CN201984317U - PLC (Programmable Logic Controller) output circuit with protection - Google Patents
PLC (Programmable Logic Controller) output circuit with protection Download PDFInfo
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- CN201984317U CN201984317U CN2011200065489U CN201120006548U CN201984317U CN 201984317 U CN201984317 U CN 201984317U CN 2011200065489 U CN2011200065489 U CN 2011200065489U CN 201120006548 U CN201120006548 U CN 201120006548U CN 201984317 U CN201984317 U CN 201984317U
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- triode
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- resistor
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Abstract
The utility model, which is applicable to the technical field of circuits, provides an PLC (Programmable Logic Controller) output circuit with protection, which comprises an optical coupler, a triode, a Zener diode and a transistor, the input end of the optical coupler is connected with an output signal of a CPU (Central Processing Unit), one output end of the optical coupler is connected with the emitter of the transistor through a first resistor, the other output end of the optical coupler is connected with the emitter of the triode, the base of the transistor is connected with one output end of the optical coupler through a second resistor, a third resistor is connected in series with a fourth resistor, one end of the third resistor and the fourth resistor is connected with the collector of the transistor, the other end of the third resistor and the fourth resistor is connected with the emitter of the triode, the middle point between the third resistor and the fourth resistor is connected with the base of the triode, the collector of the triode is connected with the emitter of the transistor, one end of the Zener diode is connected with the emitter of the transistor, the other end of the Zener diode is connected with the emitter of the triode and grounded, one of the two ends of the Zener diode is connected with the power end of a relay, and the other end of the Zener diode is connected with the grounded end of the relay. The PLC output circuit guarantees the reliability of a drive circuit after input wiring is wrong or the relay is short-circuited, and reduces the conduction loss.
Description
Technical field
The utility model relates to the circuit engineering field, relates in particular to a kind of PLC output circuit with protection.
Background technology
PLC output circuit in the market as shown in Figure 1, the output signal of the input termination CPU of optocoupler U1, the output terminal of optocoupler U1 links to each other with base stage and the collector of triode Q2 respectively, the base stage of triode Q2 links to each other through the emitter of resistance R 7 with triode Q2, stabilivolt D1 is connected in parallel between the collector and emitter of triode Q2, and stabilivolt D1 succeeds at two ends the power end and the ground end of electrical equipment.
In the foregoing circuit, when improper use occurring, as output port misconnection, relay short circuit, used the voltage that applies in the load that is not complementary or the load improper etc., switching tube will flow through bigger electric current and cause its damage; Simultaneously, be operated in the amplification region during switching tube conducting, conduction loss is big.
The utility model content
The purpose of this utility model is to provide a kind of PLC output circuit with protection.
The utility model purpose is achieved through the following technical solutions.
A kind of PLC output circuit with protection; comprise: optocoupler; triode; stabilivolt; the output signal of the input termination CPU of optocoupler; also comprise transistor; output terminal one end of optocoupler links to each other with transistorized emitter through first resistance; the other end links to each other with the emitter of triode; transistorized base stage links to each other with output terminal one end of optocoupler through second resistance; the 3rd resistance links to each other with transistorized collector with the 4th resistance series connection back one end; the other end links to each other with the emitter of triode; the mid point of the 3rd resistance and the 4th resistance links to each other with the base stage of triode; the collector of triode and transistorized emitter cross-over connection, an end of stabilivolt links to each other with emitter, and the other end links to each other with the emitter of triode and ground connection; the power end of stabilivolt two ends one relay termination, another relay termination ground end.
Wherein, also comprise the 5th resistance, an end of described the 5th resistance links to each other with the collector of triode, and the other end links to each other with transistorized emitter.
Wherein, also comprise thermistor, stabilivolt two ends one end is succeeded the power end of electrical equipment through thermistor.
The utility model embodiment compared with prior art, beneficial effect is:
1, guarantees reliable at input wires mistake or relay short circuit back driving circuit, effectively solved the situation of conventional line damage product when improper the use occurring;
2, change the quiescent point of circuit, made the output driving tube be operated in the saturation region effectively, reduced its conduction loss.
Description of drawings
Fig. 1 is existing P LC output circuit figure;
Fig. 2 is the PLC output circuit figure of the utility model band protection.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
See also shown in Figure 2, the output signal of the input termination CPU of optocoupler U1, output terminal one end of optocoupler U1 links to each other through the emitter of resistance R 1 with transistor Q1, the other end links to each other with the emitter of triode Q2, the base stage of transistor Q1 links to each other with output terminal one end of optocoupler U1 through resistance R 2, resistance R 3 links to each other with the collector of transistor Q1 with resistance R 4 series connection backs one end, the other end links to each other with the emitter of triode Q2, the mid point of resistance R 3 and resistance R 4 links to each other with the base stage of triode Q2, the collector of triode Q2 links to each other through the emitter of resistance R 5 with transistor Q1, the end of stabilivolt D1 links to each other with transistor Q1 emitter, the other end links to each other with the emitter of triode Q2 and ground connection, stabilivolt D1 two ends one end is succeeded the power end of electrical equipment through thermistor F1, another relay termination ground end.
Fig. 2 has increased a transistor Q1 and has constituted Darlington transistor in order to strengthen the saturation depth of switching tube Q2 on Fig. 1 basis, guarantee that all the time triode Q2 works on off state, reduces the loss of triode Q2
Among Fig. 2, thermistor F1 of transistor Q1 emitter serial connection, when load current occurring and increase suddenly, can be in hundreds of milliseconds rapidly increase direct impedance protection switch pipe not by the overcurrent impact failure.Can guarantee reliable at input wires mistake or relay short circuit back driving circuit so effectively.
Also increased a current-limiting resistance R5 among Fig. 2, can prevent in the moment of relay short circuit, the electric current of triode was not flow through in restriction before thermistor F1 also had enough time to respond, and the protection triode is not wanted instantaneous power and damaged.Provide bias voltage when relay work, guarantee that Q2 is operated in the saturation region, the CE shunt regulator tube of switching tube Q2 has effectively stoped short time internal cause overvoltage and has damaged switching tube.
When relay needed work, CPU sent the connection signal, and LY is a low level, optocoupler U1 conducting, and then triode Q1 conducting causes the Q2 saturation conduction, then relay adhesive.
The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection domain of the present utility model.
Claims (3)
1. PLC output circuit with protection; comprise: optocoupler (U1); triode (Q2); stabilivolt (D1); the output signal of the input termination CPU of optocoupler (U1); it is characterized in that; also comprise transistor (Q1); output terminal one end of optocoupler (U1) links to each other through the emitter of first resistance (R1) with transistor (Q1); the other end links to each other with the emitter of triode (Q2); the base stage of transistor (Q1) links to each other with output terminal one end of optocoupler (U1) through second resistance (R2); the 3rd resistance (R3) links to each other with the collector of transistor (Q1) with the 4th resistance (R4) series connection back one end; the other end links to each other with the emitter of triode (Q2); the mid point of the 3rd resistance (R3) and the 4th resistance (R4) links to each other with the base stage of triode (Q2); the emitter cross-over connection of the collector of triode (Q2) and transistor (Q1); one end of stabilivolt (D1) links to each other with transistor (Q1) emitter; the other end links to each other with the emitter of triode (Q2) and ground connection; the power end of stabilivolt (D1) two ends one relay termination, another relay termination ground end.
2. the PLC output circuit of band protection as claimed in claim 1 is characterized in that also comprise the 5th resistance (R5), an end of described the 5th resistance (R5) links to each other with the collector of triode (Q2), and the other end links to each other with the emitter of transistor (Q1).
3. the PLC output circuit of band protection as claimed in claim 2 is characterized in that also comprise thermistor (F1), stabilivolt (D1) two ends one end is succeeded the power end of electrical equipment through thermistor (F1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200065489U CN201984317U (en) | 2011-01-11 | 2011-01-11 | PLC (Programmable Logic Controller) output circuit with protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200065489U CN201984317U (en) | 2011-01-11 | 2011-01-11 | PLC (Programmable Logic Controller) output circuit with protection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201984317U true CN201984317U (en) | 2011-09-21 |
Family
ID=44611773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011200065489U Expired - Fee Related CN201984317U (en) | 2011-01-11 | 2011-01-11 | PLC (Programmable Logic Controller) output circuit with protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201984317U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106230270A (en) * | 2016-09-27 | 2016-12-14 | 航天长峰朝阳电源有限公司 | A kind of ultra low quiescent loss integrated power supply module |
| CN109713657A (en) * | 2019-01-28 | 2019-05-03 | 上海海得控制***股份有限公司 | A kind of protection circuit based on PLC transistor output module |
| CN109782686A (en) * | 2019-01-28 | 2019-05-21 | 周忠清 | A kind of PLC controller transistor output module and its manufacturing method and the connection type with circuit board |
| CN116093908A (en) * | 2023-03-22 | 2023-05-09 | 广东东菱电源科技有限公司 | Low surge circuit with low dimming turn-off loss |
-
2011
- 2011-01-11 CN CN2011200065489U patent/CN201984317U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106230270A (en) * | 2016-09-27 | 2016-12-14 | 航天长峰朝阳电源有限公司 | A kind of ultra low quiescent loss integrated power supply module |
| CN109713657A (en) * | 2019-01-28 | 2019-05-03 | 上海海得控制***股份有限公司 | A kind of protection circuit based on PLC transistor output module |
| CN109782686A (en) * | 2019-01-28 | 2019-05-21 | 周忠清 | A kind of PLC controller transistor output module and its manufacturing method and the connection type with circuit board |
| CN116093908A (en) * | 2023-03-22 | 2023-05-09 | 广东东菱电源科技有限公司 | Low surge circuit with low dimming turn-off loss |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110921 Termination date: 20190111 |