CN211456680U - Over-voltage and under-voltage protection device - Google Patents
Over-voltage and under-voltage protection device Download PDFInfo
- Publication number
- CN211456680U CN211456680U CN202020240604.4U CN202020240604U CN211456680U CN 211456680 U CN211456680 U CN 211456680U CN 202020240604 U CN202020240604 U CN 202020240604U CN 211456680 U CN211456680 U CN 211456680U
- Authority
- CN
- China
- Prior art keywords
- voltage
- unit
- output
- sampling
- input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The utility model discloses a cross undervoltage protection device, because the input at commercial power electric wire netting has set up the sampling comparison module, it samples the alternating voltage that the input was inputed, and detect sampling voltage, when detecting sampling voltage and being higher than or being less than preset reference voltage, turn-off output's relay, make the unable output of grid voltage, when detecting sampling voltage for presetting reference voltage, the relay of closed output, make grid voltage can export, the damage of grid voltage fluctuation to consumer has been avoided.
Description
Technical Field
The utility model relates to a power field, concretely relates to cross undervoltage protection device.
Background
In some places with poor power grids or without mains supply, the power grid voltage is unstable, the damage of the fluctuation of the power grid voltage to electric equipment is very large, and high-voltage surge in the fluctuation of the power grid voltage easily causes fatal and unrecoverable damage to the electric equipment, and the damage of the electric equipment has great influence on life of people, for example, an off-grid inverter which is frequently used in the case of poor power grids or without mains supply has very high dependence on the electric equipment, so that the electric equipment is very important to be protected from damage.
Disclosure of Invention
The invention mainly solves the technical problem of how to avoid the damage of the power grid voltage fluctuation to the electric equipment.
According to a first aspect, an embodiment provides an overvoltage and undervoltage protection device, including: the device comprises an input end, a surge absorption protection module, a sampling comparison module, a driving module, a control switch and an output end;
the input end of the sampling comparison module is connected with the input end and is used for sampling the alternating voltage input by the input end, detecting the sampling voltage and outputting a first signal when the sampling voltage is detected to be higher than or lower than a preset reference voltage; otherwise, outputting a second signal;
the input end of the driving module is connected with the output end of the sampling comparison module and is used for outputting a signal for turning off the control switch when the sampling comparison module outputs a first signal; when the sampling comparison module outputs a second signal, a signal for closing the control switch is output;
the input end of the surge absorption protection module is connected with the input end and used for attenuating the surge voltage to obtain a stable voltage and outputting the stable voltage when the surge voltage appears in the input voltage of the input end;
the first end of the control switch is connected with the output end of the surge absorption module, the second end of the control switch is connected with the output end, the control end of the control switch is connected with the output end of the driving module, and when the driving module outputs a signal for closing the control switch, the first end and the second end of the control switch are connected; and when the driving module outputs a signal for turning off the control switch, the first end and the second end of the control switch are disconnected.
Further, the surge absorption protection module includes: a first piezoresistor, a second piezoresistor, a third piezoresistor, a fourth piezoresistor, a fifth piezoresistor, a sixth piezoresistor and a gas discharge tube, the input end of the voltage-dependent resistor is connected with one end of the first piezoresistor, the other end of the first piezoresistor is connected with one end of the third piezoresistor, the other end of the third piezoresistor is connected with the ground, the second piezoresistor is connected in parallel with two ends of the first piezoresistor, the fourth piezoresistor is connected in parallel with two ends of the third piezoresistor, a node A is led out between the first piezoresistor and the third piezoresistor, the node A is connected with the input end of the gas discharge tube, the output end of the gas discharge tube is connected with the ground, one end of the fifth piezoresistor is connected with the input end, the other end of the fifth piezoresistor is connected with the ground, the sixth piezoresistor is connected in parallel with two ends of the fifth piezoresistor, and the voltage at two ends of the sixth piezoresistor is the stable voltage output by.
Further, the sample comparison module comprises: the device comprises a rectifier bridge unit, a first voltage attenuation unit, a first sampling unit, an overvoltage comparison unit, a second voltage attenuation unit, a second sampling unit, an undervoltage comparison unit and a feedback output unit;
the input end of the rectifier bridge unit is connected with the input end and is used for rectifying alternating current input by the input end into positive alternating current;
the input end of the first voltage attenuation unit is connected with the output end of the rectifier bridge unit and is used for attenuating the forward alternating voltage output by the rectifier bridge unit to a preset attenuation voltage; the input end of the first sampling unit is connected with the output end of the first voltage attenuation unit and is used for sampling a preset attenuation voltage; the first input end of the overvoltage comparison unit is connected with the output end of the first sampling unit, and the second input end of the overvoltage comparison unit inputs a preset reference voltage and is used for outputting a low-resistance signal when the sampled voltage is higher than the preset reference voltage; otherwise, outputting a high-impedance state signal; the input end of the feedback output unit is connected with the output end of the overvoltage comparison unit, and the feedback output unit is used for outputting a first signal when the overvoltage comparison unit outputs a low-impedance state signal, otherwise, outputting a second signal, and a feedback node is led out from the output end of the feedback output unit and connected with the second input end of the overvoltage comparison unit;
the input end of the second voltage attenuation unit is connected with the output end of the rectifier bridge unit and is used for attenuating the forward alternating voltage output by the rectifier bridge unit to a preset attenuation voltage; the input end of the second sampling unit is connected with the output end of the second voltage attenuation unit and is used for sampling a preset attenuation voltage; the first input end of the undervoltage comparison unit is connected with the output end of the second sampling unit, and the second input end of the undervoltage comparison unit inputs a preset reference voltage and is used for outputting a low-resistance signal when the sampled voltage is lower than the preset reference voltage; otherwise, outputting a high-impedance state signal; the input end of the feedback output unit is connected with the output end of the undervoltage comparison unit, and the feedback output unit is used for outputting a first signal when the undervoltage comparison unit outputs a low configuration signal, otherwise, outputting a second signal, and a feedback node is led out from the output end of the feedback output unit and connected with the second input end of the undervoltage comparison unit.
Furthermore, the first voltage attenuation unit and the second voltage attenuation unit are attenuation resistors, the input end of each attenuation resistor is connected with the output end of the rectifier bridge, and the output end of each attenuation resistor is connected with the first sampling unit or the second sampling unit.
Furthermore, the first sampling unit and the second sampling unit are sampling resistors, one end of each sampling resistor is connected with the output end of the attenuation resistor, the other end of each sampling resistor is connected with the ground, a sampling node is led out between each sampling resistor and the attenuation resistor, and the sampling node is connected with the overvoltage comparison unit or the undervoltage price comparison unit.
Further, the overvoltage comparing unit comprises a first comparator, the sampling node is connected with a first input end of the first comparator, a second input end of the first comparator inputs a preset reference voltage, and when the sampled voltage is higher than the preset reference voltage, an output end of the first comparator outputs a low-impedance signal; otherwise, outputting a high-impedance state signal; and a first feedback node is led out from the output end of the first comparator, and the first feedback node is connected with the first input end of the first comparator.
Further, the undervoltage comparison unit includes a second comparator, the sampling node is connected to a first input terminal of the second comparator, a second input terminal of the second comparator inputs a preset reference voltage, and when the sampled voltage is lower than the preset reference voltage, an output terminal of the second comparator outputs a low impedance state signal; otherwise, outputting a high-impedance state signal; a first feedback node is led out from the output end of the second comparator, and the first feedback node is connected with the first input end of the second comparator;
the output end of the first comparator and the output end of the second comparator are connected with a comparison output node.
Further, the feedback output unit includes a third comparator, the comparison output node is connected to a first input terminal of the third comparator, a preset reference voltage is input to a second input terminal of the third comparator, when the overvoltage comparison unit or the undervoltage comparison unit outputs a low impedance state signal, an output terminal of the third comparator outputs a first signal, otherwise, a second signal is output, a feedback node is led out from an output terminal of the third comparator, and the feedback node is connected to the second input terminal of the overvoltage comparison unit or the undervoltage comparison unit.
Further, the control switch is a relay.
The power supply module is connected with the input end and used for converting alternating-current voltage input by the input end into preset direct-current voltage.
According to the overvoltage and undervoltage protection device of the embodiment, the sampling comparison module is arranged at the input end of the mains supply power grid, the sampling comparison module samples the alternating voltage input by the input end and detects the sampling voltage, when the sampling voltage is detected to be higher than or lower than the preset reference voltage, the relay at the output end is turned off, the power grid voltage cannot be output, when the sampling voltage is detected to be the preset reference voltage, the relay at the output end is closed, the power grid voltage can be output, and the damage of power grid voltage fluctuation to electric equipment is avoided.
Drawings
FIG. 1 is a structural diagram of an over-voltage and under-voltage protection device;
FIG. 2 is a circuit diagram of a surge absorption module of an embodiment;
FIG. 3 is a circuit diagram of a sample comparison module of an embodiment;
FIG. 4 is a circuit diagram of a driver module according to an embodiment;
FIG. 5 is a circuit diagram of a power module of an embodiment;
FIG. 6 is a diagram of a prior art over-voltage and under-voltage protection device;
fig. 7 is a structural diagram of another overvoltage/undervoltage protection device in the prior art.
Detailed Description
The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.
Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.
The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).
In the prior art, for grid voltage fluctuation, software in a microprocessor is mostly adopted to control the turn-off and turn-on of a relay arranged at an output end, please refer to fig. 6, fig. 6 is a structure diagram of a overvoltage and undervoltage protection device in the prior art, the voltage of the input end of a grid is sampled through a voltage sampling circuit, the sampled voltage is input into the microprocessor, whether the fluctuation occurs or not is judged through the software in the microprocessor, if the fluctuation occurs, a magnetic latching relay is controlled to be turned off through a driving circuit, otherwise, the magnetic latching relay is turned on and is arranged at the output end, and after the fluctuation occurs, the output of the grid voltage is cut off. Because the software in the microprocessor is adopted to control the opening and closing of the magnetic latching relay, certain time delay is achieved, the risk of untimely protection exists for the severe mains supply environment with frequent power grid fluctuation, and the cost is high.
Referring to fig. 7, fig. 7 is a structural diagram of another overvoltage/undervoltage protection device in the prior art, which is implemented by arranging an automatic voltage regulator between an input end and an output end, and when voltage fluctuation (overvoltage or undervoltage) occurs at the input end, the output voltage at the output end is kept stable by automatically adjusting the turn ratio of a coil of the voltage regulator, and the automatic voltage regulator relates to a transformer, and has the advantages of large volume, high cost, slow response speed, limited voltage stabilization range, and no protection effect on the impact of instantaneous high voltage.
In this embodiment, the sampling comparison module has been connected on the input, the alternating voltage that inputs to the input samples, and detect sampling voltage, when detecting that sampling voltage is higher than or is less than preset reference voltage, export the signal that makes control switch disconnection to control switch's drive module, otherwise export the signal that makes control switch closed to control switch's drive module, control switch sets up at the output, when its turn-off, the unable output voltage of output, the influence of grid voltage fluctuation to output connection consumer has been avoided, and sampling comparison module passes through hardware circuit and realizes, no time delay and with low costs.
The first embodiment is as follows:
referring to fig. 1, fig. 1 is a structural diagram of an overvoltage and undervoltage protection device, which includes an input terminal 1, a surge absorption protection module 5, a sampling comparison module 2, a driving module 3, a control switch 4, and an output terminal 6;
the input end of the surge absorption protection module 5 is connected with the input end 1, and is used for attenuating the surge voltage to obtain a stable voltage when the surge voltage appears in the input voltage of the input end 1, and outputting the stable voltage. The input terminal 1 in this embodiment is a power grid input terminal, which includes a neutral line (N) and a live line (L).
Wherein the surge absorption module is shown in fig. 2, and comprises: a first varistor MOV1, a second varistor MOV2, a third varistor MOV3, a fourth varistor MOV4, a fifth varistor MOV5, a sixth varistor MOV6 and a GAS discharge tube GAS, wherein the input terminal 1 is connected with one terminal of the first varistor MOV1, the other terminal of the first varistor MOV1 is connected with one terminal of the third varistor MOV3, the other terminal of the third varistor MOV3 is connected with ground, the second varistor MOV2 is connected in parallel with both terminals of the first varistor MOV1, the fourth varistor MOV4 is connected in parallel with both terminals of the third varistor MOV3, a node A is led out between the first varistor 1 and the third varistor MOV3, the node A is connected with the input terminal of the GAS DAS, the output terminal of the GAS discharge tube GAS is connected with ground, one terminal of the fifth varistor MOV 636 is connected with the input terminal 1, the other terminal of the fifth varistor 3535357378 is connected with both terminals of the GAS discharge tube GND 6, the voltage across the sixth varistor MOV6 is the regulated voltage output by the surge absorption module 5. The voltage dependent resistor is a voltage limiting type protection device, which utilizes the nonlinear characteristic of the voltage dependent resistor, when the voltage at two ends of the voltage dependent resistor is higher, the resistance of the voltage dependent resistor becomes smaller in a certain range, so if the voltage at two ends of the first voltage dependent resistor MOV1 in the surge absorption module 2 is too high (positive overvoltage at the input end), the voltage dependent resistor discharges through the GAS discharge tube GAS, and if the voltage at two ends of the third voltage dependent resistor MOV3 is too high (negative overvoltage at the input end), the voltage dependent resistor discharges through the GAS discharge device GAS, so that when the voltage is input at the input end, the surge voltage is surge-attenuated to obtain a stable voltage.
The input end of the sampling comparison module 2 is connected with the input end 1 and is used for sampling the alternating-current voltage input by the input end, detecting the sampling voltage and outputting a first signal when the sampling voltage is detected to be higher than or lower than a preset reference voltage; otherwise, a second signal is output.
As shown in fig. 3, the sampling comparison module 2 includes: the voltage-stabilizing circuit comprises a rectifier bridge unit 201, a first voltage attenuation unit 202, a first sampling unit 203, an overvoltage comparison unit 204, a second voltage attenuation unit 206, a second sampling unit 207, an undervoltage comparison unit 208 and a feedback output unit 205;
the input end of the rectifier bridge unit 201 is connected with the input end 1, and is used for rectifying the alternating current input from the input end 1 into positive alternating current; in this embodiment, the input terminal 1 is a sine alternating current, and the alternating current is rectified to be a positive alternating current by the rectifier bridge unit 201.
The input end of the first voltage attenuation unit 202 is connected with the output end of the rectifier bridge unit and is used for attenuating the forward alternating voltage output by the rectifier bridge unit to a preset attenuation voltage; first voltage decay is singly for the decay resistance, the input of decay resistance links to each other with the output of rectifier bridge, the output of decay resistance links to each other with first sampling unit or second sampling unit, divide the voltage amplitude of input through the decay resistance in order to carry out the voltage decay, resistance R1 to resistance R5 are the decay resistance of overvoltage control comparison branch in fig. 3, resistance R15 to resistance R18 are the decay resistance of undervoltage control comparison branch, can establish ties the resistance of different resistances according to the voltage condition that needs the decay, this embodiment is equipped with the short circuit interface at resistance R5, R18's both ends, when not needing resistance R5, R18 to divide the voltage, carry out the short circuit with resistance R5, R18 through the short circuit interface.
The input end of the first sampling unit 203 is connected with the output end of the first voltage attenuation unit 202, and is used for sampling a preset attenuation voltage; after the voltage at the input end is subjected to voltage division and attenuation through the attenuation resistor, the sampling is performed through the sampling resistor, one end of the sampling resistor is connected with the output end of the attenuation resistor, the other end of the sampling resistor is connected with the ground, a sampling node is led out between the sampling resistor and the attenuation resistor, the sampling node is connected with the overvoltage comparison unit or the undervoltage comparison unit, in the diagram of fig. 3, R6 and R7 are sampling resistors of an overvoltage control comparison branch, and R19 and R20 are sampling resistors of an undervoltage control comparison branch.
In the overvoltage control comparison branch, a first input end of an overvoltage comparison unit 204 is connected with an output end of a first sampling unit 203, and a second input end of the overvoltage comparison unit 204 inputs a preset reference voltage VREF, so that a low-resistance signal is output when the sampled voltage is higher than the preset reference voltage VREF; otherwise, outputting a high-impedance state signal; the input end of the feedback output unit 205 is connected to the output end of the overvoltage comparing unit 204, and is configured to output a first signal at the output end of the feedback output unit 205 when the overvoltage comparing unit 204 outputs a low impedance state signal, or output a second signal, and a feedback node is led out from the output end of the feedback output unit 205, where the feedback node is connected to the second input end of the overvoltage comparing unit 204.
The overvoltage comparing unit 204 comprises a first comparator, the sampling node is connected with a first input end of the first comparator, a second input end of the first comparator inputs a preset reference voltage, and when the sampled voltage is higher than the preset reference voltage, an output end of the first comparator outputs a low-impedance signal; otherwise, outputting a high-impedance state signal; and a first feedback node is led out from the output end of the first comparator, and the first feedback node is connected with the first input end of the first comparator.
Similarly, in the under-voltage control comparison branch, the input end of the second voltage attenuation unit 206 is connected to the output end of the rectifier bridge unit 201, and is configured to attenuate the forward ac voltage output by the rectifier bridge unit 201 to a preset attenuation voltage; the input end of the second sampling unit 207 is connected to the output end of the second voltage attenuation unit 206, and is configured to sample a preset attenuation voltage; a first input end of the under-voltage comparison unit 208 is connected with an output end of the second sampling unit 207, and a second input end of the under-voltage comparison unit 208 inputs a preset reference voltage and is used for outputting a low-resistance state signal when the sampled voltage is lower than the preset reference voltage; otherwise, outputting a high-impedance state signal; the input end of the feedback output unit 205 is connected to the output end of the undervoltage comparison unit, and is configured to output a first signal at the output end of the feedback output unit 205 when the undervoltage comparison unit 208 outputs a low-resistance state signal, or output a second signal, and a feedback node is led out from the output end of the feedback output unit 205, and the feedback node is connected to the second input end of the undervoltage comparison unit 208.
The undervoltage comparison unit 208 includes a second comparator, the sampling node is connected to a first input terminal of the second comparator, a second input terminal of the second comparator inputs a preset reference voltage, and when the sampled voltage is lower than the preset reference voltage, an output terminal of the second comparator outputs a low impedance state signal; otherwise, outputting a high-impedance state signal; a first feedback node is led out from the output end of the second comparator, and the first feedback node is connected with the first input end of the second comparator; the output end of the first comparator and the output end of the second comparator are connected with a comparison output node.
Fig. 3 shows that the feedback node is connected to the under-voltage comparison unit 208 through a resistor R23 and a diode D3, and the connection between the feedback node and the over-voltage comparison unit 204 is the same as that of the under-voltage comparison unit 208 (not shown in fig. 3).
The feedback output unit 205 includes a third comparator, the comparison output node is connected to a first input terminal of the third comparator, a second input terminal of the third comparator inputs a preset reference voltage, when the overvoltage comparison unit 204 or the undervoltage comparison unit 208 outputs a low impedance state signal, an output terminal of the third comparator outputs a first signal, otherwise, a second signal is output, a feedback node is led out from an output terminal of the third comparator, and the feedback node is connected to the second input terminal of the overvoltage comparison unit or the undervoltage comparison unit.
The input end of the driving module 3 is connected with the output end of the sampling comparison module 2 and is used for outputting a signal for turning off the control switch 4 when the sampling comparison module 2 outputs a first signal; when the sampling comparison module 2 outputs a second signal, a signal for closing the control switch 4 is output; the specific circuit of the driving module 3 is shown in fig. 4, where RLY in fig. 4 is an output signal output by the driving module 3, if the output signal is a signal for turning off the control switch 4, the control switch is controlled to be turned off, and if the output signal is a signal for turning on the control switch 4, the control switch is controlled to be turned on.
The first end of the control switch 4 is connected with the output end of the surge absorption module 5, the second end of the control switch 4 is connected with the output end 6, the control end of the control switch 4 is connected with the output end of the driving module 3, when the driving module 3 outputs a signal for closing the control switch 4, the voltage input by the input end is stable, the first end and the second end of the control switch 4 are connected, and the output end 6 is connected with the surge absorption protection module 5; when the driving module 3 outputs a signal for turning off the control switch 4, the voltage input at the input end fluctuates at this time, and the first end and the second end of the control switch 4 are disconnected, so that the output end 6 is disconnected from the surge absorption protection module 5. The control switch 4 in this embodiment may be an electronic switch, such as a relay, which is controlled by high and low levels.
The present embodiment further includes a power module 7, wherein an input end of the power module 7 is connected to the input end 1, and is configured to convert an ac voltage input by the input end 1 into a preset dc voltage. The preset dc voltage in this embodiment is a dc voltage VCC and a preset reference voltage VREF required by the surge absorption module 5, the sampling comparison module 2, the driving module 3, and the control switch 4, and as shown in fig. 5, the ac voltage at the input terminal 1(N and L) is converted into VCC and VREF for output.
The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.
Claims (10)
1. An overvoltage and undervoltage protection device, comprising: the device comprises an input end, a surge absorption protection module, a sampling comparison module, a driving module, a control switch and an output end;
the input end of the sampling comparison module is connected with the input end and is used for sampling the alternating voltage input by the input end, detecting the sampling voltage and outputting a first signal when the sampling voltage is detected to be higher than or lower than a preset reference voltage; otherwise, outputting a second signal;
the input end of the driving module is connected with the output end of the sampling comparison module and is used for outputting a signal for turning off the control switch when the sampling comparison module outputs a first signal; when the sampling comparison module outputs a second signal, a signal for closing the control switch is output;
the input end of the surge absorption protection module is connected with the input end and used for attenuating the surge voltage to obtain a stable voltage and outputting the stable voltage when the surge voltage appears in the input voltage of the input end;
the first end of the control switch is connected with the output end of the surge absorption module, the second end of the control switch is connected with the output end, the control end of the control switch is connected with the output end of the driving module, and when the driving module outputs a signal for closing the control switch, the first end and the second end of the control switch are connected; and when the driving module outputs a signal for turning off the control switch, the first end and the second end of the control switch are disconnected.
2. The overvoltage and undervoltage protection device of claim 1, wherein the surge absorption protection module comprises: a first piezoresistor, a second piezoresistor, a third piezoresistor, a fourth piezoresistor, a fifth piezoresistor, a sixth piezoresistor and a gas discharge tube, the input end of the voltage-dependent resistor is connected with one end of the first piezoresistor, the other end of the first piezoresistor is connected with one end of the third piezoresistor, the other end of the third piezoresistor is connected with the ground, the second piezoresistor is connected in parallel with two ends of the first piezoresistor, the fourth piezoresistor is connected in parallel with two ends of the third piezoresistor, a node A is led out between the first piezoresistor and the third piezoresistor, the node A is connected with the input end of the gas discharge tube, the output end of the gas discharge tube is connected with the ground, one end of the fifth piezoresistor is connected with the input end, the other end of the fifth piezoresistor is connected with the ground, the sixth piezoresistor is connected in parallel with two ends of the fifth piezoresistor, and the voltage at two ends of the sixth piezoresistor is the stable voltage output by.
3. The under-voltage and overvoltage protection device of claim 1, wherein the sampling comparison module comprises: the device comprises a rectifier bridge unit, a first voltage attenuation unit, a first sampling unit, an overvoltage comparison unit, a second voltage attenuation unit, a second sampling unit, an undervoltage comparison unit and a feedback output unit;
the input end of the rectifier bridge unit is connected with the input end and is used for rectifying alternating current input by the input end into positive alternating current;
the input end of the first voltage attenuation unit is connected with the output end of the rectifier bridge unit and is used for attenuating the forward alternating voltage output by the rectifier bridge unit to a preset attenuation voltage; the input end of the first sampling unit is connected with the output end of the first voltage attenuation unit and is used for sampling a preset attenuation voltage; the first input end of the overvoltage comparison unit is connected with the output end of the first sampling unit, and the second input end of the overvoltage comparison unit inputs a preset reference voltage and is used for outputting a low-resistance signal when the sampled voltage is higher than the preset reference voltage; otherwise, outputting a high-impedance state signal; the input end of the feedback output unit is connected with the output end of the overvoltage comparison unit, and the feedback output unit is used for outputting a first signal when the overvoltage comparison unit outputs a low-impedance state signal, otherwise, outputting a second signal, and a feedback node is led out from the output end of the feedback output unit and connected with the second input end of the overvoltage comparison unit;
the input end of the second voltage attenuation unit is connected with the output end of the rectifier bridge unit and is used for attenuating the forward alternating voltage output by the rectifier bridge unit to a preset attenuation voltage; the input end of the second sampling unit is connected with the output end of the second voltage attenuation unit and is used for sampling a preset attenuation voltage; the first input end of the undervoltage comparison unit is connected with the output end of the second sampling unit, and the second input end of the undervoltage comparison unit inputs a preset reference voltage and is used for outputting a low-resistance signal when the sampled voltage is lower than the preset reference voltage; otherwise, outputting a high-impedance state signal; the input end of the feedback output unit is connected with the output end of the undervoltage comparison unit, and the feedback output unit is used for outputting a first signal when the undervoltage comparison unit outputs a low configuration signal, otherwise, outputting a second signal, and a feedback node is led out from the output end of the feedback output unit and connected with the second input end of the undervoltage comparison unit.
4. The overvoltage and undervoltage protection device of claim 3, wherein the first voltage attenuation unit and the second voltage attenuation unit are attenuation resistors, input ends of the attenuation resistors are connected with output ends of the rectifier bridge, and output ends of the attenuation resistors are connected with the first sampling unit or the second sampling unit.
5. The overvoltage and undervoltage protection device according to claim 4, wherein the first sampling unit and the second sampling unit are sampling resistors, one end of each sampling resistor is connected with the output end of the attenuation resistor, the other end of each sampling resistor is connected with the ground, a sampling node is led out between each sampling resistor and the attenuation resistor, and the sampling node is connected with the overvoltage comparing unit or the undervoltage comparing unit.
6. The overvoltage and undervoltage protection device of claim 5, wherein the overvoltage comparing unit comprises a first comparator, the sampling node is connected to a first input terminal of the first comparator, a second input terminal of the first comparator inputs a preset reference voltage, and when the sampled voltage is higher than the preset reference voltage, an output terminal of the first comparator outputs a low-impedance signal; otherwise, outputting a high-impedance state signal; and a first feedback node is led out from the output end of the first comparator, and the first feedback node is connected with the first input end of the first comparator.
7. The under-voltage and over-voltage protection device of claim 6, wherein the under-voltage comparison unit comprises a second comparator, the sampling node is connected to a first input terminal of the second comparator, a preset reference voltage is input to a second input terminal of the second comparator, and when the sampled voltage is lower than the preset reference voltage, an output terminal of the second comparator outputs a low impedance state signal; otherwise, outputting a high-impedance state signal; a first feedback node is led out from the output end of the second comparator, and the first feedback node is connected with the first input end of the second comparator;
the output end of the first comparator and the output end of the second comparator are connected with a comparison output node.
8. The over-voltage and under-voltage protection device of claim 7, wherein the feedback output unit comprises a third comparator, the comparison output node is connected to a first input terminal of the third comparator, a predetermined reference voltage is input to a second input terminal of the third comparator, when the over-voltage comparison unit or the under-voltage comparison unit outputs a low impedance state signal, an output terminal of the third comparator outputs the first signal, otherwise, a second signal is output, a feedback node is led out from an output terminal of the third comparator, and the feedback node is connected to the second input terminal of the over-voltage comparison unit or the under-voltage comparison unit.
9. The overvoltage and undervoltage protection device of claim 1, wherein the control switch is a relay.
10. The device according to any one of claims 1 to 9, further comprising a power module, wherein an input terminal of the power module is connected to the input terminal, and the power module is configured to convert an ac voltage input from the input terminal into a predetermined dc voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020240604.4U CN211456680U (en) | 2020-03-02 | 2020-03-02 | Over-voltage and under-voltage protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020240604.4U CN211456680U (en) | 2020-03-02 | 2020-03-02 | Over-voltage and under-voltage protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211456680U true CN211456680U (en) | 2020-09-08 |
Family
ID=72317197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020240604.4U Active CN211456680U (en) | 2020-03-02 | 2020-03-02 | Over-voltage and under-voltage protection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211456680U (en) |
-
2020
- 2020-03-02 CN CN202020240604.4U patent/CN211456680U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2469554B1 (en) | Hybrid switch circuit | |
| US8482885B2 (en) | Hybrid switch circuit | |
| US4396882A (en) | Inrush current limiter | |
| CA2833384C (en) | Voltage sag corrector using a variable duty cycle boost converter | |
| CN2552047Y (en) | Switch power with wide input voltage range | |
| EP2999075A1 (en) | Power supply with surge voltage protection | |
| US20060232906A1 (en) | Surge detector/counter | |
| CN104617571A (en) | Over-voltage over-current protector of electronic and electric equipment | |
| CN109245056A (en) | A kind of DC power source adapter protective device | |
| KR100657872B1 (en) | Temporary overvoltage test simulator of surge protective device and the control method | |
| CN201345530Y (en) | Current foldback circuit | |
| JPH08503357A (en) | Switching device | |
| CN211456680U (en) | Over-voltage and under-voltage protection device | |
| EP3499670A1 (en) | Crowbar overvoltage protection with current limiting function | |
| CN109217273B (en) | Non-delay anti-surge circuit for closing power switch | |
| CN112134267A (en) | Surge protection circuit, electromagnetic heating circuit and household appliance | |
| US9654022B2 (en) | Power conversion device and control method thereof | |
| CN204166072U (en) | Earthing detection equipment | |
| CN214069550U (en) | Overcurrent detection protection device for vehicle electrical equipment | |
| CN211127137U (en) | Direct current power supply positive and negative polarity universal device and charging equipment | |
| EP3284150B1 (en) | Voltage shunt regulator for the protection of an electrical load from overvoltages and voltage transients | |
| CN114649805A (en) | Accurate surge-impact-prevention input overvoltage protection circuit | |
| CN209250236U (en) | Surge protection circuit, circuit system and electronic equipment | |
| CN209250235U (en) | Surge protection circuit, circuit system and electronic equipment | |
| CN109994340A (en) | A repeat circuit and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |