CN217108406U

CN217108406U - Valve controller based on narrowband thing networking

Info

Publication number: CN217108406U
Application number: CN202123409887.4U
Authority: CN
Inventors: 苏涛; 艾毅; 张奎伟; 张军
Original assignee: Tianjin Yunwo Internet Of Things Technology Co ltd
Current assignee: Tianjin Yunwo Internet Of Things Technology Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-08-02
Anticipated expiration: 2031-12-30

Abstract

The utility model provides a valve controller based on narrowband thing networking is equipped with STM32 series core processor in the controller, system power supply circuit, RTC clock circuit, NB-IOT processing circuit, battery voltage acquisition circuit, valve aperture acquisition circuit, temperature acquisition circuit, power supply control circuit, motor drive circuit, circuit components such as motor control circuit and LED status indication circuit. A valve controller based on narrowband thing networking utilizes STM32 serial processor, and NB-IOT narrowband thing networking and peripheral circuit have realized low-power consumption, high accuracy control and measurement, can transmit the server through the narrowband thing networking with gathering valve aperture, temperature and voltage data simultaneously, the administrator remote monitoring of being convenient for is by the temperature data of monitoring point, in time makes reasonable action to the aperture of valve. Can meet the requirements of a thermal heating system on energy conservation, emission reduction and pollution reduction, and has wide development prospect.

Description

Valve controller based on narrowband thing networking

Technical Field

The utility model belongs to the technical field of thing networking valve control, especially, relate to a valve controller based on narrowband thing networking.

Background

Among the prior art, the thing networking valve ware is uncontrollable according to the real-time temperature of pipeline, adjusts the aperture of pipeline valve in real time, can not effectively solve the problem of excessive heat supply, realizes energy saving and emission reduction's target, along with intelligent city and internet of things's development, how safe, effective, scientific control heating system pipeline temperature becomes the needs of building the wisdom city.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model aims at providing a valve controller based on narrowband thing networking to solve the problem of excessive heat supply, realize energy saving and emission reduction's target.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

a valve controller based on a narrowband Internet of things comprises a main control MCU circuit, a system power supply circuit, a power supply control circuit, an LED state indicating circuit, an RTC clock circuit, an NB-IOT processing circuit, a battery voltage acquisition circuit, a temperature acquisition circuit, a motor drive circuit, a motor control circuit and a valve opening detection circuit, the master control MCU circuit, the power supply control circuit, the LED state indicating circuit, the RTC clock circuit, the NB-IOT processing circuit, the battery voltage acquisition circuit, the temperature acquisition circuit, the motor drive circuit, the motor control circuit and the valve opening detection circuit are all connected with the system power supply circuit, the LED state indicating circuit, the RTC clock circuit, the NB-IOT processing circuit, the battery voltage acquisition circuit, the temperature acquisition circuit, the motor driving circuit, the motor control circuit and the valve opening detection circuit are all connected with the master control MCU circuit.

Furthermore, the system power supply circuit comprises an overvoltage and overcurrent protection circuit, a power supply selection control circuit, an LDO circuit and a DC-DC Boost circuit, wherein the input end of the power supply selection control circuit is connected to the output end of the overvoltage and overcurrent protection circuit, and the output end of the power supply selection control circuit is respectively connected to the LDO circuit and the DC-DC Boost circuit.

Further, the power supply control circuit comprises AN analog power supply control circuit and AN NB-IOT power supply control circuit, the analog power supply control circuit comprises a MOS transistor Q3, a MOS transistor Q4, a resistor R20, and a resistor R22, a pin 3 of the MOS transistor Q3 is connected to VC1, a pin 2 of the MOS transistor Q3 is connected to VBRD, a pin 1 of the MOS transistor Q3 is connected to a pin 3 of the MOS transistor Q4, one end of the resistor R20 is connected to VBRD, the other end of the resistor R4 is connected to a pin 3 of the MOS transistor Q4, a pin 1 of the MOS transistor Q4 is connected to PWR AN, a pin 2 of the MOS transistor Q4 is grounded, one end of the resistor R22 is connected to PWR AN, and the other end of the resistor R4 is grounded.

Furthermore, the main control MCU circuit comprises a first operational amplifier circuit, a second operational amplifier circuit and a crystal oscillator circuit, the first operational amplifier circuit comprises an operational amplifier U5A, a reed switch S1, a reed switch S2, a resistor R9, a resistor R11, a capacitor C18, a capacitor C19, a serial port P4, a serial port P11 and a serial port P12, the 7 pins of the operational amplifier U5A are respectively connected with one end of a reed switch S2 and one end of a capacitor C18, the 14 pin of the operational amplifier U5A is respectively connected with one end of a resistor R11 and one end of a capacitor C9, the 21 pin and the 22 pin of the operational amplifier U5A are both connected with a serial port P4, the 44 pin of the operational amplifier U5A is grounded through a resistor R9, the 38 pin, the 39 pin, the 40 pin and the 41 pin of the operational amplifier U5A are all connected with a serial port P11, the 42 pin of the operational amplifier U5A is connected with the serial port P12, the other end of the reed switch S2, the other end of the capacitor C18 and the other end of the capacitor C9 are all grounded, and the other end of the resistor R11 is connected with the VBRD through a reed switch S1.

Furthermore, the RTC clock circuit includes an RTC real-time clock ICU6, a capacitor C20, a resistor R12, a resistor R13, and a resistor R15, and one end of the capacitor C20 is grounded. The other end is connected with VBRD, pin 8 of RTC real-time clock ICU6 is connected with VBRD, pin 8 is connected with one end of resistor R15, the other end of resistor R15 is connected with VBRD, one end of resistor R12 and one end of resistor R13 are both connected with VBRD, the other end of resistor R12 is connected with SDA, the other end of resistor R13 is connected with SCL, and pin RTC real-time clock ICU64 is grounded.

Furthermore, the battery voltage acquisition circuit comprises an operational amplifier U8, a capacitor C21, a capacitor C27, a resistor R17, a resistor R18, a resistor R19 and a resistor R21, wherein a pin 1 of the operational amplifier U8 is respectively connected with one end of the resistor R17 and one end of the resistor R19, a pin 3 of the operational amplifier U8 is respectively connected with one end of the resistor R21 and one end of the resistor R18, a pin 5 of the operational amplifier U8 is connected with the VC1, one end of the capacitor C21 is connected with the VC1, the other end of the capacitor R17 is connected with the pin 4, the other end of the resistor R19 is connected with the AIN2, the other end of the resistor R21 is connected with the ground, the other end of the resistor R18 is connected with the Vbat, one end of the capacitor C27 is connected with the AIN2, and the other end of the capacitor C is connected with the ground.

Furthermore, the temperature acquisition circuit comprises a socket P6, a capacitor C30, a resistor R23, a resistor R24, a diode TVS4, a socket P7, a capacitor C44, a diode TVS5, a temperature sensor ICU1, a capacitor C1 and a socket P1, wherein

pins

4, 5 and 6 of the socket P6 are all grounded, pin 1 of the socket P6 is respectively connected with pin 6 of VC1 and diode TVS4, pin 2 of the socket P6 is respectively connected with one end of the resistor R24 and pin 5 of the diode TVS4, pin 3 of the socket P6 is respectively connected with one end of the resistor R23 and pin 4 of the diode TVS4, the other end of the resistor R23 and the other end of the resistor R24 are both connected with RD, one end of the capacitor C30 is grounded, the other end of the resistor R1 is connected with pin 2 of the diode TVS 4;

the 4 pin, the 5pin and the 6 pin of the socket P7 are all grounded, the 1 pin of the socket P6 is respectively connected with VC1 and the 6 pin of the diode TVS5, the 2 pin of the socket P7 is respectively connected with I2C1_ SDA and the 5pin of the diode TVS5, the 3 pin of the socket P7 is respectively connected with I2C1_ SCL and the 4 pin of the diode TVS5, one end of the capacitor C44 is grounded, the other end is connected with VC1, and the 2 pin of the diode TVS5 is grounded;

the pin 5 of the temperature sensor ICU1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is grounded, the

pins

2, 4 and 7 of the temperature sensor ICU1 are grounded, the

pins

1 and 6 of the temperature sensor ICU1 are connected with a socket P1, and the pin 4 of the socket P1 is grounded.

Further, the NB-IoT circuit includes NB circuit ICU2A, diode D1, capacitor C5, capacitor C11, resistor R3, resistor R4, resistor R5, socket P2, diode TVS1, main serial port P8, debug serial port P10, NB circuit ICU2B, capacitor C8, capacitor C9, capacitor C10, diode TVS2, NB circuit ICU2B, capacitor C12, capacitor C13, capacitor C14, e-SIM card U4, resistor R6, resistor R7, resistor R8, and capacitor C15;

a pin 34 of the NB circuit ICU2A is connected to NB _ RI through a resistor R3, a pin 30 of the NB circuit ICU2A is connected to NB _ TXD through a resistor R4, a pin 29 of the NB circuit ICU2A is connected to one end of a resistor R5 and a pin 1 of a diode D1, the other end of the resistor R5 is connected to VDD _ EXT, a pin 3 of the diode D1 is connected to NB _ RXD, a pin 26 of the NB circuit ICU2A is connected to VDD _ EXT and 3V, one end of a capacitor C11 is connected to 3V and the other end of the capacitor C1 is connected to ground, a pin 19 and a pin 20 of the NB circuit ICU2A are connected to a main serial port P8, a pin 3 of the main serial port 695p 2 is connected to ground, a pin 2, a pin 54, a pin 52 pin, a pin 51 pin and a pin 47 of the NB circuit ICU2A are connected to ground, a pin 45 and a pin 46 of the NB circuit ICU2A are connected to VNB, a pin 53 and a pin 5 of the NB circuit ICU2A is connected to one end of the capacitor C867, a socket 937 and a socket 36s 3872 and another end of the other end of the diode P36s 1 and the other end of the diode 36p 3872;

one end of the capacitor C8, one end of the capacitor C9, one end of the capacitor C10 and one end of the diode TVS2 are all connected with the VNB, and the other end of the capacitor C8, the other end of the capacitor C9, the other end of the capacitor C10 and the other end of the diode TVS2 are all grounded;

pins 59, 60, 61, 62, 63, 64, 65, 66, 71, 72, 73, 74, 81, 82, 83, 92, 93 and 94 of the NB circuit ICU2B are all grounded;

pins

1 and 9 of the e-SIM card U4 are both grounded, pin 8 of the e-SIM card U4 is grounded through a capacitor C15, pin 6 of the e-SIM card U4 is connected with one end of a capacitor C14 and one end of a resistor R6 respectively, pin 3 of the e-SIM card U4 is connected with one end of a capacitor C13 and one end of a resistor R7 respectively, pin 7 of the e-SIM card U4 is connected with one end of a capacitor C12 and one end of a resistor R8 respectively, the other end of the capacitor C12, the other end of the capacitor C13 and the other end of the capacitor C14 are both grounded, the other end of the resistor R6 is connected with USIM _ CLK, the other end of the resistor R7 is connected with USIM _ DATA, and the other end of the resistor R8 is connected with the USIM _ RST.

Furthermore, the valve opening detection circuit comprises an operational amplifier U9, a capacitor C42, a capacitor C43, a resistor R31, a resistor R33, a resistor R34 and a socket CN4, wherein a pin 1 of the operational amplifier U9 is respectively connected with one end of the resistor R33 and one end of the resistor R34, a pin 5 of the operational amplifier U9 is respectively connected with one end of the VC1 and one end of the capacitor C42, a pin 4 of the operational amplifier U9 is connected with the other end of the resistor R33, a pin 2 of the operational amplifier U9 is grounded, a pin 3 of the operational amplifier U9 is respectively connected with one end of the resistor R31 and one pin 1 of the socket CN4, a pin 2 of the socket CN4 is connected with the VC1, the

pins

4 and 5 of the socket CN4 are both grounded, the other end of the resistor R31 is grounded, the other end of the resistor R34 is respectively connected with one end of the AIN3 and one end of the capacitor C43, the other end of the capacitor C43 is grounded, and the other end of the capacitor C42 is grounded.

Compared with the prior art, a valve controller based on narrowband thing networking have following advantage:

(1) a valve controller based on narrowband thing networking, reasonable in design can let heating department remote control valve's aperture through this valve controller, has improved the temperature management and control ability to each pipeline, has saved the energy, has reduced the emission of pollutant, has wide development prospect.

Drawings

The accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. In the drawings:

fig. 1 is a schematic diagram of a system power supply circuit according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a DC-DC Boost circuit according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a power supply control circuit of an analog circuit according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a power supply control circuit of an NB-IOT module according to an embodiment of the present invention;

fig. 5 is a schematic circuit diagram of a master MCU according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a master MCU circuit filter circuit according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a peripheral circuit of a master control MCU circuit according to an embodiment of the present invention;

fig. 8 is a schematic diagram of an RTC clock circuit according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a battery voltage acquisition circuit according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a temperature acquisition circuit according to an embodiment of the present invention;

fig. 11 is a schematic circuit diagram of a temperature sensor according to an embodiment of the present invention;

fig. 12 is a schematic diagram of an NB-IoT circuit according to an embodiment of the present invention;

fig. 13 is a schematic diagram of a circuit of an LED status indicator lamp according to an embodiment of the present invention;

fig. 14 is a schematic circuit diagram of an LED driving board according to an embodiment of the present invention;

fig. 15 is a schematic diagram of a motor driving circuit according to an embodiment of the present invention;

fig. 16 is a schematic diagram of a valve opening detection circuit according to an embodiment of the present invention;

fig. 17 is a schematic diagram of a motor control circuit according to an embodiment of the present invention;

fig. 18 is a schematic circuit diagram of a motor control small board according to an embodiment of the present invention;

fig. 19 is a schematic block diagram of an overall structure according to an embodiment of the present invention.

Detailed Description

It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

As shown in fig. 1 to 19, a valve controller based on narrowband internet of things comprises a main control MCU circuit, a system power supply circuit, a power supply control circuit, an LED status indication circuit, an RTC clock circuit, an NB-IOT processing circuit, a battery voltage acquisition circuit, a temperature acquisition circuit, a motor drive circuit, a motor control circuit and a valve opening detection circuit, the master control MCU circuit, the power supply control circuit, the LED state indicating circuit, the RTC clock circuit, the NB-IOT processing circuit, the battery voltage acquisition circuit, the temperature acquisition circuit, the motor drive circuit, the motor control circuit and the valve opening detection circuit are all connected with the system power supply circuit, the LED state indicating circuit, the RTC clock circuit, the NB-IOT processing circuit, the battery voltage acquisition circuit, the temperature acquisition circuit, the motor driving circuit, the motor control circuit and the valve opening detection circuit are all connected with the master control MCU circuit. The utility model relates to a rationally, can let heating department remote control valve's aperture through this valve controller, improve the temperature management and control ability to each pipeline, save the energy, reduce the emission of pollutant, have wide development prospect.

The system power supply circuit comprises an overvoltage and overcurrent protection circuit, a power supply selection control circuit, an LDO circuit and a DC-DC Boost circuit, wherein the input end of the power supply selection control circuit is connected to the output end of the overvoltage and overcurrent protection circuit, and the output end of the power supply selection control circuit is respectively connected to the LDO circuit and the DC-DC Boost circuit.

The overvoltage and overcurrent protection circuit comprises 2 battery sockets P1, a fuse F1, a fuse F2, a MOS tube Q1 and a diode D0, wherein 2 battery sockets P1 are all grounded, the 2 battery sockets P1 are respectively connected to one end of the fuse F1 and one end of the fuse F2, the other end of the fuse F1 is connected with a Vbat2, the other end of the fuse F2 is connected with one end of the MOS tube Q1, the other end of the MOS tube Q1 is connected with a power supply selection control circuit, one end of the diode D0 is connected with the Vbat2, and the other end of the diode D0 is grounded.

The power supply selection control circuit comprises a double diode D, a resistor R, a capacitor C, an operational amplifier U, an MOS tube Q and an MOS tube Q, wherein one end of the resistor R is connected with Vbat, the other end of the resistor R is connected with a pin 3 of the operational amplifier U, one end of the resistor R is grounded, the other end of the resistor R is connected with the resistor R, the other end of the resistor R is connected with a pin 4 of the operational amplifier U, one end of the resistor R is grounded, the other end of the resistor R is connected with the resistor R, a pin 5 of the operational amplifier U is connected with the capacitor C, one end of the capacitor C is grounded, the other end of the resistor R is connected with a pin 3 of the double diode D, a pin 1 of the double diode D is connected with the Vbat, a pin 2 of the double diode D is connected with the pin 2 of the Vbat, one end of the resistor R is respectively connected with a pin 1 of the MOS tube Q, the other end of the resistor R is connected with a pin 1 of the MOS tube Q, the other end of the resistor R39 is grounded, the pin 2 of the MOS transistor Q7 is grounded, the pin 3 of the MOS transistor Q7 is connected with the pin 1 of the MOS transistor Q8, the pin 2 of the MOS transistor Q8 and the pin 2 of the MOS transistor Q2 are both connected with the LDO circuit, the pin 3 of the MOS transistor Q8 is connected with the Vbat2, the pin 3 of the MOS transistor Q2 is connected with the Vbat1, one end of the resistor R39 is connected with the capacitor C45, the other end of the resistor R39 is connected with the resistor R40, and the other end of the resistor R40 is connected with the pin 1 of the MOS transistor Q8.

The LDO circuit comprises an LDO ICU1, a capacitor C1, a capacitor C2, a capacitor C3 and a capacitor C4.

The DC-DC Boost booster circuit comprises a DC-DC Boost control ICU1, a capacitor C6, a capacitor C7, a capacitor C31, a capacitor C32, a capacitor C33, a capacitor C34, a capacitor C35, a capacitor C36, a capacitor 37, a capacitor C38, an inductor L1, a resistor R1, a resistor R2, a resistor R10, a resistor R28, a resistor R29, a resistor R30 and a resistor R32.

In this embodiment, (1) the system power supply circuit:

as shown in fig. 1, P1 is a battery socket for accessing a battery to power the system. Pin 1 of P1 is negative and pin 2 is positive.

F1: the fuse is a 12V/1.5A fuse for protecting overvoltage and overcurrent of a following circuit.

Q1: the P-MOS is used for preventing positive and negative reverse connection of the circuit, and when the positive and negative are normally connected, the Q1 is conducted; when the positive and negative are reversely connected, the Q1 is cut off, and the following circuit is protected.

CN2 is an external power socket.

F2: the fuse is a 12V/1.5A fuse for protecting the overvoltage and overcurrent protection of a following circuit.

D0: and an anti-static diode.

The circuit in the dotted line box of fig. 1 is a power supply selection control circuit.

The functions are as follows: when the electric quantity of the internal battery is insufficient or no electricity is available, the system can be maintained to work normally by accessing an external power supply.

The principle is as follows: in the figure, "Vbat 2" is an external power supply, and "Vbat 1" is an internal power supply.

When Vbat2> Vbat1, the comparator U10 outputs a high level, and Q2 is turned off. At the same time Q7 is on and Q8 is on, the circuit is powered by Vbat 2.

When Vbat2< Vbat1, the comparator U10 outputs a low level, Q7 is turned off, and further Q8 is turned off, and at the same time, Q2 is turned on, and the circuit is powered by Vbat 1.

As shown in fig. 2, C1, C2, U1, C3, and C4 form an LDO circuit. For converting the battery voltage to a stable 3V voltage. C1, C2 are input filter capacitors, C3, C4 are output filter capacitors.

The DC-DC Boost circuit in FIG. 2 is used for boosting the battery voltage to 12V to drive the motor to act.

U3 is DC-DC boost control IC, TPS61089RNRR, manufactured by TI corporation.

C6 and C7 are input filter capacitors of the Boost circuit.

C34, C35, C37 and C38 are output filter capacitors of the boost circuit.

L1, is a boost energy storage inductor.

C31, is the bootstrap capacitor.

The values of R1 and R1 determine the switching frequency of the boost circuit.

The values of R2 and R2 are used for adjusting the peak current of the switch. A typical restriction value is 8.1A when R2 ═ 127K.

R10, C33 and C36 form a loop compensation network for stabilizing the normal operation of the system.

C32, is the output filter capacitor of the IC internal voltage regulator.

R32, which is a pull-down resistor of an enable control pin "EN" of an IC, enables the IC when a control signal "Boost-EN" from the MCU is high; when "Boost-EN" is low, IC action is inhibited.

R28, R29 and R30 form a resistor voltage division network for determining the output voltage of the Boost circuit. The calculation formula is:

1.212*((R28+R29+R30)/R28)＝1.212*((75+110+560)/75)＝12.04V。

the power supply control circuit comprises AN analog power supply control circuit and AN NB-IOT power supply control circuit, wherein the analog power supply control circuit comprises a MOS tube Q3, a MOS tube Q4, a resistor R20 and a resistor R22, a pin 3 of the MOS tube Q3 is connected with VC1, a pin 2 of the MOS tube Q3 is connected with VBRD, a pin 1 of the MOS tube Q3 is connected with a pin 3 of the MOS tube Q4, one end of the resistor R20 is connected with VBRD, the other end of the resistor R20 is connected with a pin 3 of the MOS tube Q4, a pin 1 of the MOS tube Q4 is connected with PWR AN, a pin 2 of the MOS tube Q4 is grounded, one end of the resistor R22 is connected with PWR AN, and the other end of the resistor R8632 is grounded;

the NB-IOT power supply control circuit comprises a MOS transistor Q5, a MOS transistor Q6, a resistor R25, a resistor R26 and a resistor R27, wherein a pin 3 of the MOS transistor Q5 is connected with one end of the resistor R27, the other end of the resistor R27 is connected with a VNB, a pin 2 of the MOS transistor Q5 is connected with a Vbat, a pin 1 of the MOS transistor Q5 is connected with a pin 3 of the MOS transistor Q6, one end of the resistor R25 is connected with the Vbat, the other end of the resistor R6 is connected with a pin 3 of the MOS transistor Q6, a pin 1 of the MOS transistor Q6 is connected with an NBPWR EN, a pin 2 of the MOS transistor Q6 is grounded, one end of the resistor R26 is connected with the NBPWR EN, and the other end of the resistor R26 is grounded.

In this embodiment, (2) the power supply control circuit:

as shown in fig. 3, which is a power supply control circuit of the analog circuit, when power needs to be supplied to the analog portion, the MCU controls "PWR _ AN" to be high, so that Q4 is turned on, and thus Q3 is turned on, and "VC 1" has AN output of 3V. When power supply to the analog part is not needed, the MCU controls 'PWR _ AN' to be low level, so that Q4 is cut off, therefore Q3 is also cut off, and no voltage exists on 'VC 1'. The control can effectively reduce the power consumption of the system and prolong the service life of the product.

As shown in fig. 4, is a power supply control circuit of BC35(NB-IOT module). When power needs to be supplied to the BC35 module, the MCU controls the NBPWR _ EN to be at a high level, so that the Q6 is conducted, the Q5 is further conducted, and the power supply VNB of the BC35 has voltage; when the BC35 module is not needed, the MCU controls "NBPWR _ EN" to be low, so that Q6 is turned off, and further Q5 is also turned off, and the power supply "VNB" of BC35 has no voltage. The purpose of reducing the power consumption of the system is achieved through the control.

The main control MCU circuit comprises a first operational amplifier circuit, a second operational amplifier circuit and a crystal oscillator circuit, the first operational amplifier circuit comprises an operational amplifier U5A, a reed switch S1, a reed switch S2, a resistor R9, a resistor R11, a capacitor C18, a capacitor C19, a serial port P4, a serial port P11 and a serial port P12, pins 7 of the operational amplifier U5A are respectively connected with one end of a reed switch S2 and one end of a capacitor C18, pins 14 of the operational amplifier U5A are respectively connected with one end of a resistor R11 and one end of a capacitor C9, pins 21 and 22 of the operational amplifier U5A are both connected with a serial port P4, pins 44 of the operational amplifier U5A are grounded through a resistor R9, pins 38, 39, 40 and 41 of the operational amplifier U5A are all connected with a serial port P11, pins 42 of the operational amplifier U5A are connected with a serial port P12, the other end of the reed switch S2, the other end of the capacitor C18 and the other end of the capacitor C9 are all grounded, and the other end of the resistor R11 is connected with VBRD through a reed switch S1;

the second operational amplifier circuit comprises an operational amplifier U5B, a magnetic bead FB1, a capacitor C28, a capacitor C29, a capacitor C26, a capacitor C22, a capacitor C23, a capacitor C24 and a capacitor C25, pins 25, 47 and 8 of the operational amplifier U5B are all grounded, pin 1, pin 24, pin 36 and pin 48 of the operational amplifier U5B are all grounded, pin 9 of the operational amplifier U5B is respectively grounded to one end of the magnetic bead FB1, one end of the capacitor C28 and one end of the capacitor C29, the other end of the FB1 is grounded, the other end of the capacitor C1 and the other end of the capacitor C1 are both grounded, one end of the capacitor C1 and one end of the capacitor C1 are both grounded;

the crystal oscillator circuit comprises a serial port P3, a capacitor C16, a capacitor C17 and a crystal oscillator X1, wherein a pin 1 of the serial port P3 is connected with VBRD, pins 5, 6 and 7 of the serial port P3 are all grounded, a pin 2 and a pin 4 of the crystal oscillator X1 are all grounded, a pin 3 of the crystal oscillator X1 is connected with one end of the capacitor C16, a pin 1 of the crystal oscillator X1 is connected with one end of the capacitor C17, and the other end of the capacitor C16 and the other end of the capacitor C17 are all grounded.

In this embodiment, (3) the main control MCU circuit:

as shown in fig. 5-7, the MCU and its peripheral circuits.

C22, C23, C24, C25, C26, C28 and C29 form a filter circuit powered by the MCU.

C18, is the power-on reset capacitance of the MCU.

FB 1: is a magnetic bead to prevent interference.

S1: the reed switch is a reed switch, when a magnet is close to S1, S1 is conducted, and PA4 of the MCU is pulled to a high level; when there is no magnet, S1 is off and the MCU PA4 remains low. Thus, functions of waking up the system, uploading data and the like are realized through the adsorption of the magnet.

S2: and the reed switch is used for restarting the MCU.

R11 and C19 form an RC filter circuit for filtering noise possibly generated when the reed switch is switched.

X1 is the position crystal oscillator of MCU, oscillation frequency is 16 MHz.

C16 and C17 are load capacitors of the external crystal oscillator X1, and the capacitance values of C16 and C17 are both 10 pF.

The P4 is a reserved UART serial port, and can be used to read the system running log and monitor the running status of the system.

P3 is the program programming port of the MCU.

P11 is a reserved OLED liquid crystal interface.

The RTC clock circuit comprises an RTC real-time clock ICU6, a capacitor C20, a resistor R12, a resistor R13 and a resistor R15, wherein one end of the capacitor C20 is grounded. The other end is connected with VBRD, pin 8 of RTC real-time clock ICU6 is connected with VBRD, pin 8 is connected with one end of resistor R15, the other end of resistor R15 is connected with VBRD, one end of resistor R12 and one end of resistor R13 are both connected with VBRD, the other end of resistor R12 is connected with SDA, the other end of resistor R13 is connected with SCL, and pin RTC real-time clock ICU64 is grounded.

In this embodiment, (4) the RTC clock circuit:

as shown in fig. 8, R12 and R13 are pull-up resistors of the data line SDA and the clock line SCL for I2C communication.

C20, filter capacitance of U6.

U6(RX-8010SJ) is provided with an RTC real-time clock IC of a crystal oscillator, and can be used for system timing. When the timing time expires, pin 7 of U6 outputs a low level, pulling the "RTC _ IRQ _ SYS _ WAK" signal, i.e., the "PC 13" pin of the MCU low.

R15 is the pull-up resistance of RTC _ IRQ _ SYS _ WAK, when there is no timing time-out signal, pull up the MCU 'PC 13'.

The battery voltage acquisition circuit comprises an operational amplifier U8, a capacitor C21, a capacitor C27, a resistor R17, a resistor R18, a resistor R19 and a resistor R21, wherein a pin 1 of the operational amplifier U8 is respectively connected with one end of the resistor R17 and one end of the resistor R19, a pin 3 of the operational amplifier U8 is respectively connected with one end of the resistor R21 and one end of the resistor R18, a pin 5 of the operational amplifier U8 is connected with the VC1, one end of the capacitor C21 is connected with the VC1, the other end of the capacitor R17 is connected with the pin 4, the other end of the resistor R19 is connected with the AIN2, the other end of the resistor R21 is connected with the ground, the other end of the resistor R18 is connected with the Vbat, one end of the capacitor C27 is connected with the AIN2, and the other end of the capacitor C is connected with the ground.

In this embodiment, (5) the battery voltage acquisition circuit:

as shown in fig. 9, R18 and R21 form a 1 to 1 voltage divider circuit that supplies 1/2 the battery voltage "Vbat" to the non-inverting input of the operational amplifier U8.

U8, R17 and C21 form a voltage follower circuit. So that "AIN 2" equals the battery voltage of 1/2. That is, the voltage of the AD sampling pin of the MCU is the battery voltage of 1/2.

R19 and C27 form an RC filter circuit for filtering interference in the circuit.

The temperature acquisition circuit comprises a socket P6, a capacitor C30, a resistor R23, a resistor R24, a diode TVS4, a socket P7, a capacitor C44, a diode TVS5, a temperature sensor ICU1, a capacitor C1 and a socket P1, wherein pins 4, 5 and 6 of the socket P6 are all grounded, pin 1 of the socket P6 is respectively connected with pin 6 of VC1 and pin 6 of diode TVS4, pin 2 of the socket P6 is respectively connected with one end of a resistor R24 and pin 5 of the diode TVS4, pin 3 of the socket P6 is respectively connected with one end of a resistor R23 and pin 4 of the diode TVS4, the other end of the resistor R23 and the other end of the resistor R24 are both connected with VBRD, one end of the capacitor C30 is grounded, the other end is connected with pin VC1, and pin 2 of the diode TVS4 is grounded;

pins

2, 4 and 7 of the temperature sensor ICU1 are grounded, the

pins

In this embodiment, (6) the temperature acquisition circuit:

as shown in fig. 10-11, the product can simultaneously collect two paths of temperatures. The two temperature sensors are respectively connected through a socket P6 and a socket P7. (P6 and P7 are female sockets on the motherboard and P1 is a male socket on the temperature acquisition platelet.) in actual use, none of P6, P7 and P1 are soldered, and the motherboard and the temperature acquisition platelet are connected by 4 wires.

U1(TMP116) is a temperature sensor IC for the I2C bus. The MCU reads the temperature data collected by the U1 through the I2C for processing.

R23, R24 are pull-up resistors for the I2C bus.

C1, C30 and C44 are filter capacitors.

TVS4 and TVS5 are electrostatic discharge prevention diodes.

The NB-IoT circuit comprises an NB circuit ICU2A, a diode D1, a capacitor C5, a capacitor C11, a resistor R3, a resistor R4, a resistor R5, a socket P2, a diode TVS1, a main serial port P8, a debugging serial port P10, an NB circuit ICU2B, a capacitor C8, a capacitor C9, a capacitor C10, a diode TVS2, an NB circuit ICU2B, a capacitor C12, a capacitor C13, a capacitor C14, an e-SIM card U4, a resistor R6, a resistor R7, a resistor R8 and a capacitor C15;

pins

1 and 9 of the e-SIM card U4 are both grounded, pin 8 of the e-SIM card U4 is grounded through a capacitor C15, pin 6 of the e-SIM card U4 is connected to one end of a capacitor C14 and one end of a resistor R6, pin 3 of the e-SIM card U4 is connected to one end of a capacitor C13 and one end of a resistor R7, pin 7 of the e-SIM card U4 is connected to one end of a capacitor C12 and one end of a resistor R8, the other end of the capacitor C12, the other end of the capacitor C13 and the other end of the capacitor C14 are both grounded, the other end of the resistor R6 is connected to USIM _ CLK, the other end of the resistor R7 is connected to USIM _ DATA, and the other end of the resistor R8 is connected to USIM _ RST.

In this embodiment, (7) the NB-IoT circuit:

as shown in fig. 12, the NB-IOT circuit is mainly composed of an NB communication module BC35 and its peripheral circuits. The MCU communicates with BC35 through UART.

C8, C9 and C10 are power supply filter capacitors of the BC35 module.

TVS2, is an anti-static diode.

R5, D1 constitute a level shift circuit of the "NB _ RXD" signal. The MCU and the BC35 can be ensured to normally communicate. Meanwhile, R5 can also play a role in reducing high-frequency noise and overcharge voltage.

R3, high frequency noise and overcharge voltage of the "NB _ RI" signal can be reduced.

R4, high frequency noise and overcharge voltage of the "NB _ TXD" signal can be reduced.

P2, an IPEX socket, for connecting to an external antenna.

The TVS1 is a TVS diode for preventing electrostatic interference when an external antenna is mounted.

C5, is the impedance matching capacitance of the antenna loop.

U4, is an e-SIM card.

R6, R7, R8, C12, C13 and C14 respectively form an RC filter circuit to filter the interference between the BC35 module and the SIM card.

And C15, a filter capacitor of the power supply end of the SIM card.

The P8 and the P10 are respectively a main serial port and a debugging serial port of the reserved BC35 module and are used for program debugging.

In this embodiment, (8) the LED status indicator lamp circuit:

as shown in fig. 13, P12 is a socket on the motherboard for accessing a small circuit board with LED drivers;

as shown in fig. 14, this is an LED driver board circuit.

And C1 and C2 are lamp panel power supply filter capacitors.

D1, R1, R3, Q1 constitute LED and its control circuit all the way. When the MCU control System is in high level, Q1 is conducted, and the LED lamp D1 is conducted to emit light. When the MCU control "System" is low, Q1 is turned off and D1 is not lit.

D2, R2, R4 and Q2 form another path of LED and a control circuit thereof. When the MCU controls NET _ LINK to be at high level, Q2 is conducted, and therefore the LED lamp D2 is conducted to emit light. When the MCU controls NET _ LINK to be low level, Q2 is cut off, and D2 is not bright.

The valve opening detection circuit comprises an operational amplifier U9, a capacitor C42, a capacitor C43, a resistor R31, a resistor R33, a resistor R34 and a socket CN4, wherein a pin 1 of the operational amplifier U9 is respectively connected with one end of the resistor R33 and one end of the resistor R34, a pin 5 of the operational amplifier U9 is respectively connected with one end of the VC1 and one end of the capacitor C42, a pin 4 of the operational amplifier U9 is connected with the other end of the resistor R33, a pin 2 of the operational amplifier U9 is grounded, a pin 3 of the operational amplifier U9 is respectively connected with one end of the resistor R31 and one pin 1 of the socket CN4, a pin 2 of the socket CN4 is connected with the VC1, a pin 4 and a pin 5 of the socket CN4 are both grounded, the other end of the resistor R31 is grounded, the other end of the resistor R34 is respectively connected with one end of the AIN3 and one end of the capacitor C43, the other end of the capacitor C43 is grounded, and the other end of the capacitor C42 is grounded.

In this embodiment, (9) the valve opening detection circuit:

as shown in fig. 16, the valve opening detection circuit, in which the socket CN4 is connected to a potentiometer linked with a motor, is provided. The resistance value of the potentiometer is divided by R31 and then input to the non-inverting input end of an operational amplifier U9(TLV 521). U9, C42 and R33 form a voltage follower circuit, and the voltage divided by the potentiometer and R31 is sent to the AD pin of the MCU. The resistance value of the potentiometer is deduced through the collected voltage, and the opening and closing degree of the valve is further calculated.

R34 and C43 form an RC filter circuit.

(10) The motor drive circuit:

as shown in fig. 15, the motor drive circuit is mainly composed of a motor drive IC (DRV8871DDAR) and its peripheral circuits. When the control signal 1 of the MCU is high, "MOTO-A" and "MOTO-B" are low, the OUTA outputs 12V, and the OUTB is 0V;

"MOTO-A" is low, and "MOTO-B" is high, OUTB outputs 12V, OUTA is 0V;

when MOTO-A is high and MOTO-B is high, OUTA outputs high-resistance state and OUTB outputs high-resistance state;

when MOTO-A is low and MOTO-B is low, OUTA outputs A brake state and OUTB outputs A brake state;

wherein:

c40, C41 are filter capacitors for 12V supply.

C39 is the filter capacitance across the motor.

F3, when abnormal conditions such as self-recovery insurance and motor stalling occur, the circuit is protected.

R42 is the output current limit control resistor of motor control U7.

(11) The motor control circuit:

as shown in fig. 17, the motherboard has associated circuitry for motor control, and socket CN1 is used to connect to the motor control board. R35 is the pull-up resistor for the "MOTO-B-Check" signal, and R36 is the pull-up resistor for the "MOTO-A-Check" signal.

As shown in fig. 18, the motor controls the circuit diagram of the small board. Wherein

CN1 is a 5pin socket for connection to the socket CN1 on the motherboard.

CN2 is a motor socket for connecting a motor.

SW1 is an open limit switch, SW3 is an open feedback switch; SW2 is an off limit switch and SW4 is an off feedback switch.

D1 and D2 are freewheeling diodes for switching the motor direction.

The operation from a to B, i.e., OUTA is high, and OUTB is low, is the operation of closing the valve.

The operation from B to a, i.e., OUTB is high, and OUTA is low, is an operation of opening the valve.

Valve fully-closed state definition: SW2 and SW4 are in the upper half of the PCB, MOTO-B-CHECK is 0, current flow from OUTA to OUTB is inhibited and the valve is fully closed.

The valve full-open state is defined as follows: SW1 and SW3 are in the lower half of the PCB, MOTO-A-CHECK is 0, current flow from OUTB to outA is inhibited and the valve is fully open.

The resistance of the potentiometer is increased from full open to full close. If a resistance value of 1K is crossed, it becomes larger starting from 0.

The resistance of the potentiometer is reduced from full close to full open. If a resistance of 0 Ω is crossed, it becomes smaller from 1K.

The valve controller relates to a valve control system of the Internet of things, and is particularly suitable for being installed on equipment such as a heat supply pipeline, intelligently controlling the opening degree of a pipeline valve, intelligently acquiring the temperature of the pipeline, and transmitting information such as the opening degree of the valve and the temperature of the pipeline to a system server by utilizing the NB-IOT Internet of things. The pipeline temperature is convenient to be remotely controlled in real time.

The valve controller utilizes the embedded software system through the sensor and the motor controller to collect the valve opening and the temperature in the memory of the MCU, then transmits the opening and the temperature data to the NB-IOT communication module through the URAT, and transmits the opening and the temperature to the cloud server through the NB network.

The above description is only for the preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a valve controller based on narrowband thing networking which characterized in that: the intelligent LED power supply system comprises a master control MCU circuit, a system power supply circuit, a power supply control circuit, an LED state indicating circuit, an RTC clock circuit, an NB-IOT processing circuit, a battery voltage acquisition circuit, a temperature acquisition circuit, a motor drive circuit, a motor control circuit and a valve opening detection circuit, wherein the master control MCU circuit, the power supply control circuit, the LED state indicating circuit, the RTC clock circuit, the NB-IOT processing circuit, the battery voltage acquisition circuit, the temperature acquisition circuit, the motor drive circuit, the motor control circuit and the valve opening detection circuit are all connected with the system power supply circuit, and the LED state indicating circuit, the RTC clock circuit, the NB-IOT processing circuit, the battery voltage acquisition circuit, the temperature acquisition circuit, the motor drive circuit, the motor control circuit and the valve opening detection circuit are all connected with the master control MCU circuit.

2. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the system power supply circuit comprises an overvoltage and overcurrent protection circuit, a power supply selection control circuit, an LDO circuit and a DC-DC Boost circuit, wherein the input end of the power supply selection control circuit is connected to the output end of the overvoltage and overcurrent protection circuit, and the output end of the power supply selection control circuit is respectively connected to the LDO circuit and the DC-DC Boost circuit.

3. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the power supply control circuit comprises AN analog power supply control circuit and AN NB-IOT power supply control circuit, wherein the analog power supply control circuit comprises AN MOS tube Q3, AN MOS tube Q4, a resistor R20 and a resistor R22, a pin 3 of the MOS tube Q3 is connected with VC1, a pin 2 of the MOS tube Q3 is connected with VBRD, a pin 1 of the MOS tube Q3 is connected with a pin 3 of the MOS tube Q4, one end of the resistor R20 is connected with VBRD, the other end of the resistor R20 is connected with a pin 3 of the MOS tube Q4, a pin 1 of the MOS tube Q4 is connected with PWR AN, a pin 2 of the MOS tube Q4 is grounded, one end of the resistor R22 is connected with PWR AN, and the other end of the resistor R22 is grounded.

4. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the main control MCU circuit comprises a first operational amplifier circuit, a second operational amplifier circuit and a crystal oscillator circuit, the first operational amplifier circuit comprises an operational amplifier U5A, a reed switch S1, a reed switch S2, a resistor R9, a resistor R11, a capacitor C18, a capacitor C19, a serial port P4, a serial port P11 and a serial port P12, the 7 pins of the operational amplifier U5A are respectively connected with one end of a reed switch S2 and one end of a capacitor C18, the 14 pin of the operational amplifier U5A is respectively connected with one end of a resistor R11 and one end of a capacitor C9, the 21 pin and the 22 pin of the operational amplifier U5A are both connected with a serial port P4, the 44 pin of the operational amplifier U5A is grounded through a resistor R9, the 38 pin, the 39 pin, the 40 pin and the 41 pin of the operational amplifier U5A are all connected with a serial port P11, the 42 pin of the operational amplifier U5A is connected with the serial port P12, the other end of the reed switch S2, the other end of the capacitor C18 and the other end of the capacitor C9 are all grounded, and the other end of the resistor R11 is connected with the VBRD through a reed switch S1.

5. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the RTC clock circuit comprises an RTC real-time clock ICU6, a capacitor C20, a resistor R12, a resistor R13 and a resistor R15, wherein one end of the capacitor C20 is grounded, the other end of the capacitor C20 is connected with VBRD, the 8 pin of the RTC real-time clock ICU6 is connected with VBRD, the 8 pin is connected with one end of the resistor R15, the other end of the resistor R15 is connected with VBRD, one end of the resistor R12 and one end of the resistor R13 are both connected with VBRD, the other end of the resistor R12 is connected with SDA, the other end of the resistor R13 is connected with SCL, and the pin of the RTC real-time clock ICU64 is grounded.

6. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the battery voltage acquisition circuit comprises an operational amplifier U8, a capacitor C21, a capacitor C27, a resistor R17, a resistor R18, a resistor R19 and a resistor R21, wherein a pin 1 of the operational amplifier U8 is respectively connected with one end of the resistor R17 and one end of the resistor R19, a pin 3 of the operational amplifier U8 is respectively connected with one end of the resistor R21 and one end of the resistor R18, a pin 5 of the operational amplifier U8 is connected with the VC1, one end of the capacitor C21 is connected with the VC1, the other end of the capacitor R17 is connected with the pin 4, the other end of the resistor R19 is connected with the AIN2, the other end of the resistor R21 is connected with the ground, the other end of the resistor R18 is connected with the Vbat, one end of the capacitor C27 is connected with the AIN2, and the other end of the capacitor C is connected with the ground.

7. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the temperature acquisition circuit comprises a socket P6, a capacitor C30, a resistor R23, a resistor R24, a diode TVS4, a socket P7, a capacitor C44, a diode TVS5, a temperature sensor ICU1, a capacitor C1 and a socket P1, wherein pins 4, 5 and 6 of the socket P6 are all grounded, pin 1 of the socket P6 is respectively connected with pin 6 of VC1 and pin 6 of diode TVS4, pin 2 of the socket P6 is respectively connected with one end of a resistor R24 and pin 5 of the diode TVS4, pin 3 of the socket P6 is respectively connected with one end of a resistor R23 and pin 4 of the diode TVS4, the other end of the resistor R23 and the other end of the resistor R24 are both connected with VBRD, one end of the capacitor C30 is grounded, the other end is connected with pin VC1, and pin 2 of the diode TVS4 is grounded;

the pin 5 of the temperature sensor ICU1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is grounded, the pins 2, 4 and 7 of the temperature sensor ICU1 are grounded, the pins 1 and 6 of the temperature sensor ICU1 are connected with a socket P1, and the pin 4 of the socket P1 is grounded.

8. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the NB-IoT circuit comprises an NB circuit ICU2A, a diode D1, a capacitor C5, a capacitor C11, a resistor R3, a resistor R4, a resistor R5, a socket P2, a diode TVS1, a main serial port P8, a debugging serial port P10, an NB circuit ICU2B, a capacitor C8, a capacitor C9, a capacitor C10, a diode TVS2, an NB circuit ICU2B, a capacitor C12, a capacitor C13, a capacitor C14, an e-SIM card U4, a resistor R6, a resistor R7, a resistor R8 and a capacitor C15;

pins 1 and 9 of the e-SIM card U4 are both grounded, pin 8 of the e-SIM card U4 is grounded through a capacitor C15, pin 6 of the e-SIM card U4 is connected to one end of a capacitor C14 and one end of a resistor R6, pin 3 of the e-SIM card U4 is connected to one end of a capacitor C13 and one end of a resistor R7, pin 7 of the e-SIM card U4 is connected to one end of a capacitor C12 and one end of a resistor R8, the other end of the capacitor C12, the other end of the capacitor C13 and the other end of the capacitor C14 are both grounded, the other end of the resistor R6 is connected to USIM _ CLK, the other end of the resistor R7 is connected to USIM _ DATA, and the other end of the resistor R8 is connected to USIM _ RST.

9. The narrow-band internet of things-based valve controller according to claim 1, characterized in that: the valve opening degree detection circuit comprises an operational amplifier U9, a capacitor C42, a capacitor C43, a resistor R31, a resistor R33, a resistor R34 and a socket CN4, wherein a pin 1 of the operational amplifier U9 is respectively connected with one end of the resistor R33 and one end of the resistor R34, a pin 5 of the operational amplifier U9 is respectively connected with one end of a VC1 and one end of a capacitor C42, a pin 4 of the operational amplifier U9 is connected with the other end of the resistor R33, a pin 2 of the operational amplifier U9 is grounded, a pin 3 of the operational amplifier U9 is respectively connected with one end of the resistor R31 and one end of the socket CN4, a pin 2 of the socket CN4 is connected with a VC1, a pin 4 and a pin 5 of the socket CN4 are both grounded, the other end of the resistor R31 is grounded, the other end of the resistor R34 is respectively connected with one end of an AIN3 and one end of the capacitor C43, the other end of the capacitor C43 is grounded, and the other end of the capacitor C42 is grounded.