CN212380941U - Overvoltage and surge protection circuit and electronic equipment - Google Patents
Overvoltage and surge protection circuit and electronic equipment Download PDFInfo
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- CN212380941U CN212380941U CN202021191179.0U CN202021191179U CN212380941U CN 212380941 U CN212380941 U CN 212380941U CN 202021191179 U CN202021191179 U CN 202021191179U CN 212380941 U CN212380941 U CN 212380941U
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Abstract
The utility model discloses an overvoltage and surge protection circuit, which relates to the technical field of electronic circuits and comprises a first end for receiving input voltage and a second end for generating output voltage, wherein the protection circuit comprises a voltage-regulator tube, a voltage-dividing circuit, a first electronic switch, a second electronic switch, a third resistor and a fourth resistor, and the positive electrode and the negative electrode of the voltage-regulator tube are respectively connected with the first end and the first end; the control end of the third electronic switch is connected to the first end through a voltage division circuit, the input end of the third electronic switch is connected to the control end of the second electronic switch, the control end of the second electronic switch is further connected to the first end through a third resistor, the input end of the second electronic switch is connected to the control end of the first electronic switch through a fourth resistor, and the input end and the output end of the first electronic switch are respectively connected to the first end and the second end. The utility model also discloses an electronic equipment. The utility model discloses the cost is lower relatively, can solve surge and overvoltage protection problem again.
Description
Technical Field
The embodiment of the utility model provides an relate to electronic circuit technical field, concretely relates to excessive pressure and surge protection circuit and electronic equipment.
Background
In the current electronic equipment, a common power signal is connected with an OVP device in series to prevent surge and abnormal high voltage from damaging the electronic equipment, but the OVP chip is relatively expensive and is not beneficial to reducing the product cost.
SUMMERY OF THE UTILITY MODEL
In order to overcome the defects of the prior art, the utility model aims to provide an overvoltage and surge protection circuit and electronic equipment, the cost is relatively low, and the problems of surge and overvoltage protection can be solved.
In a first aspect, an embodiment of the present invention provides an overvoltage and surge protection circuit, which has a first end for receiving an input voltage and a second end for generating an output voltage, the protection circuit includes a voltage regulator tube, a voltage dividing circuit, a first electronic switch, a second electronic switch, a third resistor, and a fourth resistor, an anode of the voltage regulator tube is grounded, and a cathode of the voltage regulator tube is connected to the first end; the control end of the third electronic switch is connected to the first end through a voltage division circuit, the input end of the third electronic switch is connected to the control end of the second electronic switch, the output end of the third electronic switch and the output end of the second electronic switch are grounded, one end of the third resistor is connected to the first end, the other end of the third resistor is connected to the control end of the second electronic switch, the input end of the second electronic switch is connected to the control end of the first electronic switch through a fourth resistor, and the input end and the output end of the first electronic switch are connected to the first end and the second end respectively.
In a preferred embodiment, the first electronic switch, the second electronic switch and the third electronic switch are any one of a triode, a MOS transistor, a relay and a thyristor.
In a preferred embodiment, the first electronic switch, the second electronic switch and the third electronic switch are a PMOS transistor Q1, an NMOS transistor Q2 and an NMOS transistor Q3, respectively; the control end, the input end and the output end of the first electronic switch respectively correspond to the grid electrode, the source electrode and the drain electrode of the PMOS tube Q1; the control end, the input end and the output end of the second electronic switch respectively correspond to the grid electrode, the drain electrode and the source electrode of the NMOS tube Q2; and the control end, the input end and the output end of the third electronic switch respectively correspond to the grid electrode, the drain electrode and the source electrode of the NMOS tube Q3.
In a preferred embodiment, the voltage dividing circuit includes a first resistor and a second resistor, one end of the first resistor and the second resistor connected in series is connected to the first end, the other end of the first resistor and the second resistor connected in series is grounded, and a control end of the third electronic switch is connected between the first resistor and the second resistor.
In a preferred embodiment, the protection circuit further comprises a filter circuit, one end of the filter circuit is connected between the output end and the second end of the first electronic switch, and the other end of the filter circuit is grounded.
In a preferred embodiment, the filter circuit includes one or more filter capacitors, and when a plurality of filter capacitors are used, one end of the filter capacitors connected in parallel is connected between the output end and the second end of the first electronic switch, and the other end of the filter capacitors connected in parallel is grounded.
In a second aspect, an embodiment of the present invention provides an electronic device, which includes a power source, an electronic device body and the first aspect of the present invention provides the overvoltage and surge protection circuit, wherein the first end is connected to the power source, and the second end is connected to the electronic device body.
Compared with the prior art, the embodiment of the utility model provides a realize overvoltage protection through the stabilivolt, realize surge protection through the cooperation of first electronic switch, second electronic switch and third electronic switch, realize that the cost is lower relatively, can solve surge and overvoltage protection problem again, but wide application carries out excessive pressure and surge protection to electronic equipment in the electronic equipment of arbitrary direct current power supply.
Drawings
Fig. 1 is a schematic diagram of an overvoltage and surge protection circuit according to a first embodiment.
Detailed Description
Embodiments of the present invention will be further described with reference to the accompanying drawings and specific embodiments, and it should be noted that, in the premise of no conflict, any combination between the embodiments or technical features described below may form a new embodiment. Except as specifically noted, the materials and equipment used in this example are commercially available.
The first embodiment is as follows:
referring to fig. 1, an overvoltage and surge protection circuit includes a first terminal for receiving an input voltage (denoted as Vin) and a second terminal for generating an output voltage (denoted as Vout), and the overvoltage and surge protection circuit mainly includes an overvoltage protection circuit and a surge protection circuit, wherein the surge protection circuit includes a voltage regulator D1, and the overvoltage protection circuit mainly includes a voltage divider circuit, a first electronic switch, a second electronic switch, a third resistor R3, and a fourth resistor R4.
The anode of the voltage regulator tube D1 is grounded, and the cathode of the voltage regulator tube D1 is connected to the first end. When the voltage at the first end is greater than the set OVP voltage, for example, when a surge greater than the OVP voltage occurs, the stabilivolt D1 clamps the voltage at the first end to about the OVP voltage, thereby playing a role in preventing the surge.
The control end of the third electronic switch is connected to the first end through a voltage division circuit, the input end of the third electronic switch is connected to the control end of the second electronic switch, the output end of the third electronic switch and the output end of the second electronic switch are both grounded, one end of a third resistor R3 is connected to the first end, the other end of the third resistor R3 is connected to the control end of the second electronic switch, the input end of the second electronic switch is connected to the control end of the first electronic switch through a fourth resistor R4, and the input end and the output end of the first electronic switch are respectively connected to the first end and the second end.
When an overvoltage occurs, the third electronic switch is switched on, so that the second electronic switch is not switched on, and the first electronic switch is also not switched on because the second electronic switch is not switched on, so that the port connection is formed between the first end and the second end. When the voltage is normal, the third electronic switch is not conducted, the second electronic switch is conducted, so that the first electronic switch is conducted, and a passage is formed between the first end and the second end.
Based on the logic, the first electronic switch, the second electronic switch and the third electronic switch are all any one of a triode, an MOS (metal oxide semiconductor) tube, a relay and a silicon controlled rectifier. For example, the first electronic switch is a PNP transistor, and the second electronic switch and the third electronic switch are NPN transistors.
In a preferred embodiment of the present invention, please refer to fig. 1, the first electronic switch, the second electronic switch and the third electronic switch are a PMOS transistor Q1, an NMOS transistor Q2 and an NMOS transistor Q3, respectively; the control end, the input end and the output end of the first electronic switch respectively correspond to the grid electrode, the source electrode and the drain electrode of the PMOS tube Q1; the control end, the input end and the output end of the second electronic switch respectively correspond to the grid electrode, the drain electrode and the source electrode of the NMOS tube Q2; the control end, the input end and the output end of the third electronic switch respectively correspond to the grid electrode, the drain electrode and the source electrode of the NMOS tube Q3.
The voltage dividing circuit may adopt a resistance voltage dividing manner, for example, the voltage dividing circuit includes a first resistor R1 and a second resistor R2, the first resistor R1 and the second resistor R2 are connected in series, a gate of the NMOS transistor Q3 is connected between the first resistor R1 and the second resistor R2, the other end of the first resistor R1 is connected to the first end, and the other end of the second resistor R2 is grounded.
In addition, a filter circuit may be disposed at each of the first terminal and the second terminal for filtering out ripples in the circuit, for example, a filter capacitor C1 is disposed at the second terminal, one terminal of the filter capacitor C1 is connected between the drains of the PMOS transistors Q1, and the other terminal of the filter capacitor C1 is grounded.
Taking OVP voltage of 7.5V as an example, the turn-on voltages of PMOS transistor Q1, NMOS transistor Q2 and NMOS transistor Q3 are set to-1.5V, 1.5V and 1.5V, respectively. The resistances of the resistors R1, R2, R3 and R4 are 300K Ω, 75K Ω, 10K Ω and 1K Ω respectively, the capacitance of the filter capacitor C1 is 2.2UF, and the clamping voltage of the voltage regulator tube D1 is 7.5V.
When the device normally operates, for example, the input voltage Vin at the first end is 5V, at this time, Vgs of the NMOS transistor Q3 is subjected to resistance voltage division through the resistors R1 and R2 to obtain 5 × 75/(300+75) ═ 1V, and the turn-on voltage of the NMOS transistor Q3 is not reached, so that the NMOS transistor Q3 is not turned on; at this time, Vgs of the NMOS transistor Q2 is 5V, which is greater than its on-state voltage by 1.5V, so the NMOS transistor Q2 is turned on; since the NMOS transistor Q2 is turned on, the gate voltage of the PMOS transistor Q1 is 0V, and Vgs of the PMOS transistor Q1 is-5V, which is smaller than the on voltage of-1.5V, the PMOS transistor Q1 is turned on, and the input voltage Vout is equal to Vin and equal to 5V.
When an abnormal condition occurs, Vin inputs a high voltage, and Vin input voltage is higher than a set OVP voltage, that is, when Vin input is higher than 7.5V, the NMOS transistor Q3 is turned on, and at the same time, the gate voltage of the NMOS transistor Q2 is 0V, the NMOS transistor Q2 is not turned on, the PMOS transistor Q1 is not turned on, so that Vout is 0V. The overvoltage protection function is realized.
Because the clamping voltage of the voltage regulator tube D1 is 7.5V, when a surge exceeding 7.5V occurs, the voltage regulator tube D1 clamps the voltage at about 7.5V, and the logic circuit in the figure 1 is combined to effectively protect the following devices from being damaged.
The parameters of the above devices can be matched according to design requirements, and the applicable circuit voltage is not limited to the assumed parameter value.
Example two:
the second embodiment discloses an electronic device, which may be any terminal device powered by dc power, such as a notebook computer, a tablet computer, a mobile phone, and the like. The electronic equipment comprises a power supply, an overvoltage and surge protection circuit and an electronic equipment body, wherein the power supply can be a direct-current power supply or an alternating-current power supply subjected to rectification conversion, limitation is not required, only the direct-current voltage output by the power supply is ensured, the output end of the power supply is connected to the first end of the overvoltage and surge protection circuit, the second end of the overvoltage and surge protection circuit is connected to the power supply end of the electronic equipment body, and the power supply supplies power to the electronic equipment body through the overvoltage and surge protection circuit. In addition, the electronic device further includes some necessary components, such as a PCB board for mounting components of the overvoltage and surge protection circuit, and a housing for mounting the electronic device body, the PCB board, the output interface, the indicator light, the display screen, and the like.
The above embodiments are only preferred embodiments of the present invention, and the protection scope of the embodiments of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the embodiments of the present invention are all within the protection scope of the embodiments of the present invention.
Claims (7)
1. An overvoltage and surge protection circuit is provided with a first end for receiving input voltage and a second end for generating output voltage, and is characterized in that the protection circuit comprises a voltage-regulator tube, a voltage-dividing circuit, a first electronic switch, a second electronic switch, a third resistor and a fourth resistor, wherein the anode of the voltage-regulator tube is grounded, and the cathode of the voltage-regulator tube is connected to the first end; the control end of the third electronic switch is connected to the first end through a voltage division circuit, the input end of the third electronic switch is connected to the control end of the second electronic switch, the output end of the third electronic switch and the output end of the second electronic switch are grounded, one end of the third resistor is connected to the first end, the other end of the third resistor is connected to the control end of the second electronic switch, the input end of the second electronic switch is connected to the control end of the first electronic switch through a fourth resistor, and the input end and the output end of the first electronic switch are connected to the first end and the second end respectively.
2. The protection circuit of claim 1, wherein the first electronic switch, the second electronic switch, and the third electronic switch are any one of a triode, a MOS transistor, a relay, and a thyristor.
3. The protection circuit of claim 2, wherein the first electronic switch, the second electronic switch, and the third electronic switch are a PMOS transistor Q1, an NMOS transistor Q2, and an NMOS transistor Q3, respectively; the control end, the input end and the output end of the first electronic switch respectively correspond to the grid electrode, the source electrode and the drain electrode of the PMOS tube Q1; the control end, the input end and the output end of the second electronic switch respectively correspond to the grid electrode, the drain electrode and the source electrode of the NMOS tube Q2; and the control end, the input end and the output end of the third electronic switch respectively correspond to the grid electrode, the drain electrode and the source electrode of the NMOS tube Q3.
4. The protection circuit according to any one of claims 1 to 3, wherein the voltage divider circuit includes a first resistor and a second resistor, one end of the first resistor and the second resistor connected in series is connected to the first end, the other end of the first resistor and the second resistor connected in series is grounded, and a control end of the third electronic switch is connected between the first resistor and the second resistor.
5. The protection circuit according to any one of claims 1 to 3, further comprising a filter circuit, one end of the filter circuit being connected between the output terminal and the second terminal of the first electronic switch, the other end of the filter circuit being connected to ground.
6. The protection circuit of claim 5, wherein the filter circuit comprises one or more filter capacitors, and when a plurality of filter capacitors are used, one end of the filter capacitors connected in parallel is connected between the output end and the second end of the first electronic switch, and the other end of the filter capacitors connected in parallel is grounded.
7. An electronic device comprising a power source, an electronic device body, and the protection circuit of any one of claims 1 to 6, wherein the first terminal is connected to the power source, and the second terminal is connected to the electronic device body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021191179.0U CN212380941U (en) | 2020-06-23 | 2020-06-23 | Overvoltage and surge protection circuit and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021191179.0U CN212380941U (en) | 2020-06-23 | 2020-06-23 | Overvoltage and surge protection circuit and electronic equipment |
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| CN212380941U true CN212380941U (en) | 2021-01-19 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113872147A (en) * | 2021-11-10 | 2021-12-31 | 珠海格力智能装备有限公司 | Overvoltage protection circuit and controller with same |
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- 2020-06-23 CN CN202021191179.0U patent/CN212380941U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113872147A (en) * | 2021-11-10 | 2021-12-31 | 珠海格力智能装备有限公司 | Overvoltage protection circuit and controller with same |
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