CN207184455U - A kind of wide-voltage range level signal detects circuit - Google Patents

Abstract

A kind of wide-voltage range level signal detects circuit, including constant-current drive circuit and light-coupled isolation output circuit, the constant-current drive circuit electrically connect with the light-coupled isolation output circuit；The constant-current drive circuit electrically connects with Width funtion input.The beneficial effect of the application is：Using 5mA constant current driving and light-coupled isolation, the detection of the level signal of wide-voltage range is realized, 0V, 5V level signal that wide-voltage range level signal is converted into being identified extensively, the level communication being easy between distinct device.

Description

A kind of wide-voltage range level signal detects circuit

Technical field

The application belongs to level detection technique field, specifically, is related to a kind of wide-voltage range level signal detection electricity Road.

Background technology

With the continuous development of industrial technology, information technology, in field of industrial automation control, same system is electrically set The class that makes preparations for sowing is more and more, and different equipment rooms is frequently necessary to carry out information transmission, wherein just having the transmission of level signal.It is various Level signal voltage is different between electrical equipment, and most practical way is exactly that different level signals is converted into known be total to Level voltage, make level signal can be identified between distinct device, so as to realize the transmission of level signal.

The content of the invention

In view of this, technical problems to be solved in this application there is provided a kind of wide-voltage range level signal detection electricity Road, it can realize and the constant current output of wide-voltage range input is controlled, realize the level signal detection of wide-voltage range.

In order to solve the above-mentioned technical problem, this application discloses a kind of wide-voltage range level signal to detect circuit, and adopts Realized with following technical scheme.

A kind of wide-voltage range level signal detects circuit, including constant-current drive circuit and light-coupled isolation output circuit, institute Constant-current drive circuit is stated to electrically connect with the light-coupled isolation output circuit；The constant-current drive circuit is electrically connected with Width funtion input Connect.

Further, the constant-current drive circuit includes triode Q1 and triode Q2, and the Width funtion input is just Electrically connected respectively with the colelctor electrode of the triode Q1 and the base stage of the triode Q2 after the series resistance R1 of pole；The triode Emitter stage after Q1 base series resistor R3 with the triode Q2 electrically connects；The emitter stage series resistance of the triode Q2 Negative pole after R5 with the Width funtion input electrically connects；The emitter stage of the triode Q1 is negative with the Width funtion input Pole electrically connects；The colelctor electrode of the triode Q2 electrically connects with the light-coupled isolation output circuit；The Width funtion input Electrically connected after cathode series resistance R2 with the light-coupled isolation output circuit.

Preferably, the triode Q1 and triode Q2 selects SFT1202 models.

Further, the light-coupled isolation output circuit includes optocoupler IC1, the optocoupler IC1 input anodes with it is described End points electrical connection after the positive pole series connection resistance R2 of Width funtion input；The negative pole of the optocoupler IC1 inputs with it is described Triode Q2 colelctor electrode electrical connection；Electrically connected after the optocoupler IC1 output head anodes connection pull-up resistor R4 with power supply VCC, The optocoupler IC1 negative pole of output end electrically connects with GND；Output letter of the positive pole of the optocoupler IC1 output ends as detection circuit Number end output detection signal LV_OUT.

Preferably, the model of the optocoupler IC1 selects EL357N.

Preferably, the resistance R5 resistances are 150 ohm；The resistance of the resistance R2 is 5.1K ohms, power 3W.

Further, the input voltage range of the Width funtion input is DC12V-DC120V.

Compared with prior art, the application can be obtained including following technique effect：Utilize 5mA constant current driving and optocoupler Isolation, realizes the detection of the level signal of wide-voltage range, wide-voltage range level signal is converted into what can be identified extensively 0V, 5V level signal, the level communication being easy between distinct device.

Certainly, implementing any product of the application must be not necessarily required to reach all the above technique effect simultaneously.

Brief description of the drawings

Accompanying drawing described herein is used for providing further understanding of the present application, forms the part of the application, this Shen Schematic description and description please is used to explain the application, does not form the improper restriction to the application.In the accompanying drawings：

Fig. 1 is the theory diagram that the application detects circuit.

Fig. 2 is the circuit theory diagrams that the application detects circuit.

Embodiment

Presently filed embodiment is described in detail below in conjunction with drawings and Examples, and thereby how the application is applied Technological means can fully understand and implement according to this to solve technical problem and reach the implementation process of technical effect.

As shown in figure 1, a kind of wide-voltage range level signal detection circuit, including constant-current drive circuit and light-coupled isolation it is defeated Go out circuit.Constant-current drive circuit is connected with Width funtion input, inputs DC12V-120V voltage range.Constant-current drive circuit with Light-coupled isolation output circuit electrically connects.The application utilizes the constant current driving principle of optic coupling element, by high-voltage power triode and Power current-limiting resistance realizes that optic coupling element drives, and then realizes the detection of level signal.

As shown in Fig. 2 constant-current drive circuit includes triode Q1 and triode Q2, Q1 and Q2 select SFT1202 models.It is defeated Electrically connected respectively with triode Q1 colelctor electrode and triode Q2 base stage after entering the cathode series resistance R1 of voltage.Triode Q1 Base series resistor R3 after electrically connected with triode Q2 emitter stage.After triode Q2 emitter stage series resistance R5 with input The negative pole electrical connection of voltage.Triode Q1 emitter stage directly electrically connects with the negative pole of input voltage.Triode Q2 colelctor electrode Electrically connected with light-coupled isolation output circuit.Also it is electrically connected after the cathode series resistance R2 of input voltage with light-coupled isolation output circuit Connect.

Light-coupled isolation output circuit includes optocoupler IC1, and optocoupler IC1 model selects EL357N.Optocoupler IC1 input anodes Electrically connected with the end points after input voltage cathode series resistance R2, the negative pole of optocoupler IC1 inputs and triode Q2 colelctor electrode Electrical connection.Electrically connected after optocoupler IC1 output head anodes connection pull-up resistor R4 with power supply VCC, negative pole electrically connects with GND.Optocoupler Output signal end output detection signal LV_OUT of the positive pole of IC1 output ends as detection circuit.

Wherein, resistance R5 is current sampling resistor, and resistance is 150 ohm.Resistance R2 resistance is 5.1K ohms, and power is 3W, when high voltage inputs, resistance R2 plays the function of current limliting.

When input voltage reaches minimum voltage, input voltage drives triode Q2 to turn on through resistance R1, and electric current is by electricity Hinder R2 and flow into optocoupler IC1 inputs, when electric current reaches 5mA, resistance R5 both ends produce 0.7V voltages.0.7V voltages are through resistance R3 Drive triode Q1 base stage, triode Q1 conductings.After Q1 conductings, Q1 colelctor electrode and Q2 base voltage are by Q1 emitter stage 0V is dragged down into, triode Q2 cut-offs, optocoupler IC1 inputs no current is by the way that now current sampling resistor R5 both end voltages are changed into 0V, triode Q1 end.Now input voltage drives triode Q2 again through resistance R1, Q2 conductings, into circulating next time. And so on circulate, realize 5mA constant current driving.It should be noted that above-described 0V, 0.7V, 5mA are what is be approximately equal to Value, not necessarily, actual and perfect condition has some errors in electronic circuit.

Because resistance R2 resistances are 5.1K ohms, and the constant current 5mA of circuit so that there is about 25V pressure at resistance R2 both ends Difference, when high voltage inputs, protection can be played a part of to circuit.

Pull-up resistor R4 connections DC5V power supply.When input voltage is in the range of 24-120V, optocoupler IC1 input All the time in running order, optocoupler IC1 output signal is low level.Conversely, it is then high level.So as to realize that Width funtion inputs The level signal detection of scope.

The beneficial effect of the application is：The detection of the level signal of wide-voltage range can be realized, by wide-voltage range electricity Ordinary mail number is converted into 0V, 5V level signal that can be identified extensively, the level communication being easy between distinct device.

A kind of wide-voltage range level signal detection circuit provided above the embodiment of the present application, has carried out detailed Jie Continue.The explanation of above example is only intended to help and understands the present processes and its core concept；Meanwhile for this area Those skilled in the art, according to the thought of the application, there will be changes in specific embodiments and applications, to sum up institute State, this specification content should not be construed as the limitation to the application.

Some vocabulary has such as been used to censure specific components among specification and claim.Those skilled in the art should It is understood that hardware manufacturer may call same component with different nouns.This specification and claims are not with name The difference of title is used as the mode for distinguishing component, but is used as the criterion of differentiation with the difference of component functionally.Such as logical The "comprising" of piece specification and claim mentioned in is an open language, therefore should be construed to " include but do not limit In "." substantially " refer in receivable error range, those skilled in the art can be described within a certain error range solution Technical problem, basically reach the technique effect.Specification subsequent descriptions are so described to implement the better embodiment of the application Description is for the purpose of the rule for illustrating the application, is not limited to scope of the present application.The protection domain of the application It is defined when depending on appended claims institute defender.

It should also be noted that, term " comprising ", "comprising" or its any other variant are intended to nonexcludability Comprising, so that commodity or system including a series of elements not only include those key elements, but also including without clear and definite The other element listed, or also include for this commodity or the intrinsic key element of system.In the feelings not limited more Under condition, the key element that is limited by sentence "including a ...", it is not excluded that in the commodity including the key element or system also Other identical element be present.

Some preferred embodiments of the application have shown and described in described above, but as previously described, it should be understood that the application Be not limited to form disclosed herein, be not to be taken as the exclusion to other embodiment, and available for various other combinations, Modification and environment, and above-mentioned teaching or the technology or knowledge of association area can be passed through in application contemplated scope described herein It is modified., then all should be in this Shen and the change and change that those skilled in the art are carried out do not depart from spirit and scope Please be in the protection domain of appended claims.

Claims (7)

1. a kind of wide-voltage range level signal detects circuit, it is characterised in that：It is defeated including constant-current drive circuit and light-coupled isolation Go out circuit, the constant-current drive circuit electrically connects with the light-coupled isolation output circuit；The constant-current drive circuit and Width funtion Input electrically connects.

2. wide-voltage range level signal detection circuit according to claim 1, it is characterised in that：The constant-current drive circuit Including after triode Q1 and triode Q2, the cathode series resistance R1 of the Width funtion input respectively with the triode Q1's Colelctor electrode and the triode Q2 base stage electrically connect；After the base series resistor R3 of the triode Q1 with the triode Q2 Emitter stage electrical connection；Negative pole after the emitter stage series resistance R5 of the triode Q2 with the Width funtion input is electrically connected Connect；The emitter stage of the triode Q1 electrically connects with the negative pole of the Width funtion input；The colelctor electrode of the triode Q2 with The light-coupled isolation output circuit electrical connection；It is defeated with the light-coupled isolation after the cathode series resistance R2 of the Width funtion input Go out circuit electrical connection.

3. wide-voltage range level signal detection circuit according to claim 2, it is characterised in that：The triode Q1 and institute State triode Q2 and select SFT1202 models.

4. circuit is detected according to any wide-voltage range level signals of claim 1-3, it is characterised in that：The optocoupler every Include optocoupler IC1 from output circuit, the optocoupler IC1 input anodes are connected the electricity with the positive pole of the Width funtion input Hinder the end points electrical connection after R2；The negative pole of the optocoupler IC1 inputs electrically connects with the colelctor electrode of the triode Q2；The light Electrically connected after coupling IC1 output head anodes connection pull-up resistor R4 with power supply VCC, the optocoupler IC1 negative pole of output end is electrically connected with GND Connect；Output signal end output detection signal LV_OUT of the positive pole of the optocoupler IC1 output ends as detection circuit.

5. wide-voltage range level signal detection circuit according to claim 4, it is characterised in that：The type of the optocoupler IC1 Number select EL357N.

6. detect circuit according to claim 1-3,5 any wide-voltage range level signals, it is characterised in that：The resistance R5 resistances are 150 ohm；The resistance of the resistance R2 is 5.1K ohms, power 3W.

7. wide-voltage range level signal detection circuit according to claim 6, it is characterised in that：The Width funtion input Input voltage range be DC12V-DC120V.