CN108288846A - A kind of optocoupler input protection circuit and its guard method - Google Patents
A kind of optocoupler input protection circuit and its guard method Download PDFInfo
- Publication number
- CN108288846A CN108288846A CN201710013160.3A CN201710013160A CN108288846A CN 108288846 A CN108288846 A CN 108288846A CN 201710013160 A CN201710013160 A CN 201710013160A CN 108288846 A CN108288846 A CN 108288846A
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- Prior art keywords
- circuit
- signal input
- input unit
- photoelectrical coupler
- ports
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/06—Details with automatic reconnection
- H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
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Abstract
The application discloses a kind of optocoupler input protection circuit and its guard method, including signal input unit, input protection circuit and photoelectrical coupler, signal input unit are connect with input protection circuit, photoelectrical coupler successively；The ports IN of signal input unit are connect with photoelectrical coupler respectively, in photoelectric coupling input circuit, have diode pair high back voltage to be ended；It connects between the COM port and internal circuit of signal input unit self-recovery fuse；The ports IN of signal input unit are connected by diode with internal common terminal COM1 respectively.Optocoupler input protection circuit to user scene the active high pressure of signal input unit misconnection (AC/DC) operating mode; it realizes to the circuit function self- recoverage after the protection of control panel itself and abnormal signal revocation; it effectively reduces the control panel caused by field connection mistake to damage, and the time thus brought and economic loss.
Description
Technical field
This application involves a kind of field of circuit technology, specifically, being related to a kind of optocoupler input protection circuit and its protection
Method.
Background technology
In circuit for checking input signals common at present, usually by being passed to internal circuit after photoelectric coupler isolation again,
In this way while realizing the filtration to high-frequency interferencing signal, the electrical isolation between different electrical modules is realized.But
Such circuit still remains a problem：If scene needs artificial wiring, active/passive is existed simultaneously, low pressure/high pressure
When difference access signal, detection signal input is inputted for passive or low pressure optocoupler, after misconnection enters high-voltage signal, behind
Photoelectrical coupler and resistance breakdown will burn up, be likely to require the controller more renewed in this way so that whole process
Time-consuming and laborious, very troublesome, especially foregoing circuit is applied in industrial circles such as similar elevators, is related to human safety issues
When, circuit is just particularly important the protection of unusual service condition.
In view of the above-mentioned problems, wish to propose that there is one kind abnormal signal self-protection and abnormal signal to cancel self- recoverage, with
And optocoupler input protection circuit and its guard method of protection act detection function.
Invention content
In order to solve the above-mentioned technical problem, this application discloses a kind of optocoupler input protection circuit and its guard methods.
A kind of optocoupler input protection circuit, including signal input unit, input protection circuit and photoelectrical coupler, signal are defeated
Enter unit to connect with input protection circuit, photoelectrical coupler successively；
The ports IN of signal input unit are connect with photoelectrical coupler respectively, in photoelectric coupling input circuit, there is diode
High back voltage is ended；
It connects between the COM port and internal circuit of signal input unit self-recovery fuse；
The ports IN of signal input unit are connected by diode with inside COM1 respectively；
Further, further include a protection act detection circuit, protection act detection circuit includes photoelectrical coupler, reversed
Diode and current-limiting resistance；
Further, signal input unit is passive signal input；
Further, signal input unit includes several signal input ports and a public end interface of input；
Further, the polar orientation point of the ports IN of signal input unit and the diode in photoelectric coupling input circuit
It is not consistent with the input terminal polar orientation of photoelectrical coupler always；
Further, the ports IN of signal input unit pass through positive a diode and internal common terminal COM1 phases respectively
Even.
Further, the ports IN of signal input unit pass through a reversed diode and internal common terminal COM1 phases respectively
Even.
Using the guard method of optocoupler input protection circuit as described in claim 1, including：
When between any two ends mouth of the ports IN of signal input unit there are when high pressure, due to have in circuit to high pressure into
The diode of the reverse protection of row cut-off, at this point, entire circuit loop is not turned on, corresponding photoelectrical coupler does not have high current warp
It crosses, ensure that photoelectrical coupler will not be burned off；
When there are when high pressure between the COM port of signal input unit and the ports signal input unit IN：Have in circuit pair
High pressure end and the diode of reverse protection, at this point, entire circuit loop is not turned on, corresponding photoelectrical coupler is not big
Electric current passes through, and ensure that photoelectrical coupler will not be burned off；Or voltage is connected by bypass diode, forms short-circuit loop,
Self-recovery fuse is broken, and the photoelectrical coupler being connect with the ports IN does not have high current process, ensure that photoelectrical coupler will not
It is burned off；
Further, further include a protection act detection circuit, once self-recovery fuse fuses, signal input unit
The connection of COM port to COM1 disconnect, and the photoelectrical coupler of protection act detection circuit is not turned on, in protection act detection circuit
Photoelectric coupler output end detect output signal saltus step, prompt current self-recovery fuse to fuse；
Further, a period of time, self-recovery fuse can restore low-resistance automatically after the loss of voltage that input terminal applies
State；
Further, the diode of optocoupler input protection circuit and self-recovery fuse are high pressure resistant.
Compared with prior art, on the one hand the application is avoided when misconnection high-voltage signal to signal input part, makes photoelectricity coupling
Clutch is burned off the time-consuming and laborious problem of repair caused by leading to fault；On the other hand, due to having accessed protection act inspection
Slowdown monitoring circuit, when having improper backward voltage between the COM port of signal input unit and any ports IN, electric current passes through certainly
Restore fuse and bypass diode is directly formed into a loop between COM and the corresponding ports IN, self-recovery fuse passes through excess
It is produced from fusing (high resistant) after constant current, and then protects photoelectrical coupler and other internal circuits, meanwhile, it is dynamic by protecting
Whether making the conducting of photoelectrical coupler in detection circuit, it can prompt whether current self-recovery fuse disconnects；Finally, certainly
Restore fuse have can self-righting performance, the number of product reprocessed and serviced can be reduced, to reduce cost.
Certainly, implement any product of the application it is not absolutely required to and meanwhile reach all the above technique effect.
Description of the drawings
Attached drawing described herein is used for providing further understanding of the present application, constitutes part of this application, this Shen
Illustrative embodiments and their description please do not constitute the restriction to the application for explaining the application.In the accompanying drawings：
Fig. 1 is existing common optocoupler input detecting circuit.
Fig. 2 is the improved optocoupler input detecting circuit one with defencive function of the application.
Fig. 3 is the improved optocoupler input detecting circuit two with defencive function of the application.
Specific implementation mode
Presently filed embodiment is described in detail below in conjunction with accompanying drawings and embodiments, thereby how the application is applied
Technological means solves technical problem and reaches the realization process of technical effect to fully understand and implement.
As shown in Figure 1, existing common optocoupler input detecting circuit, input signal by passing again after photoelectric coupler isolation
Enter internal circuit, while realizing to the filtration of high-frequency interferencing signal, realize between different electrical modules it is electrical every
From.But such circuit still remains problem：After intervening high-voltage signal, subsequent photoelectrical coupler and resistance can
It can puncture burn-up, need the controller more renewed immediately in this way so that whole process is cumbersome, and time-consuming and laborious.
As shown in Fig. 2, the improved optocoupler input detecting circuit one with defencive function of the application, including signal input are single
Member, input protection circuit and several photoelectrical couplers.
Signal input unit includes several ports IN and a COM port (public port).Signal input unit is general
It is passive signal, such as relay output contact etc etc..As shown in Fig. 2, when normal work, when the ends IN of signal input unit
When mouth (IN1~IN4) and COM port (public port) short circuit, at this point, with the photoelectrical coupler input terminal of the corresponding ports IN connection
Conducting, at this moment the photoelectric coupler output end is low level " 0 ", as the ports IN (IN1~IN4) of signal input unit and COM
When port (public port) disconnects, at this point, the photoelectrical coupler input terminal connected with the corresponding ports IN is not turned on, the at this moment photoelectricity
Coupler output is high level " 1 ".
Since the light emitting source of photoelectrical coupler input terminal is mostly light emitting diode, its conducting electric current and breakdown reverse voltage
It is general all smaller, when in use, if there is misconnection enters high-voltage signal, it be easy to cause burning for photoelectrical coupler.
Input protection circuit：By passing through a reversed resistance to height respectively in the ports IN (IN1~IN4) of signal input unit
Pressure diode (D1~D4) is connect with the cathode input terminal of a photoelectrical coupler, the purpose for the arrangement is that high pressure is believed in order to prevent
Number by the ports IN access photoelectrical coupler cathode input, cause the high back voltage of photoelectrical coupler input terminal to puncture；Signal
One self-recovery fuse of series connection between the COM port and internal common terminal COM1 of input unit, when the electric current for flowing through common end
More than fuse protection value when, by fuse melting, disconnect common end automatically, protect subsequent conditioning circuit；Internal common terminal COM1
It is connected respectively by a positive diode (D11~D14) with the ports IN of signal input unit.When high-voltage signal access is public
End COM is returned directly to the ports IN, the big short circuit of generation by self-recovery fuse by the diode (D11~D14) of bypass
Electric current directly fuses self- recoverage insurance circuit (high resistant), protects subsequent conditioning circuit.
After external exception signals cancel, self- recoverage insurance circuit can restore (low-resistance) automatically, ensure the normal of circuit
Work.
Further, which further includes the protection act detection circuit of self- recoverage insurance comprising a photoelectricity coupling
The COM port of clutch, a backward dioded (D5) and current-limiting resistance, signal input unit is (reversed by a backward dioded
Voltage cut-off) it is connect with the cathode input terminal of photoelectrical coupler；The anode input terminal of photoelectrical coupler is connected by current-limiting resistance
Internal electric source VDD；When self- recoverage insurance does not act, the photoelectrical coupler in protection act detection circuit can be connected, at this moment
The photoelectric coupler output end is low level " 0 ", when self- recoverage safe action, since circuit disconnects, and protection act detection electricity
Photoelectrical coupler in road can not be connected, and at this moment the photoelectric coupler output end is high level " 1 ".
Controller can be by the detection of the photoelectrical coupler output signal to protection act detection circuit, to judge to protect
Whether motion detector circuit acts, and gives the relevant prompt of user.
It is illustrated with reference to embodiment：
As shown in Fig. 2, embodiment one：When being high pressure between the current ports IN any two port, for example, working as VIN1=
220V,VIN2When=0V, due to the backward voltage cut-off effect for the diode (D1) being connect with the ports IN1 so that entire circuit is not
It can be formed into a loop, at this point, the photoelectrical coupler being connect respectively with the ports IN1 and the ports IN2 and the shadow for being not affected by this high input voltage
It rings, so that it is protected will not be burned off.
As shown in Fig. 2, embodiment two：It is current to have the ports IN for high voltage, when COM port is low-voltage, for example, working as VIN1
=220V, VCOMWhen=0V, due to the backward voltage cut-off effect for the diode (D1) being connect with the ports IN1 so that entire circuit
It cannot be formed into a loop, corresponding photoelectrical coupler is not broken down by high-voltage burn-up.
As shown in Fig. 2, embodiment three：Current COM port is high voltage, when to have the ports IN be low-voltage, for example, working as VIN1
=0V, VCOMWhen=220V, at this point, diode (D11) by-path turn-on being connect with the ports IN of low-voltage, forms short-circuit loop,
Self-recovery fuse (L1) fuses, and the photoelectrical coupler being connect with the ports IN does not have high current process, ensure that the photoelectricity coupling
Clutch will not be burned off.The high-impedance state that the optocoupler input of protection act detection circuit is insured due to self- recoverage, by original
Conducting state, which is switched to, is unable to conducting state, and output signal is detected in the photoelectric coupler output end of protection act detection circuit
Saltus step prompts current self-recovery fuse to fuse, and control panel can be detected according to the state change of this detection optocoupler
The action of self- recoverage insurance.
As shown in figure 3, being the improved optocoupler input detecting circuit two with defencive function of the application, including signal input list
Member, input protection circuit and several photoelectrical couplers.Compared with the circuit of Fig. 2, the also following main distinction：
Current direction：The common end of Fig. 2 meets the GND of internal electric source by self- recoverage insurance, when normal work, external signal
Current direction is from the ends IN to the ends COM；And the common end of Fig. 3 meets the VDD of internal electric source by self- recoverage insurance, normal work
When, external signal current direction is from the ends COM to the ends IN.
Bypass circuit：The ports IN of Fig. 2 internal common terminals COM1 and signal input unit pass through a two positive poles respectively
It manages (D11~D14) to be connected, the unusual service condition for bypassing the ends COM high pressure；And Fig. 3 internal common terminals COM1 and signal input are single
The ports IN of member are connected by a reversed diode (D11~D14) respectively, the unusual service condition for bypassing the ends IN high pressure.
Input signal optocoupler circuit：The ports IN of Fig. 2 signal input units first connect after reverse protection diode again and light
The cathode of electric coupler connects；The ports IN of Fig. 3 signal input units are first connected with the anode of photoelectrical coupler, photoelectrical coupler
Cathode reconnect reverse protection diode；But two pole of reverse protection in the input signal optocoupler circuit of above 2 kinds of circuits
The polar orientation of pipe is all consistent with the input terminal polar orientation of photoelectrical coupler.Two pole of reverse protection of Fig. 2 in the specific implementation
Link position of the pipe in input signal optocoupler circuit may be equally applicable for Fig. 3.
As shown in figure 3, example IV：When being high pressure between the current ports IN any two port, for example, working as VIN1=
When 220V, VIN2=0V, due to the backward voltage cut-off effect for the diode (D2) being connect with the ports IN2 so that entire circuit
It cannot be formed into a loop, at this point, the photoelectrical coupler being connect respectively with the ports IN1 and the ports IN2 and being not affected by this high input voltage
It influences, so that it is protected will not be burned off.
As shown in figure 3, embodiment five：It is current to have the ports IN for low-voltage, when COM port is high voltage, for example, working as VIN1
=0V, VCOMWhen=220V, due to the backward voltage cut-off effect for the diode (D1) being connect with the ports IN1 so that entire circuit
It cannot be formed into a loop, corresponding photoelectrical coupler is not broken down by high-voltage burn-up.
As shown in figure 3, embodiment six：Current COM port is low-voltage, when to have the ports IN be high voltage, for example, working as VIN1
=220V, VCOMWhen=0V, at this point, diode (D11) by-path turn-on being connect with the ports IN of high voltage, forms short-circuit loop,
Self-recovery fuse (L1) fusing in self-repairing circuit, the photoelectrical coupler being connect with the ports IN do not have high current process, protect
Having demonstrate,proved the photoelectrical coupler will not be burned off.The high resistant that the optocoupler input of protection act detection circuit is insured due to self- recoverage
State is switched to by original conducting state and is unable to conducting state, in the photoelectric coupler output end of protection act detection circuit
It detects output signal saltus step, current self-recovery fuse is prompted to fuse, control panel detects the state of optocoupler according to this
Variation can detect the action of self- recoverage insurance.
In specific application, user can select the signal input unit of more multiport according to actual conditions, and not only limit
This type mentioned in the application.
The diode and self-recovery fuse of the optocoupler input protection circuit are high pressure resistant.
Foregoing circuit design can be applied in DC voltage or alternating voltage input protection.
The type of access circuit can be not specifically limited depending on actual conditions.
Several preferred embodiments of the present invention have shown and described in above description, but as previously described, it should be understood that the present invention
Be not limited to form disclosed herein, be not to be taken as excluding other embodiments, and can be used for various other combinations,
Modification and environment, and the above teachings or related fields of technology or knowledge can be passed through in the scope of the invention is set forth herein
It is modified.And changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, then it all should be in this hair
In the protection domain of bright appended claims.
Claims (11)
1. a kind of optocoupler input protection circuit, including signal input unit, input protection circuit and photoelectrical coupler, signal input
Unit is connect with input protection circuit, photoelectrical coupler successively, it is characterised in that：
The ports IN of signal input unit are connect with photoelectrical coupler respectively, in photoelectric coupling input circuit, have diode pair anti-
Ended to high pressure；
It connects between the COM port and internal circuit of signal input unit self-recovery fuse；
The ports IN of signal input unit are connected by diode with internal common terminal COM1 respectively.
2. optocoupler input protection circuit according to claim 1, which is characterized in that further include protection act detection electricity
Road, the protection act detection circuit include photoelectrical coupler, backward dioded and current-limiting resistance.
3. optocoupler input protection circuit according to claim 1, which is characterized in that the signal input unit is passive letter
Number input.
4. the optocoupler input protection circuit according to claims 1 to 3 any claim, which is characterized in that the signal
Input unit includes several signal input ports and a public end interface of input.
5. optocoupler input protection circuit according to claim 1, which is characterized in that the ports IN of the signal input unit
With the polar orientation of the diode in the photoelectric coupling input circuit respectively always with the input terminal pole of the photoelectrical coupler
Property direction is consistent.
6. optocoupler input protection circuit according to claim 1, which is characterized in that the ports IN of the signal input unit
It is connected respectively with internal common terminal COM1 by a positive diode.
7. optocoupler input protection circuit according to claim 1, which is characterized in that the ports IN of the signal input unit
It is connected respectively with internal common terminal COM1 by a reversed diode.
8. utilizing the guard method of optocoupler input protection circuit as described in claim 1, it is characterised in that：
When, there are when high pressure, being cut to high pressure due to having in circuit between any two ends mouth of the ports IN of signal input unit
The diode of reverse protection only, at this point, entire circuit loop is not turned on, corresponding photoelectrical coupler does not have high current process,
It ensure that the photoelectrical coupler will not be burned off；
When there are when high pressure between the COM port of signal input unit and the ports IN of signal input unit：Have to height in circuit
Pressure end and the diode of reverse protection, at this point, entire circuit loop is not turned on, corresponding photoelectrical coupler is without big electricity
Stream passes through, and ensure that the photoelectrical coupler will not be burned off；Or voltage is connected by bypass diode, is formed short circuit and is returned
Road, self-recovery fuse are broken, and the photoelectrical coupler being connect with the ports IN does not have high current process, ensure that the photoelectric coupling
Device will not be burned off.
9. according to the guard method of optocoupler input protection circuit as claimed in claim 8, it is characterised in that：It further include a protection
Motion detector circuit, once self-recovery fuse fuses, the COM port of the signal input unit to the interior of signal input unit
The connection of portion common end COM1 disconnects, and the photoelectrical coupler of protection act detection circuit is not turned on, in protection act detection circuit
Photoelectric coupler output end detect output signal saltus step, prompt presently described self-recovery fuse to fuse.
10. the guard method of optocoupler input protection circuit according to claim 8, it is characterised in that：When input terminal applies
Loss of voltage after a period of time, the self-recovery fuse can restore low resistive state automatically.
11. the guard method of optocoupler input protection circuit according to claim 8, it is characterised in that：The optocoupler input
The diode and self-recovery fuse for protecting circuit are high pressure resistant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710013160.3A CN108288846B (en) | 2017-01-09 | 2017-01-09 | Optical coupler input protection circuit and protection method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710013160.3A CN108288846B (en) | 2017-01-09 | 2017-01-09 | Optical coupler input protection circuit and protection method thereof |
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| Publication Number | Publication Date |
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| CN108288846A true CN108288846A (en) | 2018-07-17 |
| CN108288846B CN108288846B (en) | 2020-07-03 |
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| CN201710013160.3A Active CN108288846B (en) | 2017-01-09 | 2017-01-09 | Optical coupler input protection circuit and protection method thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109302773A (en) * | 2018-11-15 | 2019-02-01 | 常州格林照明股份有限公司 | A kind of LED projector lamp driving circuit |
| CN111007434A (en) * | 2019-12-25 | 2020-04-14 | 深圳万讯自控股份有限公司 | Output short circuit detection protection circuit and method |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN108288846B (en) | 2020-07-03 |
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