CN219799768U

CN219799768U - Laser type photoelectric sensor circuit

Info

Publication number: CN219799768U
Application number: CN202320942660.6U
Authority: CN
Inventors: 师霖; 郭红戈; 谢海波; 许齐; 杨娜
Original assignee: Taiyuan University of Science and Technology
Current assignee: Taiyuan University of Science and Technology
Priority date: 2023-04-24
Filing date: 2023-04-24
Publication date: 2023-10-03
Anticipated expiration: 2033-04-24

Abstract

The utility model discloses a laser type photoelectric sensor circuit, which belongs to the technical field of photoelectric sensing, and comprises the following specific technical scheme: the device comprises a first power supply module and a second power supply module, wherein the first power supply module is a DC 24V-DC 6V power supply module, the first power supply module supplies power for a frequency generation module and a laser driving module, the second power supply module is a DC 24V-DC 5V power supply module, the second power supply module supplies power for a photosensitive receiving module, a signal output port of the frequency generation module is connected with a signal input port of the laser driving module, a signal output end of the laser driving module is connected with a signal input port of the photosensitive receiving module, and a signal output port of the photosensitive receiving module is connected with a signal input port of a signal processing module; according to the utility model, by adjusting the duty ratio of the PWM waves, the technical problem that the laser light source cannot be in a working state for a long time is solved, and the requirement that the photoelectric sensor needs to be electrified for a long time for use is met.

Description

Laser type photoelectric sensor circuit

Technical Field

The utility model belongs to the technical field of photoelectric sensing, and particularly relates to a laser type photoelectric sensor circuit.

Background

A laser type photoelectric sensor is a photoelectric sensor that uses a laser beam as a detection light source, and that realizes detection of a target object by measuring a change in distance between the laser beam and the target object. The optical system of the laser type photoelectric sensor generally consists of a transmitter and a receiver, wherein the transmitter transmits laser beams, the receiver receives laser signals reflected by a target object, measures the time difference of light paths, and converts the time difference into distance information to be output.

The laser type photoelectric sensor has the advantages of high precision, high speed, long service life, strong anti-interference capability and the like, and is widely applied to the fields of automatic production lines, robots, measuring instruments, security monitoring and the like. Common application scenarios include object distance measurement, object position detection, object identification, workpiece positioning, and the like.

At present, the domestic and foreign photoelectric sensors are difficult to meet the use requirements of most laser light sources, the price of the domestic and foreign photoelectric sensors is different due to factors such as brands, models, functions, performances, quantity and the like, the photoelectric sensors with stable performances are higher in price, the photoelectric sensors with lower prices are unstable in performances, the laser light sources cannot be in a working state for a long time, and the practical use requirements are difficult to meet, so that a laser type photoelectric sensor circuit with low price and stable performances is needed.

Disclosure of Invention

In order to solve the technical problems in the prior art, the utility model provides the laser type photoelectric sensor circuit which has stable performance, low price and strong applicability and can be used under the condition of long-time power on.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows: the laser type photoelectric sensor circuit comprises a first power supply module, wherein the first power supply module is a DC 24V-DC 6V power supply module, and the first power supply module supplies power for a frequency generation module and a laser driving module.

The utility model also comprises a second power supply module, wherein the second power supply module is a DC 24V-DC 5V power supply module, and the second power supply module supplies power to the photosensitive receiving module.

The first power module comprises a first rectifying diode, a pin of VCC24V is connected with the positive electrode of the first rectifying diode, the negative electrode of the first rectifying diode is connected with one end of a first resistor and the collector electrode of a first triode, the other end of the first resistor is connected with the negative electrode of the first zener diode, the positive electrode of the first zener diode is grounded, the emitting electrode of the first triode is connected with VCC6V and one end of a first capacitor, the other end of the first capacitor is grounded, the emitting electrode of the first triode is connected with the positive electrode of the first light emitting diode through a ninth resistor, and the negative electrode of the first light emitting diode is grounded.

The second power module comprises a second rectifying diode, a pin of VCC24V is connected with the positive electrode of the second rectifying diode, the negative electrode of the second rectifying diode is connected with one end of a tenth resistor and the collector electrode of a second triode, the other end of the tenth resistor is connected with the negative electrode of the second zener diode, the positive electrode of the second zener diode is grounded, the emitter electrode of the second triode is connected with VCC5V and one end of a second capacitor, the other end of the second capacitor is grounded, the emitter electrode of the second triode is connected with the positive electrode of the second light emitting diode through an eleventh resistor, and the negative electrode of the second light emitting diode is grounded.

The signal output port of the frequency generation module is connected with the signal input port of the laser driving module, the signal output end of the laser driving module is connected with the signal input port of the photosensitive receiving module, and the signal output port of the photosensitive receiving module is connected with the signal input port of the signal processing module.

The frequency generation module comprises a timer, a No. 1 pin of the timer is grounded, a No. 2 pin and a No. 6 pin of the timer are in short circuit, a No. 3 pin of the timer is a PWM signal output interface, a No. 4 pin and a No. 8 pin of the timer are all connected with VCC6V, a No. 5 pin of the timer is connected with one end of a fourth capacitor, the other end of the fourth capacitor is grounded, the No. 2 pin and the No. 3 pin of the timer are connected through a first branch, a third rectifier diode and a third resistor are arranged on the first branch, the No. 2 pin and the No. 3 pin of the timer are connected through a second branch, and a fourth rectifier diode and a fourth resistor are arranged on the second branch.

The signal input end of the laser driving module is connected with one end of a fifth resistor, the other end of the fifth resistor is connected with the base electrode of a third triode, the collector electrode of the third triode is connected with the base electrode of a fourth triode through a sixth resistor, the collector electrode of the fourth triode is connected with one end of a light source, the other end of the light source is grounded, the collector electrode of the third triode is connected with one end of a seventh resistor, and the other end of the seventh resistor is respectively connected with VCC6V and the emitter electrode of the fourth triode.

The photosensitive receiving module comprises a receiver, a pin 1 of the receiver is connected with VCC5V, a pin 2 of the receiver is connected with a base electrode of a fifth triode through an eighth resistor, a collector electrode of the fifth triode is connected with an emitter electrode of the fifth triode through a fifth capacitor and a sixth capacitor, and a collector electrode of the fifth triode is connected with a photosensitive output port.

The signal processing module comprises a chip, a pin No. 2 of the chip is connected with the photosensitive output port, a pin No. 3 of the chip is connected with the base electrode of a sixth triode through a twelfth resistor, the collector electrode of the sixth triode is connected with the base electrode of a seventh triode through a thirteenth resistor, the collector electrode of the seventh triode is used as the signal output port, and the emitter electrode of the sixth triode is grounded.

The first rectifying diode, the second rectifying diode, the third rectifying diode and the fourth rectifying diode are common high-power rectifying diodes, and have the characteristics of high reverse voltage, low forward voltage, high rectifying efficiency and the like, and are suitable for various power supply circuits, switching circuits and inverter circuits.

The rated operating voltage of the first zener diode is 6.8V, the maximum withstand reverse voltage is as high as 44V, and the diode can stably maintain operation at the reverse voltage of 6.8V, and relatively stable voltage output can be maintained even under load and temperature changes. Diodes are commonly used in voltage regulated power supplies, voltage regulation, and the like. In addition, it also has the characteristics of small reverse current, small temperature coefficient, high response speed and the like.

The second Zener diode is a common Zener diode, belongs to one of the Zener diodes, has a rated operating voltage of 6.2V, is subjected to a reverse voltage as high as 39V, and can stably maintain the operation at the reverse voltage of 6.2V, and can maintain relatively stable voltage output even under the conditions of load variation and temperature variation. Zener diodes are commonly used in voltage regulated power supplies, voltage regulation, and the like. In addition, it also has the characteristics of small reverse current, small temperature coefficient, high response speed and the like.

The first triode, the second triode, the third triode and the fourth triode are all low-power NPN type triodes, are commonly used in a low-frequency amplifying and switching circuit, have the maximum collecting current of 700mA, have the maximum collecting-emitting voltage of 20V and the maximum power of 625mW, and have the characteristics of high voltage, high current amplifying coefficient, low noise and the like, and are suitable for a common amplifying circuit and a low-frequency power amplifying circuit.

Compared with the prior art, the utility model has the following specific beneficial effects: the utility model solves the technical problem that the laser light source 45 cannot be in a working state for a long time by adjusting the duty ratio of the PWM waves, and meets the requirement that the photoelectric sensor needs to be electrified for use for a long time. The utility model completes the processing and output of weak signals of the photosensitive diode, the signal output reaches the use standard, the circuit can realize the function of the mirror reflection type laser photoelectric sensor, the mirror reflection type photoelectric sensor can realize 0-15m, the requirements of most like products in the market are met, the cost is greatly reduced, the use is safer, and the utility model can be widely popularized and applied.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Fig. 2 is a circuit diagram of the first power module in fig. 1.

Fig. 3 is a circuit diagram of the second power module in fig. 1.

Fig. 4 is a circuit diagram of the frequency generation module in fig. 1.

Fig. 5 is a circuit diagram of the laser driving module in fig. 1.

Fig. 6 is a circuit diagram of the photosensitive receiving module in fig. 1.

Fig. 7 is a circuit diagram of the signal processing module in fig. 1.

In the figure, 11 is a first rectifying diode, 12 is a first resistor, 13 is a first triode, 14 is a first zener diode, 15 is a first capacitor, 16 is a first light emitting diode, 17 is a ninth resistor, 21 is a second rectifying diode, 22 is a tenth resistor, 23 is a second triode, 24 is a second zener diode, 25 is a second capacitor, 26 is a second light emitting diode, 27 is an eleventh resistor, 31 is a timer, 32 is a fourth capacitor, 33 is a third rectifying diode, 34 is a third resistor, 35 is a fourth rectifying diode, 36 is a fourth resistor, 41 is a fifth resistor, 42 is a third triode, 43 is a sixth resistor, 44 is a fourth triode, 45 is a light source, 46 is a seventh resistor, 51 is a receiver, 52 is an eighth resistor, 53 is a fifth triode, 54 is a fifth capacitor, 55 is a sixth capacitor, 61 is a chip, 62 is a twelfth resistor, 63 is a sixth triode, 64 is a thirteenth resistor, 65 is a seventh triode.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

As shown in fig. 1-2, the laser type photoelectric sensor circuit uses a double-path power supply to supply power in order to reduce the supply current of the power supply, prevent overheating and ensure the normal operation of each module.

The first power module comprises a first rectifying diode 11, the model number of the first zener diode 14 is 1N4736, the rated operating voltage is 6.8V, and the maximum bearing reverse voltage is up to 44V. The pin of VCC24V is connected with the positive pole of first rectifier diode 11, the negative pole of first rectifier diode 11 links to each other with the one end of first resistance 12, the collecting electrode of first triode 13, the other end of first resistance 12 links to each other with the negative pole of first zener diode 14, the positive pole ground of first zener diode 14, the projecting pole of first triode 13 links to each other with VCC6V, one end of first electric capacity 15, the other end ground of first electric capacity 15, the projecting pole of first triode 13 links to each other with the positive pole of first luminescent diode 16 through ninth resistance 17, the negative pole ground of first luminescent diode 16, first power module is DC24V to DC6V power module, first power module is frequency generation module and laser driving module power supply.

As shown in fig. 3, the second power module includes a second rectifying diode 21, and the second Zener diode 24 is a common Zener diode, which is a Zener diode, and is 1N 4735. The pin of VCC24V is connected with the positive pole of second rectifier diode 21, the negative pole of second rectifier diode 21 links to each other with the one end of tenth resistance 22, the collecting electrode of second triode 23, the other end of tenth resistance 22 links to each other with the negative pole of second zener diode 24, the positive pole ground of second zener diode 24, the projecting pole of second triode 23 links to each other with VCC5V, one end of second electric capacity 25, the other end ground of second electric capacity 25, the projecting pole of second triode 23 links to each other with the positive pole of second luminescent diode 26 through eleventh resistance 27, the negative pole ground of second luminescent diode 26. The second power supply module is a DC 24V-DC 5V power supply module, and the second power supply module supplies power to the photosensitive receiving module.

The first rectifying diode 11 and the second rectifying diode 21 are 1N4007 in type, and have the characteristics of high reverse voltage, low forward voltage, high rectifying efficiency and the like.

The first triode 13 and the second triode 23 are 8050 triodes, are low-power NPN triodes, are commonly used in low-frequency amplifying and switching circuits, and have a maximum collecting current of 700mA, a maximum collecting-emitting voltage of 20V and a maximum power of 625mW.

As shown in fig. 4, the signal output port of the frequency generation module is connected with the signal input port of the laser driving module, the signal output end of the laser driving module is connected with the signal input port of the photosensitive receiving module, and the signal output port of the photosensitive receiving module is connected with the signal input port of the signal processing module.

The frequency generation module generates PWM waves using 555 timer 31, where 555 timer 31 operates in an unsteady mode in which 555 operates as an oscillator.

The 555 timer 31 may output a continuous square wave of a particular frequency in the steady-state-free mode of operation. The first resistor 12 is connected between VCC and the discharge pin (pin 7), the first resistor 12 is connected between pin 7 and the trigger pin (pin 2), and pin 2 is shorted to the threshold pin (pin 6). In operation, the capacitor is charged to 2/3VCC through the first resistor 12 and the ninth resistor 17, then the output voltage is turned over, the capacitor is discharged to 1/3VCC through the ninth resistor 17, then the capacitor is recharged, and the output voltage is turned over again.

For bipolar 555, the use of a small first resistor 12 will cause the OC gate to saturate during discharge, resulting in a low time for the output waveform that is much longer than the results of the above calculations.

To obtain a rectangular wave with a duty cycle of less than 50% this can be achieved by connecting a diode in parallel to the ninth resistor 17. This diode is turned on during charging, shorting the ninth resistor 17 so that the power supply charges the capacitor only through the first resistor 12; and cut off during discharging to achieve the effect of reducing the charging time and the duty ratio.

The function of the 555 timer 31 to implement the waveform generator 555 timer 31 is mainly determined by two comparators. The output voltages of the two comparators control the state of the RS flip-flop and the discharge tube. When the pin 5 is suspended, the voltage at the non-inverting input terminal of the voltage comparator C1 is 2VCC/3, and the voltage at the inverting input terminal of the voltage comparator C2 is VCC/3. If the voltage at the trigger input TR is less than VCC/3, the output of the comparator C2 is0, and the RS trigger is set to 1, so that the output out=1. If the voltage at the threshold input terminal TH is greater than 2VCC/3 and the voltage at the terminal TR is greater than VCC/3, then the output of C1 is0 and the output of C2 is 1, the RS flip-flop can be set to 0, causing the output to be low.

THR is a comparator with reference voltage of 2VCC/3, TRI is a comparator with reference voltage of VCC/3, when the voltage value of two ends of the first capacitor 15 is smaller than VCC/3, the output end outputs high level, then potential difference is generated between the output end and C1, so that the capacitor is charged through the first rectifying diode 11, and when the voltage of two ends of the first capacitor 15 is smaller than 2VCC/3, the output end always outputs high level; when the voltage across the first capacitor 15 rises from charging to 2VCC/3, the output terminal of the 555 timer 31 outputs a low level, and the voltage across the first capacitor 15 is higher than the output terminal at this time, so that the capacitor discharges until the voltage across the capacitor drops to VCC/3, and the output terminal voltage becomes a high level. Thus generating a stable square wave. Wherein the duty cycle and the frequency of the square wave are adjusted by two potentiometers. The charging time is determined by the magnitude of the current, i.e. by the magnitude of the resistance in the charging and discharging circuit, so the duty cycle and frequency of the square wave can be adjusted by adjusting the magnitude of the resistance in the charging and discharging circuit.

The No. 1 pin of the timer 31 is grounded, the No. 2 pin and the No. 6 pin of the timer 31 are in short circuit, the No. 3 pin of the timer 31 is a PWM signal output interface, the No. 4 pin and the No. 8 pin of the timer 31 are connected with VCC6V, the No. 5 pin of the timer 31 is connected with one end of the fourth capacitor 32, the other end of the fourth capacitor 32 is grounded, the No. 2 pin and the No. 3 pin of the timer 31 are connected through a first branch, a third rectifier diode 33 and a third resistor 34 are arranged on the first branch, the No. 2 pin and the No. 3 pin of the timer 31 are connected through a second branch, and a fourth rectifier diode 35 and a fourth resistor 36 are arranged on the second branch.

The circuit realizes the output of PWM waves with the duty ratio of 20 percent, supplies power for the laser source 45, and the laser source 45 cannot be in a working state for a long time, otherwise, the heating is serious, and the service life is influenced.

As shown in fig. 5, the signal input end of the laser driving module is connected to one end of the fifth resistor 41, the other end of the fifth resistor 41 is connected to the base of the third triode 42, the collector of the third triode 42 is connected to the base of the fourth triode 44 through the sixth resistor 43, the collector of the fourth triode 44 is connected to one end of the light source 45, the other end of the light source 45 is grounded, the collector of the third triode 42 is connected to one end of the seventh resistor 46, and the other end of the seventh resistor 46 is connected to VCC6V and the emitter of the fourth triode 44, respectively.

The PWM band load capacity of the laser driving module emitted by the 555 timer 31 is weak, and thus current amplification is required to enhance the load capacity thereof.

In the laser driving module, an input signal is input to the base of the third triode 42 through a resistor, when the voltage of the input signal changes, the voltage of the base is changed, so that the current flow of the third triode 42 is controlled, and an output signal is output from the collector of the third triode 42 and is connected to the power supply voltage VCC through a load resistor RL.

The triode current amplification circuit is followed by a unipolar switching circuit in which the fourth triode 44 acts as a switching element. When the base voltage of the fourth transistor 44 is lower than the emitter voltage by more than 0.7V, the fourth transistor 44 is turned on and the circuit is closed. When the base voltage of the fourth transistor 44 is not lower than the emitter voltage thereof by more than 0.7V, the fourth transistor 44 is turned off and the circuit is opened. By changing the voltage of the input signal, the fourth transistor 44 can be controlled to be turned on and off, thereby controlling the on-off state of the circuit and completing the driving of the light source 45.

As shown in fig. 6, the photosensitive receiving module includes a receiver 51, a pin 1 of the receiver 51 is connected to VCC5V, a pin 2 of the receiver 51 is connected to a base of a fifth triode 53 through an eighth resistor 52, a collector and an emitter of the fifth triode 53 are connected to each other through a fifth capacitor 54 and a sixth capacitor 55, and a collector of the fifth triode 53 is connected to a photosensitive output port.

The photosensitive device of the photosensitive receiving module is a device capable of sensing light and converting the light into an electric signal and generally comprises a photosensitive diode, a photosensitive resistor, a phototriode and the like, and the circuit selects a receiver is0103 as a signal receiving photosensitive.

The electrical signal output by the photodiode has weak load carrying capacity, and the signal needs to be subjected to current amplification treatment. The electric signal output by the receiver is0103 is connected with the fifth triode 53 after passing through a resistor, when the photosensitive excitation is performed and then outputs a high level, when the base voltage of the fifth triode 53 is higher than the emitter voltage of the fifth triode, the fifth triode 53 is conducted, the circuit is closed, the sixth capacitor 55 is charged, the capacitor cannot be charged due to the fact that the output of the receiver is0103 is PWM wave, and the photosensitive output is low level. When the light is not excited, the base voltage of the fourth transistor 44 is lower than the emitter voltage thereof, the fifth transistor 53 is turned off, the circuit is opened, and the circuit output is high.

As shown in fig. 7, the signal processing module includes a chip 61, the chip 61 is a chip CD40107, pin No. 2 of the chip 61 is connected to the photosensitive output port, pin No. 3 of the chip 61 is connected to the base of a sixth triode 63 through a twelfth resistor 62, the collector of the sixth triode 63 is connected to the base of a seventh triode 65 through a thirteenth resistor 64, the collector of the seventh triode 65 is used as the signal output port, and the emitter of the sixth triode 63 is grounded.

In the signal processing module, when the light is excited, the 24V high-level output is needed to be obtained, the output needs to have certain load capacity, and the NAND gate is used for processing the light-sensitive output.

When the photosensitive is excited, the photosensitive output is low, the output of the chip CD40107 is high, the chip CD40107 is connected to the sixth triode 63 after being connected with the resistor, the sixth triode 63 is conducted, the circuit is closed, the seventh triode 65 is conducted, and the OUT output is 24V.

The utility model solves the technical problem that the laser light source 45 cannot be in a working state for a long time by adjusting the duty ratio of the PWM waves, and meets the requirement that the photoelectric sensor needs to be electrified for use for a long time. The utility model completes the processing and output of weak signals of the photosensitive diode, the signal output reaches the use standard, the circuit can realize the function of the mirror reflection type laser photoelectric sensor, the mirror reflection type photoelectric sensor can realize 0-15m, the requirements of most like products in the market are met, the cost is greatly reduced, the use is safer, and the utility model can be widely popularized and applied.

The foregoing description of the preferred embodiment of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The laser type photoelectric sensor circuit is characterized by comprising a first power supply module, wherein the first power supply module is a DC 24V-DC 6V power supply module, and the first power supply module supplies power for a frequency generation module and a laser driving module;

the light-sensitive receiving module is characterized by further comprising a second power module, wherein the second power module is a DC 24V-DC 5V power module, and the second power module supplies power to the light-sensitive receiving module;

the signal output port of the frequency generation module is connected with the signal input port of the laser driving module, the signal output end of the laser driving module is connected with the signal input port of the photosensitive receiving module, and the signal output port of the photosensitive receiving module is connected with the signal input port of the signal processing module;

the frequency generation module comprises a timer (31), a No. 1 pin of the timer (31) is grounded, a No. 2 pin and a No. 6 pin of the timer (31) are in short circuit, a No. 3 pin of the timer (31) is a PWM signal output interface, a No. 4 pin and a No. 8 pin of the timer (31) are connected with VCC6V, a No. 5 pin of the timer (31) is connected with one end of a fourth capacitor (32), the other end of the fourth capacitor (32) is grounded, the No. 2 pin and the No. 3 pin of the timer (31) are connected through a first branch, a third rectifier diode (33) and a third resistor (34) are arranged on the first branch, the No. 2 pin and the No. 3 pin of the timer (31) are connected through a second branch, and a fourth rectifier diode (35) and a fourth resistor (36) are arranged on the second branch;

the signal input end of the laser driving module is connected with one end of a fifth resistor (41), the other end of the fifth resistor (41) is connected with the base electrode of a third triode (42), the collector electrode of the third triode (42) is connected with the base electrode of a fourth triode (44) through a sixth resistor (43), the collector electrode of the fourth triode (44) is connected with one end of a light source (45), the other end of the light source (45) is grounded, the collector electrode of the third triode (42) is connected with one end of a seventh resistor (46), and the other end of the seventh resistor (46) is connected with VCC6V and the emitter electrode of the fourth triode (44) respectively;

the photosensitive receiving module comprises a receiver (51), wherein a pin 1 of the receiver (51) is connected with VCC5V, a pin 2 of the receiver (51) is connected with a base electrode of a fifth triode (53) through an eighth resistor (52), a collector electrode of the fifth triode (53) is connected with an emitting electrode of the fifth triode through a fifth capacitor (54) and a sixth capacitor (55), and a collector electrode of the fifth triode (53) is connected with a photosensitive output port;

the signal processing module comprises a chip (61), a No. 2 pin of the chip (61) is connected with a photosensitive output port, a No. 3 pin of the chip (61) is connected with a base electrode of a sixth triode (63) through a twelfth resistor (62), a collector electrode of the sixth triode (63) is connected with a base electrode of a seventh triode (65) through a thirteenth resistor (64), a collector electrode of the seventh triode (65) is used as the signal output port, and an emitter electrode of the sixth triode (63) is grounded.

2. The laser type photoelectric sensor circuit according to claim 1, wherein the first power supply module comprises a first rectifying diode (11), a pin of VCC24V is connected with an anode of the first rectifying diode (11), a cathode of the first rectifying diode (11) is connected with one end of a first resistor (12) and a collector of a first triode (13), the other end of the first resistor (12) is connected with a cathode of a first zener diode (14), the anode of the first zener diode (14) is grounded, an emitter of the first triode (13) is connected with VCC6V and one end of a first capacitor (15), the other end of the first capacitor (15) is grounded, an emitter of the first triode (13) is connected with an anode of a first light emitting diode (16) through a ninth resistor (17), and the cathode of the first light emitting diode (16) is grounded;

the second power module comprises a second rectifying diode (21), a pin of VCC24V is connected with the positive electrode of the second rectifying diode (21), the negative electrode of the second rectifying diode (21) is connected with one end of a tenth resistor (22) and the collector electrode of a second triode (23), the other end of the tenth resistor (22) is connected with the negative electrode of a second voltage stabilizing diode (24), the positive electrode of the second voltage stabilizing diode (24) is grounded, the emitter electrode of the second triode (23) is connected with VCC5V and one end of a second capacitor (25), the other end of the second capacitor (25) is grounded, the emitter electrode of the second triode (23) is connected with the positive electrode of a second light emitting diode (26) through an eleventh resistor (27), and the negative electrode of the second light emitting diode (26) is grounded.