CN202678958U - An overvoltage protecting circuit capable of maintaining states - Google Patents
An overvoltage protecting circuit capable of maintaining states Download PDFInfo
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- CN202678958U CN202678958U CN 201220354156 CN201220354156U CN202678958U CN 202678958 U CN202678958 U CN 202678958U CN 201220354156 CN201220354156 CN 201220354156 CN 201220354156 U CN201220354156 U CN 201220354156U CN 202678958 U CN202678958 U CN 202678958U
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- capacitor
- operational amplifier
- protecting
- resistance
- circuit
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Abstract
The utility model discloses an overvoltage protecting circuit capable of maintaining states. The overvoltage protecting circuit comprises a resistor R5, a resistor R6, a voltage-stabilizing tube DZ1, a diode D1, a capacitor C2, a capacitor C3, and an operational amplifier U1A. A first protecting-state-maintaining circuit is formed by the diode D1, the capacitor C2, and the resistor R6. At the moment when an input overvoltage arises, the protecting circuit is started and the protecting state lasts for some time so as to guarantee safety of post-stage circuits. In addition, a second protecting-state-maintaining circuit is formed by the capacitor C3 and the resistor R5. When protecting effect is activated, the first pin of the operational amplifier U1A outputs a high level to charge the capacitor C3. When a normal input voltage recovers, the capacitor C3 discharges through the resistor R5. Because of a long required discharging time, protecting state of the circuit still lasts for some time so as to guarantee stability of the protecting state and safety of post-stage circuits.
Description
Technical field
The utility model belongs to the overvoltage crowbar that keep in applying electronic circuit engineering field, particularly a kind of carrier state.
Background technology
At present, in many electronic products, all can use DC power supply, all need to design an overvoltage crowbar at the input of DC power supply, when preventing that input voltage is too high, power supply or load are caused damage, guarantee that the operating voltage of protected circuit is limited in the safe scope; In inverter, because input voltage can also prevent the storage battery overvoltage for the direct current that storage battery etc. provides, reach the purpose of protection battery.
Therefore the stability of protective circuit has directly determined reliability and the fail safe of electronic product.In the existing techniques in realizing method, much adopt specific overvoltage protection IC, controllable silicon etc. to realize over-voltage protecting function, but cost compare is high; Or adopt discrete component circuit to realize, and but there is not design protection state holding circuit, protective circuit stable bad understood the frequent movement that appearance is protected, and then can affect the reliability of product voltage protection point near.
Summary of the invention
The purpose of this utility model is in order to overcome the deficiencies in the prior art; the overvoltage crowbar that provides a kind of carrier state to keep; realize that by discrete component overvoltage protection and state keep, it have circuit simple, can avoid the characteristics such as frequent movement, protection good stability, the cost protected are low.
To achieve these goals, the technical solution adopted in the utility model is:
The overvoltage crowbar that a kind of carrier state is kept, comprise resistance R 5, resistance R 6, voltage-stabiliser tube DZ1, diode D1, capacitor C 2, capacitor C 3 and operational amplifier U1A, the anode of described voltage-stabiliser tube DZ1 is connected with an end of resistance R 5, the negative pole that the anode of diode D1 is connected with capacitor C respectively, and the positive pole of capacitor C 3 is connected with the output of operational amplifier U1A; The negative input termination reference voltage V ref of operational amplifier U1A, the positive supply termination power supply of operational amplifier U1A, the negative power end ground connection of operational amplifier U1A; Capacitor C 2 is connected respectively another common end grounding, the other end ground connection of resistance R 5 with resistance R 6 rear one of them common port in parallel with the negative electrode of diode D1, the positive input terminal of operational amplifier U1A.Wherein the negative electrode of voltage-stabiliser tube DZ1 links to each other with DC input voitage Vin.
Described capacitor C 3 is electrochemical capacitor.
The technical solution adopted in the utility model compared with prior art has following useful effect:
Moment of overvoltage appears in the first guard mode holding circuit that diode D1, capacitor C 2 and resistance R 6 form at input voltage, protective circuit will start and keep a period of time, to guarantee the safety of late-class circuit; In addition; form the second guard mode holding circuit by capacitor C 3 and resistance R 5; after protection is worked; operational amplifier U1A the 1st pin output will be high level, to capacitor C 3 chargings, after input voltage recovers normally; capacitor C 3 is by resistance R 5 discharges; because of the discharge required time longer so that the guard mode of circuit still can keep a period of time, with the safety of the stable and late-class circuit of guaranteeing guard mode.
Description of drawings
Fig. 1 is the circuit theory diagrams of the utility model specific embodiment.
Embodiment
Specific embodiment:
Embodiment of the present utility model as shown in Figure 1, the overvoltage crowbar that carrier state is kept, comprise resistance R 5, resistance R 6, voltage-stabiliser tube DZ1, diode D1, capacitor C 2, capacitor C 3 and operational amplifier U1A, the anode of described voltage-stabiliser tube DZ1 is connected with an end of resistance R 5, the negative pole that the anode of diode D1 is connected with capacitor C respectively, and the positive pole of capacitor C 3 is connected with the output of operational amplifier U1A; The negative input termination reference voltage V ref of operational amplifier U1A, the positive supply termination power supply of operational amplifier U1A, the negative power end ground connection of operational amplifier U1A; Capacitor C 2 is connected respectively another common end grounding, the other end ground connection of resistance R 5 with resistance R 6 rear one of them common port in parallel with the negative electrode of diode D1, the positive input terminal of operational amplifier U1A.Wherein capacitor C 3 of the present utility model is electrochemical capacitor.
The operation principle of the present embodiment:
As shown in Figure 1, when input voltage vin does not surpass the voltage stabilizing value of voltage-stabiliser tube DZ1, the reference voltage V ref of the 2nd pin negative input end of operational amplifier U1A is greater than the voltage of the 3rd pin positive input terminal of operational amplifier U1A, the 1st pin output output low level of operational amplifier U1A, protective circuit is not worked, the power supply normal operation;
When input voltage vin surpasses the voltage stabilizing value of voltage-stabiliser tube DZ1, voltage-stabiliser tube DZ1 will enter breakdown conditions, electric current charges to capacitor C 2 by voltage-stabiliser tube DZ1, diode D1, the voltage of operational amplifier U1A the 3rd pin positive input terminal is raise, when the voltage of operational amplifier U1A the 3rd pin positive input terminal during greater than reference voltage V ref, the 1st pin output output high level of operational amplifier U1A, protective circuit work, power cutoff; By the first guard mode holding circuit that diode D1, capacitor C 2, resistance R 6 form, the moment of overvoltage appears at input voltage, and protective circuit will start and keep a period of time, to guarantee the safety of late-class circuit; In addition; form the second guard mode holding circuit by capacitor C 3, resistance R 5; after protection is worked; operational amplifier U1A the 1st pin output will be high level, to capacitor C 3 chargings, after input voltage recovers normally; capacitor C 3 is by resistance R 5 discharges; because of the discharge required time longer so that the guard mode of circuit still can keep a period of time, with the safety of the stable and late-class circuit of guaranteeing guard mode.
The above; it only is the better specific embodiment of the utility model; but protection range of the present utility model is not limited to this; anyly be familiar with those skilled in the art in the scope that the utility model discloses; be equal to replacement or change according to the technical solution of the utility model, all belonged to protection range of the present utility model.
Claims (2)
1. overvoltage crowbar that carrier state is kept, it is characterized in that comprising resistance R 5, resistance R 6, voltage-stabiliser tube DZ1, diode D1, capacitor C 2, capacitor C 3 and operational amplifier U1A, the anode of described voltage-stabiliser tube DZ1 is connected with an end of resistance R 5, the negative pole that the anode of diode D1 is connected with capacitor C respectively, and the positive pole of capacitor C 3 is connected with the output of operational amplifier U1A; The negative input termination reference voltage V ref of operational amplifier U1A, the positive supply termination power supply of operational amplifier U1A, the negative power end ground connection of operational amplifier U1A; Capacitor C 2 is connected respectively another common end grounding, the other end ground connection of resistance R 5 with resistance R 6 rear one of them common port in parallel with the negative electrode of diode D1, the positive input terminal of operational amplifier U1A.
2. the overvoltage crowbar kept of described carrier state according to claim 1 is characterized in that described capacitor C 3 is electrochemical capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220354156 CN202678958U (en) | 2012-07-20 | 2012-07-20 | An overvoltage protecting circuit capable of maintaining states |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220354156 CN202678958U (en) | 2012-07-20 | 2012-07-20 | An overvoltage protecting circuit capable of maintaining states |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202678958U true CN202678958U (en) | 2013-01-16 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220354156 Expired - Fee Related CN202678958U (en) | 2012-07-20 | 2012-07-20 | An overvoltage protecting circuit capable of maintaining states |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202678958U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111193252A (en) * | 2020-01-21 | 2020-05-22 | 深圳市英德斯电子有限公司 | Overvoltage protection circuit and power input circuit of mainboard |
-
2012
- 2012-07-20 CN CN 201220354156 patent/CN202678958U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111193252A (en) * | 2020-01-21 | 2020-05-22 | 深圳市英德斯电子有限公司 | Overvoltage protection circuit and power input circuit of mainboard |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: GUANGDONG REAL-DESIGN INTELLIGENT TECHNOLOGY CO., Free format text: FORMER NAME: FOSHAN SHUNDE REALDESIGN ELECTRONICS INDUSTRY CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: 528300 Shunde, Guangdong, Daliang Industrial Park, Fengxiang, Xiang Xiang Road, No. 1 Patentee after: GUANGDONG REAL-DESIGN INTELLIGENT TECHNOLOGY CO., LTD. Address before: 528300 Shunde, Guangdong, Daliang Industrial Park, Fengxiang, Xiang Xiang Road, No. 1 Patentee before: Foshan Shunde Realdesign Electronics Industry Co., Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130116 Termination date: 20170720 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |