CN102104248A - Overvoltage protection circuit and method thereof - Google Patents
Overvoltage protection circuit and method thereof Download PDFInfo
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- CN102104248A CN102104248A CN2009101890298A CN200910189029A CN102104248A CN 102104248 A CN102104248 A CN 102104248A CN 2009101890298 A CN2009101890298 A CN 2009101890298A CN 200910189029 A CN200910189029 A CN 200910189029A CN 102104248 A CN102104248 A CN 102104248A
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- 238000000034 method Methods 0.000 title claims abstract description 15
- 230000015556 catabolic process Effects 0.000 claims abstract description 13
- 230000000087 stabilizing effect Effects 0.000 claims description 31
- 230000001681 protective effect Effects 0.000 claims description 4
- 239000003990 capacitor Substances 0.000 claims description 2
- 238000001514 detection method Methods 0.000 abstract description 2
- 239000013078 crystal Substances 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 8
- 238000012544 monitoring process Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
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Abstract
The present invention provides an overvoltage protection circuit comprising at least one overvoltage test point and one electrical level output terminal, wherein the overvoltage test point is used for acquiring a magnitude of voltage of a protected circuit and the electrical level output terminal is used for outputting control level to a power supply module. The overvoltage protection circuit also comprises a divider resistor which is used for adjusting a control voltage value, wherein one end of the divider resistor is connected with the overvoltage test point and the other end is connected with a Zener diode which is conducted by means of a breakdown when the detected magnitude of voltage reaches the control voltage value, wherein the Zener diode is connected with a positively biased conducting base electrode of a triode when the diode is conducted, wherein, the triode is connected with the electrical level output terminal. Correspondingly, the embodiment of the present invention also discloses another overvoltage protection circuit and an overvoltage protection method of a circuit. The implementation of the invention can reduce the cost of circuit through a overvoltage detection protection circuit with flexible discrete component by means of utilizing conducting features of a Zener diode and a crystal triode.
Description
Technical field
The present invention relates to the applying electronic circuit field, relate in particular to a kind of overvoltage crowbar and method.
Background technology
Circuit in a lot of electronic products all is to use positive-negative power supply, for example the field scan surface-mounted integrated circuit (integrated circuit, IC) and audio frequency power amplifier IC etc. all be to use the positive-negative power supply of symmetry.If the undesired output voltage that causes of power work is too high, just might damage these circuit or IC, in order to prevent the generation of this class phenomenon, will increase overvoltage detection defencive function to these circuit and IC.
The effect of overvoltage crowbar is: the operating voltage that guarantees protected circuit is limited in the scope of safety value; when device power supply (DPS) inside modules voltage stabilizing loop breaks down or because user's misoperation when causing that the overvoltage phenomenon appears in protected circuit; overvoltage crowbar is controlled, and for example cuts off power supply to protected circuit to prevent damage equipment.
Specific overvoltage protection IC, the controllable silicons etc. of adopting realize that overvoltage detects defencive function more in now a lot of electronic products, but cost is than higher.And voltage starts to control a little fixing, in some specific voltage protection is used, and can not flexible Application.
Summary of the invention
In view of this, the embodiment of the invention provides a kind of overvoltage crowbar and method, can realize the overvoltage protection of circuit flexibly by discrete component.
The embodiment of the invention provides a kind of overvoltage crowbar, comprises that at least one is used to obtain overvoltage test point and a level output end that is used for to power module output control level of protected circuit voltage value, also comprises:
One is used to regulate the divider resistance that starts to control magnitude of voltage, described divider resistance one end links to each other with the overvoltage test point, the other end is connected to a voltage stabilizing didoe that is used for reaching when tested magnitude of voltage breakdown and then conducting when starting to control magnitude of voltage, described voltage stabilizing didoe is connected to a base stage that is used for the triode of positively biased conducting when described diode current flow, and described triode links to each other with described level output end.
The embodiment of the invention also provides another kind of overvoltage crowbar; comprise that two are respectively applied for positive negative overpressure test point and level output end that is used for to power module output control level that obtains circuit-under-test generating positive and negative voltage value; it is characterized in that described overvoltage crowbar comprises:
Being used to regulate first divider resistance that starts to control positive voltage value links to each other with positive overvoltage test point, the other end of described first divider resistance is connected to negative pole one end that is used for reaching when tested positive voltage value first voltage stabilizing didoe of breakdown and then conducting when starting to control positive voltage value, the positive pole of described first voltage stabilizing didoe is connected to the base stage of first triode, and the collector electrode of described first triode links to each other with described level output end;
Being used to regulate second divider resistance that starts to control negative value links to each other with the negative overpressure test point, the other end of described second divider resistance is connected to positive pole one end that is used for reaching when tested negative value second voltage stabilizing didoe of breakdown and then conducting when starting to control negative value, the negative pole of described second voltage stabilizing didoe is connected to the base stage of second triode, and the emitter of described second triode links to each other with described level output end.
Correspondingly the embodiment of the invention also provides a kind of over-voltage protection method of circuit, and the over-voltage protection method of described circuit comprises:
With circuit-under-test voltage by adjustable divider resistance dividing potential drop after, be input to voltage stabilizing didoe;
When the magnitude of voltage that is input to described voltage stabilizing didoe reaches when starting to control magnitude of voltage, described voltage stabilizing didoe is punctured and conducting;
The voltage of voltage regulation of described diode output is exported to transistor base, with described triode conducting;
Reduce the voltage of the level output end that links to each other with described triode by the triode of described conducting, thereby change the control level of described level output end to power module output.
The embodiment of the invention has realized detecting protective circuit by discrete component overvoltage flexibly by utilizing the on state characteristic of voltage stabilizing didoe and transistor, has saved circuit cost and expense.
Description of drawings
Fig. 1 is that the work system structure of a kind of overvoltage crowbar in the embodiment of the invention is formed schematic diagram;
Fig. 2 is that the structure of a kind of overvoltage crowbar in the embodiment of the invention is formed schematic diagram;
Fig. 3 is that the structure of another kind of overvoltage crowbar in the embodiment of the invention is formed schematic diagram;
Fig. 4 is that the structure of a kind of overvoltage crowbar of positive and negative pair of voltage in the embodiment of the invention is formed schematic diagram;
Fig. 5 is the schematic flow sheet of a kind of over-voltage protection method of circuit in the embodiment of the invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.
Fig. 1 is that the work system structure of a kind of overvoltage crowbar in the embodiment of the invention is formed schematic diagram, comprises power module 10, protected circuit 20 and overvoltage crowbar 30 as shown in the figure:
Fig. 2 is that the structure of a kind of overvoltage crowbar in the embodiment of the invention is formed schematic diagram; as shown in the figure; this circuit comprises the positive overvoltage test point V++ and the level output end CTL who is used for to power module output control level that are used to obtain protected circuit positive voltage value, also comprises:
A divider resistance R3 who is used to regulate start to control magnitude of voltage, divider resistance R3 one end links to each other with overvoltage test point V++, the other end is connected to a negative pole that is used for reaching when tested magnitude of voltage the voltage stabilizing didoe VD1 of breakdown and then conducting when starting to control magnitude of voltage, the positive pole of VD1 is connected to a base stage that is used for the triode V1 of positively biased conducting when described diode current flow, and the collector electrode of V1 links to each other with described level output end CTL.R1, R2 are the biasing resistor of V1.
Concrete; when the V++ that gets access to when the overvoltage test point reaches and starts to control magnitude of voltage; VD1 is breakdown; the pressure reduction of V1 base stage and emitter surpasses bias voltage; the V1 conducting is that electric current flows into emitter from collector electrode, thereby has reduced the pressure drop of level output end CTL, and CTL is to the power module output low level; after power module got access to this low level control level, reduction or shutoff were to the power supply output of protected circuit.
Further, by regulating the resistance value of divider resistance R3, can the flexible overvoltage crowbar start to control magnitude of voltage.
Fig. 3 is that the structure of another kind of overvoltage crowbar in the embodiment of the invention is formed schematic diagram; as shown in the figure; this circuit comprises the negative overpressure test point V--and the level output end CTL who is used for to power module output control level that are used to obtain protected circuit negative value, also comprises:
A divider resistance R3 who is used to regulate start to control magnitude of voltage, the divider resistance R3 one end V--that links to each other with overvoltage test point V--, the other end is connected to a positive pole that is used for reaching when tested magnitude of voltage the voltage stabilizing didoe VD2 of breakdown and then conducting when starting to control magnitude of voltage, the negative pole of VD2 is connected to a base stage that is used for the triode V2 of positively biased conducting when described diode current flow, and the emitter of V2 links to each other with described level output end CTL.R1, R2 are the biasing resistor of V2.
Concrete; when the V--that gets access to when the overvoltage test point reaches and starts to control magnitude of voltage; VD2 is breakdown; the pressure reduction of V2 emitter and base stage surpasses bias voltage; the V2 conducting is that electric current flows into collector electrode from emitter, thereby has reduced the pressure drop of level output end CTL, and CTL is to the power module output low level; after power module got access to this low level control level, reduction or shutoff were to the power supply output of protected circuit.
Further, by regulating the resistance value of divider resistance R3, can the flexible overvoltage crowbar start to control magnitude of voltage.
Fig. 4 is that the structure of a kind of overvoltage crowbar of positive and negative pair of voltage in the embodiment of the invention is formed schematic diagram, and as shown in the figure, this circuit comprises:
Comprise that two are respectively applied for positive negative overpressure test point V++ and V--, level output end CTL who is used for to power module output control level who obtains circuit-under-test generating positive and negative voltage value, is characterized in that described overvoltage crowbar comprises:
Be used to regulate the divider resistance R4 and the R5 that start to control positive voltage value, R4 one end links to each other with a current-limiting circuit that comprises a current limliting diode VD1 and a shunt capacitance C1, the described current-limiting circuit other end links to each other with positive overvoltage test point V++, R5 one end ground connection, the other end of R4 and R5 together is connected to negative pole one end that is used for reaching when tested positive voltage value the voltage stabilizing didoe VD2 of breakdown and then conducting when starting to control positive voltage value, the positive pole of VD2 is connected to the base stage of triode V1, the collector electrode of V1 links to each other grounded emitter through R1 with described level output end CTL;
Be used to regulate the divider resistance R2 and the R3 that start to control negative value, R2 one end links to each other with negative overpressure test point V--, the end ground connection of R3, the other end of R2 and R3 together is connected to positive pole one end that is used for reaching when tested negative value the voltage stabilizing didoe VD3 of breakdown and then conducting when starting to control negative value, the negative pole of VD3 is connected to the base stage of triode V2, and the emitter of V2 links to each other with described level output end CTL.
Being somebody's turn to do protective circuit further can also comprise; R6, R7 are respectively the biasing resistor of triode V1 and triode V2, and C2, C3, C4, C5 are the filter capacitor of overvoltage crowbar.Circuit can be by changing the resistance value of R4, R5 and R2, R3, regulates the magnitude of voltage that starts to control that can make V++ that voltage stabilizing didoe VD2 and VD3 puncture and V--respectively.
Circuit theory is with the description of Fig. 2 and Fig. 3, and when arbitrary voltage among V++ or the V--reaches when starting to control magnitude of voltage, circuit all can be to the power module output low level, thereby power module is reduced or turn-offs power supply output to protected circuit.
Fig. 5 is the schematic flow sheet of a kind of over-voltage protection method of circuit in the embodiment of the invention, and as shown in the figure, this method comprises:
Step S10, with circuit-under-test voltage by adjustable divider resistance dividing potential drop after, be input to voltage stabilizing didoe;
Step S20 when the magnitude of voltage that is input to described voltage stabilizing didoe reaches when starting to control magnitude of voltage, punctures described voltage stabilizing didoe and conducting;
Step S30 exports to transistor base with the voltage of voltage regulation of described diode output, with described triode conducting;
Step S40 reduces the voltage of the level output end that links to each other with described triode by the triode of described conducting, thereby changes the control level of described level output end to power module output.
Further, the over-voltage protection method of described circuit can also comprise: start to control magnitude of voltage by the resistance setting that described divider resistance is set.
The embodiment of the invention has realized detecting protective circuit by discrete component overvoltage flexibly by utilizing the on state characteristic of voltage stabilizing didoe and transistor, has saved circuit cost and expense.
Above disclosed is preferred embodiment of the present invention only, can not limit the present invention's interest field certainly with this, and therefore the equivalent variations of doing according to claim of the present invention still belongs to the scope that the present invention is contained.
Claims (7)
1. overvoltage crowbar comprises that at least one is used to obtain overvoltage test point and a level output end that is used for to power module output control level of protected circuit voltage value, is characterized in that described overvoltage crowbar comprises:
One is used to regulate the divider resistance that starts to control magnitude of voltage, described divider resistance one end links to each other with the overvoltage test point, the other end is connected to a voltage stabilizing didoe that is used for reaching when tested magnitude of voltage breakdown and then conducting when starting to control magnitude of voltage, described voltage stabilizing didoe is connected to a base stage that is used for the triode of positively biased conducting when described diode current flow, and described triode links to each other with described level output end.
2. overvoltage crowbar as claimed in claim 1; it is characterized in that; when described overvoltage test point was used to obtain protected circuit positive voltage value, negative pole one end of described voltage stabilizing didoe linked to each other with described divider resistance, and the collector electrode of described triode links to each other with described level output end.
3. overvoltage crowbar as claimed in claim 1; it is characterized in that; when described overvoltage test point was used to obtain protected circuit negative value, positive pole one end of described voltage stabilizing didoe linked to each other with described divider resistance, and the emitter of described triode links to each other with described level output end.
4. positive and negative overvoltage crowbar comprises that two are respectively applied for positive negative overpressure test point and level output end that is used for to power module output control level that obtains circuit-under-test generating positive and negative voltage value, is characterized in that described overvoltage crowbar comprises:
Being used to regulate first divider resistance that starts to control positive voltage value links to each other with positive overvoltage test point, the other end of described first divider resistance is connected to negative pole one end that is used for reaching when tested positive voltage value first voltage stabilizing didoe of breakdown and then conducting when starting to control positive voltage value, the positive pole of described first voltage stabilizing didoe is connected to the base stage of first triode, and the collector electrode of described first triode links to each other with described level output end;
Being used to regulate second divider resistance that starts to control negative value links to each other with the negative overpressure test point, the other end of described second divider resistance is connected to positive pole one end that is used for reaching when tested negative value second voltage stabilizing didoe of breakdown and then conducting when starting to control negative value, the negative pole of described second voltage stabilizing didoe is connected to the base stage of second triode, and the emitter of described second triode links to each other with described level output end.
5. as each described overvoltage crowbar among the claim 1-4, it is characterized in that described overvoltage crowbar also comprises some filter capacitors and at least one protective circuit.
6. the over-voltage protection method of a circuit is characterized in that, the over-voltage protection method of described circuit comprises:
With circuit-under-test voltage by adjustable divider resistance dividing potential drop after, be input to voltage stabilizing didoe;
When the magnitude of voltage that is input to described voltage stabilizing didoe reaches when starting to control magnitude of voltage, described voltage stabilizing didoe is punctured and conducting;
The voltage of voltage regulation of described diode output is exported to transistor base, with described triode conducting;
Reduce the voltage of the level output end that links to each other with described triode by the triode of described conducting, thereby change the control level of described level output end to power module output.
7. the over-voltage protection method of circuit as claimed in claim 6 is characterized in that, the over-voltage protection method of described circuit also comprises:
Start to control magnitude of voltage by the resistance setting that described divider resistance is set.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009101890298A CN102104248A (en) | 2009-12-17 | 2009-12-17 | Overvoltage protection circuit and method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009101890298A CN102104248A (en) | 2009-12-17 | 2009-12-17 | Overvoltage protection circuit and method thereof |
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| CN102104248A true CN102104248A (en) | 2011-06-22 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2009101890298A Pending CN102104248A (en) | 2009-12-17 | 2009-12-17 | Overvoltage protection circuit and method thereof |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102709870A (en) * | 2012-06-13 | 2012-10-03 | 青岛海信电器股份有限公司 | Power supply protection circuit and electronic product |
| EP3399616A1 (en) * | 2017-05-05 | 2018-11-07 | Hamilton Sundstrand Corporation | Ground/voltage open input |
| US11084050B2 (en) | 2017-04-03 | 2021-08-10 | Delavan Inc. | Pulsed spraybar injector |
| CN113533898A (en) * | 2021-07-23 | 2021-10-22 | 中国振华集团永光电子有限公司（国营第八七三厂） | Batch photoelectric coupler aging circuit |
-
2009
- 2009-12-17 CN CN2009101890298A patent/CN102104248A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102709870A (en) * | 2012-06-13 | 2012-10-03 | 青岛海信电器股份有限公司 | Power supply protection circuit and electronic product |
| US11084050B2 (en) | 2017-04-03 | 2021-08-10 | Delavan Inc. | Pulsed spraybar injector |
| US11738356B2 (en) | 2017-04-03 | 2023-08-29 | Collins Engine Nozzles, Inc. | Pulsed spraybar injector |
| EP3399616A1 (en) * | 2017-05-05 | 2018-11-07 | Hamilton Sundstrand Corporation | Ground/voltage open input |
| US10476256B2 (en) | 2017-05-05 | 2019-11-12 | Hamilton Sundstrand Corporation | Ground/voltage open input |
| CN113533898A (en) * | 2021-07-23 | 2021-10-22 | 中国振华集团永光电子有限公司（国营第八七三厂） | Batch photoelectric coupler aging circuit |
| CN113533898B (en) * | 2021-07-23 | 2023-07-14 | 中国振华集团永光电子有限公司（国营第八七三厂） | Aging circuit of batch photoelectric coupler |
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Application publication date: 20110622 |