Temperature interference resistant pressure switch circuit

By designing an anti-temperature interference pressure switch circuit including signal shunt circuit, shaping amplifier circuit and signal processing circuit, the problem of existing pressure switches accidentally touching underwater and in high temperature environments is solved, and stable operation in a temperature-changing environment is achieved.

CN222802841UActive Publication Date: 2025-04-25LUMINES TECH CO LTD
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Patent Information

Application Number
CN202421512157.8
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-06-28
Publication Date
2025-04-25
Estimated Expiration
2034-06-28

AI Technical Summary

Technical Problem

Existing pressure switches are prone to accidentally touching in underwater environments, and may be triggered to turn on incorrectly due to thermal expansion and contraction in high temperature environments.

Method used

A pressure switch circuit that is anti-temperature interference is designed, including signal shunt circuit, shaping amplification circuit and signal processing circuit. Through a signal conditioning circuit composed of a piezoelectric buzzer and an op amp chip, the shaping amplification and low impedance conversion of the positive and negative half-peripheral signals are realized, and then the temperature changes are stable in a liquid environment.

Benefits of technology

It effectively avoids the pressure switch accidentally touching due to temperature changes, ensures normal operation in environments such as constant temperature swimming pools or hot spring pools, and avoids unnecessary troubles.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to an anti-temperature interference pressure switch circuit. The signal shunt circuit is used for outputting positive and negative half-cycle signals, the shaping and amplifying circuit is used for shaping and amplifying the positive and negative half-cycle signals output by the signal shunt circuit and converting the positive and negative half-cycle signals into low-impedance positive half-cycle signals, and the signal processing circuit is used for receiving electric signals output by the shaping and amplifying circuit. The signal shunting circuit, the shaping and amplifying circuit and the signal processing circuit are conductively connected, and the signal processing circuit receives and processes an electric signal output by the shaping and amplifying circuit so as to judge the state of the electric signal output by the signal shunting circuit. By arranging the signal processing circuit, the piezoelectric buzzer pressure switch can be used in liquid with temperature change, such as a constant-temperature swimming pool or a hot spring pool, so that the pressure switch is prevented from being mistakenly touched due to thermal expansion and cold contraction caused by sudden high and low temperatures, and unnecessary troubles are avoided.
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Description

Technical Field

[0001] The utility model relates to a pressure switch circuit, in particular to a temperature interference resistant pressure switch circuit. Background Art

[0002] Currently, there are capacitive pressure switches and piezoelectric buzzer pressure switches on the market. Capacitive pressure switches are not suitable for underwater use because they may accidentally trigger underwater. Common piezoelectric buzzer pressure switches do not have signal conditioning and may be accidentally triggered and turned on due to sudden high temperatures. Utility Model Content

[0003] The utility model aims to provide a pressure switch circuit which is resistant to temperature interference.

[0004] The purpose of the utility model is achieved in this way:

[0005] A temperature-interference-resistant pressure switch circuit comprises a signal shunt circuit for outputting positive and negative half-cycle signals, a shaping amplifier circuit for shaping and amplifying the positive and negative half-cycle signals output by the signal shunt circuit and converting them into low-impedance positive half-cycle signals, and a signal processing circuit for receiving an electrical signal output by the shaping amplifier circuit; the signal shunt circuit, the shaping amplifier circuit and the signal processing circuit are conductively connected, and the signal processing circuit receives the electrical signal output by the shaping amplifier circuit and performs signal processing to determine the state of the electrical signal output by the signal shunt circuit.

[0006] The signal shunting circuit includes a piezoelectric buzzer X1 that generates sound by inputting positive and negative half-cycle changing signals; the piezoelectric buzzer X1 generates sound when subjected to corresponding pressure and outputs corresponding pressure signals to the shaping amplifier circuit.

[0007] The shaping and amplifying circuit comprises a signal conditioning circuit A which shapes and amplifies the negative half-cycle signal output by the signal shunting circuit and converts it into a low-impedance positive half-cycle signal and outputs it to the signal processing circuit.

[0008] The shaping and amplifying circuit comprises a signal conditioning circuit B which shapes and amplifies the positive half-cycle signal output by the signal shunting circuit and converts it into a low-impedance positive half-cycle signal and outputs it to the signal processing circuit.

[0009] The signal shunting circuit includes a resistor R1 and a resistor R5 conductively connected to the piezoelectric buzzer X1. Pin 1 of the piezoelectric buzzer X1 is grounded, and pin 2 of the piezoelectric buzzer X1 is connected to the resistor R1 and the resistor R5.

[0010] The signal conditioning A circuit includes a filter capacitor, an operational amplifier chip, a resistor, and a diode D1. The filter capacitor, the operational amplifier chip, the resistor, and the diode are conductively connected to form the signal conditioning A circuit.

[0011] The filter capacitor includes a filter capacitor C1 and a filter capacitor C2, the operational amplifier chip includes an operational amplifier chip IC1A and an operational amplifier chip IC1C, and the resistor includes a resistor R3, a resistor R6, a resistor R7, and a resistor R8;

[0012] Pin No. 4 of the operational amplifier chip IC1A is connected to the filter capacitor C1, pin No. 11 of the operational amplifier chip IC1A is connected to the filter capacitor C2, and pin No. 3 of the in-phase end of the operational amplifier chip IC1A is connected to the output end of the signal shunt circuit;

[0013] Output pin No. 1 and inverting pin No. 2 of operational amplifier chip IC1A are connected to resistors R3, R6 and R8;

[0014] Output pin No. 1 of the op amp chip IC1A is connected to resistor R3 and inverting pin No. 9 of the op amp chip IC1C, and the same direction pin No. 10 of the op amp chip IC1C is grounded; inverting pin No. 9 of the op amp chip IC1C is connected to resistor R7, and pin No. 8 of the op amp chip IC1C is connected to diode D1; one end of the filter capacitor C1, the filter capacitor C2, and the resistor R8 are grounded.

[0015] The signal conditioning B circuit includes an operational amplifier chip, a diode D2, and a resistor. The operational amplifier chip, the diode D2, and the resistor are conductively connected to form: a signal conditioning B circuit.

[0016] The operational amplifier chip includes an operational amplifier chip IC1B, the resistors include a resistor R9 and a resistor R10, and a No. 3 in-phase terminal pin of the operational amplifier chip IC1B is connected to an output terminal of the signal shunt circuit;

[0017] The in-phase end pin No. 6 of the operational amplifier chip IC1B is connected to the resistor R9 and the resistor R10, and the output pin No. 7 of the operational amplifier chip IC1B is connected to the diode D2.

[0018] The signal processing circuit includes an MCU, a transistor Q1, a resistor R2, and a resistor R4. The MCU, the transistor Q1, the resistor R2, and the resistor R4 are conductively connected to form a signal processing circuit.

[0019] The beneficial effects of the utility model are as follows:

[0020] By setting up a signal processing circuit in conjunction with a signal shunt circuit, the piezoelectric buzzer pressure switch can be used in temperature-changing liquids, such as a constant-temperature swimming pool or hot spring pool, thereby avoiding accidental contact of the pressure switch due to thermal expansion and contraction caused by sudden high and low temperatures, thereby avoiding unnecessary trouble. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the temperature interference resistant pressure switch circuit of the utility model.

[0022] Figure 2It is a schematic diagram of the structure of each circuit of the temperature interference resistant pressure switch circuit of the utility model. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0024] See also Figure 1 , Figure 2 A temperature-interference-resistant pressure switch circuit includes a signal shunt circuit 1 for outputting positive and negative half-cycle signals, a shaping amplifier circuit 2 for shaping and amplifying the positive and negative half-cycle signals output by the signal shunt circuit 1 and converting them into low-impedance positive half-cycle signals, and a signal processing circuit 3 for receiving the electrical signal output by the shaping amplifier circuit 2; the signal shunt circuit 1, the shaping amplifier circuit 2, and the signal processing circuit 3 are conductively connected, and the signal processing circuit 3 receives the electrical signal output by the shaping amplifier circuit 2 and performs signal processing to determine the state of the electrical signal output by the signal shunt circuit 1.

[0025] The piezoelectric buzzer X1 of the signal shunt circuit 1 is a piezoelectric ceramic piece, which needs to input a positive and negative half-cycle change signal to make a sound. This characteristic of the piezoelectric ceramic piece is used to generate weak positive and negative half-cycle signals. The piezoelectric buzzer X1 is connected in parallel with R5 to obtain a pressure feedback signal, which is output through R1 to the subsequent shaping amplifier circuit 2 for use.

[0026] The signal shunting circuit 1 includes a piezoelectric buzzer X1 that generates sound by inputting positive and negative half-cycle changing signals; the piezoelectric buzzer X1 generates sound when subjected to corresponding pressure and outputs corresponding pressure signals to the shaping amplifier circuit 2 .

[0027] The shaping and amplifying circuit 2 includes a signal conditioning circuit A that shapes and amplifies the negative half-cycle signal output by the signal shunting circuit 1 and converts it into a low-impedance positive half-cycle signal and outputs it to the signal processing circuit 3 .

[0028] The shaping and amplifying circuit 2 includes a signal conditioning circuit B that shapes and amplifies the positive half-cycle signal output by the signal shunting circuit 1 and converts it into a low-impedance positive half-cycle signal and outputs it to the signal processing circuit 3 .

[0029] The signal shunting circuit 1 includes a resistor R1 and a resistor R5 conductively connected to the piezoelectric buzzer X1 . Pin 1 of the piezoelectric buzzer X1 is grounded, and pin 2 of the piezoelectric buzzer X1 is connected to the resistor R1 and the resistor R5 .

[0030] The signal conditioning A circuit includes a filter capacitor, an operational amplifier chip, a resistor, and a diode D1. The filter capacitor, the operational amplifier chip, the resistor, and the diode are conductively connected to form the signal conditioning A circuit.

[0031] The filter capacitor includes a filter capacitor C1 and a filter capacitor C2, the operational amplifier chip includes an operational amplifier chip IC1A and an operational amplifier chip IC1C, and the resistor includes a resistor R3, a resistor R6, a resistor R7, and a resistor R8;

[0032] Pin No. 4 of the operational amplifier chip IC1A is connected to the filter capacitor C1, pin No. 11 of the operational amplifier chip IC1A is connected to the filter capacitor C2, and pin No. 3 of the in-phase end of the operational amplifier chip IC1A is connected to the output end of the signal shunt circuit 1;

[0033] Output pin No. 1 and inverting pin No. 2 of operational amplifier chip IC1A are connected to resistors R3, R6 and R8;

[0034] Output pin No. 1 of the op amp chip IC1A is connected to resistor R3 and inverting pin No. 9 of the op amp chip IC1C, and the same direction pin No. 10 of the op amp chip IC1C is grounded; inverting pin No. 9 of the op amp chip IC1C is connected to resistor R7, and pin No. 8 of the op amp chip IC1C is connected to diode D1; one end of the filter capacitor C1, the filter capacitor C2, and the resistor R8 are grounded.

[0035] Signal ConditioningA

[0036] Since the piezoelectric buzzer chip X1 has a high impedance output and the signal is weak, it needs to be conditioned by a common-mode proportional amplifier circuit to avoid impedance mismatch and signal distortion. The op amp chip uses a FET op amp, see Figure 2 , the power supply +5V is input to the No. 4 power supply pin of the op amp chip IC1A through the filter capacitor C1, -5V is input to the No. 11 power supply pin of the op amp chip IC1A through the filter capacitor C2, the negative electrode of the 2nd foot of the piezoelectric buzzer X1 enters the No. 3 in-phase pin of the op amp chip IC1A through the resistor R1, the No. 1 output pin of the op amp chip IC1A is input to the No. 2 inverting pin of the op amp chip IC1A through the resistor R6 and the resistor R8 to form the in-phase proportional amplification, according to the formula G=1+R6 / R8, the op amp amplification factor of the op amp chip IC1A can be obtained, the No. 1 pin output of the op amp chip IC1A enters the No. 9 inverting pin of the op amp chip IC1C through the resistor R3, the No. 10 in-phase pin of the op amp chip IC1C is grounded, and the No. 8 pin output of the op amp chip IC1C is input to the op amp chip IC1C through the resistor R7 and the resistor R3. The No. 9 inverting end pin of the op amp chip is connected to form an inverting amplifier circuit. According to the formula G=R7 / R3, the op amp gain of the op amp chip IC1C can be obtained. The No. 8 pin of the op amp chip IC1C is output through the diode D1. This part shapes and amplifies the negative half-cycle signal of the piezoelectric buzzer signal and converts it into a low-impedance positive half-cycle signal for use in the subsequent signal processing circuit 3.

[0037] The signal conditioning B circuit includes an operational amplifier chip, a diode D2, and a resistor. The operational amplifier chip, the diode D2, and the resistor are conductively connected to form: a signal conditioning B circuit.

[0038] The operational amplifier chip includes an operational amplifier chip IC1B, the resistors include a resistor R9 and a resistor R10, and a No. 3 in-phase end pin of the operational amplifier chip IC1B is connected to an output end of the signal shunt circuit 1;

[0039] The in-phase end pin No. 6 of the operational amplifier chip IC1B is connected to the resistor R9 and the resistor R10, and the output pin No. 7 of the operational amplifier chip IC1B is connected to the diode D2.

[0040] See also Figure 2 The negative electrode of pin 2 of the piezoelectric buzzer X1 enters the No. 3 in-phase terminal pin of the operational amplifier chip IC1B through the resistor R1, and the No. 7 output pin of the operational amplifier chip IC1B is input to the No. 6 in-phase terminal pin of the operational amplifier chip IC1B through the resistor R9 and the resistor R10 to form an in-phase proportional amplification. According to the formula G=1+R9 / R10, the operational amplifier amplification factor of the operational amplifier chip IC1B can be obtained. The No. 7 pin of the operational amplifier chip IC1B is output through the diode D2. This part reshapes and amplifies the positive half-cycle signal of the piezoelectric buzzer signal and converts it into a low-impedance positive half-cycle signal for use in the subsequent signal processing circuit 3.

[0041] The signal processing circuit 3 includes an MCU, a transistor Q1 , a resistor R2 , and a resistor R4 . The MCU, the transistor Q1 , the resistor R2 , and the resistor R4 are conductively connected to form the signal processing circuit 3 .

[0042] The complete pressure signal of the piezoelectric buzzer X1 can be obtained by merging the output signals of the signal conditioning circuit A and the signal conditioning circuit B. The pressure signal is divided by resistors R2 and R4 and enters the transistor Q1. The MOS tube (transistor Q1) converts the pressure signal into a high-low level signal and inputs it to the pin of the MCU. The MCU triggers the interrupt processing of the pin. When the MCU detects the trigger signal on the pin, it starts to enter the signal processing. Within the limited time range (100~360ms), if the end signal is detected, the MCU determines that the pressure signal is normal, and turns it on or off according to the current state of the switch, and displays the current state of the switch by the color of the LED. For example, when the switch is in the on state, the LED lights up green, and when the switch is in the off state, the LED lights up red. If the end signal is not detected within the limited time range or the end signal is detected within the limited time range, the MCU determines that the pressure signal is abnormal, and ends the signal processing of the MCU until the trigger signal is detected again, and the MCU re-enters the signal processing.

[0043] The above is a preferred embodiment of the utility model, which shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. The utility model may have various changes and improvements without departing from the spirit and scope of the utility model, and these changes and improvements fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A temperature-resistant pressure switch circuit, characterized in that: The invention comprises a signal shunting circuit (1) for outputting positive and negative half-cycle signals, a shaping amplifier circuit (2) for shaping and amplifying the positive and negative half-cycle signals output by the signal shunting circuit (1) and converting them into low-impedance positive half-cycle signals, and a signal processing circuit (3) for receiving the electrical signal output by the shaping amplifier circuit (2); the signal shunting circuit (1), the shaping amplifier circuit (2) and the signal processing circuit (3) are conductively connected, and the signal processing circuit (3) receives the electrical signal output by the shaping amplifier circuit (2) and performs signal processing to determine the state of the electrical signal output by the signal shunting circuit (1).

2. The temperature-interference-resistant pressure switch circuit according to claim 1, characterized in that: The signal shunting circuit (1) comprises a piezoelectric buzzer X1 which generates sound by inputting a positive and negative half-cycle changing signal; the piezoelectric buzzer X1 generates sound when subjected to a corresponding pressure and outputs a corresponding pressure signal to a shaping amplifier circuit (2).

3. The temperature-interference-resistant pressure switch circuit according to claim 1, characterized in that: The shaping and amplifying circuit (2) comprises a signal conditioning circuit A which shapes and amplifies the negative half-cycle signal output by the signal shunting circuit (1) and converts it into a low-impedance positive half-cycle signal and outputs it to the signal processing circuit (3).

4. The temperature-interference-resistant pressure switch circuit according to claim 1, characterized in that: The shaping and amplifying circuit (2) comprises a signal conditioning circuit B which shapes and amplifies the positive half-cycle signal output by the signal shunting circuit (1) and converts it into a low-impedance positive half-cycle signal and outputs it to the signal processing circuit (3).

5. The temperature-interference-resistant pressure switch circuit according to claim 1, characterized in that: The signal shunting circuit (1) comprises a resistor R1 and a resistor R5 which are conductively connected to the piezoelectric buzzer X1. Pin 1 of the piezoelectric buzzer X1 is grounded, and pin 2 of the piezoelectric buzzer X1 is connected to the resistor R1 and the resistor R5.

6. The temperature-interference-resistant pressure switch circuit according to claim 3, characterized in that: The signal conditioning A circuit includes a filter capacitor, an operational amplifier chip, a resistor, and a diode D1. The filter capacitor, the operational amplifier chip, the resistor, and the diode are conductively connected to form the signal conditioning A circuit.

7. The temperature-interference-resistant pressure switch circuit according to claim 6, characterized in that: The filter capacitor includes a filter capacitor C1 and a filter capacitor C2, the operational amplifier chip includes an operational amplifier chip IC1A and an operational amplifier chip IC1C, and the resistor includes a resistor R3, a resistor R6, a resistor R7, and a resistor R8; Pin No. 4 of the operational amplifier chip IC1A is connected to the filter capacitor C1, pin No. 11 of the operational amplifier chip IC1A is connected to the filter capacitor C2, and pin No. 3 of the in-phase end of the operational amplifier chip IC1A is connected to the output end of the signal shunt circuit (1); Output pin No. 1 and inverting pin No. 2 of operational amplifier chip IC1A are connected to resistors R3, R6 and R8; Output pin No. 1 of the op amp chip IC1A is connected to resistor R3 and inverting pin No. 9 of the op amp chip IC1C, and the same direction pin No. 10 of the op amp chip IC1C is grounded; inverting pin No. 9 of the op amp chip IC1C is connected to resistor R7, and pin No. 8 of the op amp chip IC1C is connected to diode D1; one end of the filter capacitor C1, the filter capacitor C2, and the resistor R8 are grounded.

8. The temperature-interference-resistant pressure switch circuit according to claim 4, characterized in that: The signal conditioning B circuit includes an operational amplifier chip, a diode D2, and a resistor. The operational amplifier chip, the diode D2, and the resistor are conductively connected to form: a signal conditioning B circuit.

9. The temperature-interference-resistant pressure switch circuit according to claim 8, characterized in that: The operational amplifier chip includes an operational amplifier chip IC1B, the resistors include resistors R9 and R10, and the No. 3 in-phase terminal pin of the operational amplifier chip IC1B is connected to the output terminal of the signal shunt circuit (1); The in-phase end pin No. 6 of the operational amplifier chip IC1B is connected to the resistor R9 and the resistor R10, and the output pin No. 7 of the operational amplifier chip IC1B is connected to the diode D2.

10. The temperature-interference-resistant pressure switch circuit according to claim 1, characterized in that: The signal processing circuit (3) comprises an MCU, a transistor Q1, a resistor R2, and a resistor R4. The MCU, the transistor Q1, the resistor R2, and the resistor R4 are conductively connected to form the signal processing circuit (3).