CN210624836U - Protection locking and unlocking circuit and air conditioner - Google Patents
Protection locking and unlocking circuit and air conditioner Download PDFInfo
- Publication number
- CN210624836U CN210624836U CN201921537241.4U CN201921537241U CN210624836U CN 210624836 U CN210624836 U CN 210624836U CN 201921537241 U CN201921537241 U CN 201921537241U CN 210624836 U CN210624836 U CN 210624836U
- Authority
- CN
- China
- Prior art keywords
- circuit
- protection
- comparator
- resistor
- terminal
- 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.)
- Active
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model provides a protection locking and unblock circuit and air conditioner, include: the detection signal processing sub-circuit comprises an inverse proportion circuit structure, wherein the inverse input end of the inverse proportion operation circuit is connected with a detection signal, the positive input end of the inverse proportion operation circuit is connected with a fixed voltage, and the output end of the inverse proportion operation circuit is used as the output end of the detection signal processing sub-circuit; the abnormity protection sub-circuit comprises a comparator circuit, wherein the reverse input end of the comparator circuit is connected with the output end of the detection signal processing sub-circuit, the forward input end of the comparator circuit is connected with a reference voltage, the output end and the forward input end of the comparator are connected with a conductive device, the conductive device is conducted when the level of the output end is higher than that of the forward input end of the comparator, and the output end of the comparator provides a level overturning signal as a judgment signal for triggering protection. The circuit structure can rapidly improve the reference signal threshold value after the comparator triggers protection, lock the protection circuit and prevent the protection circuit from frequently acting.
Description
Technical Field
The utility model relates to an air conditioner technical field particularly, relates to a protection locking and unblock circuit and air conditioner.
Background
The comparator is commonly used in some voltage and current protection circuits, the common method is that a reference signal is input at one input end of the comparator, a detected voltage/current signal is input at the other input end of the comparator, when an input voltage/current detection signal is higher than a reference signal Vref of the low-voltage comparator, the output level of the comparator is inverted, and meanwhile, a signal processing chip judges that the circuit needs to be protected after detecting that the output level of the comparator is inverted and outputs a protection action signal. However, under some working conditions, the detection signal may fluctuate around the reference signal Vref, which causes the comparator to be triggered frequently, and the protection circuit to act frequently, which affects the reliability and the service life of the circuit.
SUMMERY OF THE UTILITY MODEL
The utility model provides a problem provide a protection locking and unblock circuit and air conditioner that prevent protection circuit frequent action.
In order to solve the above problem, the utility model provides a protection locking and unblock circuit, include:
the detection signal processing sub-circuit comprises an inverse proportion circuit structure, wherein the inverse input end of the inverse proportion operation circuit is connected with a detection signal Vs, the positive input end of the inverse proportion operation circuit is connected with a fixed voltage, and the output end of the inverse proportion operation circuit is used as the output end Vout1 of the detection signal processing sub-circuit;
the abnormity protection sub-circuit comprises a comparator circuit, wherein the reverse input end of the comparator circuit is connected with the output end Vout1 of the detection signal processing sub-circuit, the forward input end of the comparator circuit is connected with a reference voltage Vref, the output end and the forward input end of the comparator circuit are connected with a conductive device, the conductive device is conducted when the level of the output end of the comparator circuit is higher than that of the forward input end of the comparator circuit, the output end Vout2 of the comparator circuit provides a level overturning signal, and the level overturning signal is used as a judgment signal for triggering protection.
Because the output end and the positive input end of the comparator circuit are connected with the conductive device, and the conductive device is conducted when the level of the output end of the comparator circuit is higher than the positive input end of the comparator circuit, the reference voltage Vref connected with the positive input end of the comparator circuit can be changed when the level of the output end is turned over, so that the comparator is locked to output a constant high level, and the circuit locking protection function is further realized.
Further, in the abnormal protection sub-circuit, the conductive device is a PNP triode Q1, the base of the triode Q1 is grounded, the collector is connected to the positive input terminal of the comparator circuit, and the emitter is connected to the output terminal of the comparator circuit.
Further, in the abnormal protection sub-circuit, the conductive device is an NPN triode Q1, a base of the triode Q1 is grounded, an emitter of the triode Q1 is connected to the positive input terminal of the comparator circuit, and a collector of the triode Q1 is connected to the output terminal of the comparator circuit.
Further, in the abnormal protection sub-circuit, the connection of the positive input terminal of the comparator circuit to the reference voltage Vref includes: the positive input end of the comparator circuit is connected with the first end of a resistor R3, and the second end of the resistor R3 is grounded; the positive input end of the comparator circuit is also connected with a first end of a resistor R2, and a second end of the resistor R2 is connected with a power supply Vcc. When the comparator outputs low level, the conductive device is not conducted, and the reference voltage Vref1 is the divided voltage value of R3.
Further, the abnormality protection sub-circuit further includes: and the resistor R1, the first end of the resistor R1 is connected with the output end Vout of the comparator circuit, and the second end is connected with a power supply Vcc. When the circuit needs protection, the comparator inverts to output a high level, the conductive device is conducted, the resistors R1 and R2 are in parallel connection, the reference threshold Vref rises, and therefore the comparator locks and outputs the high level.
Further, in the abnormality protection sub-circuit, R1< R2 and R1< R3. Thus, when the conductive device is turned on, the reference threshold Vref is close to Vcc, so that the comparator output can be effectively locked out.
Further, the protection locking and unlocking circuit further includes: self-locking and unlocking action subcircuit includes:
a signal input terminal connected to the output terminal Vout2 of the comparator circuit, and used as a judgment signal for triggering a protection action signal according to the level inversion of the output terminal Vout 2;
a signal output terminal having a second conductive device connected between the signal output terminal and the output terminal Vout2 of the comparator circuit, the second conductive device being conductive when the output terminal Vout2 of the comparator circuit is at a higher level than the signal output terminal.
Therefore, when the signal of the signal input terminal is inverted from low level to high level, the protection signal action is triggered; the signal output terminal outputs low level when the protection is released, and the output of the comparator is pulled down, so that the conductive device is cut off, the protection circuit is unlocked, and the protection circuit is restored to the state before the protection.
Further, the second turn-on device is a diode D1, the anode of the diode D1 is connected to the output terminal Vout2 of the comparator circuit, and the cathode of the diode D1 is connected to the signal output terminal.
Further, the inverse proportion operational circuit in the detection signal processing sub-circuit comprises an operational amplifier, a positive input end of the operational amplifier is connected with a first end of a resistor R4 and a first end of a resistor R5, a second end of the resistor R4 is grounded, and a second end of the resistor R5 is connected with a power supply Vcc; the inverting input terminal of the operational amplifier is connected to the first terminal of the resistor R6 and the first terminal of the resistor R7, the second terminal of the resistor R6 is connected to the output terminal of the operational amplifier, and the second terminal of the resistor R7 is connected to the detection signal Vs. Due to the arrangement of the inverse proportion operation circuit, the output signal of the circuit and the detection signal are in inverse proportion, namely the larger the detection signal is, the smaller the output signal is, and therefore, the locking and unlocking of the protection circuit can be realized by matching with the abnormal protection sub-circuit.
Drawings
FIG. 1 is a schematic diagram of a conventional protection circuit using a comparator;
fig. 2 is a schematic structural diagram of a protection locking and unlocking circuit according to an embodiment of the present invention;
fig. 3 is an equivalent circuit of the abnormal protection sub-circuit according to the embodiment of the present invention before the abnormal protection operation;
fig. 4 is an equivalent circuit of the abnormal protection sub-circuit according to the embodiment of the present invention after the abnormal protection operation.
Detailed Description
Fig. 1 is a schematic structural diagram of a conventional protection circuit using a comparator. The existing comparator circuit has the disadvantages that when the circuit works in certain extreme severe conditions, the amplitude of a detection signal Vs can fluctuate back and forth above and below a Vref value, so that the comparator is frequently triggered, a protection circuit also frequently acts, and the circuit works in the extreme conditions for a long time, so that the reliability and the service life of the circuit can be reduced.
The utility model provides a protection locking and unblock circuit, this circuit structure can improve reference signal Vref threshold value rapidly after comparator trigger protection, locks protection circuit, prevents that protection circuit from frequently moving. Meanwhile, after the signal processing chip judges that the circuit can work normally, the signal processing chip can output a reset signal to unlock the protection circuit.
In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.
Fig. 2 is a schematic structural diagram of the protection locking and unlocking circuit according to the embodiment of the present invention. As shown in fig. 2, the protection locking and unlocking circuit of the present embodiment includes a detection signal processing sub-circuit, an abnormal protection sub-circuit, and a self-locking and unlocking action sub-circuit, which are connected in sequence.
The detection signal processing sub-circuit comprises an inverse proportion circuit structure, wherein the inverse input end of the inverse proportion operation circuit is connected with a detection signal Vs, the positive input end of the inverse proportion operation circuit is connected with a fixed voltage, and the output end of the inverse proportion operation circuit is used as the output end Vout1 of the detection signal processing sub-circuit; due to the arrangement of the inverse proportion operation circuit, the output signal of the circuit and the detection signal are in inverse proportion, namely the larger the detection signal is, the smaller the output signal is, and therefore, the locking and unlocking of the protection circuit can be realized by matching with the abnormal protection sub-circuit.
As shown in fig. 2, in the present embodiment, the detection signal processing sub-circuit includes an inverse proportion operation circuit formed by an operational amplifier LM 258: the voltage of the R5 and the R4 is divided and input into the LM258 equidirectional end of the operational amplifier, and the detection signal Vs is input into the reverse end of the operational amplifier, specifically, the reverse input end of the operational amplifier LM258 is connected with the first end of the resistor R6 and the first end of the resistor R7, the second end of the resistor R6 is connected with the output end of the operational amplifier, and the second end of the resistor R7 is connected with the detection signal Vs. The analysis circuit can know that when the detection signal Vs is 0V, the operational amplifier outputs a reference voltage signal; as the magnitude of the sense signal Vs changes, the value of the operational amplifier output Vout1 changes in inverse proportional relationship to Vs, starting from the reference voltage value.
Specifically, in the inverting proportional amplifying circuit in this embodiment, the voltage at the forward input terminal of the operational amplifier LM258 is a fixed voltage V0Vcc R4/(R4+ R5), the reverse input voltage is also V due to the virtual short of the forward reverse input0And since the current at the inverting input terminal is approximately 0, the currents flowing through R6 and R7 are approximately equal to obtain (Vs-V)0)/R7＝(V0Vout1)/R6, i.e., Vout1 ═ V0-R6*(Vs-V0) and/R7. According to the formula, V is0Is a fixed voltage, so the output Vout1 is smaller as the detection signal Vs is larger; conversely, when the detection signal Vs is smaller, the output Vout1 is larger.
The abnormal protection sub-circuit comprises a comparator circuit, because the detection signal Vs is in inverse proportion to the output Vout1, when the Vout1 is smaller than the reference voltage Vref, which indicates that the detection signal Vs is larger, the comparator circuit should output a protection action trigger signal and realize locking, otherwise, the protection action is not triggered when the Vout1 is larger than the reference voltage Vref.
In order to realize the functions, the reverse input end of the comparator circuit is connected with the output end Vout1 of the detection signal processing sub-circuit, the forward input end of the comparator circuit is connected with the reference voltage Vref, the output end and the forward input end of the comparator circuit are connected with a conductive device, the conductive device is conducted when the level of the output end of the comparator circuit is higher than that of the forward input end of the comparator circuit, the output end Vout2 of the comparator circuit provides a level flip signal, and the level flip signal is used as a judgment signal for triggering protection. The conductive device comprises a PNP triode or a PNP triode.
The output end and the positive input end of the comparator circuit are connected with the conductive device, the conductive device is conducted when the output end level of the comparator circuit is higher than the positive input end of the comparator circuit, and the reference voltage Vref connected with the positive input end of the comparator circuit can be changed when the output end level is turned over, so that the comparator is locked to output a constant high level, and the circuit locking protection function is further realized.
Compared with the conventional comparator circuit, the abnormal protection in the embodiment has the advantages that a PNP triode Q1 is connected to the output end and the reverse input end of the comparator LM 293; the base electrode of the triode Q1 is grounded, the collector electrode is connected with the positive input end of the comparator circuit, and the emitter electrode is connected with the output end of the comparator circuit. The output end of the comparator is connected with the signal input port of the DSP chip and is simultaneously connected with the output port of the DSP chip through a diode D1 to realize the functions of protection locking and unlocking, and the specific working principle is as follows:
fig. 3 is an equivalent circuit of the abnormal protection sub-circuit according to the embodiment of the present invention before the abnormal protection operation. As shown in fig. 3, the positive input terminal of the comparator circuit is connected to the first terminal of the resistor R3, and the second terminal of the resistor R3 is grounded; the positive input end of the comparator circuit is also connected with a first end of a resistor R2, and a second end of the resistor R2 is connected with a power supply Vcc. When the circuit works normally, the voltage of the detection output signal Vout1 is larger than the protection threshold Vref, the comparator outputs low level, and the triode Q1 is cut off. The DSP chip detects that the comparator LM293 outputs a low level signal to judge that the signal is a normal working signal of the circuit, the DSP protects the action signal from being enabled, the reference voltage Vref1 is a divided voltage value on R3, and the reference voltage Vref1 is calculated as follows:
the resistor R1 has a first end connected to the output terminal Vout of the comparator circuit and a second end connected to a power supply Vcc. Fig. 4 is an equivalent circuit of the abnormal protection sub-circuit according to the embodiment of the present invention after the abnormal protection operation. As shown in fig. 4, when the circuit needs protection, the voltage of the detection output signal Vout1 is less than the protection threshold Vref, the comparator inverts to output a high level, and at this time, the PNP transistor Q1 is turned on, and the reference threshold Vref rises to Vref2, so that the comparator latches and outputs a high level. Assuming that transistor Q1 is in a saturated conducting state, Vref2 is calculated as follows:
assuming that the influence of a voltage drop Vces of the Q1 on is neglected, the resistors R1 and R2 are in parallel connection; if R1< R2 and R1< R3, the value of the comparator reference voltage Vref2 is approximately Vcc, the comparator is locked to output a constant high level, and the DSP chip detects the high level signal of the comparator and immediately outputs a protection enable signal, thereby realizing the circuit locking protection function.
It should be noted that the conductive device is not limited to the PNP transistor in this embodiment, and may also be an NPN transistor Q1, where a base of the NPN transistor Q1 is grounded, an emitter of the NPN transistor is connected to the positive input terminal of the comparator circuit, and a collector of the NPN transistor is connected to the output terminal of the comparator circuit.
Referring to fig. 2, the abnormal protection sub-circuit is connected to the self-locking and unlocking action sub-circuit. The self-locking and unlocking action sub-circuit comprises a signal input terminal, a signal output terminal and a signal processing chip. Wherein the signal input terminal is connected to the output terminal Vout2 of the comparator circuit, and is used as a judgment signal for triggering a protection action signal according to the level inversion of the output terminal Vout 2; a second conductive device is connected between the signal output terminal and the output end Vout2 of the comparator circuit, and the second conductive device is conducted when the output end Vout2 level of the comparator circuit is higher than the level of the signal output terminal; the IO port of the signal processing chip is connected to the signal input terminal and the signal output terminal, the signal processing chip determines whether to output a protection action signal or not by judging signal level inversion of the signal input terminal, and outputs a low-level reset signal to the signal output terminal when protection is finished.
Therefore, when the signal of the signal input terminal is inverted from low level to high level, the protection signal action is triggered; the signal output terminal outputs low level when the protection is released, and the output of the comparator is pulled down, so that the conductive device is cut off, the protection circuit is unlocked, and the protection circuit is restored to the state before the protection.
In this embodiment, the second conductive device is a diode D1, the anode of the diode D1 is connected to the output terminal Vout2 of the comparator circuit, and the cathode of the diode D1 is connected to the signal output terminal. When the DSP judges that the protection is finished, the output port of the DSP chip outputs a low-level reset signal, the output pin of the comparator is pulled down, the triode Q1 is cut off, the reference voltage of the comparator is changed into Vref1, the protection circuit is unlocked, and the state before the protection is recovered.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present invention, and the scope of the present invention is defined by the appended claims.
Claims (10)
1. A protective lock and unlock circuit, comprising:
the detection signal processing sub-circuit comprises an inverse proportion circuit structure, wherein the inverse input end of the inverse proportion operation circuit is connected with a detection signal Vs, the positive input end of the inverse proportion operation circuit is connected with a fixed voltage, and the output end of the inverse proportion operation circuit is used as the output end Vout1 of the detection signal processing sub-circuit;
the abnormity protection sub-circuit comprises a comparator circuit, wherein the reverse input end of the comparator circuit is connected with the output end Vout1 of the detection signal processing sub-circuit, the forward input end of the comparator circuit is connected with a reference voltage Vref, the output end and the forward input end of the comparator circuit are connected with a conductive device, the conductive device is conducted when the level of the output end of the comparator circuit is higher than that of the forward input end of the comparator circuit, the output end Vout2 of the comparator circuit provides a level overturning signal, and the level overturning signal is used as a judgment signal for triggering protection.
2. The protection lock and unlock circuit of claim 1 wherein, in said abnormal protection subcircuit,
the conductive device is a PNP triode Q1, the base of the triode Q1 is grounded, the collector of the triode is connected with the positive input end of the comparator circuit, and the emitter of the triode is connected with the output end of the comparator circuit.
3. The protection lock and unlock circuit of claim 1 wherein, in said abnormal protection subcircuit,
the conductive device is an NPN triode Q1, the base electrode of the triode Q1 is grounded, the emitter electrode of the triode is connected with the positive input end of the comparator circuit, and the collector electrode of the triode is connected with the output end of the comparator circuit.
4. The protection locking and unlocking circuit as claimed in claim 1, wherein the abnormal protection sub-circuit in which a positive input terminal of the comparator circuit is connected to a reference voltage Vref includes,
the positive input end of the comparator circuit is connected with the first end of a resistor R3, and the second end of the resistor R3 is grounded; the positive input end of the comparator circuit is also connected with a first end of a resistor R2, and a second end of the resistor R2 is connected with a power supply Vcc.
5. The protection lock and unlock circuit of claim 4 wherein said exception protection subcircuit further comprises:
and the resistor R1, the first end of the resistor R1 is connected with the output end Vout of the comparator circuit, and the second end is connected with a power supply Vcc.
6. The protection lock and unlock circuit of claim 5 wherein in said abnormal protection subcircuit, R1< < R2 and R1< < R3.
7. The protection locking and unlocking circuit of claim 1, further comprising:
self-locking and unlocking action subcircuit includes:
a signal input terminal connected to the output terminal Vout2 of the comparator circuit, and used as a judgment signal for triggering a protection action signal according to the level inversion of the output terminal Vout 2;
a signal output terminal having a second conductive device connected between the signal output terminal and the output terminal Vout2 of the comparator circuit, the second conductive device being conductive when the output terminal Vout2 of the comparator circuit is at a higher level than the signal output terminal.
8. The protection locking and unlocking circuit as claimed in claim 7, wherein said second conductive device is a diode D1, said diode D1 is connected with the output terminal Vout2 of said comparator circuit at the positive pole, and said diode D1 is connected with said signal output terminal at the negative pole.
9. The protection lock and unlock circuit of claim 1 wherein the inverse proportional operational circuit of the detection signal processing sub-circuit comprises an operational amplifier, the forward input terminal of the operational amplifier is connected to the first terminal of the resistor R4 and the first terminal of the resistor R5, the second terminal of the resistor R4 is connected to ground, and the second terminal of the resistor R5 is connected to the power Vcc; the inverting input terminal of the operational amplifier is connected to the first terminal of the resistor R6 and the first terminal of the resistor R7, the second terminal of the resistor R6 is connected to the output terminal of the operational amplifier, and the second terminal of the resistor R7 is connected to the detection signal Vs.
10. An air conditioner characterized by comprising the protection locking and unlocking circuit according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921537241.4U CN210624836U (en) | 2019-09-16 | 2019-09-16 | Protection locking and unlocking circuit and air conditioner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921537241.4U CN210624836U (en) | 2019-09-16 | 2019-09-16 | Protection locking and unlocking circuit and air conditioner |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210624836U true CN210624836U (en) | 2020-05-26 |
Family
ID=70763210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921537241.4U Active CN210624836U (en) | 2019-09-16 | 2019-09-16 | Protection locking and unlocking circuit and air conditioner |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210624836U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110469948A (en) * | 2019-09-16 | 2019-11-19 | 宁波奥克斯电气股份有限公司 | A kind of protection locking and release circuit and air conditioner |
-
2019
- 2019-09-16 CN CN201921537241.4U patent/CN210624836U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110469948A (en) * | 2019-09-16 | 2019-11-19 | 宁波奥克斯电气股份有限公司 | A kind of protection locking and release circuit and air conditioner |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106571803B (en) | Over-voltage and under-voltage detection circuit | |
| WO2020257959A1 (en) | Glitch signal detection circuit, security chip, and electronic apparatus | |
| CN210624836U (en) | Protection locking and unlocking circuit and air conditioner | |
| US20090174564A1 (en) | Dust detecting circuit | |
| CN112134262B (en) | Protection circuit and circuit protection method for power device | |
| CN202142836U (en) | Over-current signal detection circuit | |
| WO2020257958A1 (en) | Glitch signal detection circuit, security chip, and electronic device | |
| CN110469948A (en) | A kind of protection locking and release circuit and air conditioner | |
| CN112117740B (en) | Under-voltage protection trigger circuit, under-voltage protection device and power supply system | |
| CN214577875U (en) | Fan fault detection circuit and device | |
| CN108923386B (en) | A kind of over current protecting self-locking circuit and air conditioner | |
| CN209514845U (en) | A kind of simple signal warning circuit | |
| CN208753973U (en) | A kind of low level triggering latching circuit | |
| CN212304717U (en) | Overvoltage self-locking protection circuit based on triode | |
| CN101425514B (en) | Protection circuit and integrated circuit using the protection circuit | |
| CN106802360B (en) | Radio frequency ESD voltage detection circuit | |
| CN218958795U (en) | Module for quick response to voltage drop | |
| CN204719168U (en) | A kind of current anomaly checking circuit | |
| CN218958528U (en) | Self-locking protection circuit, electronic equipment and vehicle | |
| CN111722663B (en) | Self-locking overvoltage protection circuit | |
| CN212556124U (en) | Triode protection circuit for interface, instrument and automobile | |
| CN109326092B (en) | Simple signal alarm circuit | |
| CN219574231U (en) | Overcurrent detection circuit | |
| CN217007453U (en) | Voltage rapid detection circuit and electronic equipment | |
| CN212540516U (en) | High voltage power supply undervoltage monitoring circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |