Control circuit of liquid crystal constant temperature control switch

Abstract

The invention discloses a control circuit of a liquid crystal constant temperature control switch, which is applied to a temperature control valve and comprises a main control module, a power supply input module, a switch power supply module, a boosting module, a motor control module, a motor signal acquisition module, a temperature acquisition module, a communication module and a display control module, the main control module is respectively connected with the power supply input module, the switching power supply module, the boosting module, the motor control module, the motor signal acquisition module, the temperature acquisition module, the communication module and the display control module; the power supply input module is connected with the switching power supply module and the boost module. And the boosting module is connected with the motor control module. The temperature can be visually displayed and adjusted, constant-temperature control can be achieved, and the temperature control device has the advantages of being low in energy consumption and long in service life.

Description

Technical Field

[0001] The invention relates to the technical field of temperature control switches, in particular to a control circuit of a liquid crystal constant temperature temperature control switch. Background Art

[0002] Liquid crystal temperature control valve is a temperature control valve integrated with liquid crystal display technology. It combines the advantages of temperature control and liquid crystal display, and can intuitively and accurately display and adjust the temperature. Liquid crystal temperature control valve is suitable for various occasions that require temperature control, such as home, office, laboratory, production workshop, etc. Liquid crystal temperature control valve is connected to the pipeline of heating or air conditioning system to control the flow of fluid (such as water, steam or refrigerant) flowing through the pipeline, thereby realizing the regulation of indoor temperature. For example, the Chinese utility model patent with authorization announcement number CN214623368U discloses a temperature control valve control circuit for a heating system, including a power module, an information acquisition module, an adjustment module, a controller and a drive module, wherein the power module is connected to the controller and the drive module for providing power; the information acquisition module is connected to the controller for sending the collected temperature signal to the controller; the adjustment module is connected to the controller for inputting a reference temperature signal; the drive module is connected to the controller for receiving the control signal output by the controller to control the opening and closing degree of the temperature control valve. Conventional temperature control valve control circuits generally do not have a switching power supply module, so the temperature control valve is in a working state for a long time, which will generate more unnecessary energy consumption and also reduce the service life of the temperature control valve. Summary of the invention

[0003] The object of the present invention is to provide a control circuit of a liquid crystal constant temperature temperature control switch. The present invention can intuitively display and adjust the temperature, and can realize constant temperature control, and has the advantages of low energy consumption and long service life.

[0004] The technical solution of the present invention is as follows: a control circuit of a liquid crystal constant temperature temperature control switch, applied to a temperature control valve, comprising a main control module, a power input module, a switching power module, a boost module, a motor control module, a motor signal acquisition module, a temperature acquisition module, a communication module and a display control module; the main control module is respectively connected to the power input module, the switching power module, the boost module, the motor control module, the motor signal acquisition module, the temperature acquisition module, the communication module and the display control module; the power input module is respectively connected to the switching power module and the boost module; the boost module is connected to the motor control module; the main control module sends a control signal to the motor control module according to the temperature information collected by the temperature acquisition module; the motor control module controls the rotation of the motor of the temperature control valve and adjusts the flow of the temperature control valve; the display control module is used to display the temperature; the switching power module controls the switch of the power input module; the boost module is used to stabilize the output of the power input module; the motor signal acquisition module detects the current of the motor to ensure the safety of the motor operation.

[0005] The control circuit of the above-mentioned liquid crystal constant temperature temperature control switch, the main control module includes a chip U1, a resistor R1, a capacitor C11, a capacitor C12, a capacitor C15, a capacitor C16, a capacitor C23 and a capacitor C24; the VCAP pin of the chip U1 is connected to one end of the capacitor C11 and one end of the capacitor C12; the other end of the capacitor C11 is connected to the other end of the capacitor C12 and is grounded; the AVCC pin of the chip U1 is connected to one end of the capacitor C23 and one end of the capacitor C24, and outputs a voltage source VOUT; the other end of the capacitor C23 is connected to the other end of the capacitor C24 and is grounded; the DVSS pins of the chip U1 are all grounded; the PD03 pin of the chip U1 is connected to one end of the resistor R1, and the other end of the resistor R1 is grounded; the DVCC pin of the chip U1 is connected to one end of the capacitor C15 and one end of the capacitor C16, and outputs a voltage source VOUT; the other end of the capacitor C15 is connected to the other end of the capacitor C16 and is grounded.

[0006] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the power input module includes a wiring terminal P1, a MOS tube Q1, a resistor R25, a resistor R32, a capacitor C3, a capacitor C20, a capacitor C21, a capacitor C22 and a chip U3; the No. 1 port of the wiring terminal P1 is connected to the drain of the MOS tube Q1; the source of the MOS tube Q1 is connected to one end of the resistor R25, one end of the capacitor C21, one end of the capacitor C22 and the VIN pin of the chip U3, and the other end of the resistor R25 is connected to one end of the capacitor C3 and the main control module ; The gate of the MOS tube Q1 is connected to port No. 2 of the wiring terminal P1, the other end of the capacitor C3, the other end of the capacitor C21 and the other end of the capacitor C22, and is grounded; the C- pin of the chip U3 is connected to one end of the capacitor C20, and the C+ pin of the chip U3 is connected to the other end of the capacitor C20; the EN pin of the chip U3 is connected to one end of the resistor R32, and the other end of the resistor R32 is connected to the main control module; the GND pin of the chip U3 is grounded; the VOUT pin of the chip U3 outputs a 3.3V voltage source.

[0007] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the switching power supply module includes a MOS tube Q3, a MOS tube Q4, a MOS tube Q5, a resistor R11, a resistor R12, a resistor R13 and a capacitor C5; the drain of the MOS tube Q3 is connected to the voltage source VCC, the gate of the MOS tube Q3 is connected to one end of the resistor R11 and the drain of the MOS tube Q4, and is connected to the 3.3V voltage source; the source of the MOS tube Q3 is connected to the source of the MOS tube Q4, one end of the resistor R12 and one end of the capacitor C5, and is connected to the voltage source VOUT; the other end of the capacitor C5 is grounded; the other end of the resistor R12 is connected to the gate of the MOS tube Q4 and the drain of the MOS tube Q5; the gate of the MOS tube Q5 is connected to one end of the resistor R13 and the main control module; the source of the MOS tube Q5 is connected to the other end of the resistor R13, and is grounded.

[0008] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the boost module includes a MOS tube Q2, a resistor R5, a resistor R21, a resistor R22, a capacitor C25, a capacitor C30, a capacitor C31, a capacitor C32, an inductor L1, a diode D2 and a chip U8; one end of the resistor R5 is connected to the source of the MOS tube Q2 and to the voltage source VCC; the other end of the power supply R5 is connected to the gate of the MOS tube Q2 and to the main control module; the drain of the MOS tube Q2 is connected to one end of the capacitor C31, the capacitor C 30, one end of the inductor L1, the VIN pin of the chip U8 and the EN pin of the chip U8; the SW pin of the chip U8 is connected to the other end of the inductor L1 and the positive electrode of the diode D2; the negative electrode of the diode D2 is connected to one end of the capacitor C32, one end of the capacitor C25, one end of the resistor R21, and connected to the motor control module; the GND pin of the chip U8 is grounded; the FB pin of the chip U8 is connected to the other end of the resistor R21 and one end of the resistor R22, and the other end of the resistor R22 is grounded.

[0009] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the motor control module includes chip U6, chip U7, capacitor C26, capacitor C27, capacitor C28 and terminal P2; the IN2 pin of chip U6 and the IN1 pin of chip U6 are respectively connected to the main control module; the VCC pin of the chip U6 is connected to the boost module; the GND pin of the chip U6 is grounded; the OUT2 pin of the chip U6 is connected to one end of the capacitor C26 and port 2 of the terminal P2; the OUT1 pin of the chip U6 is connected to the other end of the capacitor C26 and port 4 of the terminal P2; the IN2 pin of the chip U7 and the IN1 pin of the chip U7 are respectively connected to the main control module; the VCC pin of the chip U7 is connected to one end of the capacitor C28, and the other end of the capacitor C28 is grounded; the GND pin of the chip U7 is connected to the motor; the OUT2 pin of the chip U7 is connected to one end of the capacitor C27 and port 3 of the terminal P2; the OUT1 pin of the chip U7 is connected to the other end of the capacitor C27 and port 1 of the terminal P2.

[0010] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the motor signal acquisition module includes an operational amplifier U9, a resistor R10, a resistor R24, a resistor R26, a resistor R27, a resistor R28, a capacitor C8, a capacitor C9 and a capacitor C10; the positive power supply terminal of the operational amplifier U9 is connected to a 3.3V voltage source; the negative power supply terminal of the operational amplifier U9 is grounded; the inverting input terminal of the operational amplifier U9 is connected to one end of the resistor R24 ​​and one end of the resistor R28, and the other end of the resistor R24 ​​is grounded; the same power supply terminal of the operational amplifier U9 is connected to the ground. The phase input end is connected to one end of the resistor R27, the other end of the resistor R27 is connected to one end of the resistor R26 and one end of the capacitor C9, and is connected to a motor; the other end of the capacitor C9 is connected to the other end of the resistor R26 and is grounded; the output end of the operational amplifier U9 is connected to the other end of the resistor R28 and one end of the resistor R10; the other end of the resistor R10 is connected to one end of the capacitor C8 and is connected to the main control module; the other end of the capacitor C8 is grounded; one end of the capacitor C10 is connected to a 3.3V voltage source, and the other end of the capacitor C10 is grounded.

[0011] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the temperature acquisition module includes a resistor R9, a resistor R23 and a thermistor NTC; one end of the resistor R9 is connected to a 3.3V voltage source, and the other end of the resistor R9 is connected to one end of the resistor R23 and one end of the thermistor NTC; the other end of the resistor R23 is connected to the main control module; the other end of the thermistor NTC is grounded.

[0012] In the control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the communication module includes a wireless module and a Bluetooth module; the wireless module and the Bluetooth module are respectively connected to the main control module.

[0013] The control circuit of the aforementioned liquid crystal constant temperature temperature control switch, the display control module includes an LED display module and a liquid crystal display module; the LED display module is connected to the main control module; the liquid crystal display module is connected to an encoder module, and the encoder module is connected to the main control module.

[0014] Compared with the prior art, the main control module of the present invention sends a control signal to the motor control module according to the temperature information collected by the temperature acquisition module; the motor control module controls the rotation of the motor of the temperature control valve and adjusts the flow of the temperature control valve; the display control module is used to display the temperature; the switching power supply module controls the switch of the power input module; the boost module is used to stabilize the output of the power input module; the motor signal acquisition module detects the current of the motor to ensure the safety of the motor operation; the present invention can intuitively display and adjust the temperature, and can realize constant temperature control, and has the advantages of low energy consumption and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a circuit diagram of the main control module of the present invention;

[0016] Figure 2 This is the circuit diagram of the power input module;

[0017] Figure 3 It is the circuit diagram of the switching power supply module;

[0018] Figure 4 This is the circuit diagram of the boost module;

[0019] Figure 5 This is the circuit diagram of the motor control module;

[0020] Figure 6 This is the circuit diagram of the motor signal acquisition module;

[0021] Figure 7 This is the circuit diagram of the temperature acquisition module;

[0022] Figure 8 This is the circuit diagram of the wireless module;

[0023] Fig. 9 This is the circuit diagram of the Bluetooth module;

[0024] Fig.10 This is the circuit diagram of the LED display module;

[0025] Fig.11 It is the circuit diagram of the LCD module;

[0026] Fig.12 is the circuit diagram of the encoder module. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0028] Embodiment: The control circuit of the liquid crystal constant temperature temperature control switch is applied to the temperature control valve, including a main control module, a power input module, a switching power module, a boost module, a motor control module, a motor signal acquisition module, a temperature acquisition module, a communication module and a display control module; the main control module is respectively connected to the power input module, the switching power module, the boost module, the motor control module, the motor signal acquisition module, the temperature acquisition module, the communication module and the display control module; the power input module is respectively connected to the switching power module and the boost module; the boost module is connected to the motor control module; the main control module of the present invention sends a control signal to the motor control module according to the temperature information collected by the temperature acquisition module; the motor control module controls the rotation of the motor of the temperature control valve and adjusts the flow of the temperature control valve; the display control module is used to display the temperature; the switching power module controls the switch of the power input module; the boost module is used to stabilize the output of the power input module; the motor signal acquisition module detects the current of the motor to ensure the safety of the motor operation; the present invention can intuitively display and adjust the temperature, and can realize constant temperature control, and has the advantages of low energy consumption and long service life.

[0029] The main control module is Figure 1As shown, the main control module includes a chip U1, a resistor R1, a capacitor C11, a capacitor C12, a capacitor C15, a capacitor C16, a capacitor C23 and a capacitor C24; the VCAP pin of the chip U1 is connected to one end of the capacitor C11 and one end of the capacitor C12; the other end of the capacitor C11 is connected to the other end of the capacitor C12 and is grounded; the AVCC pin of the chip U1 is connected to one end of the capacitor C23 and one end of the capacitor C24, and outputs a voltage source VOUT; the other end of the capacitor C23 is connected to the other end of the capacitor C24 and is grounded; the DVSS pins of the chip U1 are all grounded; the PD03 pin of the chip U1 is connected to one end of the resistor R1, and the other end of the resistor R1 is grounded; the DVCC pin of the chip U1 is connected to one end of the capacitor C15 and one end of the capacitor C16, and outputs a voltage source VOUT; the other end of the capacitor C15 is connected to the other end of the capacitor C16 and is grounded. The chip U1 of the main control module adopts the HC32L103 series of single-chip microcomputers. The HC32L103 series is a single-chip microcomputer with ultra-low power consumption and wide voltage operating range designed to extend the battery life of the portable measurement system. It integrates 12-bit 1Msps high-precision SARADC and integrated comparators, op amps, built-in high-performance PWM timers, LCD displays, multiple UARTs, SPI, I2C and other rich communication peripherals, built-in AES, TRNG and other information security modules, and has the characteristics of high integration, high anti-interference, high reliability and ultra-low power consumption. The capacitors C11 and C12 in the main control module are decoupling capacitors, which play an anti-interference role, avoid the voltage drop due to the sudden change of current, and reduce the noise of the components coupled to the power supply end. Capacitors C15 and C16 are filter capacitors for digital power supply, which are mainly used for filtering power supply signals to provide a stable power supply and reduce the noise of the power supply. Capacitors C23 and C24 are filter capacitors for analog circuits, which are mainly used for filtering power supply signals to provide a stable power supply and reduce the noise of the power supply. Resistor R1 is a signal pull-down resistor. When reset, the PD03 pin of chip U1 is at a low level. Chip U1 works in user mode. Chip U1 executes the program code in the Flash and can program the Flash through the SWD protocol.

[0030] Power input module such as Figure 2As shown, the power input module includes a wiring terminal P1, a MOS tube Q1, a resistor R25, a resistor R32, a capacitor C3, a capacitor C20, a capacitor C21, a capacitor C22 and a chip U3; port 1 of the wiring terminal P1 is connected to the drain of the MOS tube Q1; the source of the MOS tube Q1 is connected to one end of the resistor R25, one end of the capacitor C21, one end of the capacitor C22 and the VIN pin of the chip U3, and the other end of the resistor R25 is connected to one end of the capacitor C3 and the main control module; the MOS tube The gate of Q1 is connected to the No. 2 port of the wiring terminal P1, the other end of the capacitor C3, the other end of the capacitor C21 and the other end of the capacitor C22, and is grounded; the C- pin of the chip U3 is connected to one end of the capacitor C20, and the C+ pin of the chip U3 is connected to the other end of the capacitor C20; the EN pin of the chip U3 is connected to one end of the resistor R32, and the other end of the resistor R32 is connected to the main control module; the GND pin of the chip U3 is grounded; the VOUT pin of the chip U3 outputs a 3.3V voltage source. The chip U3 of the power input module uses the HE9008M6R charge pump boost chip. The HE9008M6R is a low-noise, constant-frequency switch capacitor voltage multiplier that generates an adjustable output voltage from 1.8V to 5V input, and the output current is up to 250mA. The MOS tube Q1 of its power input module is a power switch protection tube, which prevents safety problems caused by short circuits when the battery is reversely connected and short-circuited. Resistor R25 and capacitor C3 form a battery power sampling circuit. The current signal is converted into a voltage signal through the sampling resistor R25, which is then maintained by capacitor C3 and finally quantized by an analog-to-digital converter (ADC). Capacitors C21 and C22 are filter capacitors used to remove the clutter generated by the power supply and stabilize the power supply. Capacitor C20 is a flying capacitor, which can balance the voltage difference of the single cells in the series battery pack to prevent problems such as overcharging, over-discharging or overheating runaway, thereby extending the overall life of the battery pack. Resistor R1 is a signal pull-up resistor that provides a high-level output value.

[0031] Switching power supply module such as Figure 3As shown, the switching power supply module includes MOS tube Q3, MOS tube Q4, MOS tube Q5, resistor R11, resistor R12, resistor R13 and capacitor C5; the drain of the MOS tube Q3 is connected to the voltage source VCC, the gate of the MOS tube Q3 is connected to one end of the resistor R11 and the drain of the MOS tube Q4, and is connected to the 3.3V voltage source; the source of the MOS tube Q3 is connected to the source of the MOS tube Q4, one end of the resistor R12 and one end of the capacitor C5, and is connected to the voltage source VOUT; the other end of the capacitor C5 is grounded; the other end of the resistor R12 is connected to the gate of the MOS tube Q4 and the drain of the MOS tube Q5; the gate of the MOS tube Q5 is connected to one end of the resistor R13 and the main control module; the source of the MOS tube Q5 is connected to the other end of the resistor R13 and is grounded. The switching power supply module realizes the function of reducing power consumption and extending battery life through the switching characteristics of the MOS tubes Q3 and Q4.

[0032] Boost module such as Figure 4As shown, the boost module includes a MOS tube Q2, a resistor R5, a resistor R21, a resistor R22, a capacitor C25, a capacitor C30, a capacitor C31, a capacitor C32, an inductor L1, a diode D2 and a chip U8; one end of the resistor R5 is connected to the source of the MOS tube Q2 and to the voltage source VCC; the other end of the power supply R5 is connected to the gate of the MOS tube Q2 and to the main control module; the drain of the MOS tube Q2 is connected to one end of the capacitor C31, one end of the capacitor C30, one end of the inductor L1, the VIN pin of the chip U8 and the EN pin of the chip U8; the SW pin of the chip U8 is connected to the other end of the inductor L1 and the positive electrode of the diode D2; the negative electrode of the diode D2 is connected to one end of the capacitor C32, one end of the capacitor C25, one end of the resistor R21, and to the motor control module; the GND pin of the chip U8 is grounded; the FB pin of the chip U8 is connected to the other end of the resistor R21 and one end of the resistor R22, and the other end of the resistor R22 is grounded. The chip U8 of the boost module uses the MT3608 boost converter. The MT3608 is a constant frequency, 6-pin SOT23 current mode boost converter with a switching frequency of 1.2MHz. It is equipped with an internal soft start to generate a small inrush current and extend battery life. It has the function of automatically switching to pulse frequency modulation mode under light load. In addition, it also has undervoltage lockout, current limiting and overheating protection to prevent damage in the case of output overload. The MOS tube Q2 of the boost module is a switch tube, which controls the chip U8 to work or stop, and plays a role in protecting and reducing circuit power consumption. Capacitors C30 and C31 are filter capacitors that filter the noise generated by the power supply, provide a stable power input, and also play a role in preventing power supply mutations. Inductor L1 is a boost inductor, and its main functions include providing directional electromotive force, limiting current, controlling the conduction and cutoff of the switch tube, reducing the loss of MOS tube Q2, and smoothing current and storing energy. When MOS tube Q2 is closed, inductor L1 starts to charge and the current gradually increases; when MOS tube Q2 is disconnected, inductor L1 starts to discharge and the current gradually decreases. Due to the self-inductance of inductor L1, it can keep the current stable at the moment of switching of MOS tube Q2, thereby smoothing the current fluctuation. Diode D2 is an anti-reverse charging protection diode, which prevents the boosted voltage or current from reverse supply, playing a protective role. Capacitor C32 and capacitor C25 are filter capacitors, which are mainly used to remove output power clutter and maintain stable power output. Resistors R21 and R22 are feedback sampling resistors, and different voltages and currents can be output by controlling their different ratios.

[0033] Motor control module such as Figure 5As shown, the motor control module includes a chip U6, a chip U7, a capacitor C26, a capacitor C27, a capacitor C28 and a terminal P2; the IN2 pin of the chip U6 and the IN1 pin of the chip U6 are respectively connected to the main control module; the VCC pin of the chip U6 is connected to the boost module; the GND pin of the chip U6 is grounded; the OUT2 pin of the chip U6 is connected to one end of the capacitor C26 and the port No. 2 of the terminal P2; the OUT1 pin of the chip U6 is connected to the other end of the capacitor C26 and the port No. 4 of the terminal P2; the IN2 pin of the chip U7 and the IN1 pin of the chip U7 are respectively connected to the main control module; the VCC pin of the chip U7 is connected to one end of the capacitor C28, and the other end of the capacitor C28 is grounded; the GND pin of the chip U7 is connected to the motor; the OUT2 pin of the chip U7 is connected to one end of the capacitor C27 and the port No. 3 of the terminal P2; the OUT1 pin of the chip U7 is connected to the other end of the capacitor C27 and the port No. 1 of the terminal P2. Chip U6 and chip U7 of the motor control module both use the MS3111S motor driver chip. The MS3111S is a low-voltage 5V DC motor driver chip that can provide an output current of up to 0.8A and can work on a power supply voltage of 1.8 to 6V. It has a PWM (IN / IN) input interface, is compatible with industry standard devices, and has an over-temperature protection function. Capacitor C28 of the motor control module is a filter capacitor, which is used to filter out the clutter and interference generated by the boost module and also acts as a stable power supply; capacitors C26 and C27 are motor filter capacitors, which are used to reduce the electromagnetic interference generated when the motor is working and prevent voltage mutations generated when the motor is working.

[0034] Motor signal acquisition module such as Figure 6As shown, the motor signal acquisition module includes an operational amplifier U9, a resistor R10, a resistor R24, a resistor R26, a resistor R27, a resistor R28, a capacitor C8, a capacitor C9 and a capacitor C10; the positive power supply terminal of the operational amplifier U9 is connected to a 3.3V voltage source; the negative power supply terminal of the operational amplifier U9 is grounded; the inverting input terminal of the operational amplifier U9 is connected to one end of the resistor R24 ​​and one end of the resistor R28, and the other end of the resistor R24 ​​is grounded; the in-phase input terminal of the operational amplifier U9 is connected to the One end of the resistor R27, the other end of the resistor R27 is connected to one end of the resistor R26 and one end of the capacitor C9, and is connected to a motor; the other end of the capacitor C9 is connected to the other end of the resistor R26 and is grounded; the output end of the operational amplifier U9 is connected to the other end of the resistor R28 and one end of the resistor R10; the other end of the resistor R10 is connected to one end of the capacitor C8 and is connected to the main control module; the other end of the capacitor C8 is grounded; one end of the capacitor C10 is connected to a 3.3V voltage source, and the other end of the capacitor C10 is grounded. The operational amplifier U9 of the motor signal acquisition module adopts the LM321 operational amplifier, which is a high-performance operational amplifier chip with the characteristics of wide operating voltage range, low power consumption, high gain and fast response. The resistor R26 of the motor signal acquisition module is a motor signal sampling resistor, which ensures that the motor runs within a safe range by measuring the current flowing through the motor to prevent overload and overheating. Capacitor C9 is a filter capacitor used to stabilize the transmission of motor signals. Resistor R28 and resistor R24 ​​form a signal feedback circuit, where resistor R28 is a feedback resistor used to adjust the gain of operational amplifier U9 and improve the phase characteristics. Resistor R10 and capacitor C8 form an amplifier output circuit used to control the amplitude, waveform and stability of the output signal of operational amplifier U9. Capacitor C10 is a filter capacitor to ensure the stability of the amplifier power supply and remove clutter.

[0035] Temperature acquisition module such as Figure 7 As shown, the temperature acquisition module includes a resistor R9, a resistor R23 and a thermistor NTC; one end of the resistor R9 is connected to a 3.3V voltage source, and the other end of the resistor R9 is connected to one end of the resistor R23 and one end of the thermistor NTC; the other end of the resistor R23 is connected to the main control module; the other end of the thermistor NTC is grounded. The temperature acquisition module is constructed using the thermistor NTC and a conventional resistor. By detecting the electrical characteristics of the thermistor NTC, its resistance value changes with temperature, thereby obtaining temperature information and realizing temperature acquisition.

[0036] The formula for the relationship between the temperature of the thermistor NTC and its resistance value is:

[0037]

[0038] Among them, R tis the resistance value of thermistor NTC at the current temperature; R0 is the resistance value of thermistor NTC at the standard temperature; T0 is the standard temperature; T is the current temperature; B is the constant of thermistor NTC; e is the natural constant.

[0039] Communication modules such as Figure 8 and Fig. 9 As shown, the communication module includes a wireless module and a Bluetooth module; the wireless module and the Bluetooth module are connected to the main control module respectively. The wireless module adopts the module of the Tuya ZT series. ZT5 consists of a highly integrated wireless RF processor chip Z2 and a small number of peripheral devices. ZT5 is embedded with a low-power 32-bit CPU core, 1024-KB-flash, 64KB RAM and rich peripheral resources. Its main frequency supports 48MHz, the wide operating voltage is 1.8V-3.6V, and the peripherals include 6xGPIOs, 1xuart and 1xADC.

[0040] The Bluetooth module adopts Tuya ZS3 series. ZS3L consists of a highly integrated wireless RF processor chip EFR32MG21A020F768IM32-B and a small number of peripheral devices, with built-in 802.15.4PHY / MAC Zigbee network protocol stack and rich library functions. It has a built-in low-power 32-bit CPU, ARM Cortex-M33 processor, with DSP instructions and floating-point unit, which can also serve as an application processor; it supports a main frequency of 80MHz, a wide operating voltage of 2.0V-3.8V, and peripherals include 9xGPIOs, 1xURAT and 1xADC.

[0041] Display control module Fig.10 and Fig.11 As shown, the display control module includes an LED display module and a liquid crystal display module; the LED display module is connected to the main control module; the liquid crystal display module is connected to an encoder module, and the encoder module is connected to the main control module. The LED display module adopts the TM1616 digital tube driver chip, which is a special module for LED drive control, and internally integrates modules such as MCU digital interface, data latch and LED high-voltage driver. The capacitor C17 and capacitor C18 of the LED display module are filter capacitors for stabilizing the power supply, removing clutter and preventing voltage mutation; resistors R29, R30 and R31 are signal transmission resistors for improving the stability of the level and preventing input signal waveform interference and distortion. The light-emitting diodes LED1 to LED20 are digital display lamps, which display corresponding numbers and modes by lighting different lamp beads.

[0042] The liquid crystal display module adopts CXM1621B 32x4 LCD control driver chip, which is a peripheral device used to expand the I / O port of MCU. The display matrix is ​​32×4, which is a 128-dot memory mapping multifunctional LCD driver module. Its operating voltage is 2.4V-5.2V, with a built-in 256KHz RC oscillation module, a Time base frequency source, in which the Power down command reduces power loss, a Time base and WDT watchdog module, and 8 Time base / WDT clock sources; the resistor R4 of the liquid crystal display module is a pull-up resistor to improve the stability of the level and prevent input signal waveform interference and distortion. The capacitor C3 is a filter capacitor to stabilize the power supply, remove clutter and prevent voltage mutations. The resistor R14 and the light-emitting diode LED21 constitute an indicator light module. When the liquid crystal display module is working, LED1 is on, otherwise it is off.

[0043] Encoder module such as Fig.12 As shown, the encoder module adopts EC06 micro encoder, whose rated voltage is DC5V, positioning number is 12, pulse number is 6P / 360°, and rotation torque is 15-50gf.cm. The resistors R2, R3 and R4 of the encoder module are signal pull-up resistors, which improve the stability of the level and prevent input signal waveform interference and distortion, thereby ensuring the accuracy and reliability of digital signal processing. Surge protection tube TV1 and surge protection tube TV2 are electrostatic surge protection tubes, which provide electrostatic protection to prevent the circuit from being damaged by electrostatic discharge. Capacitor C4, capacitor C6 and capacitor C7 are filter capacitors to ensure the stability of the current signal, remove clutter and prevent voltage mutation.

[0044] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. In this embodiment, the words "up", "down", "left", "right", "front" and "rear" only represent their relative positions and do not represent their absolute positions. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A control circuit of a liquid crystal constant temperature temperature control switch, applied to a temperature control valve, characterized in that: It includes a main control module, a power input module, a switching power module, a boost module, a motor control module, a motor signal acquisition module, a temperature acquisition module, a communication module and a display control module; the main control module is respectively connected to the power input module, the switching power module, the boost module, the motor control module, the motor signal acquisition module, the temperature acquisition module, the communication module and the display control module; the power input module is respectively connected to the switching power module and the boost module; the boost module is connected to the motor control module; the main control module sends a control signal to the motor control module according to the temperature information collected by the temperature acquisition module; the motor control module controls the motor rotation of the temperature control valve and adjusts the flow of the temperature control valve; the display control module is used to display the temperature; the switching power module controls the switch of the power input module; the boost module is used to stabilize the output of the power input module; the motor signal acquisition module detects the current of the motor to ensure the safety of the motor operation.

2. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The main control module includes a chip U1, a resistor R1, a capacitor C11, a capacitor C12, a capacitor C15, a capacitor C16, a capacitor C23 and a capacitor C24; the VCAP pin of the chip U1 is connected to one end of the capacitor C11 and one end of the capacitor C12; the other end of the capacitor C11 is connected to the other end of the capacitor C12 and is grounded; the AVCC pin of the chip U1 is connected to one end of the capacitor C23 and one end of the capacitor C24, and outputs a voltage source VOUT; the other end of the capacitor C23 is connected to the other end of the capacitor C24 and is grounded; the DVSS pins of the chip U1 are all grounded; the PD03 pin of the chip U1 is connected to one end of the resistor R1, and the other end of the resistor R1 is grounded; the DVCC pin of the chip U1 is connected to one end of the capacitor C15 and one end of the capacitor C16, and outputs a voltage source VOUT; the other end of the capacitor C15 is connected to the other end of the capacitor C16 and is grounded.

3. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The power input module includes a wiring terminal P1, a MOS tube Q1, a resistor R25, a resistor R32, a capacitor C3, a capacitor C20, a capacitor C21, a capacitor C22 and a chip U3; port 1 of the wiring terminal P1 is connected to the drain of the MOS tube Q1; the source of the MOS tube Q1 is connected to one end of the resistor R25, one end of the capacitor C21, one end of the capacitor C22 and the VIN pin of the chip U3, and the other end of the resistor R25 is connected to one end of the capacitor C3 and the main control module; the MOS tube Q1 is connected to the drain of the MOS tube Q1; the source of the MOS tube Q1 is connected to one end of the resistor R25, one end of the capacitor C21, one end of the capacitor C22 and the VIN pin of the chip U3, and the other end of the resistor R25 is connected to one end of the capacitor C3 and the main control module; The gate of the chip U1 is connected to port No. 2 of the wiring terminal P1, the other end of the capacitor C3, the other end of the capacitor C21 and the other end of the capacitor C22, and is grounded; the C- pin of the chip U3 is connected to one end of the capacitor C20, and the C+ pin of the chip U3 is connected to the other end of the capacitor C20; the EN pin of the chip U3 is connected to one end of the resistor R32, and the other end of the resistor R32 is connected to the main control module; the GND pin of the chip U3 is grounded; the VOUT pin of the chip U3 outputs a 3.3V voltage source.

4. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The switch power supply module includes a MOS tube Q3, a MOS tube Q4, a MOS tube Q5, a resistor R11, a resistor R12, a resistor R13 and a capacitor C5; the drain of the MOS tube Q3 is connected to a voltage source VCC, the gate of the MOS tube Q3 is connected to one end of the resistor R11 and the drain of the MOS tube Q4, and is connected to a 3.3V voltage source; the source of the MOS tube Q3 is connected to the source of the MOS tube Q4, one end of the resistor R12 and one end of the capacitor C5, and is connected to a voltage source VOUT; the other end of the capacitor C5 is grounded; the other end of the resistor R12 is connected to the gate of the MOS tube Q4 and the drain of the MOS tube Q5; the gate of the MOS tube Q5 is connected to one end of the resistor R13 and a main control module; the source of the MOS tube Q5 is connected to the other end of the resistor R13 and is grounded.

5. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The boost module includes a MOS tube Q2, a resistor R5, a resistor R21, a resistor R22, a capacitor C25, a capacitor C30, a capacitor C31, a capacitor C32, an inductor L1, a diode D2 and a chip U8; one end of the resistor R5 is connected to the source of the MOS tube Q2 and to the voltage source VCC; the other end of the power supply R5 is connected to the gate of the MOS tube Q2 and to the main control module; the drain of the MOS tube Q2 is connected to one end of the capacitor C31, one end of the capacitor C30, one end of the inductor L1, the VIN pin of the chip U8 and the EN pin of the chip U8; the SW pin of the chip U8 is connected to the other end of the inductor L1 and the positive electrode of the diode D2; the negative electrode of the diode D2 is connected to one end of the capacitor C32, one end of the capacitor C25, one end of the resistor R21, and to the motor control module; the GND pin of the chip U8 is grounded; the FB pin of the chip U8 is connected to the other end of the resistor R21 and one end of the resistor R22, and the other end of the resistor R22 is grounded.

6. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The motor control module includes chip U6, chip U7, capacitor C26, capacitor C27, capacitor C28 and terminal P2; the IN2 pin of chip U6 and the IN1 pin of chip U6 are respectively connected to the main control module; the VCC pin of chip U6 is connected to the boost module; the GND pin of chip U6 is grounded; the OUT2 pin of chip U6 is connected to one end of capacitor C26 and port 2 of terminal P2; the OUT1 pin of chip U6 is connected to the other end of capacitor C26 and port 4 of terminal P2; the IN2 pin of chip U7 and the IN1 pin of chip U7 are respectively connected to the main control module; the VCC pin of chip U7 is connected to one end of capacitor C28, and the other end of capacitor C28 is grounded; the GND pin of chip U7 is connected to the motor; the OUT2 pin of chip U7 is connected to one end of capacitor C27 and port 3 of terminal P2; the OUT1 pin of chip U7 is connected to the other end of capacitor C27 and port 1 of terminal P2.

7. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The motor signal acquisition module includes an operational amplifier U9, a resistor R10, a resistor R24, a resistor R26, a resistor R27, a resistor R28, a capacitor C8, a capacitor C9 and a capacitor C10; the positive power supply terminal of the operational amplifier U9 is connected to a 3.3V voltage source; the negative power supply terminal of the operational amplifier U9 is grounded; the inverting input terminal of the operational amplifier U9 is connected to one end of the resistor R24 ​​and one end of the resistor R28, and the other end of the resistor R24 ​​is grounded; the in-phase input terminal of the operational amplifier U9 is connected to one end of the resistor R27, the other end of the resistor R27 is connected to one end of the resistor R26 and one end of the capacitor C9, and is connected to a motor; the other end of the capacitor C9 is connected to the other end of the resistor R26 and is grounded; the output terminal of the operational amplifier U9 is connected to the other end of the resistor R28 and one end of the resistor R10; the other end of the resistor R10 is connected to one end of the capacitor C8 and is connected to the main control module; the other end of the capacitor C8 is grounded; one end of the capacitor C10 is connected to a 3.3V voltage source, and the other end of the capacitor C10 is grounded.

8. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The temperature acquisition module includes a resistor R9, a resistor R23 and a thermistor NTC; one end of the resistor R9 is connected to a 3.3V voltage source, and the other end of the resistor R9 is connected to one end of the resistor R23 and one end of the thermistor NTC; the other end of the resistor R23 is connected to the main control module; the other end of the thermistor NTC is grounded.

9. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The communication module includes a wireless module and a Bluetooth module; the wireless module and the Bluetooth module are respectively connected to the main control module.

10. The control circuit of the liquid crystal constant temperature temperature control switch according to claim 1, characterized in that: The display control module includes an LED display module and a liquid crystal display module; the LED display module is connected to the main control module; the liquid crystal display module is connected to an encoder module, and the encoder module is connected to the main control module.

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