Fan control circuit of advertising machine

Abstract

The utility model relates to a fan control circuit of an advertising machine, which comprises a power supply circuit, a main control unit, a temperature monitoring unit, a temperature display unit and a plurality of cooling fans, the power supply circuit is connected with the main control unit, and the main control unit is respectively connected with the temperature monitoring unit, the temperature display unit and the cooling fans; the power supply circuit comprises a voltage transformation circuit, a voltage stabilization protection circuit and a voltage stabilization output circuit which are connected in sequence; the main control unit comprises a main control MCU chip which is used for adjusting a PWM output voltage value and an output duty ratio according to the internal environment temperature. The temperature monitoring unit comprises a temperature sensor and is used for monitoring the internal environment temperature of the advertising machine; the temperature display unit is used for displaying the current internal environment temperature of the advertising machine; the fan can accurately control the internal temperature of the advertising machine, and has the characteristics of intelligent temperature control, automatic speed regulation, stable work, low cost, energy conservation, consumption reduction and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of advertising machines, and in particular to a fan control circuit of an advertising machine. Background Art

[0002] At present, the common advertising machine heat dissipation mainly relies on the built-in fan. The fan is connected to the output end of the switching power supply and gets power from the output end of the switching power supply. The problem is that in this way, as long as the switching power supply is turned on, the fan will always work regardless of whether it is in a no-load or light-load state. On the one hand, it is not conducive to saving energy and affects the life of the fan; on the other hand, the noise generated by the fan's continuous rotation affects the surrounding environment. Moreover, the power supply voltage in the power supply circuit may be affected by factors such as power grid fluctuations and load changes, resulting in voltage instability. If the power supply voltage of the cooling fan fluctuates too much, it may affect the normal operation of the fan and even damage the fan motor, thereby affecting the working performance of the advertising machine, thereby reducing the reliability of the system and even damaging components. Utility Model Content

[0003] In view of this, the utility model aims to solve the deficiencies in the prior art, and its main purpose is to provide a fan control circuit for an advertising machine, which can realize the precise control of the internal temperature of the advertising machine by the fan, and has the characteristics of intelligent temperature control, automatic speed regulation, stable operation, low cost, energy saving and consumption reduction.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A fan control circuit for an advertising machine comprises a power supply circuit, a main control unit, a temperature monitoring unit, a temperature display unit and a plurality of cooling fans, wherein the power supply circuit is connected to the main control unit, and the main control unit is respectively connected to the temperature monitoring unit, the temperature display unit and the cooling fans; the power supply circuit comprises a voltage conversion circuit, a voltage stabilization protection circuit and a voltage stabilization output circuit which are connected in sequence; the main control unit comprises a main control MCU chip which is used to adjust a PWM output voltage value and an output duty cycle according to the internal ambient temperature; the temperature monitoring unit comprises a temperature sensor which is used to measure the internal ambient temperature of the advertising machine; and the temperature display unit is used to display the current internal ambient temperature of the advertising machine.

[0006] As a preferred solution, the voltage transformer circuit includes a high-voltage regulator chip U1, an input pin of the high-voltage regulator chip U1 is connected to an input power supply, an adjustment pin is connected to an output pin of the high-voltage regulator chip U1 through a first voltage-dividing resistor R1, and an output pin DC2 of the high-voltage regulator chip U1 is connected to an output end DC3 of the voltage transformer circuit.

[0007] As a preferred solution, the voltage stabilizing protection circuit includes a voltage stabilizing power supply chip U2, the input end of the voltage stabilizing power supply chip U2 is connected to the output end DC3 of the voltage transformer circuit, the output end of the voltage stabilizing power supply chip U2 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the first output end DC4 of the voltage stabilizing protection circuit.

[0008] As a preferred solution, the voltage-stabilized output circuit includes a voltage-stabilized output chip U3, the input end of the voltage-stabilized output chip U3 is connected to the first output end DC4 of the voltage-stabilized protection circuit, the output end is connected to the PWM0 pin of the main control MCU chip, a fifth voltage-dividing resistor R5 is connected in series between the output end of the voltage-stabilized output chip U3 and the PWM0 pin of the main control MCU chip, the output end of the voltage-stabilized output chip U3 is connected to the base of the transistor V1, and the collector of the transistor V1 is respectively connected to the fan interface J2, the fan interface J3 and the fan interface J4.

[0009] As a preferred solution, the second output terminal TL1 of the voltage stabilizing protection circuit is grounded through the connector X1, the MISO pin of the main control MCU chip is connected to the collector of the transistor V1 through the connector X1, and a fourth voltage-dividing resistor R4 is connected in series between the MISO pin of the main control MCU chip and the collector of the transistor V1 through the connector X1.

[0010] As a preferred solution, the temperature monitoring unit includes a temperature detection circuit, and the temperature detection circuit is connected to the SCLK pin of the main control MCU chip.

[0011] As a preferred solution, the temperature display unit includes an LED digital tube chip and a digital tube display drive circuit, the LED digital tube chip is connected to the digital tube display drive circuit, and the digital tube display drive circuit is connected to the main control MCU chip.

[0012] As a preferred solution, the digital tube display driving circuit includes a transistor Q1, a transistor Q2 and a transistor Q3, the bases of the transistor Q1, the transistor Q2 and the transistor Q3 are respectively connected to the main control MCU chip, the emitters are respectively connected to the LED digital tube chip, and the collectors are connected to a 5V power supply.

[0013] As a preferred solution, the burning circuit includes a burning interface J6, and the burning interface J6 is connected to the main control MCU chip.

[0014] As a preferred solution, the crystal oscillator circuit is connected to the main control MCU chip.

[0015] The fan control circuit of the above-mentioned advertising machine has obvious advantages and beneficial effects compared with the prior art. Specifically, it can be seen from the above-mentioned technical scheme that it mainly realizes the fan's precise control of the internal temperature of the advertising machine by setting a power supply circuit, a main control unit, a temperature monitoring unit, a temperature display unit and multiple cooling fans, and adjusting the PWM duty cycle by the main control unit in combination with the ambient temperature of the device collected by the temperature monitoring unit, and then adjusting the fan speed, etc.; the temperature-controlled and speed-regulating fan has the characteristics of intelligent temperature control, automatic speed regulation, stable operation, low cost, energy saving and consumption reduction, etc., which can reduce the noise when the fan is running while ensuring the heat dissipation effect, and can effectively reduce the energy consumption of the cooling fan and save electricity costs; by setting a voltage transformer circuit, a voltage stabilizing protection circuit and a voltage stabilizing output circuit to rectify, stabilize, limit current and overload protect the input power supply, it is ensured that the entire fan control circuit can operate stably and improve the reliability of the advertising machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a pin diagram of the main control MCU chip of an embodiment of the utility model.

[0017] Figure 2 It is a transformer circuit diagram of an embodiment of the utility model.

[0018] Figure 3 It is a voltage stabilizing protection circuit diagram of an embodiment of the utility model.

[0019] Figure 4 It is a voltage-stabilizing output circuit diagram of an embodiment of the utility model.

[0020] Figure 5 It is a temperature detection circuit diagram of an embodiment of the utility model.

[0021] Figure 6 This is a pin diagram of an LED digital tube chip according to an embodiment of the present utility model.

[0022] Figure 7 It is a digital tube display driving circuit diagram of an embodiment of the utility model.

[0023] Figure 8 It is a burning circuit diagram of an embodiment of the utility model.

[0024] Fig. 9 It is a crystal oscillator circuit diagram of an embodiment of the utility model.

[0025] Fig.10 It is a circuit diagram of a connector X1 according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments; based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0027] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0028] See also Figures 1 to 10 , showing a fan control circuit of an advertising machine provided by an embodiment of the utility model, including a power supply circuit, a main control unit, a temperature monitoring unit, a temperature display unit and a plurality of cooling fans, the power supply circuit is connected to the main control unit, and the main control unit is respectively connected to the temperature monitoring unit, the temperature display unit and the cooling fan; the power supply circuit includes a voltage conversion circuit, a voltage stabilizing protection circuit and a voltage stabilizing output circuit connected in sequence; the main control unit includes a main control MCU chip, which is used to adjust the PWM output voltage value and the output duty cycle according to the internal ambient temperature; the temperature monitoring unit includes a temperature sensor, which is used for the internal ambient temperature of the advertising machine; the temperature display unit is used to display the current internal ambient temperature of the advertising machine. In this embodiment, the main control MCU chip adopts the STC12C5616AD chip. The main control circuit module is the core of the overall system design, which has the functions of controlling temperature collection and display, setting and judging temperature limits through software programming, and outputting control signals at its I / O port to switch or adjust the speed of the fan. The STC12C5616AD single-chip microcomputer is used as the main control MCU chip, combined with temperature sensors, cooling fans and other components, to achieve multi-channel temperature and cooling fan speed monitoring and control. The multi-channel high-speed A / D sampling function of the STC12C5616AD can accurately read the resistance value of the temperature sensor, and display the corresponding temperature after chip processing. At the same time, different pulse voltages are output to the cooling fan control module through the PWM control pin of the STC12C5616AD, thereby controlling the speed and switch state of the cooling fan. Through the PWM signal line of the controller, the cooling fan speed can be accurately controlled, effectively reducing the energy consumption of the cooling fan and saving electricity costs.

[0029] Furthermore, the voltage conversion circuit includes a high-voltage regulator chip U1, an input pin of the high-voltage regulator chip U1 is connected to an input power supply, an adjustment pin is connected to an output pin of the high-voltage regulator chip U1 through a first voltage-dividing resistor R1, and an output pin DC2 of the high-voltage regulator chip U1 is connected to an output end DC3 of the voltage conversion circuit. The voltage conversion circuit is used to convert an external input power supply into a low voltage required by the control circuit by adjusting the first voltage-dividing resistor R1. In this embodiment, the high-voltage regulator chip U1 adopts a TL783C chip, such as Figure 2 As shown, a grounded filter capacitor C1 is connected in parallel between the external input power supply and the input end of the TL783C chip, a second voltage-dividing resistor R2 and a third voltage-dividing resistor R3 are also connected in parallel between the adjustment pin and the first voltage-dividing resistor R1, the other ends of the second voltage-dividing resistor R2 and the third voltage-dividing resistor R3 are both grounded, a diode D2 is connected between the output pin DC2 of the TL783C chip and the output end DC3 of the transformer circuit, the positive electrode of the diode D2 is connected to the output pin DC2 of the TL783C chip, and the negative electrode is connected to the output end DC3 of the transformer circuit, a filter capacitor C6 and a polarity filter capacitor C7 are connected in parallel between the diode D2 and the output end DC3 of the transformer circuit, the other end of the filter capacitor C6 is grounded, and the negative electrode of the polarity filter capacitor C7 is grounded; the TL783C chip can provide a stable output voltage, and its output voltage fluctuates little for fluctuations in the input voltage. When the internal temperature of the chip or the input voltage is too high, the thermal shutdown function or the overvoltage protection function will automatically start to cut off the output current to protect the chip and the peripheral circuit from damage.

[0030] Furthermore, the voltage stabilizing protection circuit includes a voltage stabilizing power supply chip U2, the input end of the voltage stabilizing power supply chip U2 is connected to the output end DC3 of the voltage transformer circuit, the output end of the voltage stabilizing power supply chip U2 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the first output end DC4 of the voltage stabilizing protection circuit. The voltage stabilizing protection circuit is used to convert the voltage output by the voltage transformer circuit into a fixed voltage output. In this embodiment, the voltage stabilizing power supply chip U2 adopts a KA7810 chip, such as Figure 3 As shown, the input pin of the KA7810 chip is connected to the output terminal DC3 of the transformer circuit, the ground pin of the KA7810 chip is grounded through the diode D3, the output pin of the KA7810 chip is connected to the positive electrode of the diode D1, and a filter capacitor C3 and a polarity filter capacitor C2 are connected in parallel between the output pin of the KA7810 chip and the positive electrode of the diode D1, the other end of the filter capacitor C3 is grounded, the negative electrode of the polarity filter capacitor C2 is grounded, and a filter capacitor C4 and a polarity filter capacitor C5 are connected in parallel between the negative electrode of the diode D1 and the first output terminal DC4 of the voltage stabilizing protection circuit, the other end of the filter capacitor C4 is grounded, and the negative electrode of the polarity filter capacitor C5 is grounded; the KA7810 chip also has current limiting, thermal shutdown and short-circuit protection functions to further protect the circuit.

[0031] Furthermore, the voltage-stabilized output circuit includes a voltage-stabilized output chip U3, the input end of the voltage-stabilized output chip U3 is connected to the first output end DC4 of the voltage-stabilized protection circuit, the output end is connected to the PWM0 pin of the main control MCU chip, a fifth voltage-dividing resistor R5 is connected in series between the output end of the voltage-stabilized output chip U3 and the PWM0 pin of the main control MCU chip, the output end of the voltage-stabilized output chip U3 is connected to the base of the transistor V1, and the collector of the transistor V1 is respectively connected to the fan interface J2, the fan interface J3 and the fan interface J4. The voltage-stabilized output circuit is used to convert the voltage input to the voltage-stabilized protection circuit into a stable voltage output. In this embodiment, the voltage-stabilized output chip U3 adopts a 78L05 chip, such as Figure 4 As shown, a sixth voltage-dividing resistor R6 is connected in series between the output end of the 78L05 chip and the fifth voltage-dividing resistor R5, and a polarity filter capacitor C8 is connected in parallel, and the negative electrode of the polarity filter capacitor C8 is grounded; when the input voltage or load of the 78L05 chip changes, it can provide a very stable 5V output voltage and maintain high stability.

[0032] Furthermore, if Fig.10 As shown, the second output terminal TL1 of the voltage stabilizing protection circuit is grounded through the connector X1, the MISO pin of the main control MCU chip is connected to the collector of the transistor V1 through the connector X1, and a fourth voltage-dividing resistor R4 is connected in series between the MISO pin of the main control MCU chip and the collector of the transistor V1 through the connector X1. The model of the connector X1 is DC3-2.54-2X3P-S.

[0033] Furthermore, the temperature monitoring unit includes a temperature detection circuit, and the temperature detection circuit is connected to the SCLK pin of the main control MCU chip. Figure 5 As shown, the temperature detection circuit includes a sensor interface J4, the sensor interface J4 is connected to the temperature sensor, the output end of the temperature sensor is connected in series with a ninth voltage-dividing resistor R9 and connected to the SCLK pin of the main control MCU chip, a filter capacitor C9 is connected in parallel between the ninth voltage-dividing resistor R9 and the SCLK pin of the main control MCU chip, the other end of the filter capacitor C9 is grounded, the output end of the temperature sensor is also connected in series with a seventh voltage-dividing resistor R7, an eighth voltage-dividing resistor R8 and a light-emitting diode LED1 in sequence, a 5V power supply is connected between the seventh voltage-dividing resistor R7 and the eighth voltage-dividing resistor R8, the positive pole of the light-emitting diode LED1 is connected to the output end of the temperature sensor, and the negative pole is grounded.

[0034] Furthermore, the temperature display unit includes an LED digital tube chip and a digital tube display driving circuit, the LED digital tube chip is connected to the digital tube display driving circuit, and the digital tube display driving circuit is connected to the main control MCU chip. Figure 6 and Figure 7As shown, the LED digital tube chip uses the SP420361N digital tube. The E, D, DP, C, G, A, F and B pins of the SP420361N digital tube are respectively connected to the P2.4, P2.3, P2.7, P2.2, P2.6, P2.0, P2.5 and P2.1 pins of the main control MCU chip. The SP420361N digital tube can convert digital signals into visual LED digital displays, which is convenient for users to read and identify.

[0035] Furthermore, the digital tube display driving circuit includes transistors Q1, Q2 and Q3, the bases of transistors Q1, Q2 and Q3 are respectively connected to the main control MCU chip, the emitters are respectively connected to the LED digital tube chip, and the collectors are connected to the 5V power supply; specifically, Figure 7 As shown, the base of the transistor Q1 is connected to the P1.2 pin of the main control MCU chip through the tenth voltage-dividing resistor R10, the base of the transistor Q2 is connected to the P1.1 pin of the main control MCU chip through the thirteenth voltage-dividing resistor R13, the base of the transistor Q3 is connected to the P1.0 pin of the main control MCU chip through the seventeenth voltage-dividing resistor R17, the emitter of the transistor Q1 is connected to the DIG3 pin of the LED digital tube chip through the eleventh voltage-dividing resistor R11, the emitter of the transistor Q2 is connected to the DIG2 pin of the LED digital tube chip through the fourteenth voltage-dividing resistor R14, and the emitter of the transistor Q3 is connected to the DIG1 pin of the LED digital tube chip through the eighteenth voltage-dividing resistor R13.

[0036] Furthermore, it also includes a burning circuit, which includes a burning interface J6, and the burning interface J6 is connected to the main control MCU chip; specifically, Figure 8 As shown, the 2nd and 3rd pins of the burning interface J6 are connected to the TXD and RXD pins of the main control MCU chip respectively, the 4th pin of the burning interface J6 is grounded, the 1st pin of the burning interface J6 is connected to the RST pin of the main control MCU chip through the switch SW1, the filter capacitor C10 and the polarity filter capacitor C11 are connected in parallel between the 1st pin of the burning interface J6 and the switch SW1, the other end of the filter capacitor C10 is grounded, the negative electrode of the polarity filter capacitor C11 is connected to the RST pin of the main control MCU chip, the 28th voltage-dividing resistor R28 is connected in parallel between the switch SW1 and the RST pin of the main control MCU chip, and the other end of the 28th voltage-dividing resistor R28 is grounded. Software programming is used to implement PWM (pulse width modulation) speed regulation, and the motor speed is controlled by controlling the duty cycle of the rectangular wave PWM signal. The motor speed is proportional to the duty cycle. The larger the duty cycle, the faster the speed. If the output is all high, the duty cycle is 100% and the speed is maximum. Compared with other speed regulation methods such as hardware or a combination of hardware and software, PWM speed regulation through software programming can reduce costs while giving full play to the compilation function of the microcontroller.

[0037] Furthermore, it also includes a crystal oscillator circuit, which is connected to the main control MCU chip; specifically, Fig. 9 As shown, the two ends of the crystal oscillator circuit are respectively connected to the XTLA2 pin and the XTAL1 pin of the main control MCU chip to provide the clock signal required by the chip.

[0038] The fan control circuit of the above-mentioned advertising machine has obvious advantages and beneficial effects compared with the prior art. Specifically, it can be seen from the above-mentioned technical scheme that it mainly realizes the precise control of the internal temperature of the advertising machine by the fan by setting a power supply circuit, a main control unit, a temperature monitoring unit, a temperature display unit and multiple cooling fans, and adjusting the PWM duty cycle by the main control unit in combination with the ambient temperature of the device collected by the temperature monitoring unit, and then adjusting the fan speed, etc.; the temperature-controlled and speed-regulating fan has the characteristics of intelligent temperature control, automatic speed regulation, stable operation, low cost, energy saving and consumption reduction, etc., which can reduce the noise when the fan is running while ensuring the heat dissipation effect, and can effectively reduce the energy consumption of the cooling fan and save electricity costs; by setting the power supply circuit to rectify, stabilize, limit current and overload protection the input power supply, it is ensured that the entire fan control circuit can operate stably and improve the reliability of the advertising machine.

[0039] It should be noted that the present invention is not limited to the above-mentioned embodiments. According to the creative spirit of the present invention, those skilled in the art may also make other changes. These changes made according to the creative spirit of the present invention should be included in the scope of protection required by the present invention.

Claims

1. A fan control circuit for an advertising machine, characterized in that: It includes a power supply circuit, a main control unit, a temperature monitoring unit, a temperature display unit and a plurality of cooling fans, wherein the power supply circuit is connected to the main control unit, and the main control unit is respectively connected to the temperature monitoring unit, the temperature display unit and the cooling fans; The power supply circuit includes a voltage conversion circuit, a voltage stabilization protection circuit and a voltage stabilization output circuit connected in sequence; The temperature monitoring unit includes a temperature sensor for monitoring the internal environment temperature of the advertising machine; The main control unit includes a main control MCU chip, which is used to adjust the PWM output voltage value and output duty cycle according to the internal ambient temperature of the advertising machine; The temperature display unit is used to display the current internal ambient temperature of the advertising machine.

2. The fan control circuit of the advertising machine according to claim 1, characterized in that: The voltage conversion circuit includes a high-voltage regulator chip U1, an input pin of the high-voltage regulator chip U1 is connected to an input power supply, an adjustment pin is connected to an output pin of the high-voltage regulator chip U1 via a first voltage-dividing resistor R1, and an output pin DC2 of the high-voltage regulator chip U1 is connected to an output end DC3 of the voltage conversion circuit.

3. The fan control circuit of the advertising machine as claimed in claim 2, characterized in that: The voltage stabilizing protection circuit includes a voltage stabilizing power supply chip U2, the input end of the voltage stabilizing power supply chip U2 is connected to the output end DC3 of the voltage transformer circuit, the output end of the voltage stabilizing power supply chip U2 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the first output end DC4 of the voltage stabilizing protection circuit.

4. The fan control circuit of the advertising machine as claimed in claim 3, characterized in that: The voltage-stabilized output circuit includes a voltage-stabilized output chip U3, the input end of the voltage-stabilized output chip U3 is connected to the first output end DC4 of the voltage-stabilized protection circuit, the output end is connected to the PWM0 pin of the main control MCU chip, a fifth voltage-dividing resistor R5 is connected in series between the output end of the voltage-stabilized output chip U3 and the PWM0 pin of the main control MCU chip, the output end of the voltage-stabilized output chip U3 is connected to the base of the transistor V1, and the collector of the transistor V1 is respectively connected to the fan interface J2, the fan interface J3 and the fan interface J4.

5. The fan control circuit of the advertising machine as claimed in claim 4, characterized in that: The second output terminal TL1 of the voltage stabilizing protection circuit is grounded through the connector X1, the MISO pin of the main control MCU chip is connected to the collector of the transistor V1 through the connector X1, and a fourth voltage dividing resistor R4 is connected in series between the MISO pin of the main control MCU chip and the collector of the transistor V1 through the connector X1.

6. The fan control circuit of the advertising machine according to claim 1, characterized in that: The temperature monitoring unit comprises a temperature detection circuit, and the temperature detection circuit is connected to the SCLK pin of the main control MCU chip.

7. The fan control circuit of the advertising machine according to claim 1, characterized in that: The temperature display unit comprises an LED digital tube chip and a digital tube display driving circuit, the LED digital tube chip is connected to the digital tube display driving circuit, and the digital tube display driving circuit is connected to the main control MCU chip.

8. The fan control circuit of the advertising machine as claimed in claim 7, characterized in that: The digital tube display driving circuit includes a transistor Q1, a transistor Q2 and a transistor Q3, wherein the bases of the transistors Q1, Q2 and Q3 are respectively connected to the main control MCU chip, the emitters are respectively connected to the LED digital tube chip, and the collectors are connected to a 5V power supply.

9. The fan control circuit of the advertising machine according to claim 1, characterized in that: It also includes a burning circuit, which includes a burning interface J6, and the burning interface J6 is connected to the main control MCU chip.

10. The fan control circuit of the advertising machine according to claim 1, characterized in that: It also includes a crystal oscillator circuit, which is connected to the main control MCU chip.

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