Constant temperature and humidity control circuit

Abstract

According to the constant temperature and humidity control circuit provided by the utility model, temperature information and humidity information in the display screen are detected through the temperature and humidity detection circuit; the temperature information and the humidity information are received through the control circuit, and the working states of a display screen heating control circuit and a fan adjusting circuit are controlled according to the detection result; the display screen is heated through the display screen heating control circuit according to the humidity information; the rotating speed of the fan is adjusted through the fan adjusting circuit according to the temperature information; through cooperative work of the power supply circuit, the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjusting circuit and the control circuit, the operation environment of the outdoor display screen can be effectively improved, the service life of equipment is prolonged, the reliability and economical efficiency of the whole system are improved, and the system has remarkable practical value.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic circuit technical field especially relates to a constant temperature and humidity control circuit. BACKGROUND

[0002] In recent years, with the wide application of outdoor electronic display screens in the fields of advertising, transportation, information publishing, etc., their working environment often faces changing climate conditions, such as high humidity, low temperature, and rainy and snowy weather. The performance and lifespan of the display screen are easily affected by changes in temperature and humidity, especially moisture and condensation water, which can lead to the formation of water mist inside the display screen, thereby reducing the display effect and even damaging electronic components. In addition, the heat generated by the long-running display screen can also cause the internal temperature to be too high, affecting the stability of the equipment.

[0003] To address these problems, the existing technology usually uses heating modules or fans to regulate the temperature and humidity inside the display screen. However, these solutions usually operate independently, lack effective cooperative control mechanisms, leading to increased energy consumption, low regulation efficiency, and high long-term maintenance costs of the equipment.

[0004] In summary, the problems in the existing technology need to be solved. INVENTION CONTENTS

[0005] The utility model provides a constant temperature and humidity control circuit to solve the defects in the prior art and realize automatic regulation of the internal environment of the equipment.

[0006] The utility model provides a constant temperature and humidity control circuit, comprising: a power supply circuit, a temperature and humidity detection circuit, a display screen heating control circuit, a fan regulation circuit, and a control circuit.

[0007] The power supply circuit is used to provide stable working voltage for the temperature and humidity detection circuit, the display screen heating control circuit, the fan regulation circuit, and the control circuit.

[0008] The temperature and humidity detection circuit is used to detect the temperature information and humidity information inside the display screen.

[0009] The control circuit is used to receive the temperature information and humidity information and control the working state of the display screen heating control circuit and the fan regulation circuit according to the detection results.

[0010] The display screen heating control circuit is used to heat the display screen according to the humidity information.

[0011] The fan regulation circuit is used to adjust the rotating speed of the fan according to the temperature information.

[0012] The output end of the temperature and humidity detection circuit is connected to the input end of the control circuit, the first output end of the control circuit is connected to the input end of the display screen heating control circuit, and the second output end of the control circuit is connected to the input end of the fan adjustment circuit.

[0013] According to a constant temperature and humidity control circuit provided by the utility model, the power supply circuit includes: a DC-DC step-down regulator, a filter capacitor and a freewheeling diode;

[0014] The DC-DC step-down regulator is used to reduce the external input voltage to the required stable output voltage;

[0015] The filter capacitor and the freewheeling diode are used to eliminate noise in the power supply and provide a continuous and stable voltage output.

[0016] According to a constant temperature and humidity control circuit provided by the utility model, the temperature and humidity detection circuit includes: a temperature and humidity sensor, a pull-up resistor and a filter capacitor;

[0017] The temperature and humidity sensor is used to monitor the temperature and humidity of the internal environment of the display screen and transmit the signal to the control circuit;

[0018] The pull-up resistor and filter capacitor are used to stabilize the signal output of the temperature and humidity sensor.

[0019] According to a constant temperature and humidity control circuit provided by the utility model, the display screen heating control circuit includes: a relay, a transistor and a diode;

[0020] The relay is used to turn on the display screen heating power supply when the humidity is high;

[0021] The triode is used to drive the relay;

[0022] The diode is used to prevent reverse current.

[0023] According to a constant temperature and humidity control circuit provided by the utility model, the fan adjustment circuit includes: a fan and a P-type MOS tube;

[0024] The conduction state of the P-type MOS tube is controlled by a PWM signal of a control circuit;

[0025] The PWM signal is used to adjust the fan voltage and speed.

[0026] According to a constant temperature and humidity control circuit provided by the utility model, the control circuit includes: a microcontroller;

[0027] The microcontroller is used to receive signals from the temperature and humidity sensor through the I2C interface, and control the working states of the heating control circuit and the fan adjustment circuit according to the detected temperature and humidity.

[0028] According to a constant temperature and humidity control circuit provided by the utility model, the microcontroller is a 32-bit microcontroller with a Cortex-M4 core, an operating frequency of 150 MHz, and a built-in 256K flash memory.

[0029] According to a constant temperature and humidity control circuit provided by the utility model, the microcontroller is a 32-bit microcontroller with a Cortex-M4 core, an operating frequency of 150 MHz, and a built-in 256K flash memory.

[0030] According to a constant temperature and humidity control circuit provided by the utility model, the input end of the DC-DC step-down regulator is connected to the external input voltage, and the output end is connected to the filter capacitor; the positive end of the filter capacitor is connected to the positive end of the freewheeling diode, and the negative end of the freewheeling diode is connected to the load end, and the load end is the power input end of the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjustment circuit and the control circuit.

[0031] According to a constant temperature and humidity control circuit provided by the present invention, the signal output end of the temperature and humidity sensor is connected to the I2C interface input end of the control circuit through the pull-up resistor, the power supply end of the temperature and humidity sensor is connected to the output end of the power supply circuit through the filter capacitor, and the ground end of the temperature and humidity sensor is connected to the common ground of the circuit.

[0032] According to a constant temperature and humidity control circuit provided by the utility model, one end of the relay is connected to the output end of the power supply circuit, and the other end is connected to the heating port of the load device; the control end of the relay is connected to the collector of the transistor, the base of the transistor is connected to the GPIO output end of the control circuit through a current-limiting resistor, and the emitter of the transistor is connected to the common ground; the two ends of the relay are connected in parallel with the diode to protect the relay from damage by reverse current.

[0033] According to a constant temperature and humidity control circuit provided by the utility model, the input end of the DC-DC step-down regulator is connected to the external input voltage, and the output end is connected to the filter capacitor; the positive end of the filter capacitor is connected to the positive end of the freewheeling diode, and the negative end of the freewheeling diode is connected to the load end, and the load end is the power input end of the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjustment circuit and the control circuit.

[0034] According to the constant temperature and humidity control circuit, the signal output end of the temperature and humidity sensor is connected to the I 2C interface input end of the control circuit through the pull-up resistor, the power supply end of the temperature and humidity sensor is connected to the output end of the power supply circuit through the filter capacitor, and the grounding end of the temperature and humidity sensor is connected with the common ground of the circuit.

[0035] According to the constant temperature and humidity control circuit, one end of the relay is connected to the output end of the power supply circuit, and the other end is connected to the heating port of the load device; the control end of the relay is connected with the collector of the triode, the base of the triode is connected to the GPIO output end of the control circuit through the current limiting resistor, and the emitter of the triode is connected to the common ground; the two ends of the relay are connected with the diode in parallel, and the diode is used for protecting the relay from being damaged by reverse current.

[0036] The constant temperature and humidity control circuit provided by the utility model, through the power supply circuit, the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjusting circuit and the control circuit provide stable working voltage for the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjusting circuit and the control circuit; the temperature information and humidity information inside the display screen are detected through the temperature and humidity detection circuit; the temperature information and humidity information are received by the control circuit, and the working state of the display screen heating control circuit and the fan adjusting circuit is controlled according to the detection result; the display screen is heated according to the humidity information through the display screen heating control circuit; the rotating speed of the fan is adjusted according to the temperature information through the fan adjusting circuit; the utility model discloses through the power supply circuit, the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjusting circuit and the control circuit, can effectively improve the operation environment of outdoor display screen, prolong the service life of equipment, improve the reliability and economy of overall system, have remarkable practical value. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical scheme in the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0038] Figure 1 It is the module schematic view of the constant temperature and humidity control circuit provided by the utility model;

[0039] Figure 2 It is the power supply circuit diagram of the constant temperature and humidity control circuit provided by the utility model;

[0040] Figure 3 It is the temperature and humidity detection circuit diagram of the constant temperature and humidity control circuit provided by the utility model;

[0041] Figure 4 This is a display screen heating control circuit diagram of a constant temperature and humidity control circuit provided by the utility model;

[0042] Figure 5 This is a fan adjustment circuit diagram of a constant temperature and humidity control circuit provided by the utility model;

[0043] Figure 6 This is a control circuit diagram of a constant temperature and humidity control circuit provided by the utility model. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the accompanying drawings to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] In order to solve the problems in the prior art, the present invention proposes a constant temperature and humidity control circuit to achieve automatic adjustment of the internal environment of the equipment. The constant temperature and humidity control circuit is described below. Figure 1 As shown, it includes: power supply circuit, temperature and humidity detection circuit, display screen heating control circuit, fan adjustment circuit and control circuit;

[0046] The power supply circuit is used to provide a stable operating voltage for the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjustment circuit and the control circuit;

[0047] The temperature and humidity detection circuit is used to detect the temperature and humidity information inside the display screen;

[0048] The control circuit is used to receive the temperature information and humidity information, and control the working state of the display screen heating control circuit and the fan adjustment circuit according to the detection results;

[0049] The display screen heating control circuit is used to heat the display screen according to the humidity information;

[0050] The fan regulating circuit is used to regulate the speed of the fan according to the temperature information;

[0051] The output end of the temperature and humidity detection circuit is connected to the input end of the control circuit, the first output end of the control circuit is connected to the input end of the display screen heating control circuit, and the second output end of the control circuit is connected to the input end of the fan adjustment circuit.

[0052] When the system starts, the temperature and humidity detection circuit begins to detect the temperature and humidity inside the display screen and sends the detection data to the control circuit through the I2C interface. The control circuit analyzes the current environmental status based on the temperature and humidity data:

[0053] When the humidity exceeds the set threshold, the control circuit drives the relay of the display heating control circuit by outputting a high-level signal, starting the heating element to heat the display to remove water mist.

[0054] When the temperature exceeds the set threshold, the control circuit outputs a PWM signal to control the field effect tube of the fan regulation circuit to conduct, and adjusts the fan speed according to the PWM duty cycle to reduce the internal temperature of the display.

[0055] Through the coordinated work of the above circuits, the present invention can intelligently control the temperature and humidity of the outdoor display screen, ensure the stable operation of the system, and at the same time reduce maintenance costs and increase service life.

[0056] As a further optional embodiment, the power supply circuit includes: a DC-DC step-down regulator, a filter capacitor and a freewheeling diode;

[0057] The DC-DC step-down regulator is used to reduce the external input voltage to the required stable output voltage;

[0058] The filter capacitor and the freewheeling diode are used to eliminate noise in the power supply and provide a continuous and stable voltage output.

[0059] like Figure 2 As shown in the figure, the power supply circuit uses a DC-DC step-down regulator U4 (ME3116AM6G) with a voltage range of 4.75V-40V. The circuit receives a 12V external input, which is filtered by capacitors C1 and C17 to eliminate noise before supplying power to the subsequent circuits. The input voltage is regulated by U4 (ME3116AM6G), which adjusts the output voltage based on an external voltage feedback signal and an internal reference voltage. The output voltage range is 0.3V-40V.

[0060] In the circuit, diode D9 (SS34) is used as a freewheeling diode, and inductor L2 is used for energy storage. Voltage feedback is configured through resistors R15 and R1, and the output voltage can be calculated according to the formula

[0061]

[0062] Calculation shows that capacitor C9 is a feedforward capacitor used to improve the loop's transient response and phase margin, while capacitors C19, C18, and C16 play a filtering and energy storage role, ensuring a stable 5V output voltage for subsequent use.

[0063] The circuit also uses the 5V voltage provided by the previous stage, filtered by C20 and C21, before being fed to the DC-DC voltage regulator chip U6 (AMS117-3.3V), which converts the 5V to 3.3V. Capacitors C23 and C22 are used for filtering and energy storage, while Zener diode D7 (BZT52B3V6) ensures a stable 3.3V output, effectively protecting subsequent circuits from overvoltage. This circuit features adjustable output voltage, making it suitable for a wide range of voltage applications and offering great practicality and flexibility.

[0064] As a further optional embodiment, the temperature and humidity detection circuit includes: a temperature and humidity sensor, a pull-up resistor and a filter capacitor;

[0065] The temperature and humidity sensor is used to monitor the temperature and humidity of the internal environment of the display screen and transmit the signal to the control circuit;

[0066] The pull-up resistor and filter capacitor are used to stabilize the signal output of the temperature and humidity sensor.

[0067] like Figure 3 As shown in the figure, the temperature and humidity detection circuit uses a high-precision temperature and humidity sensor U35 (SHT20). Its temperature measurement accuracy is ±0.3°C, with a detection range of -40°C to 125°C; its humidity measurement accuracy is ±3%RH, with a detection range of 0%RH to 100%RH. Humidity measurement is achieved through changes in the sensor's internal capacitance, while temperature measurement is achieved through changes in the resistance of the sensor's internal thermistor.

[0068] Sensor U35 (SHT20) converts analog signals into digital signals through its internal analog-to-digital converter (ADC). This digital signal then communicates with microcontroller U10 (AT32F413CBT7) via the I2C interface on pins 1 (SDA) and 6 (SCL). This circuit enables real-time, rapid monitoring of ambient temperature and humidity, making it suitable for applications requiring high-performance environmental parameters.

[0069] As a further optional embodiment, the display screen heating control circuit includes: a relay, a transistor and a diode;

[0070] The relay is used to turn on the display screen heating power supply when the humidity is high;

[0071] The triode is used to drive the relay;

[0072] The diode is used to prevent reverse current.

[0073] like Figure 4As shown in the figure, the display heating control circuit is used to remove moisture from the display to ensure clear viewing. When microcontroller U10 (AT32F413CBT7) receives ambient humidity information from temperature and humidity sensor U35 (SHT20), if the humidity is high and may cause moisture to form, the microcontroller outputs a high-level signal through GPIO pin 28 (S_CON), triggering transistor Q4 (SS8050) to conduct, which in turn drives relay J3 (G5NB-1A-E-DC5V) to operate.

[0074] When the relay is turned on, a 12V voltage is supplied to the heated glass display through the output terminal VOUT. This voltage drives the glass display to heat up, quickly eliminating mist and restoring display clarity. If the humidity does not reach the mist-inducing threshold, the microcontroller controls the relay to stop operating, thus avoiding energy waste and achieving efficient energy management.

[0075] As a further optional embodiment, the fan regulating circuit includes: a fan and a P-type MOS tube;

[0076] The conduction state of the P-type MOS tube is controlled by a PWM signal of a control circuit;

[0077] The PWM signal is used to adjust the fan voltage and speed.

[0078] like Figure 5 As shown in the figure, the fan regulation circuit dynamically adjusts the fan speed by detecting temperature changes. When microcontroller U10 (AT32F413CBT7) receives a temperature increase signal from the temperature and humidity sensor, it outputs a PWM signal through GPIO pin 29 (PWM). This signal is transmitted through resistor R2 to the base of transistor Q7, turning on Q7 and, consequently, the P-type MOS transistor Q1.

[0079] The PWM signal's duty cycle ranges from 0% to 100%, corresponding to the fan voltage being adjusted from 0V to its rated maximum voltage. This allows for linear fan speed regulation to meet cooling requirements under varying temperature conditions. Diode D2 in the circuit provides freewheeling protection, inductor L1 stores energy, and capacitor CE1 filters the voltage, providing a stable output for the preceding circuitry. This circuit also supports 25kHz PWM signal speed regulation, effectively reducing inductance and switching noise, extending component life, and lowering long-term operating costs.

[0080] As a further optional embodiment, the control circuit includes: a microcontroller;

[0081] The microcontroller is used to receive signals from the temperature and humidity sensor through the I2C interface, and control the working states of the heating control circuit and the fan adjustment circuit according to the detected temperature and humidity.

[0082] As a further optional embodiment, the microcontroller is a 32-bit microcontroller with Cortex-M4 core, the working frequency is 150MHz, and the built-in 256K flash memory.

[0083] As shown in Figure 6 The control circuit uses an AT32F413 single-chip microcomputer (U10) as the core processing unit, which is used to receive the signals of the temperature and humidity detection circuit, and control the working state of the display screen heating control circuit and the fan regulation circuit according to the temperature and humidity information. The I 2C interface (PA9, PA10 pins) of the single-chip microcomputer is used to receive the temperature and humidity data from the temperature and humidity detection circuit; the PWM interface (PA6 pin) outputs signals to the fan regulation circuit; and the GPIO interface (PA8 pin) outputs control signals to the display screen heating control circuit. The control circuit analyzes the temperature and humidity data through a software algorithm to realize intelligent adjustment.

[0084] As a further optional embodiment, the input end of the DC-DC voltage stabilizer is connected to an external input voltage, and the output end is connected to the filter capacitor; the positive end of the filter capacitor is connected to the positive end of the freewheeling diode, the negative end of the freewheeling diode is connected to the load end, and the load end is the power input end of the temperature and humidity detection circuit, the display screen heating control circuit, the fan regulation circuit and the control circuit.

[0085] As a further optional embodiment, the signal output end of the temperature and humidity sensor is connected to the I2C interface input end of the control circuit through the pull-up resistor, the power supply end of the temperature and humidity sensor is connected to the output end of the power supply circuit through the filter capacitor, and the ground end of the temperature and humidity sensor is connected to the common ground of the circuit.

[0086] As a further optional embodiment, one end of the relay is connected to the output end of the power supply circuit, and the other end is connected to the heating port of the load device; the control end of the relay is connected to the collector of the triode, the base of the triode is connected to the GPIO output end of the control circuit through the current limiting resistor, and the emitter of the triode is connected to the common ground; the two ends of the relay are connected in parallel with the diode, which is used to protect the relay from reverse current damage.

[0087] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A constant temperature and humidity control circuit, characterized in that: include: Power supply circuit, temperature and humidity detection circuit, display screen heating control circuit, fan adjustment circuit and control circuit; The power supply circuit is used to provide a stable operating voltage for the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjustment circuit and the control circuit; The temperature and humidity detection circuit is used to detect the temperature and humidity information inside the display screen; The control circuit is used to receive the temperature information and humidity information, and control the working state of the display screen heating control circuit and the fan adjustment circuit according to the detection results; The display screen heating control circuit is used to heat the display screen according to the humidity information; The fan regulating circuit is used to regulate the speed of the fan according to the temperature information; The output end of the temperature and humidity detection circuit is connected to the input end of the control circuit, the first output end of the control circuit is connected to the input end of the display screen heating control circuit, and the second output end of the control circuit is connected to the input end of the fan adjustment circuit.

2. The constant temperature and humidity control circuit according to claim 1, characterized in that: The power supply circuit includes: a DC-DC step-down regulator, a filter capacitor and a freewheeling diode; The DC-DC step-down regulator is used to reduce the external input voltage to the required stable output voltage; The filter capacitor and the freewheeling diode are used to eliminate noise in the power supply and provide a continuous and stable voltage output.

3. The constant temperature and humidity control circuit according to claim 1, characterized in that: The temperature and humidity detection circuit includes: a temperature and humidity sensor, a pull-up resistor and a filter capacitor; The temperature and humidity sensor is used to monitor the temperature and humidity of the internal environment of the display screen and transmit the signal to the control circuit; The pull-up resistor and filter capacitor are used to stabilize the signal output of the temperature and humidity sensor.

4. The constant temperature and humidity control circuit according to claim 1, characterized in that: The display screen heating control circuit includes: a relay, a transistor and a diode; The relay is used to turn on the display screen heating power supply when the humidity is high; The triode is used to drive the relay; The diode is used to prevent reverse current.

5. The constant temperature and humidity control circuit according to claim 1, characterized in that: The fan regulating circuit includes: a fan and a P-type MOS tube; The conduction state of the P-type MOS tube is controlled by a PWM signal of a control circuit; The PWM signal is used to adjust the fan voltage and speed.

6. The constant temperature and humidity control circuit according to claim 1, characterized in that: The control circuit includes: a microcontroller; The microcontroller is used to receive signals from the temperature and humidity sensor through the I2C interface, and control the working states of the heating control circuit and the fan adjustment circuit according to the detected temperature and humidity.

7. The constant temperature and humidity control circuit according to claim 6, characterized in that: The microcontroller is a 32-bit microcontroller with a Cortex-M4 core, an operating frequency of 150 MHz, and a built-in 256K flash memory.

8. The constant temperature and humidity control circuit according to claim 2, characterized in that: The input end of the DC-DC step-down regulator is connected to the external input voltage, and the output end is connected to the filter capacitor; the positive end of the filter capacitor is connected to the positive end of the freewheeling diode, and the negative end of the freewheeling diode is connected to the load end, and the load end is the power input end of the temperature and humidity detection circuit, the display screen heating control circuit, the fan adjustment circuit and the control circuit.

9. The constant temperature and humidity control circuit according to claim 3, characterized in that: The signal output end of the temperature and humidity sensor is connected to the I2C interface input end of the control circuit through the pull-up resistor, the power supply end of the temperature and humidity sensor is connected to the output end of the power supply circuit through the filter capacitor, and the ground end of the temperature and humidity sensor is connected to the common ground of the circuit.

10. The constant temperature and humidity control circuit according to claim 4, characterized in that: One end of the relay is connected to the output end of the power supply circuit, and the other end is connected to the heating port of the load device; the control end of the relay is connected to the collector of the transistor, the base of the transistor is connected to the GPIO output end of the control circuit through a current-limiting resistor, and the emitter of the transistor is connected to the common ground; the diode is connected in parallel at both ends of the relay to protect the relay from damage by reverse current.

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