CN210221889U

CN210221889U - Capacitive leaf surface humidity conversion circuit

Info

Publication number: CN210221889U
Application number: CN201921098730.4U
Authority: CN
Inventors: Xiang Wang; 王相; Dawei Song; 宋大伟; Xilong Pang; 庞喜龙
Original assignee: Weihai Jing Jing Tong Electronic Technology Co Ltd
Current assignee: Weihai Jing Jing Tong Electronic Technology Co Ltd; Weihai Jingxun Changtong Electronic Technology Co Ltd
Priority date: 2019-07-12
Filing date: 2019-07-12
Publication date: 2020-03-31
Anticipated expiration: 2029-07-12

Abstract

The utility model provides a pair of capacitanc leaf surface humidity converting circuit, include: the device comprises a monostable trigger circuit, a capacitance conversion circuit, a capacitance discharge circuit, a capacitance filter circuit and a controller; the monostable trigger circuit outputs square waves with fixed frequency and duty ratio to the capacitance conversion circuit, and a humidity-sensitive capacitor for monitoring leaf surface humidity conversion is arranged in the capacitance conversion circuit; the capacitance conversion circuit is respectively connected with the capacitance discharge circuit and the capacitance filter circuit, and discharges electricity through the capacitance discharge circuit and converts the electricity into smooth voltage through the capacitance filter circuit; the controller adopts the singlechip, and the controller passes through singlechip AD acquisition circuit and is connected with electric capacity filter circuit, the controller is used for gathering the voltage of humidity sensitive electric capacity.

Description

Capacitive leaf surface humidity conversion circuit

Technical Field

The utility model relates to an electronic equipment technical field, more specifically the saying so relates to a capacitanc leaf surface humidity conversion circuit.

Background

The humidity of the plant leaf surface is very important for the growth of the leaf, and in the past, people often monitor the humidity of air, but ignore the monitoring of the leaf surface humidity. In fact, the leaf surface humidity can reflect the real growth index of the leaf surface. The leaf surface humidity sensor can accurately measure the humidity of the leaf surface, so that the growth environment of the plant leaf can be detected, and the purpose of preventing plant diseases and insect pests is achieved.

The traditional mode of collecting the leaf surface humidity is a resistance type detection method, and the mode has large detection error and short service life caused by the fact that a probe is easy to corrode by moisture in the air.

SUMMERY OF THE UTILITY MODEL

To the above problem, an object of the utility model is to provide a capacitanc leaf surface humidity conversion circuit realizes the accurate measurement to leaf surface humidity data.

The utility model discloses a realize above-mentioned purpose, realize through following technical scheme: a capacitive leaf surface moisture conversion circuit comprising: the device comprises a monostable trigger circuit, a capacitance conversion circuit, a capacitance discharge circuit, a capacitance filter circuit and a controller; the monostable trigger circuit is connected with the capacitance conversion circuit, the monostable trigger circuit is used for outputting square waves with fixed frequency and duty ratio to the capacitance conversion circuit, and a humidity-sensitive capacitor for monitoring leaf surface humidity conversion is arranged in the capacitance conversion circuit; the capacitance conversion circuit is respectively connected with the capacitance discharge circuit and the capacitance filter circuit, and discharges electricity through the capacitance discharge circuit and converts the electricity into smooth voltage through the capacitance filter circuit; the controller adopts a single chip microcomputer, is connected with the capacitor filter circuit through a single chip microcomputer AD acquisition circuit and is used for acquiring the voltage of the humidity-sensitive capacitor; the humidity-sensitive capacitor is a printed circuit board, crossed wires are drawn on the printed circuit board, and the wires are in a plant vein shape and form a capacitor.

Further, the monostable flip-flop circuit includes: the circuit comprises a timer U2, a resistor R3, a resistor R4, a capacitor C4 and a capacitor C5; a pin I of the timer U2 and a second end of the capacitor C4 are respectively grounded; the second pin of the timer U2 is respectively connected with the sixth pin of the timer U2, the first end of the capacitor C5 and the second end of the resistor R4; the second end of the capacitor C5 is grounded; a fifth pin of the timer U2 is connected with a first end of the capacitor C4; a fourth pin of the timer U2, an eighth pin of the timer U2 and a first end of the resistor R3 are respectively connected with a power supply; a seventh pin of the timer U2 is respectively connected with the second end of the resistor R3 and the first end of the resistor R4; the third pin of the timer U2 is connected to the first end of the resistor R5, and the second end of the resistor R5 is connected to the capacitance conversion circuit.

Further, the capacitance conversion circuit comprises a humidity sensitive capacitor O1; the second end of the humidity sensitive capacitor is connected with the second end of the resistor R5, and the first end of the humidity sensitive capacitor is grounded.

Further, the capacitance discharge circuit includes: diode D1, resistor R6; the anode of the diode D1 is connected to the second terminal of the resistor R5, the cathode of the diode D1 is connected to the first terminal of the resistor R6, and the second terminal of the resistor R6 is grounded.

Further, the capacitive filter circuit includes a capacitor C6; a first terminal of the capacitor C6 is connected to a first terminal of the resistor R6, and a second terminal of the capacitor C6 is grounded.

Further, the single chip microcomputer AD acquisition circuit comprises a single chip microcomputer U1 and a resistor R1; a first pin of the singlechip U1 is connected with a first end of a resistor R1, and a second end of the resistor R1 is grounded; a fifth pin of the singlechip U1 is connected with a power supply, and a sixth pin of the singlechip U1 is connected with a first end of the capacitor C6; the fifteenth pin of the single chip microcomputer U1 is grounded, and the sixteenth pin of the single chip microcomputer U1 is connected with a power supply.

Further, the timer adopts a TLC555 timer.

Further, the single chip microcomputer is of the type STM32F030F4P 6.

Contrast prior art, the utility model discloses beneficial effect lies in: the utility model provides a capacitanc foliage humidity converting circuit constitutes monostable trigger circuit, the fixed square wave of output frequency and duty cycle by TLC 555. The leaf vein imitating the plant is achieved by drawing crossed wires on the PCB, a capacitor is formed, the dielectric constant of the capacitor is influenced by the presence of water dew on the capacitor, according to the formula C ═ epsilon S/4 pi kd, S, d is fixed and constant because the leaf vein grain area imitated by the PCB and the distance between leaf veins are also fixed and constant, and the size of the capacitor is influenced by the dielectric constant epsilon and is in direct proportion to the size of the capacitor. The capacitor is discharged through the discharge loop, and the step realizes continuous charging and discharging of the capacitor. Converted to a smoothed voltage by capacitive filtering. And collecting the voltage through the singlechip. The change of the leaf surface humidity is calculated by monitoring the change of the voltage, and the accurate measurement of the leaf surface humidity data is realized.

Crossed wires are drawn on the printed circuit board, and the wires are in a plant vein shape and form a capacitor. The shape of simulation blade is favorable to the humidity of accurate measurement page, the utility model discloses can wide application in agricultural production and agricultural scientific research, the growth and development of research crop, pest control.

Therefore, compared with the prior art, the utility model has the outstanding substantive features and the obvious progress, and the beneficial effect of the implementation is also obvious.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a block diagram of the present invention.

Fig. 2 is a diagram of a monostable flip-flop circuit.

Fig. 3 is a structural diagram of a capacitance conversion circuit.

Fig. 4 is a diagram of a capacitor discharge circuit.

Fig. 5 is a diagram of a capacitive filter circuit.

Fig. 6 is a structure diagram of an AD acquisition circuit of the singlechip.

Fig. 7 is a diagram of the overall circuit structure of the present invention.

FIG. 8 is a schematic circuit diagram of a humidity sensitive capacitor.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings.

The capacitive leaf surface humidity conversion circuit shown in fig. 1 comprises a monostable trigger circuit, a capacitance conversion circuit, a capacitance discharge circuit, a capacitance filter circuit and a controller; the monostable trigger circuit outputs square waves with fixed frequency and duty ratio to the capacitance conversion circuit, and a humidity-sensitive capacitor for monitoring leaf surface humidity conversion is arranged in the capacitance conversion circuit; the capacitance conversion circuit is respectively connected with the capacitance discharge circuit and the capacitance filter circuit, and discharges electricity through the capacitance discharge circuit and converts the electricity into smooth voltage through the capacitance filter circuit; the controller adopts a single chip microcomputer, is connected with the capacitor filter circuit through a single chip microcomputer AD acquisition circuit and is used for acquiring the voltage of the humidity-sensitive capacitor; as shown in fig. 8, the moisture-sensitive capacitor is a printed circuit board, and crossed wires are drawn on the printed circuit board, and the wires are in a plant vein shape and form a capacitor.

As shown in fig. 2, the monostable flip-flop circuit includes: the circuit comprises a timer U2, a resistor R3, a resistor R4, a capacitor C4 and a capacitor C5; a pin I of the timer U2 and a second end of the capacitor C4 are respectively grounded; the second pin of the timer U2 is respectively connected with the sixth pin of the timer U2, the first end of the capacitor C5 and the second end of the resistor R4; the second end of the capacitor C5 is grounded; a fifth pin of the timer U2 is connected with a first end of the capacitor C4; a fourth pin of the timer U2, an eighth pin of the timer U2 and a first end of the resistor R3 are respectively connected with a power supply; a seventh pin of the timer U2 is respectively connected with the second end of the resistor R3 and the first end of the resistor R4; the third pin of the timer U2 is connected to the first end of the resistor R5, and the second end of the resistor R5 is connected to the capacitance conversion circuit. Wherein, the timer U2 adopts a TLC555 timer. The power supply adopts a 3.3V power supply, the resistance value of the resistor R3 is 330 omega, the resistance value of the resistor R4 is 2K omega, the resistance value of the resistor R5 is 10K omega, the capacitance value of the capacitor C4 is 100nF, and the capacitance value of the capacitor C5 is 1 nF.

As shown in fig. 3, the capacitance conversion circuit includes a humidity sensitive capacitor O1; the second end of the humidity sensitive capacitor is connected with the second end of the resistor R5, and the first end of the humidity sensitive capacitor is grounded. The humidity-sensitive capacitor is a printed circuit board, crossed wires are drawn on the printed circuit board, and the wires are in a plant vein shape and form a capacitor.

As shown in fig. 4, the capacitance discharge circuit includes: diode D1, resistor R6; the anode of the diode D1 is connected to the second terminal of the resistor R5, the cathode of the diode D1 is connected to the first terminal of the resistor R6, and the second terminal of the resistor R6 is grounded. The resistance of the resistor R6 is 1M omega.

As shown in fig. 5, the capacitive filter circuit includes a capacitor C6; a first terminal of the capacitor C6 is connected to a first terminal of the resistor R6, and a second terminal of the capacitor C6 is grounded. The capacitance value of the capacitor C6 is 1 muF.

As shown in fig. 6, the single chip microcomputer AD acquisition circuit comprises a single chip microcomputer U1 and a resistor R1; a first pin of the singlechip U1 is connected with a first end of a resistor R1, and a second end of the resistor R1 is grounded; a fifth pin of the singlechip U1 is connected with a power supply, and a sixth pin of the singlechip U1 is connected with a first end of the capacitor C6; the fifteenth pin of the single chip microcomputer U1 is grounded, and the sixteenth pin of the single chip microcomputer U1 is connected with a power supply. The single chip microcomputer U1 is an STM32F030F4P6 single chip microcomputer. The resistance of the resistor R1 is 1K omega.

As shown in FIG. 7, a monostable trigger circuit is composed of TLC555, and a square wave with fixed frequency and duty ratio is output. The leaf vein imitating the plant is achieved by drawing crossed wires on the printed circuit board, a capacitor is formed, the dielectric constant of the capacitor is influenced by the presence of water dew on the capacitor, according to the formula C ═ epsilon S/4 pi kd, S, d is fixed and constant because the leaf vein grain area imitated by the printed circuit board and the distance between leaf veins are also fixed and constant, 4 pi k is constant, so that the size of the capacitor is influenced by the dielectric constant epsilon and is in direct proportion to the size of the capacitor. The capacitor is discharged through the capacitor discharge circuit, and the step realizes continuous charging and discharging of the capacitor. Converted to a smooth voltage by a capacitive filter circuit. And collecting the voltage through the singlechip.

The present invention will be further described with reference to the accompanying drawings and specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope defined in the present application.

Claims

1. A capacitive leaf surface humidity conversion circuit, comprising: the device comprises a monostable trigger circuit, a capacitance conversion circuit, a capacitance discharge circuit, a capacitance filter circuit and a controller;

the monostable trigger circuit is connected with the capacitance conversion circuit, the monostable trigger circuit is used for outputting square waves with fixed frequency and duty ratio to the capacitance conversion circuit, and a humidity-sensitive capacitor for monitoring leaf surface humidity conversion is arranged in the capacitance conversion circuit; the capacitance conversion circuit is respectively connected with the capacitance discharge circuit and the capacitance filter circuit, and discharges electricity through the capacitance discharge circuit and converts the electricity into smooth voltage through the capacitance filter circuit;

the controller adopts a single chip microcomputer, is connected with the capacitor filter circuit through a single chip microcomputer AD acquisition circuit and is used for acquiring the voltage of the humidity-sensitive capacitor;

the humidity-sensitive capacitor is a printed circuit board, crossed wires are drawn on the printed circuit board, and the wires are in a plant vein shape and form a capacitor.

2. The capacitive foliar moisture conversion circuit of claim 1 wherein the monostable trigger circuit comprises: the circuit comprises a timer U2, a resistor R3, a resistor R4, a capacitor C4 and a capacitor C5;

a pin I of the timer U2 and a second end of the capacitor C4 are respectively grounded; the second pin of the timer U2 is respectively connected with the sixth pin of the timer U2, the first end of the capacitor C5 and the second end of the resistor R4; the second end of the capacitor C5 is grounded; a fifth pin of the timer U2 is connected with a first end of the capacitor C4; a fourth pin of the timer U2, an eighth pin of the timer U2 and a first end of the resistor R3 are respectively connected with a power supply; a seventh pin of the timer U2 is respectively connected with the second end of the resistor R3 and the first end of the resistor R4; the third pin of the timer U2 is connected to the first end of the resistor R5, and the second end of the resistor R5 is connected to the capacitance conversion circuit.

3. The capacitive foliar moisture conversion circuit of claim 2 wherein the capacitance conversion circuit includes a moisture sensitive capacitance O1; the second end of the humidity sensitive capacitor is connected with the second end of the resistor R5, and the first end of the humidity sensitive capacitor is grounded.

4. The capacitive foliar humidity conversion circuit of claim 3 wherein the capacitive discharge circuit comprises: diode D1, resistor R6; the anode of the diode D1 is connected to the second terminal of the resistor R5, the cathode of the diode D1 is connected to the first terminal of the resistor R6, and the second terminal of the resistor R6 is grounded.

5. The capacitive foliar moisture conversion circuit of claim 4 wherein the capacitive filter circuit includes a capacitance C6; a first terminal of the capacitor C6 is connected to a first terminal of the resistor R6, and a second terminal of the capacitor C6 is grounded.

6. The capacitive foliar humidity conversion circuit according to claim 5, wherein the single-chip microcomputer AD acquisition circuit comprises a single-chip microcomputer U1 and a resistor R1; a first pin of the singlechip U1 is connected with a first end of a resistor R1, and a second end of the resistor R1 is grounded; a fifth pin of the singlechip U1 is connected with a power supply, and a sixth pin of the singlechip U1 is connected with a first end of the capacitor C6; the fifteenth pin of the single chip microcomputer U1 is grounded, and the sixteenth pin of the single chip microcomputer U1 is connected with a power supply.

7. The capacitive foliar moisture conversion circuit of claim 2 wherein the timer is a TLC555 timer.