Multiplexing switch for intelligent laser system

Abstract

The invention provides a multiplexing switch for an intelligent laser system. The multiplexing switch comprises a multi-path analog switch, a solid-state relay, a protective resistor and a NOT gate, the multi-channel analog switch receives the digital instruction signal, realizes single-channel conduction control by controlling the level state of a pin, converts a control instruction into a current signal and transmits the current signal to the solid-state relay; an optical coupling switch in the solid-state relay performs on-off operation on externally connected electronic equipment based on the received current signal; in the closed state, the pin A of the NOT gate is set to be in a low level, the pin A is converted to be in a high level through the NOT gate and then is transmitted to the port of the multi-channel analog switch, and the multi-channel analog switch is locked to prevent misoperation. The multi-way switch multiplexing function is achieved, the technical problem that a traditional multiplexing switch is difficult to bear large current is solved, and the multi-way switch has the advantage that small current controls large current, has the advantages of being high in integration level, large in rated current, wide in application scene, low in cost and the like, and has extremely high application and popularization value.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, specifically a multiplexer switch for intelligent laser systems. Background Technology

[0002] In intelligent laser systems, to reduce the number of components and improve system integration, a single drive is often used to drive multiple devices. Multiplexed switches, as the core hub of electronic equipment control, play a crucial role. However, traditional multiplexed analog switches, represented by the 74HC4051, have an on-resistance as high as 80Ω (VCC=4.5V) and a rated current carrying capacity of only ≤100mA. When driving high-current loads, additional multi-stage amplifier circuits are required, leading to a more complex system architecture.

[0003] The current technological bottleneck in the industry is mainly reflected in the insufficient high current carrying capacity. Commercially available products generally only support a maximum current of about 0.5A, and are also expensive and unreliable. In addition, in the standby state of the system, the enable pin of the multi-channel analog switch is susceptible to electromagnetic interference, which can cause false triggering and jitter. When facing inductive loads such as solenoid valves and motors, the voltage spike of 3-5 times the rated voltage generated at the moment of turn-off can easily damage the internal MOS device of the solid-state relay. In extreme environments, the performance of traditional solutions is significantly degraded, and additional temperature control equipment is required to ensure operation.

[0004] It is worth noting that, in terms of hardware configuration, its design and implementation require a large amount of hardware resources, and the circuit design is extremely complex. On the one hand, the numerous electronic components and complex wiring increase the manufacturing cost of the product, making the price of multiplexers high and limiting their widespread adoption in cost-sensitive large-scale application scenarios; on the other hand, the complex hardware structure also reduces the reliability of the system. Once a component or circuit fails, troubleshooting and repair are difficult, which can easily lead to prolonged system downtime. Summary of the Invention

[0005] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a multiplexer for intelligent laser systems that uses a small current signal chain to control a large current power chain, thereby achieving safe energy isolation through "weak current controlling strong current".

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A multiplexing switch for a smart laser system, comprising:

[0008] A multiplexer analog switch is used to receive command signals from the outside and control the conduction of a single channel; the multiplexer analog switch is a multi-channel analog multiplexer / demultiplexer, featuring a single-pole multi-throw switch structure and N digital selection input pins S0 to S10. n ,2 n+1 -1 output terminal Yn to Where N≥2; 1 common input / output terminal Z; 1 digital enable input pin in When the pin is low, the switch is allowed to turn on; when the pin is high, all switches are locked.

[0009] Multiple solid-state relays are connected to the output pins of the multi-channel analog switch to receive current signals output by the multi-channel analog switch and control the on / off state of external electronic devices. The solid-state relays are MOS output type and include: positive / negative input pins: connected to the output pins of the multi-channel analog switch via a series current-limiting protection resistor. The current-limiting protection resistor limits the input current to the safe operating range of 5-30mA for the solid-state relay, preventing overcurrent damage to the internal optocoupler structure or MOS device; positive / negative load pins: used to connect external loads, with a load voltage ≤40V, load current ≤6A, and on-resistance ≤0.06Ω; input / output isolation voltage ≥5000Vrms.

[0010] NOT gate, and the digital enable input pin of a multiplexed analog switch The connection, with its input pin A connected to an external voltage level, is used to convert a low voltage level to a high voltage level and send it to the external voltage level when the switch is idle. Pin, locks the multiplex analog switch.

[0011] Preferably, the digital selection input pin of the multiplexer analog switch supports a binary encoding gating mechanism, corresponding to gating 2... n+1 -1 output terminal Y n to The only channel in the system has a channel switching delay of ≤12ns when the power supply voltage is 5V.

[0012] Preferably, the operating temperature range of the multi-channel analog switch is -40℃ to +125℃; the digital selection input pins S0 to S... n Supports logic level compatibility: When VCC = 2.0V to 6.0V, it is compatible with JEDEC standard logic levels, VIH ≥ 0.7 × VCC, VIL ≤ 0.3 × VCC; On-resistance exhibits low non-linearity with input voltage: when the input voltage is between 0 and V... CC -V EE Within the specified range, resistance fluctuation is ≤±15%.

[0013] Preferably, the on-resistance R of the multi-channel analog switch ON With power supply voltage V CC -V EE Dynamic changes:

[0014] 1) When V CC -V EEAt 4.5V, the typical resistance is 80Ω, and the maximum resistance is 180Ω.

[0015] 2) When V CC -V EE At 6.0V, the typical value is 70Ω, and the maximum value is 160Ω;

[0016] 3) At room temperature, the deviation of conduction resistance between channels (ΔR) ON )≤9Ω.

[0017] Preferably, the input side of the solid-state relay adopts an optically coupled isolation structure, and the input current I... F It has a linear relationship with the load conduction state: when I F When I is ≥5mA, the load side conducts; under a load voltage of 40V, when I F When the current is ≤0.5mA, the load side is turned off, and the leakage current in the off state is ≤0.1μA; the multi-channel analog switch and the solid-state relay adopt a differential wiring layout, the signal line spacing is ≥2 times the line width, and a 300Ω matching resistor is connected in series to suppress signal reflection. When the power supply voltage is 4.5V, the signal rise / fall slope is ≤139ns / V.

[0018] Preferably, the load side of the solid-state relay supports surge current suppression: when an inductive load is connected, a resistor buffer circuit with R=300Ω is connected in parallel to the load pin to limit the voltage spike to within 1.5 times the rated value, thus protecting the MOS device.

[0019] Preferably, the communication baud rate of the multi-channel analog switch is ≥1Mbps, and it supports real-time monitoring of the pin E level status of the multi-channel analog switch. In case of an abnormality, a hardware interrupt is triggered to lock all channels.

[0020] Preferably, the ESD protection performance of the multi-channel analog switch meets the following requirements:

[0021] 1) Human body discharge mode HBM≥2000V, device charging mode CDM≥1000V;

[0022] 2) An embedded diode in the input pin allows the input voltage to momentarily exceed V. CC +0.5V without damaging the device.

[0023] Preferably, the solid-state relay operates in a temperature range of -40°C to +85°C and a storage temperature range of -40°C to +100°C. Under high temperature conditions of 85°C, the load current is dated to 2.0A for continuous operation, and the on-resistance temperature rise is ≤30K.

[0024] Preferably, the solder joint between the protection resistor and the input pin of the solid-state relay adopts a teardrop-shaped pad design with a mechanical strength ≥2N·m and can withstand a reflow soldering temperature of 260℃.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] Multiplexer switches, through innovative architectural design and precise technical integration, demonstrate significant benefits in several key areas such as signal processing, circuit safety, system compatibility, and environmental adaptability, providing an efficient and reliable solution for cluster control of electronic equipment.

[0027] 1. Efficiency: As the core of multiplexing switching devices, the multi-channel analog switch achieves precise switching of multiple signals based on binary encoding logic. Taking an eight-channel multiplexer as an example, TI's CD4051 multi-channel analog switch can quickly identify three-bit binary codes. Upon receiving different encoded signals, it can activate the corresponding channel within an extremely short time of 12ns, enabling the common output terminal to conduct with the independent output terminal, thus achieving efficient signal transmission. This precise and rapid signal switching capability makes the device perform excellently in high-frequency signal processing scenarios, meeting the application requirements of high-speed data acquisition and high-frequency communication, which have extremely high requirements for signal transmission speed and accuracy. It ensures that signals from multiple channels can be transmitted and processed quickly and orderly, improving the overall data processing efficiency of the system.

[0028] 2. Versatility: The multiplexer is compatible with 2.0V-6.0V TTL / CMOS high and low level signals, enabling seamless integration with the vast majority of electronic devices on the market. Whether it's traditional industrial control equipment or emerging IoT and AI hardware platforms, the multiplexer can adapt to their signal standards, breaking down signal barriers between different devices. This compatibility greatly expands the device's application range. Users no longer need to design separate signal conversion circuits for different devices, reducing the complexity and cost of system integration while enhancing the system's versatility and scalability.

[0029] 3. Safety: To address the issue of voltage spikes reaching 3-5 times the rated value when inductive loads are turned off, the current-limiting protection resistor connected in series on the input side of the solid-state relay plays a crucial role. By dynamically calculating and selecting a suitable resistor value using the formula R = (VIN - VF) / IF, the current surge is effectively limited at the moment of inductive load turn-off, reducing the impact of voltage spikes on circuit components. The solid-state relay employs an optocoupler isolation structure, achieving high voltage isolation of ≥5000Vrms between the input and output sides through the coordinated operation of gallium arsenide LEDs and photosensitive MOSFETs. This electrical isolation effectively blocks the transmission path of interference signals between different circuits, suppressing common-mode interference common in industrial environments and ensuring stable operation of the load equipment. Simultaneously, the NOT gate and multiplex analog switch are connected using twisted-pair shielded cable, coupled with a single-point grounding design, resulting in a grounding impedance ≤0.1Ω. Under an electric field strength of 10V / m, the latching signal error rate is ≤0.005%, an improvement of two orders of magnitude compared to traditional solutions. These anti-interference design measures significantly enhance the reliability of the device in complex electromagnetic environments and reduce the risk of signal transmission errors and system malfunctions.

[0030] 4. Flexibility: Employing a matrix architecture of "one multi-channel analog switch driving multiple solid-state relays," taking an eight-channel multiplexer as an example, only one multi-channel analog switch is needed to control and switch eight signals. Compared to the traditional method of controlling multiple independent switches, this significantly reduces the number of hardware components. This highly integrated design not only saves PCB board space and simplifies circuit layout but also reduces overall hardware costs. Simultaneously, the design of multiple solid-state relay input pins connected in parallel to the common terminal of the multi-channel analog switch ensures the consistency of signals across channels, improving system stability and reliability.

[0031] 5. Low power consumption and energy-saving design

[0032] In standby mode, the "bistable latch-up circuit" constructed by the NOT gates ensures that the power consumption of the multi-channel analog switch is ≤10μA, maintaining extremely low energy consumption. This low-power design not only helps reduce the overall system energy consumption, aligning with the trend of green energy conservation, but also reduces circuit heat generation and extends the device's lifespan. It is particularly suitable for portable electronic devices with strict power consumption requirements or automated systems that operate for extended periods, reducing equipment operating costs and energy consumption. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall system principle of the present invention;

[0034] Figure 2 This is a schematic diagram of the multi-channel analog switch function in this invention;

[0035] Figure 3 This is a schematic diagram of the internal workings of the solid-state relay in this invention;

[0036] Figure 4 This is a PCB layout of a multiplexer switch.

[0037] in:

[0038] 01. Protective resistor; 02. Multiplexer analog switch; 03. NOT gate; 04. Connecting wire; 05. Solid-state relay; 021. Logic level converter; 022. Logic decoder; 051. Low-level input pin; 052. Photoresistor; 053. Single-pass MOS switch; 054. High-level input / output pin. Detailed Implementation

[0039] The invention will now be further described with reference to the accompanying drawings.

[0040] A multiplexer for a smart laser system includes a multiplexer analog switch 02, multiple solid-state relays 05, a NOT gate 03, a protection resistor 01, and a PCB package board.

[0041] The multiplexer analog switch 02, acting as the core of signal processing, receives TTL / CMOS high and low level signals (compatible with 2.0V to 6.0V logic levels) from external outputs via the digital selection S port. Based on binary encoding logic, it converts the bit-digital signals into N analog signal outputs. Specifically, when "001" is input to S0-Sn, the internal logic decoder 022 activates the corresponding channel, making the common output terminal (Z) and the independent output terminal Y1 conduct. At this time, the multiplexer analog switch 02 delivers a control current of ≤30mA to the input side of the solid-state relay 05 through a 0.3mm wide tinned copper wire (current carrying capacity ≤0.5A). This wire is treated with a silver-plated shielding layer, has an impedance ≤50Ω, and a signal transmission delay ≤12ns (VCC=5V), ensuring high-frequency signal integrity.

[0042] like Figure 1 , Figure 3 As shown, the solid-state relay 05 is configured with a low-level input pin 051, a photoresistor 052, a single-pass MOSFET 053, and a high-level input / output pin 054. The input side of the solid-state relay 05 adopts an optocoupler isolation structure (CTR current transfer ratio ≥ 50%). When the input current at the Y port is ≥ 5mA, the internal gallium arsenide light-emitting diode (LED) conducts and emits light, illuminating the gate of the photosensitive MOSFET, thus opening its channel (on-resistance ≤ 0.06Ω), thereby conducting the large current (≤ 2.5A / 40V) on the load side. Taking driving a 24V / 2A solenoid valve as an example, after the MOSFET channel is opened, the external 24V power supply drives the device through the load pin. At this time, the optocoupler isolation voltage is ≥ 5000Vrms, effectively suppressing common-mode interference in the industrial environment. The pins of the multiplexer analog switch 02 and the solid-state relay 05 are connected via connecting wire 04.

[0043] To suppress voltage spikes (up to 3-5 times the rated value) generated when an inductive load is turned off, solid-state relay 05 has a current-limiting protection resistor 01 connected in series on the input side. The specific resistance value can be determined by R = V IN -V F / I F It is calculated dynamically.

[0044] NOT gate 03 uses a 74HC04 CMOS logic device to construct a "bistable latch-up circuit":

[0045] (1) Standby state: When the external circuitry is applied to the input pin of NOT gate 03... Set to low level, after being toggled by NOT gate 03, the output pin... When the voltage level rises to ≥0.7VCC (e.g., 3.5V when VCC = 5V), this high level is connected to the enable port of the multiplex analog switch 02. Trigger the internal latching circuit to physically disconnect all S-ports from Y-ports. At this time, the power consumption of the multiplex analog switch 02 is ≤10μA.

[0046] (2) Working status: The microcontroller will Set to high level, When the output is low, the multiplex analog switch 02 is unlocked, allowing the S port signal to control the Y port to conduct.

[0047] To enhance electromagnetic interference resistance, NOT gate 03 and multiplex analog switch 02 are connected by twisted-pair shielded cable with a conductor length ≤15cm, and the shielding layer is grounded at a single point (grounding impedance ≤0.1Ω). Actual measurements at an electric field strength of 10V / m show that the latching signal error rate is ≤0.005%, an improvement of two orders of magnitude compared to traditional single-ended wiring schemes.

[0048] This invention achieves multiplexing through a matrix architecture of "one multi-channel analog switch 02 driving multiple solid-state relays 05": the input pins of multiple solid-state relays 05 are connected in parallel to the common terminal of the multi-channel analog switch 02 through wires of a certain specification, ensuring the consistency of signals in each channel.

[0049] Furthermore, the multi-channel analog switch 02 can receive TTL / CMOS high and low level signals of 2.0V-6.0V, which enables it to seamlessly interface with many electronic devices on the market, greatly expanding the application range of the device.

[0050] The working principle of the multiplexer 02 is based on the ingenious combination of the digital selection S-port and binary encoding logic. The digital selection S-port serves as the input interface for external signals. After receiving TTL / CMOS high and low level signals, the binary encoding logic inside the multiplexer 02 begins to function. It can accurately convert the input bit-digit signal into N analog signal outputs. Taking a common three-bit binary code (S0, S1, S2) as an example, when "001" is input, the internal logic decoder 022 quickly recognizes this code and activates the corresponding channel. At this time, a conductive connection is established between the common output terminal (Z) and the independent output terminal Y1, completing the signal transmission path.

[0051] During signal transmission, the multi-channel analog switch 02 supplies control current to the input side of the solid-state relay 05 via a 0.3mm wide tinned copper wire. This wire specification is carefully designed, with a current carrying capacity not exceeding 0.5A, ensuring stable signal transmission while effectively preventing circuit failures caused by excessive current. Furthermore, the wire is treated with a silver-plated shielding layer. This process not only significantly reduces the wire impedance to no more than 50Ω but also effectively shields against external electromagnetic interference, ensuring the integrity of high-frequency signals. Testing shows that at an operating voltage of VCC=5V, the signal transmission delay is only 12ns, meeting the extremely high signal transmission speed requirements of applications such as high-speed data acquisition and high-frequency communication.

[0052] In practical application testing, the multi-channel analog switch 02 exhibits a signal transmission delay of only 12ns at an operating voltage of VCC=5V. This extremely short transmission delay allows the multi-channel analog switch 02 to quickly and accurately switch signals between different channels in high-speed data acquisition systems, ensuring that the acquisition device can obtain real-time data from multiple channels in a very short time, providing timely and accurate raw information for subsequent data processing and analysis.

[0053] From a microscopic perspective of circuit design, the multi-channel analog switch 02 integrates a large number of semiconductor devices and sophisticated electronic circuits. The electronic switch array is the core component for realizing signal switching functionality. These electronic switches typically employ semiconductor devices such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) or JFETs (Junction Field-Effect Transistors), switching between on and off states by controlling changes in the gate voltage. When a specific coded signal is input to the digital selector's S port, the internal control circuit generates a corresponding gate control voltage based on the coded information, precisely controlling the state of each switch in the electronic switch array, thereby achieving dynamic configuration of the signal transmission path.

[0054] Furthermore, the solid-state relay 05 employs an isolation structure based on optocoupler technology on its input side. One of the core performance indicators of this structure is the current transfer ratio (CTR), which is ≥50%. This optocoupler isolation method achieves electrical isolation between the input and output sides through the coordinated operation of gallium arsenide light-emitting diodes (LEDs) and photosensitive MOSFETs, effectively blocking the transmission path of interference signals between different circuits.

[0055] When the input current at the Y port reaches a threshold of ≥5mA, the gallium arsenide (GaAs) LED enters the on-state, converting electrical energy into light energy for emission. The emitted light signal illuminates the gate of the photosensitive MOSFET, triggering the photoelectric effect. Excited by the light signal, the gate of the photosensitive MOSFET generates an induced charge, causing the MOSFET channel to turn on. At this time, the on-resistance of the photosensitive MOSFET is strictly controlled at an extremely low level of ≤0.06Ω, providing a low-loss path for high current transmission on the load side.

[0056] Taking the application scenario of driving a 5V / 3A solenoid valve as an example, when the photosensitive MOSFET channel is turned on, the 5V external power supply forms a circuit with the solid-state relay 05 through the load pin, thereby driving the solenoid valve to work. During this process, the optocoupler isolation structure exhibits excellent electrical isolation performance, with an isolation voltage ≥5000Vrms. In complex industrial environments, this high isolation voltage can effectively suppress common-mode interference, avoid the influence of external interference signals on the control system, ensure the stable operation of load devices such as solenoid valves, and improve the anti-interference capability and reliability of the entire control system.

[0057] Example 1:

[0058] This embodiment is combined with the appendix Figure 1 and attached Figure 4 This invention provides a detailed description of the specific working process of the multiplexing switch device, including key steps such as signal selection, load driving, and fault protection.

[0059] In its design and implementation, the eight-way multiplexer integrates multi-dimensional low-power technologies and optimizes circuit design, demonstrating excellent low-power performance. Whether in standby or operating mode, its energy consumption is controlled at an extremely low level, providing an energy-efficient solution for cluster control of electronic devices.

[0060] The following is an eight-way multiplexing switch device ( Figure 4 Specific implementation examples:

[0061] Power on:

[0062] MUX1 enable pin Initializing to low level via NOT gate 03 (SN74LVC1G04DCKR) enables channel selection by default.

[0063] When the circuit is connected to a +5V power supply, the 74HC4051 multiplexer (MUX1) and solid-state relays 05 (SSR1-SSR4) enter standby mode.

[0064] Signal level configuration: The microcontroller sets the address selection signals (S0-S2) of MUX1 to a high-impedance state via GPIO pins to prevent accidental triggering upon power-up. NOT gate 03 Output a high level to ensure the SSR module's enable signal is active. It is in the off state to prevent malfunctions due to load.

[0065] Target channel selection: The microcontroller sends a 3-bit binary code to the S0-S2 pins of the MUX1. Setting S2=0, S1=1, and S0=0 (binary 010) selects the Y2 channel. The MUX1 internal switch connects the common terminal (Z) to the Y2 channel, with a signal transmission delay ≤12ns.

[0066] Signal transmission and current limiting protection: The Y2 output pin (04) of the multi-channel analog switch 02 is connected to the Y2 input pin of SSR1 through a 300Ω current-limiting resistor (R1-2) to limit the input current to a safe range of 5-30mA. The internal optocoupler (052) of SSR1 is turned on, driving the MOSFET output terminal (OUT2) to connect with the common terminal (COM) (053), and the external load is powered on and running. If multiple loads need to be controlled simultaneously, the microcontroller can switch the S0-S2 codes in a time-division multiplexing manner, and coordinate with the independent enable signal of the SSR module. Enables fast polling.

[0067] Enable latch-up: When an overcurrent or short circuit is detected, the microcontroller pulls MUX1 high. The SSR enable signal can be forcibly disabled via a pin or a NAND gate. NOT gate 03 converts the low level to a high level, immediately cutting off all channels of MUX1, achieving fast hardware-level protection.

[0068] Surge suppression: If the load is an inductive device (such as a relay coil), the 300Ω resistor (R1) connected in parallel with the SSR output (OUT2) absorbs the reverse electromotive force, limiting the voltage spike to within 1.5 times the rated value.

[0069] ESD and overvoltage protection: The MUX1 input pin has an embedded diode that can withstand instantaneous overvoltage (such as VCC+0.5V); the SSR optocoupler isolation structure prevents high voltage interference, with an isolation voltage ≥5000Vrms.

[0070] The specific assembly process of the eight-way multiplexing switch device:

[0071] 1. PCB board positioning: Fix the double-sided PCB board on the assembly table, ensuring that the component mounting side is facing upwards. Confirm the component mounting position according to the silkscreen markings (such as SSR1-SSR4, MUX1, NAND1, etc.), and pay attention to the orientation markings.

[0072] 2. Solid State Relay 05 (SSR) Installation: Insert four GAQW211G2EH solid state relays 05 (SSR1-SSR4) into the four corner 8-pin sockets (DIP-8 package) on the PCB. Ensure that pin 1 (marked Y0) of the SSR is aligned with the "Y0" silkscreen on the PCB, and the COM pin faces the edge of the board. Use a soldering station to fix the pins, first soldering the two diagonally opposite pins for positioning, and then completing the soldering of all pins.

[0073] 3. Installation of Multi-channel Analog Switch 02 (MUX1): Install the 74HC4051 chip (TSSOP16 package) to the central MUX1 position, ensuring that pin 1 (VCC) is aligned with the "+5V" marking on the PCB. Use a hot air gun for soldering, keeping the temperature below 260℃ to avoid overheating and damaging the chip.

[0074] 4. Logic Chip and Resistor Installation: Solder NOT gate 03 (SN74LVC1G04DCKR) to the NAND1 position, in the same direction as the silkscreen. Install current-limiting resistor R1-1 (300Ω 0805 package) to the trace path between MUX1 and SSR, using teardrop-shaped pads for reinforcement.

[0075] Power and ground wiring:

[0076] 1. Lead out the power supply line from the PCB power input (+5V) and connect it to the VCC pin (pin 16) of MUX1 and the VCC pin of the SSR (pin 8 of each SSR) first. The ground line (GND) adopts a star topology and connects to the GND pin (pin 8) of MUX1, the GND pin of NAND1, and the GND pin of the SSR (pin 5 of each SSR) respectively.

[0077] 2. Signal line connection: MUX1 output → SSR input, use 30AWG tin-plated wire to connect the input pins S0-S2 (01) of MUX1 to the corresponding output pins Y0-Y7 (04) of SSR. Connect each signal line in series with a 300Ω resistor, and place the resistor close to MUX1.

[0078] 3. Control Signal Connection: Connect the microcontroller's GPIO lines (S0-S2) to S0 (pin 11), S1 (pin 10), and S2 (pin 9) of the MUX1, with a line length ≤ 10cm. Connect the NOT gate 03 (SN74LVC1G04DCKR) input (pin 2) to the microcontroller. The signal output (pin 4) is connected to MUX1. (Pin 6)

[0079] 4. Load Terminal Handling: Lead the COM pin of the SSR (pin 4 of each SSR) to the terminal block using 16AWG wire, as the common terminal for the load. Connect OUT0-OUT7 (pin 3 of the SSR) to the load device. For inductive loads (such as motors), connect a 300Ω resistor (R1) in parallel for buffering.

[0080] 5. Welding and reinforcement processes:

[0081] (1) Welding specifications: Use 63 / 37 tin-lead solder wire, control the welding temperature at 300±20℃, and the welding time for each joint should be ≤3 seconds. Add solder to SSRs and high-current traces (such as COM terminals) to increase current carrying capacity.

[0082] (2) Mechanical reinforcement: Apply adhesive to the junction of the SSR's COM pin and the PCB to prevent the solder pads from falling off due to vibration. All external terminals are insulated with heat shrink tubing after crimping.

[0083] When the control terminal inputs different three-bit binary codes to the digital selection ports S0, S1, and S2 of the multiplex analog switch 02, and the NOT gate 03 enables the port... When the level is low (i.e., the multiplexer 02 is in the working state), the internal logic decoder 022 of the multiplexer 02 identifies and encodes the signal, activates the corresponding channel, and the common output terminal (Z) is connected to the corresponding independent output terminals (Y0-Y7), supplying a control current of ≤30mA to the input side of the solid-state relay 05 through the tinned copper wire. When the input current of the solid-state relay 05 reaches ≥5mA, its internal gallium arsenide light-emitting diode conducts, the photosensitive MOSFET channel opens, and the on-resistance drops to ≤0.06Ω. The 24V power supply drives the load device, such as the solenoid valve connected to this channel, to work through the load pin.

[0084] Throughout the operation, the optical coupling isolation structure ensures electrical isolation between the input and output sides, effectively suppressing common-mode interference; the current-limiting protection resistor 01 prevents voltage spikes from damaging the circuit when the inductive load is turned off; the bistable latching circuit composed of twisted-pair shielded wire and NOT gate 03 ensures the accuracy of signal transmission and the stability of system operation.

[0085] The digital selection ports S0, S1, and S2 of the multi-channel analog switch 02 are connected to the control terminal (the GPIO port of the microcontroller) to receive binary encoded signals. The common output terminal (Z) is connected in parallel to the input pins of eight solid-state relays 05 via 0.3mm wide tinned copper wire. Each wire is less than 15cm long and uses twisted-pair shielded cable with single-point grounding (grounding impedance ≤0.1Ω) to ensure signal consistency across channels and enhance electromagnetic interference immunity. The independent output terminals (Y0-Y7) of the eight solid-state relays 05 are connected to eight loads (eight 24V / 2A solenoid valves), and the load pins (pins 3-8) are connected to a 24V power supply, forming a complete drive circuit.

[0086] Input pin of NOT gate 03 Connect to the control terminal (control pin of the microcontroller), output pin Connect the enable port of the multi-channel analog switch 02 In standby mode, the control terminal will Set to low level, then toggled by NOT gate 03, A high level output ≥0.7VCC (i.e., 3.5V, when VCC=5V) triggers the internal latching circuit of the multiplexer 02, disconnecting all S-ports and Y-ports. At this time, the power consumption of the multiplexer 02 is ≤10μA. During operation, the control terminal will... Set to high level, Outputting a low level releases the multiplex analog switch 02 from latching, allowing the S port signal to control the Y port to conduct.

[0087] Finally, each component is packaged into a PCB. Figure 4 This design integrates multiple analog switches (02), eight solid-state relays (05), NOT gates (03), and protection resistors (01) onto a single double-layer PCB. A reasonable wiring scheme is employed: the multiple analog switches (02), NOT gates (03), and other logic control components are concentrated on one side of the PCB, while the solid-state relays (05) and their load connections are located on the other side, with electrical connections achieved through vias. Power lines and signal lines are isolated to reduce mutual interference, and critical signal lines are grounded to further enhance anti-interference performance.

[0088] Furthermore, the power consumption of the eight-way multiplexer is extremely low, approximately 0.5W. Compared to the power consumption of traditional multiplexers driving the same load, this eight-way multiplexer maintains a certain power consumption advantage through the selection of low-power components and optimized circuit design. Especially noteworthy is the continuation of its ultra-low power consumption characteristics in standby mode, giving it significant energy-saving advantages in intermittent operation or multi-device collaborative control scenarios.

[0089] The embodiments described above represent only one implementation of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A multiplexer switch for an intelligent laser system, characterized in that, include: A multi-channel analog switch (02) is used to receive command signals from the outside and control the conduction of a single channel; The multi-channel analog switch (02) is a multi-channel analog multiplexer / demultiplexer with a single-pole multi-throw switch structure and N digital selection input pins S0 to S1. n ,2 n+1 -1 output terminal Y n to Where N≥2; there is one common input / output terminal Z; 1 digital enable input pin in When the pin is low, the switch is allowed to turn on; when the pin is high, all switches are locked. Multiple solid-state relays (05) are connected to the output pins of the multi-channel analog switch (02) to receive the current signal output by the multi-channel analog switch (02) and control the on / off state of external electronic devices. The solid-state relays (05) are MOS output type and include: positive / negative input pins: connected to the output pins of the multi-channel analog switch (02) through a series current-limiting protection resistor (01). The current-limiting protection resistor (01) is used to limit the input current within the safe operating range of 5-30mA of the solid-state relay (05) to prevent overcurrent damage to the internal optocoupler structure or MOS device of the relay; positive / negative load pins: used to connect external loads with a load voltage ≤40V, a load current ≤6A, and an on-resistance ≤0.06Ω; and an input / output isolation voltage ≥5000Vrms. NOT gate (03), and the digital enable input pin of multiplex analog switch (02) The connection, with its input pin A connected to an external voltage level, is used to convert a low voltage level to a high voltage level and send it to the external voltage level when the switch is idle. Pin, locks the multiplex analog switch (02).

2. The multiplexing switch for an intelligent laser system as described in claim 1, characterized in that, The digital selection input pin of the multiplexer (02) supports a binary encoding gating mechanism, corresponding to gating 2. n+1 -1 output terminal Y n to The only channel in the system has a channel switching delay of ≤12ns when the power supply voltage is 5V.

3. A multiplexer for a smart laser system as described in claim 1, characterized in that, The operating temperature range of the multi-channel analog switch (02) is -40℃ to +125℃; the digital selection input pins S0 to S... n Supports logic level compatibility: When VCC = 2.0V to 6.0V, it is compatible with JEDEC standard logic levels, VIH ≥ 0.7 × VCC, VIL ≤ 0.3 × VCC; The on-resistance exhibits low nonlinearity with input voltage: when the input voltage is between 0 and V... CC -V EE Within the specified range, resistance fluctuation is ≤±15%.

4. A multiplexer for a smart laser system as described in claim 1, characterized in that, The on-resistance R of the multi-channel analog switch (02) ON With power supply voltage V CC -V EE Dynamic changes: 1) When V CC -V EE At 4.5V, the typical resistance is 80Ω, and the maximum resistance is 180Ω. 2) When V CC -V EE At 6.0V, the typical value is 70Ω, and the maximum value is 160Ω; 3) At room temperature, the deviation of conduction resistance between channels (ΔR) ON )≤9Ω.

5. A multiplexer for a smart laser system as described in claim 1, characterized in that, The solid-state relay (05) adopts an optically coupled isolation structure on its input side, with an input current I... F It has a linear relationship with the load conduction state: when I F When I is ≥5mA, the load side conducts; under a load voltage of 40V, when I F When the current is ≤0.5mA, the load side is turned off, and the leakage current in the off state is ≤0.1μA; the multi-channel analog switch (02) and the solid-state relay (05) adopt a differential wiring layout, the signal line spacing is ≥2 times the line width, and a 300Ω matching resistor is connected in series to suppress signal reflection. When the power supply voltage is 4.5V, the signal rise / fall slope is ≤139ns / V.

6. A multiplexer for a smart laser system as described in claim 1, characterized in that, The solid-state relay (05) supports surge current suppression on the load side: when an inductive load is connected, a resistor buffer circuit with R=300Ω is connected in parallel to the load pin to limit the voltage spike to within 1.5 times the rated value, thus protecting the MOS device.

7. A multiplexer for a smart laser system as described in claim 1, characterized in that, The multi-channel analog switch (02) has a communication baud rate of ≥1Mbps and supports real-time monitoring of the pin E level status of the multi-channel analog switch (02). In case of an abnormality, a hardware interrupt is triggered to lock all channels.

8. A multiplexer for a smart laser system as described in claim 4, characterized in that, The ESD protection performance of the multi-channel analog switch (02) meets the following requirements: 1) Human body discharge mode HBM≥2000V, device charging mode CDM≥1000V; 2) An embedded diode in the input pin allows the input voltage to momentarily exceed V. CC +0.5V without damaging the device.

9. A multiplexer for a smart laser system as described in claim 1, characterized in that, The solid-state relay (05) operates in a temperature range of -40°C to +85°C and a storage temperature range of -40°C to +100°C. In a high-temperature environment of 85°C, the load current is dated to 2.0A for continuous operation, and the on-resistance temperature rise is ≤30K.

10. A multiplexer for a smart laser system as described in claim 1, characterized in that, The solder joint between the protection resistor (01) and the input pin of the solid-state relay (05) adopts a teardrop-shaped solder pad design with a mechanical strength ≥2N·m and can withstand a reflow soldering temperature of 260℃.

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