiconductor discharge tubes. The first rectifying circuit 30 may comprise a controllable rectifying circuit or an uncontrollable rectifying circuit. Optionally, the first rectifying circuit 30 includes a rectifying bridge composed of four diodes. The second rectifying circuit 60 may comprise a controllable rectifying circuit or an uncontrollable rectifying circuit. Optionally, the second rectifying circuit 60 comprises a rectifying bridge consisting of four diodes. The first terminal V1 of the overvoltage protection circuit 100 may be electrically connected to either the hot or neutral wires. The second terminal V2 of the overvoltage protection circuit 100 may be electrically connected to either the hot or neutral wires. The third terminal V3 of the overvoltage protection circuit 100 may be electrically connected to ground. The first terminal V1 and the second terminal V2 of the overvoltage protection circuit 100 may be electrically connected to different power supply lines. For example, the first terminal V1 of the overvoltage protection circuit 100 may be electrically connected to the neutral line, the second terminal V2 of the overvoltage protection circuit 100 may be electrically connected to the hot line, and the third terminal V3 of the overvoltage protection circuit 100 may be electrically connected to the ground line. The alarm circuit 4 may alarm when the leakage current of the first voltage limiting device 10 and/or the second voltage limiting device 40 is greater than or equal to a preset threshold.
Under the condition of normal power supply, that is, when surge interference such as lightning stroke or overvoltage does not occur, the first voltage limiting device 10, the first switching device 20, the second voltage limiting device 40 and the second switching device 50 are all turned off, the currents output by the first rectifying circuit 30 and the second rectifying circuit 60 are zero, and the alarm circuit 4 does not work. If surge interference occurs between the first terminal V1 and the second terminal V2 of the overvoltage protection circuit 100, when the voltage between the first terminal V1 and the second terminal V2 is higher than the equivalent turn-on voltage after the first voltage-limiting device 10 and the first switching device 20 are connected in series, the first voltage-limiting device 10 and the first switching device 20 will be turned on to discharge surge current, and the voltage between the first terminal V1 and the second terminal V2 is limited within the voltage range that the circuit 200 to be protected can bear, at this time, the turned-on first switching device 20 makes the first rectification circuit 30 be short-circuited and no current flow through the alarm circuit 4, so that false alarm cannot be generated. If surge interference occurs between the first terminal V1 and the third terminal V3 of the overvoltage protection circuit 100, when the voltage between the first terminal V1 and the third terminal V3 is higher than the equivalent turn-on voltage after the second voltage-limiting device 40 and the second switching device 50 are connected in series, the second voltage-limiting device 40 and the second switching device 50 will be turned on, to discharge the surge current and limit the voltage between the first terminal V1 and the third terminal V3 within the voltage range that the circuit 200 to be protected can bear, at this time, if the second terminal V2 of the overvoltage protection circuit 100 is electrically connected to the hot line, the first terminal V1 of the overvoltage protection circuit 100 is electrically connected to the neutral line, the conducting second switching device 50 makes the voltage between the first input terminal In1 and the second input terminal In2 of the second rectifying circuit 60 the voltage between the live line and the ground line, which is close to the phase voltage, resulting In a short alarm generated by the alarm circuit 4.
Under the condition that the first voltage limiting device 10 and the second voltage limiting device 40 are intact and the power supply is normal, the leakage current of the first voltage limiting device 10 and the second voltage limiting device 40 is small, and the alarm circuit 4 cannot alarm. If the first voltage-limiting device 10 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the first voltage-limiting device 10 is too large, the first switching device 20 is turned off, and the leakage current of the first voltage-limiting device 10 flows through the alarm circuit 4 after flowing through the rectification function of the first rectification circuit 30, so that the alarm circuit 4 gives an alarm. If the second voltage-limiting device 40 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the second voltage-limiting device 40 is too large, the second switching device 50 is turned off, and the leakage current of the second voltage-limiting device 40 flows through the alarm circuit 4 after being rectified by the second rectifier circuit 60, so that the alarm circuit 4 gives an alarm. Therefore, when at least one of the first voltage limiting device 10 and the second voltage limiting device 40 fails (specifically, short-circuit failure occurs), and the leakage current is too large, the alarm circuit 4 can alarm, so that it is not necessary to set respective alarm circuits for the first voltage limiting device 10 and the second voltage limiting device 40, thereby reducing the use of components.
It should be noted that, no matter the first end V1 of the overvoltage protection circuit 100 is connected with the live wire, the second end V2 is connected with the zero wire, or the first end V1 of the overvoltage protection circuit 100 is connected with the zero wire, and the second end V2 is connected with the live wire, when the first voltage-limiting device 10 fails, the voltage of the loop In which the first input end In1 and the second input end In2 of the first voltage-limiting device 10 and the first rectification circuit 30 are located is the voltage between the live wire and the zero wire, so as to avoid the situation that the voltage between the first end of the first voltage-limiting device 10 and the second input end In2 of the first rectification circuit 30 is too low, the leakage current is too small, and the alarm cannot be normally performed; when the second voltage-limiting device 40 fails, the voltage of the loop In which the second voltage-limiting device 40 and the first input end In1 and the second input end In2 of the second rectifying circuit 60 are located is the voltage between the live line and the zero line, so that the situation that the voltage between the first end of the second voltage-limiting device 40 and the second input end In2 of the second rectifying circuit 60 is too low and the leakage current is too small, which results In abnormal alarm is avoided. Therefore, the first end V1 and the second end V2 of the overvoltage protection circuit 100 can be arbitrarily connected with the live wire and the zero wire, so that the purpose of preventing reverse connection of the live wire and the zero wire is achieved.
The overvoltage protection circuit in the technical scheme of this embodiment includes a first module, a second module and an alarm circuit, wherein the first module includes: the overvoltage protection circuit comprises a first voltage limiting device, a first switching device and a first rectifying circuit, wherein the first end of the first voltage limiting device is electrically connected with the first end of the overvoltage protection circuit; the second end of the first voltage limiting device is electrically connected with the second end of the overvoltage protection circuit through the first switching device; the first input end of the first rectifying circuit is electrically connected with the second end of the first voltage limiting device; the second input end of the first rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the first rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the first rectifying circuit is electrically connected with the second end of the warning circuit; the second module includes: the first end of the second voltage limiting device is electrically connected with the first end of the overvoltage protection circuit; the second end of the second voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through a second switching device; the first input end of the second rectifying circuit is electrically connected with the second end of the second voltage limiting device; the second input end of the second rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the second rectifying circuit is electrically connected with the first end of the warning circuit; and the negative electrode output end of the second rectifying circuit is electrically connected with the second end of the warning circuit. On the basis of realizing overvoltage protection, the monitoring and the alarming of the leakage current of the first voltage limiting device and the second voltage limiting device can be realized through an alarming circuit, and the aim of preventing reverse connection of a live wire and a zero wire is fulfilled.
The embodiment of the invention provides a further overvoltage protection circuit. Fig. 2 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention. On the basis of the above embodiment, the overvoltage protection circuit 100 includes: a first module 1, a third module 3 and an alarm circuit 4.
Wherein the third module 3 comprises: a third voltage limiting device 70, a third switching device 80 and a third rectifying circuit 90.
Wherein, the first terminal of the third voltage limiting device 70 is electrically connected to the second terminal V2 of the overvoltage protection circuit 100; a second terminal of the third voltage limiting device 70 is electrically connected to a third terminal V3 of the overvoltage protection circuit 100 via a third switching device 80; the first input terminal In1 of the third rectifying circuit 90 is electrically connected to the second terminal of the third voltage limiting device 70; a second input terminal In2 of the third rectification circuit 90 is electrically connected to the first terminal V1 of the overvoltage protection circuit 100; the positive output end V + of the third rectifying circuit 90 is electrically connected with the first end of the warning circuit 4; and the negative electrode output end V-of the third rectifying circuit 90 is electrically connected with the second end of the alarm circuit 4.
Wherein, optionally, the third voltage limiting device 70 comprises at least one of the following: a varistor and a transient suppression diode. Optionally, the third switching device 80 comprises at least one of: gas discharge tubes and semiconductor discharge tubes. The third rectifying circuit 90 may comprise a controllable rectifying circuit or an uncontrollable rectifying circuit. Optionally, the third rectifying circuit 90 includes a rectifying bridge composed of four diodes. The alarm circuit 4 may alarm when the leakage current of the first voltage limiting device 10 and/or the third voltage limiting device 70 is greater than or equal to a preset threshold.
It should be noted that the working principle of the first module 1 in the technical solution corresponding to fig. 2 is the same as or similar to the working principle of the first module 1 in the technical solution corresponding to fig. 1, and therefore, the description is omitted here.
Under the condition of normal power supply, that is, when surge interference such as lightning stroke or overvoltage does not occur, the first voltage limiting device 10, the first switching device 20, the third voltage limiting device 70 and the third switching device 80 are all turned off, the currents output by the first rectifying circuit 30 and the third rectifying circuit 90 are zero, and the alarm circuit 4 does not work. If surge interference occurs between the second terminal V2 and the third terminal V3 of the overvoltage protection circuit 100, when the voltage between the second terminal V2 and the third terminal is higher than the equivalent turn-on voltage after the series connection of the third voltage limiting device 70 and the third switching device 80, the third voltage limiting device 70 and the third switching device 80 will be on, so as to bleed off the surge current and limit the voltage between the second terminal V2 and the third terminal V3 within the voltage range that the circuit 200 to be protected can withstand, and at this time, if the first terminal V1 of the overvoltage protection circuit 100 is electrically connected to the hot line, the second terminal V2 of the overvoltage protection circuit 100 is electrically connected to the neutral line, the conducting third switching device 80 causes the voltage between the first input terminal In1 and the second input terminal In2 of the third rectifying circuit 90 to be the voltage between the hot line and the ground, which is close to the phase voltage, resulting In a short alarm generated by the alarm circuit 4.
Under the condition that the first voltage limiting device 10 and the third voltage limiting device 70 are intact and the power supply is normal, the leakage current of the first voltage limiting device 10 and the third voltage limiting device 70 is small, and the alarm circuit 4 does not give an alarm. If the third voltage-limiting device 70 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the third voltage-limiting device 70 is too large, the third switching device 80 is turned off, and the leakage current of the third voltage-limiting device 70 flows through the warning circuit 4 after the rectification function of the third rectification circuit 90, so that the warning circuit 4 gives a warning. Therefore, when at least one of the first voltage limiting device 10 and the third voltage limiting device 70 fails and the leakage current is too large, the alarm circuit 4 will alarm, so that it is not necessary to provide respective alarm circuits for the first voltage limiting device 10 and the third voltage limiting device 70, thereby reducing the use of components.
It should be noted that, no matter the first end V1 of the overvoltage protection circuit 100 is connected to the live wire, the second end V2 is connected to the neutral wire, or the first end V1 of the overvoltage protection circuit 100 is connected to the neutral wire, and the second end V2 is connected to the live wire, when the third voltage-limiting device 70 fails, the voltage of the loop In which the first input end In1 and the second input end In2 of the third voltage-limiting device 70 and the third rectification circuit 90 are located is the voltage between the live wire and the neutral wire, so as to avoid the situation that the voltage of the loop In1 and the second input end In2 of the third voltage-limiting device 70 and the third rectification circuit 90 is too low, and the leakage current is too small, which may cause a normal alarm. Therefore, the first end V1 and the second end V2 of the overvoltage protection circuit 100 can be arbitrarily connected with the live wire and the zero wire, so that the purpose of preventing reverse connection of the live wire and the zero wire is achieved.
The overvoltage protection circuit in the technical scheme of this embodiment includes a first module, a third module and an alarm circuit, wherein the first module includes: the overvoltage protection circuit comprises a first voltage limiting device, a first switching device and a first rectifying circuit, wherein the first end of the first voltage limiting device is electrically connected with the first end of the overvoltage protection circuit; the second end of the first voltage limiting device is electrically connected with the second end of the overvoltage protection circuit through the first switching device; the first input end of the first rectifying circuit is electrically connected with the second end of the first voltage limiting device; the second input end of the first rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the first rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the first rectifying circuit is electrically connected with the second end of the warning circuit; the third module includes: the first end of the third voltage limiting device is electrically connected with the second end of the overvoltage protection circuit; the second end of the third voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through a third switching device; the first input end of the third rectifying circuit is electrically connected with the second end of the third voltage limiting device; the second input end of the third rectifying circuit is electrically connected with the first end of the overvoltage protection circuit; the positive output end of the third rectifying circuit is electrically connected with the first end of the warning circuit; and the negative electrode output end of the third rectifying circuit is electrically connected with the second end of the warning circuit. On the basis of realizing overvoltage protection, the leakage current in the first voltage-limiting device and the third voltage-limiting device can be monitored and alarmed through one alarm circuit, and the aim of preventing reverse connection of a live wire and a zero wire is fulfilled.
The embodiment of the invention provides a further overvoltage protection circuit. Fig. 3 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention. On the basis of the above embodiment, the overvoltage protection circuit 100 includes: a second module 2, a third module 3 and an alarm circuit 4.
The warning circuit 4 may perform a warning when the leakage current of the second voltage-limiting device 40 and/or the third voltage-limiting device 70 is greater than or equal to a preset threshold.
It should be noted that the working principle of the second module 2 in the technical solution corresponding to fig. 3 is the same as or similar to the working principle of the second module 2 in the technical solution corresponding to fig. 1, and therefore, the description is omitted here. It should be noted that the working principle of the third module 3 in the technical solution corresponding to fig. 3 is the same as or similar to the working principle of the third module 3 in the technical solution corresponding to fig. 2, and therefore, the description is omitted here. When at least one of the second and third voltage limiting devices 40 and 70 fails and the leakage current is too large, the alarm circuit 4 will alarm, so that it is not necessary to set respective alarm circuits for the second and third voltage limiting devices 40 and 70, respectively, to reduce the use of components.
The overvoltage protection circuit in the technical scheme of this embodiment includes a second module, a third module and an alarm circuit, wherein the second module includes: the first end of the second voltage limiting device is electrically connected with the first end of the overvoltage protection circuit; the second end of the second voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through a second switching device; the first input end of the second rectifying circuit is electrically connected with the second end of the second voltage limiting device; the second input end of the second rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the second rectifying circuit is electrically connected with the first end of the warning circuit; the negative output end of the second rectifying circuit is electrically connected with the second end of the warning circuit; the third module includes: the first end of the third voltage limiting device is electrically connected with the second end of the overvoltage protection circuit; the second end of the third voltage limiting device is electrically connected with the third end of the overvoltage protection circuit through a third switching device; the first input end of the third rectifying circuit is electrically connected with the second end of the third voltage limiting device; the second input end of the third rectifying circuit is electrically connected with the first end of the overvoltage protection circuit; the positive output end of the third rectifying circuit is electrically connected with the first end of the warning circuit; and the negative electrode output end of the third rectifying circuit is electrically connected with the second end of the warning circuit. On the basis of realizing overvoltage protection, the leakage current in the second voltage-limiting device and the third voltage-limiting device can be monitored and alarmed through an alarm circuit, and the aim of preventing reverse connection of a live wire and a zero wire is fulfilled.
The embodiment of the invention provides a further overvoltage protection circuit. Fig. 4 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention. On the basis of the above embodiment, the overvoltage protection circuit 100 includes: a first module 1, a second module 2, a third module 3 and an alarm circuit 4.
The warning circuit 4 may perform a warning when the leakage current of at least one of the first voltage-limiting device 10, the second voltage-limiting device 40, and the third voltage-limiting device 70 is greater than or equal to a preset threshold. When at least one of the first voltage limiting device 10, the second voltage limiting device 40 and the third voltage limiting device 70 fails and the leakage current is too large, the alarm circuit 4 can alarm, so that it is not necessary to set respective alarm circuits for the first voltage limiting device 10, the second voltage limiting device 40 and the third voltage limiting device 70, thereby reducing the use of components. On the basis of realizing overvoltage protection, the monitoring and the alarming of the leakage currents of the first voltage limiting device, the second voltage limiting device and the third voltage limiting device can be realized through one alarming circuit, and the aim of preventing reverse connection of a live wire and a zero wire is fulfilled.
Optionally, on the basis of the above embodiment, fig. 5 is a schematic structural diagram of another overvoltage protection circuit provided in the embodiment of the present invention, and the alarm circuit 4 includes a first current limiting unit 41 and a first alarm device 42.
The first current limiting unit 41 is connected in series with the first alarm device 42, and both ends of the first current limiting unit 41, which are connected in series with the first alarm device 42, are electrically connected to the first end and the second end of the alarm circuit 4, respectively.
Wherein, optionally, the first current limiting unit 41 may include at least one of the following: a resistor and a zener diode. The first current limiting unit 41 has the function of current limiting and voltage dividing, and prevents the first alarm device 42 from being damaged due to overlarge current and voltage. Optionally, the first warning device 42 includes at least one of: a light emitting diode and a buzzer.
Illustratively, the first alarm device 42 is a light emitting diode, and in the case that the performance of the first voltage limiting device 10, the second voltage limiting device 40, and the third voltage limiting device 70 is intact, when the power supply is normal, that is, when no surge interference occurs, the leakage current of the first voltage limiting device 10, the second voltage limiting device 40, and the third voltage limiting device 70 is small, and the first alarm device 42 does not emit light. If the first voltage limiting device 10 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the first voltage limiting device 10 is too large, the first switching device 20 is turned off, the leakage current of the first voltage limiting device 10 flows through the first warning device 42 of the warning circuit 4 after flowing through the rectification function of the first rectification circuit 30, and the first warning device 42 emits light to make the warning circuit 4 warn, so as to prompt maintenance personnel to maintain and replace the device in time. If the second voltage-limiting device 40 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the second voltage-limiting device 40 is too large, the second switching device 50 is turned off, the leakage current of the second voltage-limiting device 40 flows through the first warning device 42 of the warning circuit 4 after the rectification action of the second rectification circuit 60, and the first warning device 42 emits light to make the warning circuit 4 give an alarm so as to prompt maintenance personnel to maintain and replace the devices in time. If the third voltage limiting device 70 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the third voltage limiting device 70 is too large, the third switching device 80 is turned off, and after the leakage current of the third voltage limiting device 70 flows through the rectification function of the third rectification circuit 90, the leakage current flows through the first alarm device 42 of the alarm circuit 4, and the first alarm device 42 emits light, so that the alarm circuit 4 gives an alarm to prompt maintenance personnel to maintain and replace the device in time. It should be noted that, the more the number of failures occurring in the first voltage limiting device 10, the second voltage limiting device 40, and the third voltage limiting device 70, the larger the current flowing through the alarm circuit 4, and the higher the brightness of the first alarm device 42, so the number of voltage limiting devices that have failures can be determined according to the brightness of the first alarm device 42.
Optionally, on the basis of the foregoing embodiment, with reference to fig. 5, the first current limiting unit 41 includes a first resistor R1 and a zener diode Z1, the first resistor R1, the zener diode Z1 and the first alarm device 42 are connected in series, and both ends of the series connection of the first resistor R1, the zener diode Z1 and the first alarm device 42 are electrically connected to the first end and the second end of the alarm circuit 4, respectively.
Optionally, the zener diode Z1 is a bidirectional zener diode or a unidirectional zener diode. The larger the resistance of the first resistor R1, the greater the current limiting and voltage dividing effect. The larger the clamping voltage of the zener diode Z1, the larger the current limiting and voltage dividing effect.
Optionally, on the basis of the above embodiment, with continued reference to fig. 5, the alarm circuit 4 further includes a first shunt device 43, and the first shunt device 43 is connected in parallel with the first alarm device 42.
Wherein, optionally, the first shunt device 43 may comprise a resistor. By arranging the first shunt device 43 to shunt the leakage current flowing through the first alarm device 42, the current flowing through the first alarm device 42 is limited, and the first alarm device 42 is prevented from being damaged due to the excessive current.
Optionally, on the basis of the foregoing embodiment, with continued reference to fig. 5, the overvoltage protection circuit 100 further includes: a second warning device 11 and a second current limiting device 12; the second alarm device 11 and the second current limiting device 12 are connected in series, and two ends of the second alarm device 11 and the second current limiting device 12 after being connected in series are respectively electrically connected with the first end V1 and the second end V2 of the overvoltage protection circuit 100.
Optionally, the second warning device 11 includes at least one of the following: a light emitting diode and a buzzer. Optionally, the second current limiting device 12 comprises a resistor. The second current limiting device 12 has the function of current limiting and voltage dividing, and the second warning device is prevented from being damaged due to overlarge current and voltage.
Illustratively, taking the second alarm device 11 as a light emitting diode as an example, in the case of normal power supply, the voltage between the first terminal V1 and the second terminal V2 of the overvoltage protection circuit 100 is a normal operating voltage, the voltage between the first terminal V1 and the second terminal V2 is transmitted to the two terminals of the second alarm device 11 and the second current limiting device 12 after being connected in series, and the second alarm device 11 will emit light; if a power failure occurs, the voltage between the first terminal V1 and the second terminal V2 of the overvoltage protection circuit 100 is 0, and the second alarm device 11 will not emit light, so that the purpose of indicating the power supply state of the second alarm device 11 is achieved.
Optionally, on the basis of the foregoing embodiment, fig. 6 is a schematic structural diagram of another overvoltage protection circuit provided in the embodiment of the present invention, where the second alarm device 11 includes a first light emitting diode, and the overvoltage protection circuit 100 further includes: and the first diode D1, wherein the first diode D1, the second alarm device 11 and the second current limiting device 12 are connected in series, the two ends of the first diode D1, the second alarm device 11 and the second current limiting device 12 after being connected in series are respectively and electrically connected with the first end V1 and the second end V2 of the overvoltage protection circuit 100, and the first light emitting diode and the first diode are connected in series in the same direction.
The first diode D1 can reduce the reverse voltage applied to the first light emitting diode, and prevent the first light emitting diode from being damaged due to the excessive reverse voltage applied to the first light emitting diode.
Optionally, on the basis of the above embodiment, fig. 7 is a schematic structural diagram of another overvoltage protection circuit according to an embodiment of the present invention, and the overvoltage protection circuit 100 further includes a first overcurrent protection device 13.
The first terminal V1 of the overvoltage protection circuit 100 is electrically connected to the first terminal of the first overcurrent protection device 13. When the overvoltage protection circuit 100 comprises the first module 1, the first terminal of the first voltage limiting device 10 is electrically connected with the second terminal of the first overcurrent protection device 13. When the overvoltage protection circuit 100 comprises the second module 2, the first terminal of the second voltage limiting device 40 is electrically connected with the second terminal of the first overcurrent protection device 13. When the overvoltage protection circuit 100 includes the third module 3, the second input terminal In2 of the third rectification circuit 90 is electrically connected to the second terminal of the first overcurrent protection device 13.
Optionally, two ends of the first diode D1, the second alarm device 11, and the second current limiting device 12 after being connected in series are electrically connected to the second end V2 of the overvoltage protection circuit 100 and the second end of the first overcurrent protection device 13, respectively. Optionally, the first overcurrent protection device 13 includes at least one of: fuses and circuit breakers. If the overcurrent detection circuit of the circuit breaker detects that the current flowing into the first end V1 of the overvoltage protection circuit 100 exceeds the rated current, the main contacts of the circuit breaker are automatically opened. The overcurrent detection circuit may be an overcurrent release.
For example, in the case that the second alarm device 11 is a light emitting diode, and the first overcurrent protection device 13 is a fuse, when the power supply is normal, the voltage between the first terminal V1 and the second terminal V2 of the overvoltage protection circuit 100 is a normal operating voltage and an operating current, the first overcurrent protection device 13 does not operate and remains in an on state, the voltage between the first terminal V1 and the second terminal V2 is transmitted to the two terminals of the second alarm device 11 and the second current limiting device 12 connected in series, and the second alarm device 11 emits light. When a lightning strike, an overvoltage or an overload occurs, which causes the current flowing through the first overcurrent protection device 13 to exceed the rated current, the first overcurrent protection device 13 will be blown out, and the second alarm device 11 will be extinguished, so as to prompt the maintenance personnel to perform maintenance.
Optionally, on the basis of the foregoing embodiment, fig. 8 is an assembly structural schematic diagram of a light condensing element, a first warning device and a second warning device provided in the embodiment of the present invention, the overvoltage protection circuit 100 further includes the light condensing element 14, the first warning device 42 is a light emitting diode, the second warning device 11 is a white light emitting diode, and a light emitting color of the first warning device 42 is different from a light emitting color of the second warning device 11. The first alarm device 42 and the second alarm device 11 are located in the hollow interior of the light-concentrating element 14.
The light condensing element 14 has a function of increasing the central light intensity, and has a light condensing function. The light gathering element may be a light guide. When the first and second alerting devices 42, 11 are simultaneously illuminated, the red light emitted from the first alerting device 42 masks the white light emitted from the second alerting device 11.
Wherein the light emitting color of the first warning device 42 may be at least one of the following: red, yellow, blue, green, purple, etc. The first alerting device 42 and the second alerting device 11 may implement a two-color indication.
For example, taking the first warning device 42 as a red light emitting diode as an example, if the first voltage limiting device 10, the second voltage limiting device 40, and the third voltage limiting device 70 are intact, and have no failure, and have no large leakage current, under the condition of normal power supply, the second warning device 11 emits white light, and the first warning device 42 does not emit light, human eyes can only see white light; if at least one of the first voltage limiting device 10, the second voltage limiting device 40 and the third voltage limiting device 70 fails, and the leakage current is too large, the first warning device 42 emits red light, and the second warning device 11 emits white light under the condition of normal power supply, but due to the light condensation effect of the light condensation element, the white light and the red light are mixed to form red light, and then the red light is seen by human eyes. If a lightning strike, an overvoltage or an overload occurs, which causes the current flowing through the first overcurrent protection device 13 to exceed the rated current, the first overcurrent protection device 13 will blow and the first alarm device 42 and the second alarm device 11 will extinguish.
Optionally, on the basis of the above embodiment, with continuing reference to fig. 6, when the overvoltage protection circuit 100 includes the first module 1, the overvoltage protection circuit 100 further includes a third current limiting device 5, and the second input terminal In2 of the first rectification circuit 30 is electrically connected to the second terminal V2 of the overvoltage protection circuit 100 through the third current limiting device 5.
Wherein, optionally, the third current limiting device 5 may comprise a resistor. The third current limiting device 5 has the functions of current limiting and voltage dividing so as to reduce reverse voltage and conduction current borne by devices such as diodes in the first rectifying circuit. If the first voltage limiting device 10 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the first voltage limiting device 10 is too large, the first switching device 20 is turned off, and the leakage current of the first voltage limiting device 10 flows through the current-limiting voltage-dividing function of the third current-limiting device 5 and the rectifying function of the first rectifying circuit 30, and then flows through the alarm circuit 4, so that the alarm circuit 4 gives an alarm.
It should be noted that the sum of the resistances of the third current limiting device 5 and the first current limiting unit 41 may be larger than the impedance of the first switching device 20 when it is turned on. The third current limiting device 5 is connected in series with the first voltage limiting device 10 and in parallel with the first switching device 20 to perform a voltage dividing function while increasing the voltage across the first switching device 20. If the first switching device 20 is an open-circuit failure type gas discharge tube, when surge overvoltage occurs between the first end V1 and the second end V2 of the overvoltage protection circuit 100, the first voltage-limiting device 10 and the first switching device 20 are turned on, due to the voltage division effect of the third current-limiting device 5, the voltage at two ends of the first switching device 20 is increased, the arc temperature of the open-circuit failure type gas discharge tube is very high, the temperature is rapidly conducted to low-temperature soldering tin, the low-temperature soldering tin melts, at this time, the closed environment of the open-circuit failure type gas discharge tube is damaged, air enters, and the open-circuit failure type gas discharge tube fails due to air leakage.
Alternatively, on the basis of the above embodiment, with continued reference to fig. 7, the first input terminal In1 of the first rectifying circuit 30 is electrically connected to the second terminal of the first voltage limiting device 10 via the third current limiting device 5.
Optionally, on the basis of the above embodiment, with continuing reference to fig. 6, when the overvoltage protection circuit 100 includes the second module 2, the overvoltage protection circuit 100 further includes a fourth current limiting device 6, and the second input terminal In2 of the second rectification circuit 60 is electrically connected to the second terminal V2 of the overvoltage protection circuit 100 through the fourth current limiting device 6.
Wherein, optionally, the fourth current limiting device 6 may comprise a resistor. The fourth current limiting device 6 has the function of current limiting and voltage dividing so as to reduce reverse voltage and conducting current borne by devices such as diodes in the second rectifying circuit. If the second voltage-limiting device 40 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the second voltage-limiting device 40 is too large, the second switching device 50 is turned off, and the leakage current of the second voltage-limiting device 40 flows through the current-limiting voltage-dividing function of the fourth current-limiting device 6 and the rectifying function of the second rectifying circuit 60, and then flows through the alarm circuit 4, so that the alarm circuit 4 gives an alarm.
Alternatively, on the basis of the above embodiment, with continued reference to fig. 7, the first input terminal In1 of the second rectifying circuit 60 is electrically connected to the second terminal of the second voltage limiting device 40 via the fourth current limiting device 6.
Optionally, on the basis of the above embodiment, with continuing reference to fig. 6, when the overvoltage protection circuit 100 includes the third module 3, the overvoltage protection circuit 100 further includes a fifth current limiting device 7, and the second input terminal In2 of the third rectification circuit 90 is electrically connected to the first terminal V1 of the overvoltage protection circuit 100 through the fifth current limiting device 7.
Wherein, optionally, the fifth current limiting device 7 may comprise a resistor. The fifth current limiting device 7 has the functions of current limiting and voltage dividing so as to reduce reverse voltage and conducting current borne by devices such as diodes in the third rectifying circuit. If the third voltage limiting device 70 fails due to breakdown caused by excessive conduction times, overcurrent surge, overvoltage surge, aging, etc., under the condition of normal power supply, i.e., when no surge interference occurs, the leakage current of the third voltage limiting device 70 is too large, the third switching device 80 is turned off, and when the leakage current of the third voltage limiting device 70 flows through the current-limiting voltage-dividing function of the fifth current-limiting device 7 and the rectifying function of the third rectifying circuit 90, the leakage current flows through the alarm circuit 4, so that the alarm circuit 4 gives an alarm.
Alternatively, on the basis of the above embodiment, with continued reference to fig. 7, the first input terminal In1 of the third rectifying circuit 90 is electrically connected to the second terminal of the third voltage limiting device 70 via the fifth current limiting device 7.
Alternatively, with continued reference to fig. 6 on the basis of the above embodiment, when the overvoltage protection circuit 100 comprises the second module 2, the second switching device 50 comprises an open failure type gas discharge tube, and the overvoltage protection circuit 100 further comprises a first voltage divider device 8, the first voltage divider device 8 being connected in parallel with the second switching device 50.
Optionally, the first voltage divider 8 may include a resistor, and a resistance value of the first voltage divider 8 is greater than an impedance of the second switching device 50 when turned on. The first voltage dividing device 8 is connected in series with the second voltage limiting device 40 and in parallel with the second switching device 50 to perform a voltage dividing function while increasing the voltage across the second switching device 50. If the second switching device 50 is an open-circuit failure type gas discharge tube, when surge overvoltage occurs between the first end V1 and the third end V3 of the overvoltage protection circuit 100, the second voltage-limiting device 40 and the second switching device 50 are conducted, due to the voltage division effect of the first voltage divider 8, the voltage at two ends of the second switching device 50 is increased, the arc temperature of the open-circuit failure type gas discharge tube is very high, the temperature is rapidly conducted to low-temperature soldering tin, the low-temperature soldering tin is melted, at this time, the closed environment of the open-circuit failure type gas discharge tube is damaged, air enters, and the open-circuit failure type gas discharge tube fails due to air leakage and open circuit. The provision of the first voltage dividing device 8 can increase the heat generation amount of the second switching device 50 and increase the withstand voltage of the second voltage limiting device 40.
Alternatively, on the basis of the above embodiment, with continued reference to fig. 6, when the overvoltage protection circuit 100 comprises the third module 3, the third switching device 80 comprises an open-failure gas discharge tube, and the overvoltage protection circuit 100 further comprises a second voltage divider component 9, the second voltage divider component 9 being connected in parallel with the third switching device 80.
Optionally, the second voltage divider 9 may include a resistor, and the resistance of the second voltage divider 9 is greater than the impedance of the third switching device 80 when it is turned on. The second voltage divider means 9 is connected in series with the third voltage limiting means 70 and in parallel with the third switching protection means 80 to perform a voltage dividing function while increasing the voltage across the third switching protection means 80. If the third switching device 80 is an open-circuit failure type gas discharge tube, when surge overvoltage occurs between the second end V2 and the third end V3 of the overvoltage protection circuit 100, the third voltage limiting device 70 and the third switching device 80 are conducted, voltage at two ends of the third switching device 80 is increased due to voltage division effect of the second voltage dividing device 9, arc temperature of the open-circuit failure type gas discharge tube is very high, the temperature is rapidly conducted to low-temperature soldering tin, the low-temperature soldering tin is melted, at this time, the closed environment of the open-circuit failure type gas discharge tube is damaged, air enters, and the open-circuit failure type gas discharge tube fails due to air leakage. By providing the second voltage divider 9, the heat generation amount of the third switching device 80 can be increased, and the withstand voltage of the third voltage limiting device 70 can be increased.
Fig. 5 exemplarily shows a case where the first voltage limiting device 10, the second voltage limiting device 40, and the third voltage limiting device 70 are varistors, and the first switching device 20, the second switching device 50, and the third switching device 80 are open-circuit failure type gas discharge tubes. The protection of each path is that the gas discharge tube is matched with the piezoresistor for use, and the problem that the leakage current is too large and the fire is easy to occur when the independent piezoresistor is used is overcome by utilizing the low leakage current characteristic of the gas discharge tube when the piezoresistor is not conducted. The clamping characteristic of the piezoresistor and the switching characteristic of the gas discharge tube are utilized to discharge lightning current.
Alternatively, the gas discharge tube may be an open-circuit failure gas discharge tube or a repeatable follow-current rupture type gas discharge tube.
Optionally, the open-circuit failure type gas discharge tube includes an insulating tube body and two conductive electrodes hermetically connected to two ends of the insulating tube body respectively to form a discharge cavity, the discharge cavity is filled with discharge gas, and at least one of the conductive electrodes is hermetically connected to the insulating tube body by a low-temperature insulating sealing adhesive. After the surge interference disappears, the continuous current generated by the normal working voltage after power supply recovery flows into the open-circuit failure type gas discharge tube, so that the low-temperature insulating sealing adhesive is melted, the external air enters the discharge inner cavity, and the open-circuit failure type gas discharge tube is caused to be out of circuit. If other devices connected with the open-circuit failure type gas discharge tube are short-circuited and failed, the open-circuit failure gas discharge tube can only bear one lightning stroke or overvoltage to fail.
Alternatively, the repeatable follow current rupture type gas discharge tube may comprise: the flexible corrugated pipe and with flexible corrugated pipe sealing connection in order to form two conductive electrode of the inner chamber of discharging, discharge the inner chamber and fill with the discharge gas. The telescopic corrugated pipe is used for stretching or contracting when discharging between the at least two conductive electrodes to enable the discharge gas to be heated and expanded so as to enlarge the discharge gap between the discharge electrode surfaces of the at least two conductive electrodes and enable the gas discharge tube to break follow current. The telescopic corrugated pipe is also used for recovering the preset length along with the cooling of the discharge gas to the low-temperature area after the follow current of the gas discharge tube is cut off. If other devices connected with the repeatable follow current breaking-off type gas discharge tube are short-circuited and failed, the repeatable follow current breaking-off type gas discharge tube can still bear multiple lightning strokes or overvoltage and fail.
The embodiment of the invention provides electronic equipment. On the basis of the above embodiment, with continued reference to fig. 5, the electronic device includes a circuit to be protected 200 and an overvoltage protection circuit 100 provided by any embodiment of the present invention.
The third terminal V3 of the overvoltage protection circuit 100 is grounded to PE; the first end V1 and the second end V2 of the overvoltage protection circuit 100 are electrically connected with the live line L and the neutral line N, respectively; the circuit to be protected 200 is electrically connected to the first terminal V1 and the second terminal V2 of the overvoltage protection circuit 100.
The overvoltage protection circuit 100 may be turned on to discharge the surge current when surge interference such as lightning strike or overvoltage occurs, so as to protect the circuit 200 to be protected. The electronic device may be, for example, a computer, a navigator, a camera, or the like in devices such as automotive electronics, communications, new energy, security, consumer electronics, industrial electronics, medical electronics, and the like. The electronic device provided by the embodiment of the present invention includes the overvoltage protection circuit in the above embodiment, and therefore, the electronic device provided by the embodiment of the present invention also has the beneficial effects described in the above embodiment, and details are not described herein again.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (10)

1. An overvoltage protection circuit, comprising: at least two of the first module, the second module and the third module, and an alarm circuit;
wherein the first module comprises:
a first voltage limiting device, a first end of the first voltage limiting device being electrically connected to a first end of the overvoltage protection circuit;
a first switching device, a second terminal of the first voltage limiting device being electrically connected to a second terminal of the overvoltage protection circuit via the first switching device;
the first input end of the first rectifying circuit is electrically connected with the second end of the first voltage limiting device; the second input end of the first rectifying circuit is electrically connected with the second end of the overvoltage protection circuit; the positive output end of the first rectifying circuit is electrically connected with the first end of the warning circuit; the negative electrode output end of the first rectifying circuit is electrically connected with the second end of the warning circuit;
the second module includes:
a second voltage limiting device, a first end of the second voltage limiting device being electrically connected to a first end of the overvoltage protection circuit;
a second switch-type device, wherein a second terminal of the second voltage-limiting device is electrically connected with a third terminal of the overvoltage protection circuit through the second switch-type device;
the first input end of the second rectifying circuit is electrically connected with the second end of the second voltage limiting device; a second input end of the second rectifying circuit is electrically connected with a second end of the overvoltage protection circuit; the positive output end of the second rectifying circuit is electrically connected with the first end of the warning circuit; the negative electrode output end of the second rectifying circuit is electrically connected with the second end of the warning circuit;
the third module includes:
a third voltage limiting device, a first end of the third voltage limiting device being electrically connected to a second end of the overvoltage protection circuit;
a third switching device, wherein a second terminal of the third voltage limiting device is electrically connected with a third terminal of the overvoltage protection circuit through the third switching device;
the first input end of the third rectifying circuit is electrically connected with the second end of the third voltage limiting device; the second input end of the third rectifying circuit is electrically connected with the first end of the overvoltage protection circuit; the positive output end of the third rectifying circuit is electrically connected with the first end of the warning circuit; and the negative electrode output end of the third rectifying circuit is electrically connected with the second end of the warning circuit.
2. The overvoltage protection circuit of claim 1, wherein the alarm circuit includes a first current limiting unit and a first alarm device,
the first current limiting unit is connected with the first warning device in series, and two ends of the first current limiting unit after being connected with the first warning device in series are respectively and electrically connected with the first end and the second end of the warning circuit.
3. The overvoltage protection circuit of claim 2, wherein the alarm circuit further comprises a first shunt device connected in parallel with the first alarm device.
4. The overvoltage protection circuit of claim 2, wherein the first current limiting unit comprises a first resistor and a zener diode, the first resistor, the zener diode and the first alarm device are connected in series, and two ends of the first resistor, the zener diode and the first alarm device after being connected in series are respectively electrically connected with a first end and a second end of the alarm circuit;
the first warning device comprises at least one of: a light emitting diode and a buzzer.
5. The overvoltage protection circuit of claim 2, further comprising: a second warning device and a second current limiting device; the second warning device is connected with the second current limiting device in series, and two ends of the second warning device, which are connected with the second current limiting device in series, are electrically connected with the first end and the second end of the overvoltage protection circuit respectively.
6. The overvoltage protection circuit of claim 5, wherein the second alarm device comprises a first light emitting diode, the overvoltage protection circuit further comprising: the first diode, the second warning device and the second current limiting device are connected in series, two ends of the first diode, the second warning device and the second current limiting device after being connected in series are respectively and electrically connected with a first end and a second end of the overvoltage protection circuit, and the first light emitting diode and the first diode are connected in series in the same direction.
7. The overvoltage protection circuit of claim 1, wherein the first rectification circuit comprises a rectifier bridge of four diodes; the second rectifying circuit comprises a rectifying bridge consisting of four diodes; the third rectifying circuit comprises a rectifying bridge consisting of four diodes;
the first voltage limiting device comprises at least one of: a varistor and a transient suppression diode; the first switching device comprises at least one of: a gas discharge tube and a semiconductor discharge tube; the second voltage limiting device comprises at least one of: a varistor and a transient suppression diode; the second switching device comprises at least one of: a gas discharge tube and a semiconductor discharge tube; the third voltage limiting device comprises at least one of: a varistor and a transient suppression diode; the third switching device comprises at least one of: a gas discharge tube and a semiconductor discharge tube;
the overvoltage protection circuit further includes a first overcurrent protection device,
wherein a first end of the overvoltage protection circuit is electrically connected with a first end of the first overcurrent protection device;
when the overvoltage protection circuit comprises a first module, the first end of the first voltage limiting device is electrically connected with the second end of the first overcurrent protection device;
when the overvoltage protection circuit comprises a second module, the first end of the second voltage limiting device is electrically connected with the second end of the first overcurrent protection device;
when the overvoltage protection circuit comprises a third module, the second input end of the third rectification circuit is electrically connected with the second end of the first overcurrent protection device.
8. The overvoltage protection circuit of claim 1, wherein when the overvoltage protection circuit includes a first module, the overvoltage protection circuit further includes a third current limiting device, the second input of the first rectification circuit is electrically connected to the second terminal of the overvoltage protection circuit via the third current limiting device, or the first input of the first rectification circuit is electrically connected to the second terminal of the first voltage limiting device via the third current limiting device;
when the overvoltage protection circuit comprises a second module, the overvoltage protection circuit further comprises a fourth current limiting device, and a second input end of the second rectifying circuit is electrically connected with a second end of the overvoltage protection circuit through the fourth current limiting device, or a first input end of the second rectifying circuit is electrically connected with a second end of the second voltage limiting device through the fourth current limiting device;
when the overvoltage protection circuit comprises a third module, the overvoltage protection circuit further comprises a fifth current limiting device, and the second input end of the third rectification circuit is electrically connected with the first end of the overvoltage protection circuit through the fifth current limiting device, or the first input end of the third rectification circuit is electrically connected with the second end of the third voltage limiting device through the fifth current limiting device.
9. The overvoltage protection circuit of claim 1, wherein when the overvoltage protection circuit includes a second module, the second switching device comprises an open-circuit failure gas discharge tube, the overvoltage protection circuit further comprising a first voltage divider device connected in parallel with the second switching device;
when the overvoltage protection circuit includes a third module, the third switching device includes an open failure type gas discharge tube, and the overvoltage protection circuit further includes a second voltage dividing device connected in parallel with the third switching device.
10. An electronic device comprising a circuit to be protected and an overvoltage protection circuit according to any one of claims 1 to 9,
the third end of the overvoltage protection circuit is grounded; the first end and the second end of the overvoltage protection circuit are respectively and electrically connected with the live wire and the zero line;
the circuit to be protected is electrically connected with the first end and the second end of the overvoltage protection circuit.
CN202011194095.7A 2020-10-30 2020-10-30 Overvoltage protection circuit and electronic equipment Pending CN112260248A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011194095.7A CN112260248A (en) 2020-10-30 2020-10-30 Overvoltage protection circuit and electronic equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011194095.7A CN112260248A (en) 2020-10-30 2020-10-30 Overvoltage protection circuit and electronic equipment

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Publication Number Publication Date
CN112260248A true CN112260248A (en) 2021-01-22

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CN202011194095.7A Pending CN112260248A (en) 2020-10-30 2020-10-30 Overvoltage protection circuit and electronic equipment

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Country Link
CN (1) CN112260248A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114221316A (en) * 2021-11-08 2022-03-22 浙江中控技术股份有限公司 Signal type surge protector and detection circuit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114221316A (en) * 2021-11-08 2022-03-22 浙江中控技术股份有限公司 Signal type surge protector and detection circuit
CN114221316B (en) * 2021-11-08 2024-02-20 中控技术股份有限公司 Signal type surge protector and detection circuit

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