A safety shutter driving control circuit

Abstract

The application provides a safety shutter driving control circuit, comprising an input protection unit, a pulse width modulation driving unit and a delay configuration unit; wherein the pulse width modulation driving unit is configured to output a direct current driving signal to an electromagnet load in a first period in response to a valid trigger level detected by a trigger signal detection end, so as to switch the safety shutter from a light blocking position to a light transmitting position, and switch the output pulse width modulation signal after the first period ends, so as to keep the safety shutter in the light transmitting position, and the length of the first period is determined by the delay configuration unit. Through the application, the direct current driving signal can provide sufficient suction force to drive the electromagnet to open the safety shutter in the first period, and the pulse width modulation signal is used to maintain the suction state of the electromagnet after the first period ends, so as to ensure the shutter response speed, greatly reduce the heat generated by the long-time power-on of the electromagnet, and reduce the influence of the heat on the laser light path and the control system accuracy.

Description

Technical Field

[0001] This application relates to the field of precision manufacturing technology, and more specifically, to a safety shutter drive control circuit. Background Technology

[0002] Lasers used in high-precision semiconductor equipment are classified as Class 4, meaning even scattered laser light can harm the eyes and skin. Therefore, installing a safety shutter in the laser path to prevent laser leakage is crucial. This safety shutter typically uses an electromagnet to drive a shutter. When the electromagnet is energized, it attracts a reed, causing the shutter to move away from the light path, allowing the laser to pass through normally. When the electromagnet is de-energized, the reed returns to its original position, blocking the light path and preventing laser output. During the initial energization phase, the electromagnet requires a large current to generate sufficient attraction force to move the shutter to the light-transmitting position. Once the shutter reaches the light-transmitting position, only a small current is needed to maintain the attraction.

[0003] Existing technologies typically apply a constant DC current to an electromagnet to keep the shutter open. This method causes the electromagnet coil to carry a large current for an extended period, generating a significant amount of heat. This heat is then conducted to the laser optical path, affecting the stability and control precision of the optical system. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a safe shutter drive control circuit that overcomes at least one of the above-mentioned defects.

[0005] In a first aspect, this application provides a safe shutter drive control circuit, including an input protection unit, a pulse width modulation drive unit, and a delay configuration unit; The drive signal output terminal of the pulse width modulation drive unit is used to drive the electromagnet load of the safety shutter to control the opening and closing of the safety shutter. The power supply pin of the pulse width modulation drive unit is connected to the internal power supply terminal of the input protection unit, and the delay configuration unit is connected to the delay configuration terminal of the pulse width modulation drive unit. The pulse width modulation driving unit is configured to, in response to a valid trigger level detected by the trigger signal detection terminal of the pulse width modulation driving unit, output a DC driving signal to the electromagnet load during a first time period, causing the safety shutter to switch from a light-blocking position to a light-transmitting position, and switch to output a pulse width modulation signal after the first time period ends, so that the safety shutter remains in the light-transmitting position. The duration of the first time period is determined by the delay configuration unit.

[0006] In one possible implementation, the delay configuration unit includes: A first capacitor, the first end of which is connected to the delay configuration terminal of the pulse width modulation driving unit, and the second end of which is grounded, wherein the duration of the first time period is determined according to the capacitance value of the first capacitor.

[0007] In one possible implementation, the pulse width modulation driving unit further includes a duty cycle configuration terminal; The circuit further includes a duty cycle configuration unit, which is connected to the duty cycle configuration terminal of the pulse width modulation driving unit and is used to set the duty cycle of the pulse width modulation signal.

[0008] In one possible implementation, the duty cycle configuration unit includes a first resistor; The first end of the first resistor is connected to the duty cycle configuration terminal of the pulse width modulation driving unit, and the second end of the first resistor is grounded.

[0009] In one possible implementation, the pulse width modulation driving unit further includes a frequency configuration terminal; The circuit further includes a frequency configuration unit, which is connected to the frequency configuration terminal of the pulse width modulation driving unit and is used to set the output frequency of the pulse width modulation signal.

[0010] In one possible implementation, the frequency configuration unit includes: The second resistor has its first end connected to the frequency configuration terminal of the pulse width modulation driving unit, and its second end grounded.

[0011] In one possible implementation, the pulse width modulation driving unit further includes a fault indication terminal; The safety shutter drive control circuit also includes a fault indication unit, which is connected to the fault indication terminal of the pulse width modulation drive unit and is used to indicate the over-temperature fault or over-current fault of the pulse width modulation drive unit.

[0012] In one possible implementation, the fault indication unit includes a third resistor and a light-emitting diode; The first end of the third resistor is connected to the fault indication terminal of the pulse width modulation driving unit, the second end of the third resistor is connected to the positive terminal of the light-emitting diode, and the negative terminal of the light-emitting diode is grounded.

[0013] In one possible implementation, the input protection unit includes a reverse protection diode; The anode of the anti-reverse diode is used to receive external power input, and the cathode of the anti-reverse diode is connected to the internal power supply terminal.

[0014] In one possible implementation, the input protection unit further includes a trigger signal input terminal and a clamping diode; The cathode of the clamping diode is connected to the trigger signal input terminal, and the anode of the clamping diode is connected to the drive signal output terminal.

[0015] This application provides a safe shutter drive control circuit, including an input protection unit, a pulse width modulation drive unit, and a delay configuration unit. The pulse width modulation drive unit is configured to output a DC drive signal through a drive signal output terminal during a first time period after a valid trigger level is detected at the trigger signal detection terminal, and to output a pulse width modulation signal through the drive signal output terminal after the first time period ends. This application enables the DC drive signal to provide sufficient attraction force to drive the electromagnet to open the safe shutter during the first time period, and to maintain the electromagnet's attraction state after the first time period ends. This significantly reduces the heat generated by the electromagnet during prolonged energization while ensuring shutter response speed, thus minimizing the impact of heat on the laser optical path and the accuracy of the control system.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural schematic diagram of the safe shutter light-blocking position provided in an embodiment of this application; Figure 2 This is a structural schematic diagram of the safe shutter light transmission position provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the safety shutter drive control circuit provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the input protection unit provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the pulse width modulation driving unit and the delay configuration unit provided in the embodiments of this application; Figure 6 This is a schematic diagram showing the connection between the safety shutter drive control circuit and the overall safety PLC system provided in the embodiments of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. Based on the embodiments of this application, every other embodiment obtained by those skilled in the art without inventive effort falls within the scope of protection of this application.

[0020] First, the applicable scenarios for this application will be introduced. This application can be applied to the technical field of precision manufacturing.

[0021] Research has found that the laser wavelengths of lasers used in high-precision semiconductor equipment can harm the human body, with the most severe damage occurring in the eyes. Industrial lasers are classified as Class 4, meaning even scattered laser light can cause damage to the eyes and skin. Therefore, adding a laser safety shutter to lasers used in semiconductor equipment is particularly important. The laser safety shutter needs to open quickly when the laser is in use and close quickly when it is not in use; only a rapid response from the safety shutter can prevent laser leakage and subsequent harm.

[0022] A safety shutter is used in the optical path of a laser to close the shutter in emergency situations to prevent laser leakage. Under normal circumstances, the shutter is open, and the optical path transmits normally. The safety shutter has a flat, rectangular box structure containing a 24VDC electromagnet. A square hole in the center of the box is designed for laser transmission, and a light-blocking plate is installed on the hole, driven by a long, thin spring. When the electromagnet is energized, the spring is attracted to the electromagnet's end face, and the plate position completely exposes the square hole, allowing the laser to pass through normally (light-transmitting position). When the electromagnet is de-energized, the spring carrying the plate returns to its original position, and the plate is in the light-blocking position.

[0023] Figure 1 The structure of the safe shutter light-blocking position is demonstrated. When the safe shutter is in the light-blocking position, the electromagnet does not need to attract the spring, the spring is in its normal position, the light-blocking sensor is a microswitch with a pressure-sensing spring, the light-blocking sensor signal is valid, indicating the light-blocking position. Figure 2 The structure of the light-transmitting position of the safety shutter is shown. When the safety shutter is in the light-transmitting position, the electromagnet needs to attract the reed to... Figure 2At the indicated position, the baffle travel is 20mm. The light transmission sensor is a microswitch with a pressure-sensing spring. The light transmission sensor signal indicates that this position is light-transmitting. The electromagnet's driving capability at this light-transmitting position requires continuous energization, which can cause the electromagnet to overheat, thus affecting the optical signal.

[0024] Electromagnets are typically used to drive the shutter blades to open and close. When a driving current is applied to the electromagnet, it moves the shutter blades to a set distance, opening the laser light path exit, allowing the laser to emit light normally. When the driving current is disconnected, the electromagnet drives the shutter blades back to their initial position, closing the laser light path exit, and the laser light path is shut down.

[0025] When the safety shutter is open, the electromagnet will overheat due to prolonged energization. This heat will affect the laser optical path and the accuracy of the control system. Therefore, it is necessary to study the control method of the electromagnet to minimize the heat generated after energization, reducing its impact, while maintaining its driving capability to reliably drive the safety blade to open and close, and to maintain a stable open state when the shutter is open. Meanwhile, the overall safety interlock of high-precision semiconductors is a crucial safety protection strategy. How to incorporate the safety shutter as a prerequisite for the overall safety interlock of semiconductor equipment to enhance the overall safety of the device is also a problem that needs to be solved.

[0026] Existing technologies related to shutter speed or safe shutter speed are generally applied to image capture. These technologies describe determining the safe shutter speed based on the speed of the moving object, with different speeds corresponding to different safe shutter speeds. Adjusting the shutter speed based on this safe shutter speed aims to capture blur-free, motion-free images, effectively improving image sharpness. Other existing technologies disclose acquiring image data and corresponding shutter speed information from a mobile terminal, analyzing the sharpness of each image, statistically determining the correspondence between shutter speed information and sharpness, and then using this correspondence to determine the safe shutter speed range for automatic exposure. Since the safe shutter speed is within this range, re-determining this range allows for adjustment of the safe shutter speed, resulting in a suitable safe shutter speed for different users. This, in turn, allows for adjustments to the automatic exposure strategy to adapt to different users' shooting habits, effectively improving the image quality of images captured by different users.

[0027] Existing technologies largely focus on electromagnet manufacturing processes, coil anti-loosening designs, measurement of motion displacement of electromagnets, and application design. Existing technologies disclose the ability to measure the attraction force and motion displacement of an electromagnet using a single measuring mechanism. Since a corresponding attraction force value exists for any motion displacement, the magnitude of the electromagnet's attraction force can be accurately measured. Another existing technology discloses a time-delay electromagnet and a circuit breaker using this electromagnet. The electromagnet includes an electromagnet assembly and a current transformer assembly connected to the main circuit. The current transformer assembly is connected to the electromagnet assembly via a time delay device, controlling the main circuit or the load equipment connected to the main circuit, thereby achieving an automatic start-up effect. This belongs to the application design of electromagnets.

[0028] Existing technologies have the following objective drawbacks. First, shutter adjustment methods in image capture, which determine the safe shutter speed based on the target object's movement speed (different speeds correspond to different safe shutter speeds) and improve image quality through shutter speed information corresponding to image data, cannot address the response speed issue of the safe shutter in semiconductor devices. Second, when using electromagnets as the drive mechanism, existing technologies primarily consider the electromagnet's attraction force and control, but fail to address the heat generated by the electromagnet itself. The heat generated by the electromagnet during prolonged operation can affect the laser optical path and the accuracy of the control system. Third, existing technologies do not integrate the detection of the safe shutter's opening and closing status with the overall safety interlock system in a closed-loop manner. The actual state of the safe shutter cannot be monitored and alarmed in real time by the overall safety system, posing a safety hazard.

[0029] Based on this, embodiments of this application provide a safety shutter drive control circuit to solve the driving and control problem of laser safety shutters in high-precision semiconductor equipment.

[0030] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a safety shutter drive control circuit according to an embodiment of this application, including an input protection unit 100, a pulse width modulation drive unit 200, and a delay configuration unit 300.

[0031] The pulse width modulation drive unit 200 includes a trigger signal detection terminal and a drive signal output terminal. The drive signal output terminal is used to connect to the electromagnet load that drives the safety shutter to control the opening and closing of the safety shutter. The power supply pin of the pulse width modulation drive unit 200 is connected to the internal power supply terminal of the input protection unit 100. The delay configuration unit 300 is connected to the delay configuration terminal of the pulse width modulation drive unit 200.

[0032] The pulse width modulation drive unit 200 is configured to output a DC drive signal to the electromagnet load during a first time period in response to a valid trigger level detected by the trigger signal detection terminal, so that the safety shutter switches from the light-blocking position to the light-transmitting position, and switches to output a pulse width modulation signal after the first time period ends so that the safety shutter remains in the light-transmitting position. The duration of the first time period is determined by the delay configuration unit 300.

[0033] Specifically, the input protection unit 100 is the interface between the circuit and the external power supply and control signals. It receives external power supply and drive trigger signals and provides a safe power supply path to the pulse width modulation drive unit 200. The input protection unit 100 has a reverse connection protection function. When the positive and negative terminals of the external power supply are reversed, the input protection unit 100 blocks the current path to prevent damage to the subsequent circuit due to reverse voltage. The input protection unit 100 also has a voltage spike suppression function, which can absorb the high-voltage transient interference generated by the electromagnet load during the switching process.

[0034] The pulse width modulation (PWM) drive unit 200 is the drive control section of the circuit. Its trigger signal detection terminal receives externally input drive command signals. When a valid trigger level is detected, the PWM drive unit 200 enters the working state. The drive signal output terminal provides drive current to the electromagnet load, and the power supply pin obtains its operating voltage from the internal power supply terminal of the input protection unit 100.

[0035] The delay configuration unit 300 is a timing control component that works in conjunction with the pulse width modulation drive unit 200, and is connected to the delay configuration terminal of the pulse width modulation drive unit 200. When the pulse width modulation drive unit 200 enters the working state, the delay configuration unit 300 performs timing according to its set parameters, and after the timing ends, it triggers the pulse width modulation drive unit 200 to switch the output mode.

[0036] The principle behind this working method is that the electromagnet load requires a large current in the initial stage of power-on to generate sufficient attraction force to drive the shutter's shutter to the light-transmitting position. Once the shutter reaches the light-transmitting position, only a small holding current is needed to maintain the attracted state. If the large initial current is continuously supplied, the electromagnet coil will generate a large amount of heat. By outputting a DC drive signal during the first time period to ensure reliable electromagnet engagement, and then switching to a pulse width modulation (PWM) signal after the first time period ends to reduce average power consumption, the response speed of the shutter is maintained while significantly reducing electromagnet heating. The PWM signal reduces the average current flowing through the electromagnet coil through high-frequency switching, allowing the electromagnet's armature to maintain a stable attracted state due to mechanical inertia and hysteresis.

[0037] This application uses a pulse control circuit and a delay control circuit to drive the electromagnet's attraction action, ensuring the electromagnet's response time while reducing its heat generation. This achieves a high response speed for the safety shutter, reaching an overall response time of 26ms, and realizes direct drive of the safety shutter, reducing its heat generation by more than 70%. The overall safety interlock of high-precision semiconductors is a crucial safety protection strategy. This application enhances the overall safety of the equipment by making the safety shutter a prerequisite for the overall safety interlock of the semiconductor device.

[0038] This application designs an interface circuit for a safe shutter control system and incorporates a reverse connection protection design for the 24VDC power supply circuit. The interface circuit features a PWM output interface, a +24V power supply interface, and a PWM drive circuit signal trigger interface. The external trigger signal is a 24VDC signal, which is divided by the circuit to obtain a trigger signal of approximately 5V. This signal can trigger the pulse width modulation drive unit 200 to operate.

[0039] Please see Figure 4 , Figure 4 This is a schematic diagram of the input protection unit 100 according to an embodiment of this application. Figure 4 As shown in the figure, this application ensures that the 24VDC power supply interface, DRV drive trigger interface, and PWM signal output interface are all connected to the J1 terminal of the connector through the interface circuit design.

[0040] The input protection unit 100 includes a reverse protection diode D1. The anode of the reverse protection diode D1 is used to receive external power input, and the cathode of the reverse protection diode D1 is connected to the internal power supply terminal. Pins 1 and 2 of connector J1 are connected to the GND ground line for common grounding. Pin 3 of connector J1 is connected to the anode of the reverse protection diode D1. Pin 4 of connector J1 is the DRV IN drive signal input terminal. Pin 5 of connector J1 is the PWM OUT signal terminal. The reverse protection diode D1 is designed at the power supply terminal of the interface circuit to form a reverse connection protection circuit, ensuring that the core circuit will not be damaged when the power supply is reversed.

[0041] The input protection unit 100 also includes a trigger signal input terminal and a clamping diode D2. The trigger signal input terminal corresponds to pin 4 of connector J1, i.e., DRV IN. The cathode of the clamping diode D2 is connected to the trigger signal input terminal, and the anode of the clamping diode D2 is connected to the drive signal output terminal, i.e., PWM OUT, to suppress voltage spikes generated by the electromagnet load during the switching process.

[0042] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of the pulse width modulation driving unit 200 and the delay configuration unit 300 according to an embodiment of this application. Figure 5As shown, this application uses a dedicated PWM driver chip DRV103H4 as the core of the safety shutter drive control. Interface circuits, start-up delay circuits, over-temperature and over-current fault indication circuits, PWM output duty cycle adjustment circuits, PWM output frequency adjustment circuits, and power supply reverse connection protection circuits are designed to collectively constitute the safety shutter drive circuit. The electromagnet voltage used in the safety shutter is 24VDC, and the starting current is 1.2A. To ensure that the electromagnet can generate sufficient attraction force when starting under load, a current drive capability greater than twice that of the electromagnet is considered when selecting the driver chip to ensure reliable engagement. The output current of the DRV103H4 chip can reach 3A.

[0043] Pin 1 of the DRV103H4 is the duty cycle configuration pin, pin 2 is the delay configuration pin, pin 3 is the frequency configuration pin, pin 4 is grounded, pin 5 is the drive signal output pin, pin 6 is the power supply pin, pin 7 is the fault indication pin, and pin 8 is the trigger signal detection pin.

[0044] The delay configuration unit 300 includes a first capacitor C1. The first terminal of the first capacitor C1 is connected to pin 2 of the DRV103H4, and the second terminal of the first capacitor C1 is grounded. The duration of the first time period is determined based on the capacitance value of the first capacitor C1. By changing the capacitance value of the first capacitor C1, the delay time can be adjusted. When the capacitance value of the first capacitor C1 varies between 100pF and 10μF, the circuit startup delay time can vary between 110μs and 11s. When the first capacitor C1 is 1nF, the corresponding delay time is 1.1ms; when the first capacitor C1 is 10nF, the corresponding delay time is 11ms; when the first capacitor C1 is 100nF, the corresponding delay time is 110ms; and when the first capacitor C1 is 1μF, the corresponding delay time is 1.1s. Additionally, by connecting a +5V signal to pin 2 of the DRV103H4, the delay time can be set to a fixed value of 1μs. If pin 2 is left floating, the delay time will be set to 18μs.

[0045] The pulse width modulation (PWM) drive unit 200 also includes a duty cycle configuration terminal, corresponding to pin 1 of the DRV103H4. The duty cycle configuration unit includes a first resistor R6. The first terminal of the first resistor R6 is connected to pin 1 of the DRV103H4, and the second terminal of the first resistor R6 is grounded. The duty cycle of the pulse width modulation signal is adjusted by changing the resistance value of the first resistor R6, and the duty cycle can be adjusted between 5% and 95%. Different duty cycles correspond to different resistance values ​​at different frequencies. At a 30% duty cycle, the resistance is configured to 374KΩ for a 5kHz frequency, 110KΩ for a 25kHz frequency, and 26.1KΩ for a 100kHz frequency.

[0046] The pulse width modulation (PWM) drive unit 200 also includes a frequency configuration terminal, corresponding to pin 3 of the DRV103H4. The frequency configuration unit includes a second resistor R4. The first terminal of the second resistor R4 is connected to pin 3 of the DRV103H4, and the second terminal of the second resistor R4 is grounded. The output frequency of the PWM signal is adjusted by changing the resistance value of the second resistor R4, and the frequency range can vary between 500Hz and 100kHz. When the second resistor R4 is 47.5KΩ, the signal frequency can be adjusted to 100kHz; when it is 100KΩ, the signal frequency can be adjusted to 50kHz; when it is 205KΩ, the signal frequency can be adjusted to 25kHz; when it is 523KΩ, the signal frequency can be adjusted to 10kHz; when it is 1.07MΩ, the signal frequency can be adjusted to 5kHz; and when it is 11.3MΩ, the signal frequency can be adjusted to 500Hz.

[0047] The pulse width modulation drive unit 200 also includes a fault indication terminal, corresponding to pin 7 of the DRV103H4. The fault indication unit includes a third resistor R5 and a light-emitting diode (LED1). The first end of the third resistor R5 is connected to pin 7 of the DRV103H4, and the second end of the third resistor R5 is connected to the positive terminal of the LED1. The negative terminal of the LED1 is grounded. Connecting the LED1 to pin 7 of the DRV103H4 and then connecting it in series with a resistor to the 24VDC power supply indicates over-temperature and over-current faults in the circuit.

[0048] Pin 8 of the DRV103H4 is connected to a voltage divider circuit consisting of resistors R2 and R3. Resistor R2 is 5.62KΩ, and resistor R3 is 18.7KΩ. When the input of the voltage divider circuit is 24VDC, the output voltage is 5.5V. This voltage is connected to pin 8 to control the generation of a PWM waveform signal at the output. This PWM output signal, along with the 24VDC signal, is connected to both ends of an electromagnet, enabling the electromagnet to drive the safety shutter to open and close.

[0049] Pin 6 of the DRV103H4 is connected to a +24VDC power input. Three filter capacitors, C2, C3, and C4, are connected in parallel between pin 6 and ground. These three capacitors are usually matched with different capacitance values ​​to filter out interference in different frequency bands. The other end of each of the three capacitors is grounded.

[0050] Please see Figure 6 , Figure 6 This is a schematic diagram showing the connection between the safety shutter drive control circuit and the overall safety PLC system according to an embodiment of this application. Figure 6As shown in the diagram, this application designs a safety shutter status detection circuit. The detection sensor is a 24V proximity sensor, and the opening and closing status of the safety shutter can be transmitted to the overall safety PLC system via the sensor detection signal. The safety PLC communicates with the host computer or master control system via an EtherCAT interface on the left side of the station. The two In input ports of the PLC receive shutter status detection sensor signal 1 and shutter status detection sensor signal 2 from the field, respectively, to detect the actual position or status of the shutter, achieving dual redundancy safety detection. One Out output port of the PLC sends a safety shutter trigger signal DRV OUT. The DRV OUT signal sent by the PLC directly corresponds to the physical connection. Figure 4 and Figure 5 The DRV IN input port drives the subsequent hardware circuitry to control the shutter's electromagnet. The overall safety detection system can promptly detect the safe shutter status and issue alarms for erroneous conditions.

[0051] The safety shutter drive control circuit provided in this application features a PWM drive circuit with adjustable start-up delay, over-temperature and over-current fault indication, PWM output duty cycle adjustment, PWM output frequency adjustment, reverse connection protection, and electromagnet freewheeling function. After startup, the circuit switches to PWM drive mode after a settable delay time. Based on the circuit duty cycle, it maintains the safety state of the shutter and significantly reduces electromagnet heating, thereby minimizing the impact of the heat generated by the electromagnet on the laser optical path and the accuracy of the control system.

[0052] The designed start-up delay circuit allows for adjustment of the delay time by varying the capacitance of the first capacitor C1, making it suitable for different start-up delay scenarios. The designed PWM wave frequency and duty cycle adjustable circuits are applicable to scenarios with varying duty cycle and PWM wave frequency requirements, broadening the circuit's application range. An innovative dedicated PWM pulse delay drive circuit with adjustable duty cycle and frequency allows for 0% to 100% duty cycle adjustment and 500Hz to 100kHz frequency adjustment, enhancing the adaptability of the control circuit. The circuit is simple to construct and debug, possesses strong driving capability, and has a low failure rate, improving the reliability of the safety shutter drive circuit.

[0053] The designed safety shutter detection circuit can detect the opening and closing status of the safety shutter through sensors and feed back to the overall safety system. Closed-loop detection further enhances the safety of the safety shutter drive system. By incorporating a system-wide safety interlock into the safety shutter control circuit, the safety of the equipment is enhanced.

[0054] Regarding alternative solutions, the driver chip used is the DRV103H4 chip. Corresponding alternative chips are available, and output current amplification designs can be implemented for different loads to achieve the driving function of high-current electromagnets. However, the circuit architecture is one of the core components of this application and cannot be replaced. The resistors and capacitors used in this application are all general-purpose low-power resistors, capacitors, diodes, and connectors; these are general-purpose components, and domestically produced components can be used as substitutes. This application suppresses power fluctuations and improves the reliability of circuit operation by designing anti-reverse and freewheeling circuits, as well as power filtering circuits.

[0055] Compared with existing technologies, this application innovatively designs a dedicated PWM pulse delay drive circuit with adjustable duty cycle and frequency, enabling 0%-100% duty cycle adjustment and 500Hz-100KHz frequency adjustment. This improves the adaptability of the control circuit, achieves a high response speed for the safety shutter, reaches an overall response time of 26ms, and innovatively realizes direct drive of the safety shutter, reducing the heat generation of the safety shutter by more than 70%.

[0056] The safety shutter PWM drive circuit designed in this application can switch to PWM drive mode after a settable delay time after circuit startup. Based on the circuit duty cycle, it can maintain the safe state of the shutter and significantly reduce electromagnet heating, thus minimizing the impact of electromagnet-generated heat on the laser optical path and the accuracy of the control system. The designed startup delay circuit allows adjustment of the circuit delay time by changing the capacitance value, making it suitable for different startup delay scenarios. The designed adjustable PWM wave frequency and duty cycle circuits are applicable to scenarios with different duty cycle and PWM wave frequency requirements, broadening the circuit's application range. The circuit is simple to construct and debug, has strong driving capability, and a low failure rate, improving the reliability of the safety shutter drive circuit. The designed safety shutter detection circuit can detect the opening and closing status of the safety shutter through a sensor and feed it back to the overall safety system. Through closed-loop detection, the safety of the safety shutter drive system is further enhanced.

[0057] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0058] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0059] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0060] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0061] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0062] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The scope of protection of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A safety shutter drive control circuit, characterized in that, It includes an input protection unit, a pulse width modulation drive unit, and a delay configuration unit; The drive signal output terminal of the pulse width modulation drive unit is used to drive the electromagnet load of the safety shutter to control the opening and closing of the safety shutter. The power supply pin of the pulse width modulation drive unit is connected to the internal power supply terminal of the input protection unit, and the delay configuration unit is connected to the delay configuration terminal of the pulse width modulation drive unit. The pulse width modulation driving unit is configured to, in response to a valid trigger level detected by the trigger signal detection terminal of the pulse width modulation driving unit, output a DC driving signal to the electromagnet load during a first time period, causing the safety shutter to switch from a light-blocking position to a light-transmitting position, and switch to output a pulse width modulation signal after the first time period ends, so that the safety shutter remains in the light-transmitting position. The duration of the first time period is determined by the delay configuration unit.

2. The circuit according to claim 1, characterized in that, The delay configuration unit includes: A first capacitor, the first end of which is connected to the delay configuration terminal of the pulse width modulation driving unit, and the second end of which is grounded, wherein the duration of the first time period is determined according to the capacitance value of the first capacitor.

3. The circuit according to claim 1, characterized in that, The pulse width modulation driving unit also includes a duty cycle configuration terminal; The circuit further includes a duty cycle configuration unit, which is connected to the duty cycle configuration terminal of the pulse width modulation driving unit and is used to set the duty cycle of the pulse width modulation signal.

4. The circuit according to claim 3, characterized in that, The duty cycle configuration unit includes a first resistor; The first end of the first resistor is connected to the duty cycle configuration terminal of the pulse width modulation driving unit, and the second end of the first resistor is grounded.

5. The circuit according to claim 1, characterized in that, The pulse width modulation driving unit also includes a frequency configuration terminal; The circuit further includes a frequency configuration unit, which is connected to the frequency configuration terminal of the pulse width modulation driving unit and is used to set the output frequency of the pulse width modulation signal.

6. The circuit according to claim 5, characterized in that, The frequency configuration unit includes: The second resistor has its first end connected to the frequency configuration terminal of the pulse width modulation driving unit, and its second end grounded.

7. The circuit according to claim 1, characterized in that, The pulse width modulation driving unit also includes a fault indication terminal; The safety shutter drive control circuit also includes a fault indication unit, which is connected to the fault indication terminal of the pulse width modulation drive unit and is used to indicate the over-temperature fault or over-current fault of the pulse width modulation drive unit.

8. The circuit according to claim 7, characterized in that, The fault indication unit includes a third resistor and a light-emitting diode; The first end of the third resistor is connected to the fault indication terminal of the pulse width modulation driving unit, the second end of the third resistor is connected to the positive terminal of the light-emitting diode, and the negative terminal of the light-emitting diode is grounded.

9. The circuit according to claim 1, characterized in that, The input protection unit includes a reverse protection diode; The anode of the anti-reverse diode is used to receive external power input, and the cathode of the anti-reverse diode is connected to the internal power supply terminal.

10. The circuit according to claim 1, characterized in that, The input protection unit also includes a trigger signal input terminal and a clamping diode; The cathode of the clamping diode is connected to the trigger signal input terminal, and the anode of the clamping diode is connected to the drive signal output terminal.

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