CN110830024A - Overvoltage protection circuit of photoelectric coupler - Google Patents
Overvoltage protection circuit of photoelectric coupler Download PDFInfo
- Publication number
- CN110830024A CN110830024A CN201911070587.2A CN201911070587A CN110830024A CN 110830024 A CN110830024 A CN 110830024A CN 201911070587 A CN201911070587 A CN 201911070587A CN 110830024 A CN110830024 A CN 110830024A
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- CN
- China
- Prior art keywords
- diode
- photoelectric coupler
- relay
- protection circuit
- triode
- 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.)
- Pending
Links
- 239000003990 capacitor Substances 0.000 claims description 10
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
- H03K19/0175—Coupling arrangements; Interface arrangements
- H03K19/017545—Coupling arrangements; Impedance matching circuits
- H03K19/017572—Coupling arrangements; Impedance matching circuits using opto-electronic devices
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/20—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for electronic equipment
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
- H03K19/003—Modifications for increasing the reliability for protection
- H03K19/00307—Modifications for increasing the reliability for protection in bipolar transistor circuits
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- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Physics & Mathematics (AREA)
- Computing Systems (AREA)
- General Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Power Engineering (AREA)
- Electronic Switches (AREA)
Abstract
When an external power supply does not exceed a set voltage, a diode D1 is cut off, a triode VT is in a cut-off state, a relay J does not attract, and a normally closed contact J1-1 of the relay J is closed to supply power to a photoelectric coupler RL. When the external power supply exceeds the set voltage once, the diode D1 becomes conductive, the diode D1 emits light to indicate voltage overvoltage, the triode VT is conductive, the relay J is attracted, the normally closed contact J1-1 of the relay J is disconnected, and the power supply of the photoelectric coupler RL is cut off to play a role in protection. When the external power supply recovers to be below the set voltage, a reset button S1 is manually pressed to cut off the diode Dl, cut off the triode VT and release the relay J to recover the power supply to the photoelectric coupler RL. The protection circuit is arranged in the photoelectric coupler, so that the photoelectric coupler is protected from being burnt out due to overlarge voltage when in work.
Description
Technical Field
The invention relates to a protection circuit, in particular to an overvoltage protection circuit of a photoelectric coupler, and belongs to the technical field of electrical maintenance.
Background
The photoelectric coupler is an electric-to-optical-to-electric conversion device for transmitting electric signals by using light as a medium. It is composed of two parts of luminous source and light receiver. The light source and the light receiver are assembled in the same closed shell and are isolated from each other by a transparent insulator. The pin of the light source is an input end, the pin of the light receiver is an output end, the common light source is a light emitting diode, and the light receiver is a photosensitive diode, a phototriode and the like.
However, the existing photoelectric coupler has a simple structure, and an overvoltage protection device is not arranged in the photoelectric coupler, so that the performance of the photoelectric coupler is unstable, and the photoelectric coupler is easy to damage once the voltage is too large during working.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides an overvoltage protection circuit of a photoelectric coupler, which is characterized in that a protection circuit is arranged in the photoelectric coupler to protect the photoelectric coupler from being burnt out due to overlarge voltage during working.
In order to achieve the purpose, the invention provides an overvoltage protection circuit of a photoelectric coupler, which comprises a protection circuit for protecting a photoelectric coupler RL, wherein the protection circuit comprises a reset button S1, a capacitor C1, a resistor R1, a resistor R2, a diode D1, a diode D2, a relay J1 and a normally closed contact J1-1 thereof, and a triode VT, one end of a power supply passes through the reset button S1 and is respectively connected with one end of the capacitor C1, the anode of the diode D1, one end of the relay J, the cathode of the diode D2, one end of the normally closed contact J1-1 of the relay J1, the other end of the capacitor C1 is respectively connected with the cathode of the diode D1, one end of the resistor R2 and one end of the resistor R1, the other end of the resistor R2 is connected with the base of the triode VT, the collector of the triode VT is respectively connected with the other end of the relay J2 and one end of the normally closed contact J1-1 of the relay RL is connected with one end, the other end of the resistor R1, the emitter of the triode VT and the other end of the photoelectric coupler RL are connected with the negative electrode of the power supply.
As a further improvement of the invention, the model of the triode VT is 9013.
As a further improvement of the invention, the type of the diodes D1 and D2 is IN 4148.
As a further improvement of the present invention, the reset button S1 is a manual reset button.
As a further improvement of the present invention, the diode D1 is a light emitting diode.
The protection circuit is arranged in the photoelectric coupler, so that the photoelectric coupler is protected from being burnt out due to overlarge voltage during working.
Drawings
Fig. 1 is a circuit schematic of the present invention.
Detailed Description
The invention will be further explained with reference to the drawings.
As shown in FIG. 1, the overvoltage protection circuit of the photoelectric coupler comprises a protection circuit for protecting a photoelectric coupler RL, wherein the protection circuit comprises a reset button S1, a capacitor C1, a resistor R1, a resistor R2, a diode D1, a diode D2, a relay J1 and a normally closed contact J1-1 thereof, and a triode VT, one end of a power supply is respectively connected with one end of the capacitor C1, the anode of the diode D1, one end of the relay J, the cathode of the diode D2, one end of the normally closed contact J1-1 of the relay J1 after passing through the reset button S1, the other end of the capacitor C1 is respectively connected with the cathode of the diode D1, one end of the resistor R2 and one end of the resistor R1, the other end of the resistor R2 is connected with the base of the triode VT, the collector of the triode VT is respectively connected with the other end of the relay J, the anode of the diode D2, the other end of the normally closed contact J1-1 of the relay, the other end of the resistor R1, the emitter of the triode VT and the other end of the photoelectric coupler RL are connected with the negative electrode of the power supply.
As a further improvement of the invention, the model of the triode VT is 9013.
As a further improvement of the invention, the type of the diodes D1 and D2 is IN 4148.
As a further improvement of the present invention, the reset button S1 is a manual reset button.
As a further improvement of the present invention, the diode D1 is a light emitting diode.
The resistance values of the elements involved in the present invention are all common knowledge, and those skilled in the art can adjust the parameters of each element according to the needs.
The working principle is as follows:
when the external power supply does not exceed the set voltage, the diode D1 (light emitting diode) is cut off, the triode VT is in a cut-off state due to no base current, the relay J does not attract, and the normally closed contact J1-1 of the relay J is closed to supply power to the photoelectric coupler RL. When the external power supply exceeds the set voltage, the diode D1 (light emitting diode) is turned on from the cut-off state, the diode D1 (light emitting diode) emits light to indicate voltage overvoltage, the current flowing through the diode D1 (light emitting diode) provides base current of the triode VT, the triode VT is turned on, the relay J is attracted, the normally closed contact J1-1 of the relay J is disconnected, the power supply of the photoelectric coupler RL is cut off, and the protective effect is achieved. When the external power supply recovers to be below the set voltage, a reset button S1 is manually pressed to cut off the diode Dl, cut off the triode VT and release the relay J to recover the power supply to the photoelectric coupler RL. The capacitor C1 connected in parallel with the diode Dl is anti-electromagnetic interference and can be selected in the range of 0.01-0.1 muF.
Claims (5)
1. An overvoltage protection circuit of a photoelectric coupler comprises a protection circuit for protecting a photoelectric coupler RL, and is characterized in that the protection circuit comprises a reset button S1, a capacitor C1, a resistor R1, a resistor R2, a diode D1, a diode D2, a relay J1 and a normally closed contact J1-1 thereof, and a triode VT, one end of a power supply passes through a reset button S1 and is respectively connected with one end of a capacitor C1, the anode of a diode D1, one end of a relay J, the cathode of a diode D2, one end of a normally closed contact J1-1 of the relay J1, the other end of a capacitor C1 is respectively connected with the cathode of a diode D1, one end of a resistor R2 and one end of a resistor R1, the other end of a resistor R2 is connected with the base of the triode VT, the collector of the triode VT is respectively connected with the other end of the relay J, the anode of a diode D2, the other end of the normally closed contact J1-1 of the relay J1, the other end of the resistor R1, the emitter of the triode VT and the other end of the photoelectric coupler RL are connected with the negative electrode of the power supply.
2. The overvoltage protection circuit of a photocoupler according to claim 1, wherein the type of the triode VT is 9013.
3. The overvoltage protection circuit of a photoelectric coupler as claimed IN claim 1, wherein the type of the diodes D1 and D2 is IN 4148.
4. The overvoltage protection circuit of a photoelectric coupler as claimed in claim 2, wherein the reset button S1 is a manual reset button.
5. The overvoltage protection circuit of a photoelectric coupler as claimed in claim 2, wherein the diode D1 is a light emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911070587.2A CN110830024A (en) | 2019-11-05 | 2019-11-05 | Overvoltage protection circuit of photoelectric coupler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911070587.2A CN110830024A (en) | 2019-11-05 | 2019-11-05 | Overvoltage protection circuit of photoelectric coupler |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110830024A true CN110830024A (en) | 2020-02-21 |
Family
ID=69552538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911070587.2A Pending CN110830024A (en) | 2019-11-05 | 2019-11-05 | Overvoltage protection circuit of photoelectric coupler |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110830024A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62214420A (en) * | 1986-03-17 | 1987-09-21 | Fujitsu Ltd | System for protecting storage by backup battery |
| CN203103907U (en) * | 2013-03-23 | 2013-07-31 | 东北林业大学 | Electrical shock controller for experimental electrical equipment |
| CN205489445U (en) * | 2016-01-08 | 2016-08-17 | 无锡工艺职业技术学院 | Teaching equipment power excessive pressure alarming protection circuit |
| WO2017152456A1 (en) * | 2016-03-08 | 2017-09-14 | 深圳市华星光电技术有限公司 | Alternating current-to-direct current power supply output system |
-
2019
- 2019-11-05 CN CN201911070587.2A patent/CN110830024A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62214420A (en) * | 1986-03-17 | 1987-09-21 | Fujitsu Ltd | System for protecting storage by backup battery |
| CN203103907U (en) * | 2013-03-23 | 2013-07-31 | 东北林业大学 | Electrical shock controller for experimental electrical equipment |
| CN205489445U (en) * | 2016-01-08 | 2016-08-17 | 无锡工艺职业技术学院 | Teaching equipment power excessive pressure alarming protection circuit |
| WO2017152456A1 (en) * | 2016-03-08 | 2017-09-14 | 深圳市华星光电技术有限公司 | Alternating current-to-direct current power supply output system |
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| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200221 |
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| WD01 | Invention patent application deemed withdrawn after publication |