Robot charging pile with short circuit protection function

Abstract

The utility model relates to a robot charging pile with a short-circuit protection function, and belongs to the technical field of robot charging piles. The robot charging pile comprises a control panel, a charging contact and a charging contact detection assembly. The charging contact comprises a charging contact positive electrode and a charging contact negative electrode; the charging contact detection assembly comprises a magnetic proximity switch and a travel switch. The magnetic proximity switch is installed in a through hole of the travel switch. The charging contact positive electrode, the charging contact negative electrode, the magnetic proximity switch and the travel switch are all electrically connected with the control panel; the control board is provided with a short circuit detection circuit which is used for detecting whether short circuit occurs between the positive electrode and the negative electrode of the charging contact in real time. The robot charging pile with the short-circuit protection function is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of robot charging piles, in particular to a robot charging pile with a short - circuit protection function. Background Art

[0002] With the wide application of robots in all walks of life, supporting facilities such as robot charging piles have also been widely used.

[0003] Robots can charge autonomously by moving to the vicinity of the charging pile and approaching the positive and negative poles of the charging contact.

[0004] At present, for the charging piles used in robot autonomous charging, the positive and negative poles of the charging contact and the trigger switch are often located outside the housing. If a metal object touches both the charging contact and its trigger switch simultaneously, it is easy to cause a short - circuit phenomenon, resulting in damage to the charging pile, and even causing a fire and affecting the mains power. Content of the Utility Model

[0005] In view of the above analysis, the utility model aims to provide a robot charging pile with a short - circuit protection function to solve the problem that the positive and negative poles of the charging contact of the existing robot charging pile are easily mis - triggered to cause a short - circuit, resulting in damage to the charging pile and even causing a fire.

[0006] The purpose of the utility model is mainly achieved through the following technical solutions:

[0007] A robot charging pile with a short - circuit protection function, the robot charging pile includes a control board, a charging contact, and a charging contact detection component;

[0008] The charging contact includes a charging contact positive pole and a charging contact negative pole;

[0009] The charging contact detection component includes a magnetic proximity switch and a travel switch, and the magnetic proximity switch is installed in the through - hole of the travel switch;

[0010] The charging contact positive pole, the charging contact negative pole, the magnetic proximity switch, and the travel switch are all electrically connected to the control board; a short - circuit detection circuit is arranged on the control board, and the short - circuit detection circuit is used to detect in real time whether a short - circuit occurs between the charging contact positive pole and the negative pole.

[0011] Furthermore, the charging contact positive pole, the charging contact negative pole, and the travel switch are arranged side by side at the position in contact with the robot, and each includes a power - receiving module, a spring, a spring fixing stop, a connecting rod, and a micro - switch;

[0012] The part of the power - receiving module protruding from the housing is a flat structure, and the part located inside the housing is a rod - shaped structure;

[0013] One end of the spring is sleeved on the rod-shaped structure of the power receiving module, and the other end is in contact with the spring fixed baffle; one end of the connecting rod is fixedly connected to the power receiving module, and the other end is connected to the moving reed of the microswitch; the microswitch is electrically connected to the control board.

[0014] Furthermore, the robot charging pile further includes an AC-DC charger; the control board includes a single-chip microcomputer, a current sampling circuit, and a relay; the current sampling circuit includes a sampling resistor and an operational amplifier;

[0015] The sampling resistor and the relay are sequentially connected in series between the positive pole of the output of the AC-DC charger and the positive pole of the charging contact; the positive pole of the voltage input pin of the operational amplifier is connected to one end of the sampling resistor, and the negative pole of the voltage input pin of the operational amplifier is connected to the other end of the sampling resistor; the voltage output pin of the operational amplifier is connected to the first voltage acquisition pin of the single-chip microcomputer, and the relay control pin of the single-chip microcomputer is connected to the control end of the relay.

[0016] Furthermore, the short-circuit detection circuit includes a DC / DC conversion chip and a voltage-dividing resistor network; the positive and negative poles of the input end of the DC / DC conversion chip are respectively connected to the positive and negative poles of the output of the AC-DC charger; the voltage-dividing resistor network includes a first voltage-dividing resistor and a second voltage-dividing resistor; one end of the first voltage-dividing resistor is connected to the positive pole of the output of the DC / DC conversion chip, and the other end of the first voltage-dividing resistor is simultaneously connected to one end of the second voltage-dividing resistor, the positive pole of the charging contact, and the second voltage acquisition pin of the single-chip microcomputer; the other end of the second voltage-dividing resistor is grounded; the negative pole of the output end of the DC / DC conversion chip is connected to the negative pole of the charging contact.

[0017] Furthermore, the short-circuit detection circuit further includes a TVS diode; the positive pole of the TVS diode is connected to the second voltage acquisition pin of the single-chip microcomputer; the negative pole of the TVS diode is connected to the positive pole of the charging contact.

[0018] Furthermore, the lower part of the charging pile housing includes an aviation connector and a network port; the aviation connector is externally connected to the power supply and internally connected to the AC-DC charger; the network port is electrically connected to the control board.

[0019] Furthermore, the control board further includes a network conversion chip; the network conversion chip is externally connected to the network port and internally connected to the serial port sending and receiving pins of the single-chip microcomputer.

[0020] Furthermore, a leakage protector is connected in series before the positive pole of the power supply of the aviation connector is connected to the AC-DC charger.

[0021] Furthermore, a fixed bracket is provided inside the charging pile housing; the control board, the spring fixed baffle, and the microswitch are all located on the fixed bracket.

[0022] Further, a buzzer and a light alarm are also arranged on the control board, and the buzzer and the light alarm are connected to the alarm pin of the single-chip microcomputer.

[0023] Compared with the prior art, the utility model can at least achieve one of the following beneficial effects:

[0024] 1. A short-circuit detection circuit is arranged on the control board of the robot charging pile of the utility model, and the short-circuit detection circuit is used to detect in real time whether a short circuit occurs between the positive electrode and the negative electrode of the charging contact. By generating a test weak voltage and loading it onto the positive electrode of the charging contact, and detecting the feedback voltage of the positive electrode of the charging contact through the single-chip microcomputer, if the feedback voltage is 0V and there is no upward trend for 2 seconds, it is judged that a short circuit may occur between the positive and negative electrodes of the charging contact. The single-chip microcomputer disconnects the relay located at the positive electrode of the charger of the charging pile, stops charging, starts the sound and light alarm, and reports the short-circuit situation to the upper computer in real time through the network port. A safe and reliable robot charging pile with a short-circuit detection function is realized.

[0025] 2. An current sampling circuit including a 0.5mΩ sampling resistor and an operational amplifier and a relay are arranged on the positive electrode of the charger of the robot charging pile of the utility model. The single-chip microcomputer calculates the sampled current by dividing the voltage across the sampling resistor by the resistance value of the sampling resistor; during the charging process, the charging current is detected in real time. If the charging current exceeds the threshold, the single-chip microcomputer judges that the charging is abnormal, and the single-chip microcomputer sends a control instruction to disconnect the relay and report an error. Through such operations, the short-circuit problem caused by human reasons or negligence can be effectively solved, and the damage to the robot or the charging pile is avoided by timely power-off.

[0026] 3. The positive electrode of the charging contact, the negative electrode of the charging contact, and the travel switch of the robot charging pile of the utility model are arranged side by side at the position in contact with the robot, and all include a power receiving module, a spring, a spring fixing stop, a connecting rod, and a micro switch; the magnetic proximity switch is installed in the through hole of the travel switch; when the magnetic proximity switch and the travel switch are both triggered and no short circuit is detected after inspection, the power supply is controlled to be turned on to charge the robot through the control board. The structure design is novel, and the simultaneous triggering of the magnetic proximity switch and the travel switch can also avoid the danger caused by mis-triggering.

[0027] 4. The hardware cost of the robot charging pile of the utility model is relatively low and the structure is simple. By using the logic control of the single-chip microcomputer in cooperation with voltage-dividing resistors, relays, DC / DC converters, AC-DC chargers, charging contacts, travel switches, and magnetic proximity switches, a robot charging pile with a short-circuit protection function can be realized; no short circuit will occur when any metal object of any shape touches any position.

[0028] In the present utility model, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present utility model will be described in the following content. Moreover, some advantages can be made obvious from the description or understood by implementing the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained from the content specifically pointed out in the text and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present utility model. Throughout the drawings, the same reference signs denote the same components.

[0030] Figure 1 FIG. is a schematic view of the appearance of a robot charging pile with a short - circuit protection function;

[0031] Figure 2 FIG. is a schematic view of the positive charging contact, negative charging contact and travel switch structure of a robot charging pile with a short - circuit protection function;

[0032] Figure 3 FIG. is a schematic view of the internal structure of a robot charging pile with a short - circuit protection function;

[0033] Figure 4 FIG. is a principle block diagram of the short - circuit detection circuit of a robot charging pile with a short - circuit protection function;

[0034] Figure 5 FIG. is a flowchart of the working principle of a robot charging pile with a short - circuit protection function.

[0035] Reference Signs:

[0036] 1 - Top Cover;

[0037] 2 - Decorative Strip;

[0038] 3 - Charging Pile Housing;

[0039] 4 - Positive Charging Contact;

[0040] 5 - Travel Switch;

[0041] 6 - Negative Charging Contact;

[0042] 8 - Light Alarm;

[0043] 9 - Power Receiving Module;

[0044] 10 - Spring;

[0045] 11 - Spring Fixed Retainer;

[0046] 12 - Connecting Rod;

[0047] 13 - Microswitch. Detailed implementation

[0048] The preferred embodiments of the present utility model will be specifically described below with reference to the accompanying drawings. The accompanying drawings form a part of this application and are used together with the embodiments of the present utility model to explain the principles of the present utility model, rather than to limit the scope of the present utility model.

[0049] A specific embodiment of the present utility model discloses a robot charging pile with a short - circuit protection function, as Figure 1 shown. The robot charging pile includes a control board, charging contacts, and a charging contact detection component;

[0050] The charging contacts include a charging contact positive electrode 4 and a charging contact negative electrode 6;

[0051] The charging contact detection component includes a magnetic proximity switch and a travel switch 5, and the magnetic proximity switch is installed in the through - hole of the travel switch 5;

[0052] The charging contact positive electrode 4, the charging contact negative electrode 6, the magnetic proximity switch, and the travel switch 5 are all electrically connected to the control board; a short - circuit detection circuit is provided on the control board, and the short - circuit detection circuit is used to detect in real time whether a short - circuit occurs between the charging contact positive electrode 4 and the negative electrode.

[0053] The working principle flow chart of the charging pile is as Figure 5 shown.

[0054] Specifically, when the robot approaches the charging pile for charging, the charging positive and negative electrodes of the robot body will be respectively aligned with the charging contact positive electrode 4 and the charging contact negative electrode 6 of the charging pile and touch and squeeze; both the charging contact positive electrode 4 and the charging contact negative electrode 6 include a spring 10 and a microswitch 13, and the microswitch 13 transmits the changing switch - quantity signal to the single - chip microcomputer. The magnetic core of the magnetic proximity switch emits electromagnetic waves forward and receives the returned electromagnetic waves. When the metal on the robot housing approaches the magnetic proximity switch, since the metal absorbs the electromagnetic, the proximity switch converts the attenuation of the electromagnetic into a switched electrical signal, and this converted switched electrical signal is transmitted to the single - chip microcomputer on the control board of the robot charging pile. The travel switch 5 is provided with a connecting rod 12, a spring 10, and a microswitch 13. When the travel switch 5 is triggered to drive the connecting rod 12 to move, the moving reed of the microswitch 13 will move accordingly, resulting in a change in the electrical signal of the microswitch 13 and being transmitted to the single - chip microcomputer.

[0055] The structural schematic diagrams of the charging contact positive electrode 4, the charging contact negative electrode 6, and the travel switch 5 of the charging pile are as Figure 2 shown.

[0056] The positive charging contact 4, the negative charging contact 6, and the travel switch 5 are arranged side by side at the position in contact with the robot, and each includes a power receiving module 9, a spring 10, a spring fixing stop 11, a connecting rod 12, and a micro switch 13;

[0057] The part of the power receiving module 9 protruding from the housing is a flat structure, and the part located inside the housing is a rod-shaped structure;

[0058] One end of the spring 10 is sleeved on the rod-shaped structure of the power receiving module 9, and the other end is in contact with the spring fixing stop 11; one end of the connecting rod 12 is fixedly connected to the power receiving module 9, and the other end is connected to the actuating reed of the micro switch 13; the micro switch 13 is electrically connected to the control board.

[0059] Specifically, when the single-chip microcomputer on the control board detects that the magnetic proximity switch and the travel switch 5 are triggered by the robot at the same time, the single-chip microcomputer on the control board applies a weak voltage to the positive charging contact 4 through the short-circuit detection circuit; the single-chip microcomputer on the control board judges whether a short circuit occurs between the positive charging contact 4 and the negative electrode by detecting the feedback voltage. If no short circuit occurs, the control board controls the AC-DC charger to charge the robot.

[0060] The internal structure schematic diagram of the charging pile is as Figure 3 shown.

[0061] The robot charging pile further includes an AC-DC charger; the control board includes a single-chip microcomputer, a current sampling circuit, and a relay; the current sampling circuit includes a sampling resistor and an operational amplifier;

[0062] The sampling resistor and the relay are connected in series in turn between the positive pole of the output end of the AC-DC charger and the positive charging contact 4; the positive pole of the voltage input pin of the operational amplifier is connected to one end of the sampling resistor, and the negative pole of the voltage input pin of the operational amplifier is connected to the other end of the sampling resistor; the voltage output pin of the operational amplifier is connected to the first voltage acquisition pin of the single-chip microcomputer, and the relay control pin of the single-chip microcomputer is connected to the control end of the relay.

[0063] In a specific embodiment of the present invention, a 0.5 mΩ sampling resistor is selected. The voltage input end of the operational amplifier receives the voltage across the sampling resistor, and after adjusting to a suitable dynamic range, it is transmitted to the single-chip microcomputer. The single-chip microcomputer divides the voltage by the sampling resistor to obtain the sampling current, and judges the sampling current. When the sampling current exceeds the threshold, the single-chip microcomputer judges that the charging is abnormal and sends a control instruction to disconnect the relay to stop charging.

[0064] The principle block diagram of the short-circuit detection circuit is as Figure 4 shown.

[0065] The short-circuit detection circuit includes a DC / DC conversion chip and a voltage-dividing resistor network. The positive and negative terminals of the input end of the DC / DC conversion chip are respectively connected to the positive and negative terminals of the output end of the AC-DC charger. The voltage-dividing resistor network includes a first voltage-dividing resistor and a second voltage-dividing resistor. One end of the first voltage-dividing resistor is connected to the positive terminal of the output end of the DC / DC conversion chip, and the other end of the first voltage-dividing resistor is simultaneously connected to one end of the second voltage-dividing resistor, the positive electrode 4 of the charging contact, and the second voltage acquisition pin of the single-chip microcomputer. The other end of the second voltage-dividing resistor is grounded. The negative terminal of the output end of the DC / DC conversion chip is connected to the negative electrode 6 of the charging contact.

[0066] In a specific embodiment of the present invention, 220V AC mains power is input to the AC-DC charger through an aviation connector. The AC-DC charger outputs 36V DC voltage. The DC / DC conversion chip converts the 36V DC voltage into 24V DC voltage. The first voltage-dividing resistor is 100k and the second voltage-dividing resistor is 10k. The 2.4V weak voltage obtained after voltage division by the voltage-dividing resistor network is applied to the positive electrode 4 of the charging contact. The single-chip microcomputer detects the feedback voltage of the positive electrode 4 of the charging contact. If the feedback voltage is 0V and there is no upward trend for 2 seconds, it is determined that the positive and negative electrodes of the charging contact may be short-circuited, and the single-chip microcomputer disconnects the relay located at the positive pole of the charging pile charger to stop charging.

[0067] The short-circuit detection circuit further includes a TVS diode. The positive pole of the TVS diode is connected to the second voltage acquisition pin of the single-chip microcomputer. The negative pole of the TVS diode is connected to the positive electrode 4 of the charging contact.

[0068] Specifically, connecting the negative pole of the TVS diode to the positive electrode 4 of the charging contact can prevent high-voltage injection at the positive electrode 4 of the charging contact from burning out the single-chip microcomputer.

[0069] The lower part of the charging pile housing 3 includes an aviation connector and a network port. The aviation connector is externally connected to the power supply and internally connected to the AC-DC charger. The network port is electrically connected to the control board.

[0070] Specifically, a top cover 1 is provided on the top of the charging pile housing 3. The internal structure of the charging pile can be disassembled and assembled by opening the top cover 1. A decorative strip 2 is provided on the upper part of the front surface of the charging pile housing 3. The light alarm 8 is located in the middle of the decorative strip 2.

[0071] The control board further includes a network conversion chip. The network conversion chip is externally connected to the network port and internally connected to the serial port transmission and reception pins of the single-chip microcomputer.

[0072] Specifically, the network conversion chip is used to convert the serial port signal of the single-chip microcomputer and the external network port signal to realize high-speed data transmission to the upper computer through the network port externally.

[0073] A leakage protector is connected in series before the positive pole of the power supply of the aviation connector is connected to the AC-DC charger.

[0074] Specifically, a leakage protector is connected in series before the AC-DC charger, which plays a protection function when a leakage fault occurs in the charging pile.

[0075] A fixed bracket is arranged inside the charging pile housing 3; the control board, the spring fixing piece 11, and the microswitch 13 are all located on the fixed bracket.

[0076] A buzzer and a light alarm 8 are also arranged on the control board, and the buzzer and the light alarm 8 are connected to the alarm pin of the single-chip microcomputer.

[0077] Specifically, when the single-chip microcomputer detects a short circuit between the positive and negative poles of the charging contact or the charging current exceeds the set threshold, it cuts off the power and gives out a sound and light alarm at the same time.

[0078] Compared with the prior art, a short-circuit detection circuit is arranged on the control board of the robot charging pile provided in this embodiment. The short-circuit detection circuit is used to detect in real time whether a short circuit occurs between the positive pole 4 and the negative pole of the charging contact. By generating a test weak voltage and loading it onto the positive pole 4 of the charging contact, and detecting the feedback voltage of the positive pole 4 of the charging contact through the single-chip microcomputer, if the feedback voltage is 0V and there is no upward trend within 2 seconds, it is judged that a short circuit may occur between the positive and negative poles of the charging contact. The single-chip microcomputer disconnects the relay located at the positive pole of the charger of the charging pile, stops charging, starts the sound and light alarm, and reports the short-circuit situation to the upper computer in real time through the network port. A safe and reliable robot charging pile with a short-circuit detection function is realized. An current sampling circuit including a 0.5mΩ sampling resistor and an operational amplifier and a relay are arranged on the positive pole of the charger of the robot charging pile in this embodiment. The single-chip microcomputer calculates the sampled current by dividing the voltage across the sampling resistor by the resistance value of the sampling resistor; in the case of overcurrent, the single-chip microcomputer judges that the charging is abnormal, disconnects the relay and gives out a sound and light alarm. The damage of the robot or the charging pile is avoided by cutting off the power in time. The positive pole 4 of the charging contact, the negative pole 6 of the charging contact, and the travel switch 5 of the robot charging pile in this embodiment are arranged side by side at the position in contact with the robot, and all include a power receiving module 9, a spring 10, a spring fixing piece 11, a connecting rod 12, and a microswitch 13; the magnetic proximity switch is installed in the through hole of the travel switch 5; when the magnetic proximity switch and the travel switch 5 are triggered at the same time, the power supply is controlled to conduct to charge the robot through the control board. The structural design is novel, and the simultaneous triggering of the magnetic proximity switch and the travel switch 5 can also avoid the danger caused by mis-triggering. The robot charging pile provided in this embodiment has a low hardware cost and a simple structure. By using the logical control of the single-chip microcomputer in cooperation with voltage dividing resistors, relays, DC / DC converters, AC-DC chargers, charging contacts, travel switches 5, and magnetic proximity switches, a robot charging pile with a short-circuit protection function can be realized; no short circuit will occur when any metal object of any shape touches at any position.

[0079] Those skilled in the art can understand that the programs / software involved in the above embodiments are common methods in the prior art, and the present utility model does not involve any improvements in software. The present utility model only needs to connect the devices with corresponding functions through the connection relationships given in the embodiments of the present utility model, and does not involve any improvements in program software. As for the connection methods between the hardware devices with corresponding functions, those skilled in the art can all implement them using the prior art and will not be elaborated here.

[0080] The above is only a preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model.

Claims

1. A robot charging pile with short-circuit protection function, characterized in that: The robot charging pile includes a control board, a charging contact, and a charging contact detection component; The charging contact includes a positive charging contact and a negative charging contact; The charging contact detection assembly includes a magnetic proximity switch and a travel switch, wherein the magnetic proximity switch is installed in a through hole of the travel switch; The positive pole of the charging contact, the negative pole of the charging contact, the magnetic proximity switch, and the travel switch are all electrically connected to the control board; a short circuit detection circuit is provided on the control board, and the short circuit detection circuit is used to detect in real time whether a short circuit occurs between the positive pole and the negative pole of the charging contact.

2. The robot charging station according to claim 1, characterized in that: The positive pole of the charging contact, the negative pole of the charging contact, and the travel switch are arranged side by side at a position in contact with the robot, and each includes a power receiving module, a spring, a spring fixing baffle, a connecting rod, and a micro switch; The part of the power receiving module protruding from the shell is a flat structure, and the part inside the shell is a rod-shaped structure; One end of the spring is sleeved on the rod-shaped structure of the power receiving module, and the other end is in contact with the spring fixed baffle; one end of the connecting rod is fixedly connected to the power receiving module, and the other end is connected to the action reed of the micro switch; the micro switch is electrically connected to the control board.

3. The robot charging station according to claim 1, characterized in that: The robot charging pile also includes an AC-DC charger; the control board includes a single-chip microcomputer, a current sampling circuit and a relay; the current sampling circuit includes a sampling resistor and an operational amplifier; The sampling resistor and the relay are connected in series between the positive pole of the AC-DC charger output terminal and the positive pole of the charging contact; the positive pole of the operational amplifier voltage input pin is connected to one end of the sampling resistor, and the negative pole of the operational amplifier voltage input pin is connected to the other end of the sampling resistor; the operational amplifier voltage output pin is connected to the first voltage collection pin of the single-chip microcomputer, and the relay control pin of the single-chip microcomputer is connected to the control end of the relay.

4. The robot charging station according to claim 3, characterized in that: The short-circuit detection circuit includes a DC / DC conversion chip and a voltage-dividing resistor network; the positive and negative input terminals of the DC / DC conversion chip are respectively connected to the positive and negative output terminals of the AC-DC charger; the voltage-dividing resistor network includes a first voltage-dividing resistor and a second voltage-dividing resistor; one end of the first voltage-dividing resistor is connected to the positive output terminal of the DC / DC conversion chip, and the other end of the first voltage-dividing resistor is simultaneously connected to one end of the second voltage-dividing resistor, the positive charging contact, and the second voltage collection pin of the single-chip computer; the other end of the second voltage-dividing resistor is grounded; the negative output terminal of the DC / DC conversion chip is connected to the negative charging contact.

5. The robot charging station according to claim 4, characterized in that: The short-circuit detection circuit also includes a TVS diode; the positive electrode of the TVS diode is connected to the second voltage collection pin of the single-chip computer; and the negative electrode of the TVS diode is connected to the positive electrode of the charging contact.

6. The robot charging station according to claim 3, characterized in that: The lower part of the charging pile shell includes an aviation head connector and a network port; the aviation head connector is connected to the power supply externally and to the AC-DC charger internally; the network port is electrically connected to the control board.

7. The robot charging station according to claim 6, characterized in that: The control board also includes a network conversion chip; the network conversion chip is externally connected to the network port and internally connected to the sending and receiving pins of the serial port of the single-chip microcomputer.

8. The robot charging station according to claim 6, characterized in that: The positive pole of the aviation connector power supply is connected in series with a leakage protector before being connected to the AC-DC charger.

9. The robot charging station according to claim 2, characterized in that: A fixed bracket is arranged inside the housing of the charging pile; the control board, the spring fixed baffle and the micro switch are all located on the fixed bracket.

10. The robot charging station according to claim 1, characterized in that: The control board is also provided with a buzzer and a light alarm, and the buzzer and the light alarm are connected to the alarm pin of the single chip computer.

Images