CN102709873B - Overvoltage protection device of electronic circuit - Google Patents
Overvoltage protection device of electronic circuit Download PDFInfo
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- CN102709873B CN102709873B CN201210191700.4A CN201210191700A CN102709873B CN 102709873 B CN102709873 B CN 102709873B CN 201210191700 A CN201210191700 A CN 201210191700A CN 102709873 B CN102709873 B CN 102709873B
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- overvoltage protection
- electronic circuit
- triode
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Abstract
The invention discloses an overvoltage protection device of an electronic circuit. The overvoltage protection device of the electronic circuit is characterized by comprising a resistor, a diode, a triode, a first pin, a second pin and a third pin, wherein the first pine, the resistor and the diode are connected in series and then are connected with the base electrode of the triode; the emitting electrode of the triode is connected with the third pin; the third pin is grounded; the collecting electrode of the triode or a composite tube is connected with the second pin; the second pin is connected with the power end of the electronic circuit; and the first pin is connected with the direct power end of a protected device in the electronic circuit. The overvoltage protection device protects the protected device which has high cost and is difficult to maintain through breakdown of the overvoltage protection device, so the overvoltage protection device has no crosstalk on the electronic circuit and has a good protective effect. The overvoltage protection device has low cost, is easy to maintain and has wide popularization and application prospect.
Description
Technical field
The present invention relates to a kind of circuit protection technical field, be mainly applicable to the overvoltage protection of electronic circuit.
Background technology
In electronic circuit, the production of such as printed circuit board or other circuit and in using, often can cause because of the overvoltage occurred in circuit some device to be damaged, even cause whole printed circuit board to scrap.At present, although there is the technical scheme of numerous overvoltage protection, main application form is by overvoltage protection serial connection in circuit, stable power-supplying voltage.But existing overvoltage protection exists some defects, such as, to the crosstalk of main circuit, or cost is high.
Summary of the invention
Technical problem to be solved by this invention is to provide a kind of overvoltage protection device of electronic circuit, and it is effective that it has overvoltage protection, feature with low cost.
For solving the problems of the technologies described above, the invention provides a kind of overvoltage protection device of electronic circuit, it is characterized in that, comprise resistance, diode, triode pipe, the first pin, the second pin and the 3rd pin, after described first pin, resistance and Diode series, connect the base stage of described triode, the emitter of described triode connects described 3rd pin, described 3rd pin ground connection, the collector electrode of described triode or multiple tube connects described second pin, and described second pin connects the power end of described electronic circuit; Described first pin connects the direct power end of protected device in described electronic circuit.
Preferably, described first pin, the second pin, the 3rd pin and protected device circuit are by mounting or the connection of plug-in mounting.
Principle of the present invention is: overvoltage protection is connected with the employing power sources in parallel mode of protected device.When the terminal voltage of protected device in electronic circuit exceedes rated voltage certain value for a certain reason; the small increase of the terminal voltage of protected device causes the electric current of triode sharply to increase; thus make triode breakdown; the power supply of electronic circuit directly with ground conducting; be equivalent to the power supply having cut off protected device, thus the protected device itself in protective circuit does not destroy by overvoltage.
Overvoltage protection of the present invention by self breakdown and protect cost high, safeguard more difficult protected device, therefore, there is not the crosstalk to electronic circuit in it, and protected effect is good; Meanwhile, the cost taken by themselves of overvoltage protection is very cheap, is easy to safeguard, has the prospect applied.
Accompanying drawing explanation
Fig. 1 is the functional circuit schematic diagram of the embodiment of the present invention.
Vcc end in figure is power end; Anti-triangle symbol is earth terminal; R1 is resistance, and about 50 Ω, Vx are the diode of several series connection, and V1 is triode or multiple tube.
Embodiment
For setting forth the present invention further for the technological means reaching predetermined goal of the invention and take and effect; below in conjunction with accompanying drawing and preferred embodiment, the embodiment of short-circuit type circuit overvoltage protection proposed according to the present invention and operation principle are described in detail.
As shown in Figure 1, connect the base stage of triode or multiple tube V1 after the first pin, resistance and Diode series, the emitter of triode or multiple tube V1 connects the 3rd pin, the 3rd pin ground connection.The collector electrode of triode or multiple tube V1 connects the second pin, and the second pin connects the power Vcc of electronic circuit; In first pin connecting circuit, the magnitude of voltage of direct power end Ui, the Ui end of protected device is the threshold voltage of protected device.
When the terminal voltage of protected device in electronic circuit exceedes rated voltage certain value for a certain reason; according to the withstand voltage situation setting of device in circuit; be generally and exceed the threshold voltage that 10% ~ 30% of rated voltage is protected device; the small increase of the voltage of Ui end causes the electric current of triode or multiple tube V1 sharply to increase; thus make triode or multiple tube V1 breakdown; power Vcc directly with ground conducting; be equivalent to the mistake voltage source having cut off protected device, thus protected device in protective circuit is unaffected.In the present embodiment, V1 triode (or multiple tube) is not less than 1 second by the moment of more than 3A electric current.
This overvoltage protection device can draw many pins from series diode needed for threshold voltage, the difference of the operating voltage of the circuit applied according to it by user, from different threshold voltage contact places in circuit; When making the overvoltage protection device of many threshold voltages, Ui end is most high threshold voltage end.
It should be noted last that, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although with reference to example to invention has been detailed description, those of ordinary skill in the art is to be understood that, can modify to technical scheme of the present invention or equivalent replacement, and not departing from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.
Claims (2)
1. an overvoltage protection device of electronic circuit, it is characterized in that, comprise resistance, diode, triode, the first pin, the second pin and the 3rd pin, after described first pin, resistance and Diode series, connect the base stage of described triode, the emitter of described triode connects described 3rd pin, described 3rd pin ground connection, the collector electrode of described triode or multiple tube connects described second pin, and described second pin connects the power end of described electronic circuit; Described first pin connects the direct power end of protected device in described electronic circuit; Described direct power end voltage is the threshold voltage of protected device, and the threshold voltage of protected device exceeds its rated operational voltage 10% ~ 30%;
Wherein, when the micro-increasing of described direct power end voltage, sharply increased by the electric current of described triode, cause electrical breakdown; And the duration that described triode can bear more than 3A electric current is greater than 1S;
Many pins are drawn from series diode, the difference of the operating voltage of the circuit applied according to it by user, from different threshold voltage contact places in circuit needed for threshold voltage; When making the overvoltage protection device of many threshold voltages, Ui end for direct power end, and is most high threshold voltage end.
2. overvoltage protection device of electronic circuit according to claim 1, is characterized in that, described first pin, the second pin, the 3rd pin and protected device circuit are by mounting or the connection of plug-in mounting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210191700.4A CN102709873B (en) | 2012-06-12 | 2012-06-12 | Overvoltage protection device of electronic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210191700.4A CN102709873B (en) | 2012-06-12 | 2012-06-12 | Overvoltage protection device of electronic circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102709873A CN102709873A (en) | 2012-10-03 |
| CN102709873B true CN102709873B (en) | 2015-07-01 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210191700.4A Active CN102709873B (en) | 2012-06-12 | 2012-06-12 | Overvoltage protection device of electronic circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN102709873B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN200950534Y (en) * | 2006-09-29 | 2007-09-19 | 深圳创维－Rgb电子有限公司 | AC overvoltage protection circuitry |
| CN200976485Y (en) * | 2006-11-30 | 2007-11-14 | 青岛海信电器股份有限公司 | Under-voltage protection circuitry |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7773355B2 (en) * | 2005-09-19 | 2010-08-10 | The Regents Of The University Of California | ESD protection circuits for RF input pins |
| CN202712815U (en) * | 2012-06-12 | 2013-01-30 | 湖北三江航天红峰控制有限公司 | Electronic circuit over-voltage protector |
-
2012
- 2012-06-12 CN CN201210191700.4A patent/CN102709873B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN200950534Y (en) * | 2006-09-29 | 2007-09-19 | 深圳创维－Rgb电子有限公司 | AC overvoltage protection circuitry |
| CN200976485Y (en) * | 2006-11-30 | 2007-11-14 | 青岛海信电器股份有限公司 | Under-voltage protection circuitry |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102709873A (en) | 2012-10-03 |
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