CN211293166U

CN211293166U - Improved circuit for detecting wind pressure switch

Info

Publication number: CN211293166U
Application number: CN201922302202.2U
Authority: CN
Inventors: 胡志恒; 刘筱明; 高中伟
Original assignee: Foshan City Ceron Electronics Technology Co ltd
Current assignee: Foshan City Ceron Electronics Technology Co ltd
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2020-08-18
Anticipated expiration: 2029-12-18

Abstract

The utility model discloses an improved generation circuit to wind pressure switch detection comprises wind pressure switch S1, resistance R1 ~ R5, diode D1, electrolytic capacitor C1, electric capacity C2 and comparator IC circuit U1A, resistance R1 is connected with the anodal VCC of system DC power supply, and its other end is connected with wind pressure switch S1, and the wind pressure switch S1 other end is connected with 2 nd foot of resistance R3 and comparator IC circuit U1A, and resistance R3' S the other end also is connected systematically with system DC power supply negative pole. Resistance R2 also is connected with the anodal VCC of system DC power supply, the utility model discloses not only can detect out two stable state of closure and disconnection of wind pressure switch accurately, also can carry out corresponding detection judgement when being in "shake" state to the wind pressure switch moreover.

Description

Improved circuit for detecting wind pressure switch

Technical Field

The utility model relates to an electric and electronic control technical field specifically is an improved generation circuit that detects wind pressure switch.

Background

In products such as gas water heaters, gas wall-mounted furnaces and the like, a wind pressure switch is an indispensable wind pressure detection sensing mechanism, and the wind pressure switch is also a necessary safety control part of the whole machine product, and the wind pressure switch is used for accurately detecting whether a fan in the machine works, whether wind power is sufficient during smoke discharge operation of the fan, and even whether a system can reliably stop operation when a smoke discharge pipe is blocked. In the prior art, the detection of the wind pressure switch is usually limited to the detection of two stable states of closing and opening of the wind pressure switch, but in practice, because high-temperature flue gas generated by a complete machine combustion system is exhausted in a turbulent flow form in the exhaust process, the generated wind pressure often has a standing wave shaking situation, and the wind pressure value sampled to enter the wind pressure switch has a shaking situation; secondly, because of being influenced by environment outside wind-force, often also can have the influence of flowing backward wind when the tobacco pipe discharges fume, therefore when carrying out the wind pressure sampling to the wind pressure switch, the wind pressure that the sampling obtained is also unstable. Because the wind pressure switch is a micro-pressure detection mechanism, any slight pressure fluctuation can cause detection results to be different. In the two situations, the final result is that the wind pressure switch has frequent shaking state. The traditional detection circuit only detects two stable states of opening or closing of the wind pressure switch, and when the wind pressure switch is in the jitter state, the judgment is carried out by taking the two states as the standard or adopting the filtering to remove the jitter. Both of the two methods have great limitations, and frequent misjudgment and misjudgment are inevitably caused. Only if the 'shaking' state of the wind pressure switch is correctly recognized, namely, the wind pressure switch is also in a normal working state, and reasonable judgment selection is specially made aiming at the shaking situation of the wind pressure switch, the problem of misjudgment can be correctly processed.

At present, in the fault reporting and repairing of the products, the complaint of the false reporting of the wind pressure switch in the industry is the first place. The utility model discloses a three kinds of operating condition to the wind pressure switch all can detect, consequently can solve this puzzlement nature technical problem that exists in the industry well.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an improved generation circuit to wind pressure switch detects to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

an improved circuit for detecting a wind pressure switch comprises a wind pressure switch S1, resistors R1-R5, a diode D1, an electrolytic capacitor C1, a capacitor C2 and a comparator IC circuit U1A, wherein the resistor R1 is connected with a positive pole VCC of a system direct current power supply, the other end of the resistor R1 is connected with the wind pressure switch S1, the other end of the wind pressure switch S1 is connected with the resistor R3 and a No. 2 pin of the comparator IC circuit U1A, and the other end of the resistor R3 is connected with a negative pole of the system direct current power supply, namely, the negative pole of the system direct current power supply is connected with the system ground. The resistor R2 is also connected to the positive terminal VCC of the system dc power supply, and the other terminal thereof is connected to the anode of the diode D1 and the 3 rd pin of the comparator IC circuit U1A, and the cathode of the diode D1 is connected to the negative terminal of the system dc power supply, i.e., the system ground. The resistor R4 is also connected with the positive pole VCC of the system DC power supply, the other end of the resistor R4 is connected with the resistor R5, the positive pole of the electrolytic capacitor C1 and the 1 st pin of the comparator IC circuit U1A, the other end of the resistor R5 is connected with the positive pole of the electrolytic capacitor C2, and the negative poles of the electrolytic capacitors C1 and C2 are both connected with the negative pole of the system DC power supply, namely the system ground.

As a further aspect of the present invention: and the connection point of the resistor R5 and the capacitor C2 is also used as a detection signal output terminal TEST _ IO and is connected into an input port of a wind pressure switch detection circuit of a singlechip of the whole system.

As a further aspect of the present invention: when the resistances of the resistor R1 and the resistor R3 are selected to ensure that the wind pressure switch S1 is in a closed state, the voltage value of the inverting end of the No. 2 pin of the comparator IC circuit U1A is greater than the voltage drop of the forward conducting tube of the diode D1.

As a further aspect of the present invention: the comparator IC circuit U1A is of type LM 393.

As a further aspect of the present invention: the voltage of the positive pole VCC of the system direct current power supply is 5V.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses not only can detect out to two closed and break off stable states of wind pressure switch accurately, also can carry out corresponding detection judgement when being in "shake" state to the wind pressure switch moreover.

Drawings

Fig. 1 is a circuit diagram of a first embodiment of the present invention.

Fig. 2 is a circuit diagram of a second embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1: referring to fig. 1-2, in an embodiment of the present invention, an improved circuit for detecting a wind pressure switch is composed of a wind pressure switch S1, resistors R1-R5, a diode D1, electrolytic capacitors C1, C2, and a comparator IC circuit U1A.

Referring to fig. 1, as one embodiment of the present invention, in the circuit, the resistor R1 is connected to the positive VCC of the dc power supply, the other end of the resistor R1 is connected to the wind pressure switch S1, the other end of the wind pressure switch S1 is connected to the resistor R3 and the 2 nd pin of the comparator IC circuit U1A, and the other end of the resistor R3 is connected to the negative pole of the dc power supply, i.e. the system ground. The resistor R2 is also connected to the positive terminal VCC of the system dc power supply, and the other terminal thereof is connected to the anode of the diode D1 and the 3 rd pin of the comparator IC circuit U1A, and the cathode of the diode D1 is connected to the negative terminal of the system dc power supply, i.e., the system ground. The resistor R4 is also connected to the positive electrode VCC of the system dc power supply, and the other end thereof is connected to the resistor R5, the positive electrode of the electrolytic capacitor C1, and the 1 st pin of the comparator IC circuit U1A. The other end of the resistor R5 is connected with the anode of the electrolytic capacitor C2, and the connection point is also used as a detection signal output terminal TEST _ IO and can be connected into an input port of a wind pressure switch detection circuit of a singlechip of the whole system. The cathodes of the electrolytic capacitors C1 and C2 are both connected with the cathode of the system direct current power supply, namely the system ground.

Referring to fig. 1, as one embodiment of the present invention, in the circuit, when the resistances of the resistors R1 and R3 are selected to ensure that the wind pressure switch S1 is in the closed state, the voltage value of the inverting terminal of the 2 nd pin of the comparator IC circuit U1A is greater than the forward conducting tube voltage drop of the diode D1. Comparator IC circuit U1A is of type LM393, or of the same type.

Referring to fig. 1, as one of the embodiments of the present invention, the circuit is characterized in that it can not only accurately detect the two stable states of the closing and the opening of the wind pressure switch, but also perform the corresponding detection and judgment when the wind pressure switch is in the "shaking" state. When the wind pressure switch S1 is in an off state, the voltage of the inverting terminal of the 2 nd pin of the comparator IC circuit U1A is zero, and the voltage of the non-inverting terminal of the 3 rd pin of the comparator IC circuit U1A is about 0.35 to 0.7V, which is the voltage drop of the conducting tube of the diode D1, so that the output port of the 1 st pin of the comparator IC circuit U1A is constantly at a high level, and thus the voltage of the TEST _ IO terminal is also constantly at a high level; when the wind pressure switch S1 is in a closed state, the voltage of the inverting terminal of the 2 nd pin of the comparator IC circuit U1A is greater than the voltage drop of the forward conducting tube of the diode D1 under the partial voltage of the resistors R1 and R2, so the output port of the 1 st pin of the comparator IC circuit U1A is constantly at a low level, and thus the voltage of the TEST _ IO terminal is also constantly at a low level; when the wind pressure switch S1 is in "shaking" state, the output port voltage of the 1 st pin of the corresponding comparator IC circuit U1A is in pulse state, and under the charging and discharging and filtering action of the capacitors C1 and C2, the TEST _ IO terminal voltage is in a certain intermediate voltage state between high level and low level.

Referring to fig. 1, as one embodiment of the present invention, when detecting that the signal output terminal TEST _ IO level is a constant high level, it can determine that the wind pressure switch S1 is in an off state; when the signal output end TEST _ IO level is detected to be a constant low level, the wind pressure switch S1 can be judged to be in a closed state; when the voltage of the signal output terminal TEST _ IO is detected to be between the high level and the low level, it can be determined that the wind pressure switch S1 is in the third state "jitter" state.

Example 2: the difference from example 1 is that, referring to fig. 2, the design; the 2 and 3 pins of the comparator IC circuit U1A are the reverse of the connections in example 1.

The circuit is characterized in that the circuit can not only accurately detect two stable states of the closing and the opening of the wind pressure switch, but also carry out corresponding detection and judgment when the wind pressure switch is in a shaking state. When the wind pressure switch S1 is in an off state, the voltage of the non-inverting terminal of the 3 rd pin of the comparator IC circuit U1A is zero, and at this time, the voltage of the inverting terminal of the 2 nd pin of the comparator IC circuit U1A is the voltage drop of the conducting tube of the diode D1, which is about 0.35 to 0.7V, so that the output port of the 1 st pin of the comparator IC circuit U1A is constantly at a low level, and thus the voltage of the TEST _ IO terminal is also constantly at a low level; when the wind pressure switch S1 is in a closed state, the voltage of the 3 rd pin in the phase of the comparator IC circuit U1A is greater than the voltage drop of the forward conducting tube of the diode D1 under the partial pressure of the resistors R1 and R2, so the output port of the 1 st pin of the comparator IC circuit U1A is constantly at a high level, and thus the voltage of the TEST _ IO terminal is also constantly at a high level; when the wind pressure switch S1 is in "shaking" state, the output port voltage of the 1 st pin of the corresponding comparator IC circuit U1A is in pulse state, and under the charging and discharging and filtering action of the capacitors C1 and C2, the TEST _ IO terminal voltage is in a certain intermediate voltage state between high level and low level. When the signal output end TEST _ IO level is detected to be a constant low level, the wind pressure switch S1 can be judged to be in a disconnected state; when the signal output end TEST _ IO level is detected to be a constant high level, the wind pressure switch S1 can be judged to be in a closed state; when the voltage of the signal output terminal TEST _ IO is detected to be between the high level and the low level, it can be determined that the wind pressure switch S1 is in the third state "jitter" state.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. An improved circuit for detecting a wind pressure switch comprises a wind pressure switch S1, resistors R1-R5, a diode D1, an electrolytic capacitor C1, a capacitor C2 and a comparator IC circuit U1A, and is characterized in that the resistor R1 is connected with a system direct current power supply anode VCC, the other end of the resistor R1 is connected with a wind pressure switch S1, the other end of the wind pressure switch S1 is connected with a resistor R3 and a 2 nd pin of the comparator IC circuit U1A, the other end of the resistor R3 is connected with a system direct current power supply cathode i.e. a system ground, a resistor R2 is also connected with the system direct current power supply anode VCC, the other end of the resistor R1 is connected with an anode of the diode D1 and a 3 rd pin of the comparator IC circuit U1A i.e. a cathode of the diode D1 is connected with the system direct current power supply cathode 68645, the resistor R4 is also connected with the system direct current power supply anode VCC, the other end of the resistor R5, the anode of the electrolytic capacitor C1 and the comparator IC circuit U1 st, the other end of the resistor R5 is connected with the anode of the electrolytic capacitor C2, and the cathodes of the electrolytic capacitors C1 and C2 are both connected with the cathode of the system direct current power supply, namely the system ground.

2. The improved circuit for detecting the wind pressure switch according to claim 1, wherein the connection point of the resistor R5 and the capacitor C2 is also used as a detection signal output terminal TEST _ IO, and is connected to an input port of the wind pressure switch detection circuit of a single chip microcomputer of the whole system.

3. The improved circuit for detecting a wind pressure switch according to claim 1, wherein the resistances of the resistor R1 and the resistor R3 are selected to ensure that when the wind pressure switch S1 is in a closed state, the voltage value of the 2 nd pin inverting terminal of the comparator IC circuit U1A is greater than the forward conducting tube voltage drop of the diode D1.

4. The improved circuit for detecting wind pressure switches according to claim 3, wherein the comparator IC circuit U1A is LM393 in model number.

5. The improved circuit for detecting wind pressure switch according to claim 2, wherein the voltage of the positive electrode VCC of the system dc power supply is 5V.