A fully digital solid-state excitation light source for a spectrometer

Abstract

The application discloses a kind of all-digital solid-state excitation light source for spectrometer, including input module, for providing stable DC voltage and storage main excitation energy for subsequent circuit;Conversion module is connected the input module;Control module is connected and controls the conversion module, for generating driving signal;Ignition module is connected the input module and is controlled by the control module;Protection module is electrically connected between conversion module, ignition module and control module, for real-time monitoring system state and quickly cutting off system when fault.The application generates PWM signal by PLC controller combined with high-precision timer, and adopts voltage-current double-loop control algorithm, which significantly improves the stability of excitation energy, thereby ensuring the repeatability and accuracy of spectral analysis;Independent energy storage unit and perfect protection module ensure the safe and stable operation of the system under various working conditions, prolong the service life of equipment.

Description

Technical Field

[0001] This invention relates to the field of spectrometer technology, specifically to a fully digital solid-state excitation source for spectrometers. Background Technology

[0002] As a core device for rapid material composition analysis, direct-reading photoelectric spectrometers are widely used in metallurgy, machinery, aerospace, and other fields. Their detection accuracy and analytical efficiency directly depend on the performance of the excitation source. Traditional excitation sources often employ analog-controlled gas discharge tubes or thyristor drive architectures. However, some traditional excitation sources suffer from problems such as low control precision, making it difficult to achieve accurate matching of excitation energy; low power density, relying on traditional wound transformers, resulting in bulky size and low conversion efficiency; insufficient reliability, with weak anti-interference capabilities in analog circuits, leading to drift phenomena during long-term operation; poor ignition performance, often using power frequency transformers for step-up ignition, resulting in unstable ignition voltage and unreliable success rates in low-temperature or low-pressure environments; and poor input adaptability, as traditional light sources often rely on mains power input, making it difficult to meet the 24VDC low-voltage power supply requirements of portable spectrometers.

[0003] With the increasing demands for detection speed, accuracy, and equipment portability in materials analysis, the development of solid-state excitation sources with 24VDC low-voltage input, fully digital control, high power density, high reliability, and stable ignition performance has become a key direction for technological upgrading in the industry. Fully digital solid-state excitation sources achieve precise timing control through microcontrollers, and combined with advanced power electronic topologies and dedicated ignition power modules, they can significantly improve energy conversion efficiency, output stability, and ignition reliability. Simultaneously, they are adaptable to low-voltage power supply scenarios, reducing equipment size and laying the foundation for the intelligent and portable development of spectrometers. Summary of the Invention

[0004] The purpose of this invention is to provide a fully digital solid-state excitation light source that improves the energy conversion efficiency, output stability and ignition reliability of spectrometers, and is adaptable to low-voltage power supply scenarios, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A fully digital solid-state excitation source for a spectrometer, comprising: The input module is used to provide a stable DC voltage for subsequent circuits and store the main excitation energy; A conversion module, connected to the input module, is used to convert the stored DC power into high-frequency AC power and perform a boost conversion to output an adjustable main power voltage required to excite the sample. A control module, which connects to and controls the conversion module, is used to generate drive signals; An ignition module, which is connected to the input module and controlled by the control module, is used to generate a high-voltage pulse to break down the excitation electrode gap; The protection module is electrically connected to the conversion module, ignition module and control module, and is used to monitor the system status in real time and quickly shut down the system in case of a fault.

[0006] Furthermore, the input module includes a 24VDC input filter unit for connecting to low-voltage DC power and filtering out external ripple interference; the 24VDC input filter unit is equipped with a first energy storage unit, which is composed of low ESR capacitors connected in parallel, for storing the main excitation energy.

[0007] Furthermore, the conversion module includes a push-pull MOSFET switching network for connecting the energy storage unit and for converting DC power into a high-frequency square wave; the push-pull MOSFET switching network is equipped with a dual-plane transformer power conversion unit, the primary winding of which is connected to the MOSFET switching network for boosting and converting the high-frequency square wave and outputting main power excitation energy that is adjustable from 200VDC under no-load and 30-50VDC under load.

[0008] Furthermore, the dual-plane transformer power conversion unit adopts a PSPS cross-stacking structure.

[0009] Furthermore, the control module includes a PLC controller equipped with a high-precision timer.

[0010] Furthermore, the PLC controller has a built-in ignition timing control unit.

[0011] Furthermore, the ignition module includes a 400VDC ignition power supply unit, which is electrically connected to the input module; an ignition drive circuit is provided between the 400VDC ignition source unit and the control module.

[0012] Furthermore, the ignition module is equipped with a second energy storage unit.

[0013] Compared with the prior art, the beneficial effects of the present invention are: This invention generates PWM signals by combining a PLC controller with a high-precision timer and adopts a voltage and current dual closed-loop control algorithm, which significantly improves the stability of excitation energy, thereby ensuring the repeatability and accuracy of spectral analysis. The fully digital control core makes the setting and adjustment of excitation parameters extremely convenient and precise. The independent energy storage unit and the comprehensive protection module ensure the safe and stable operation of the system under various working conditions and extend the service life of the equipment. Attached Figure Description

[0014] Figure 1This is a block diagram of the overall structure of the present invention.

[0015] In the diagram: 1. Input module; 2. Conversion module; 3. Control module; 4. Ignition module; 5. Protection module; 6. 24VDC input filter unit; 7. First energy storage unit; 8. Push-pull MOSFET switching network; 9. Dual-plane transformer power conversion unit; 10. PLC controller; 11. High-precision timer; 12. Ignition timing control unit; 13. 400VDC ignition power supply unit; 14. Ignition drive circuit; 15. Second energy storage unit. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 The present invention provides a technical solution: A fully digital solid-state excitation source for a spectrometer, comprising: Input module 1 is connected to an external low-voltage DC power supply and provides a stable DC voltage for subsequent circuits and stores the main excitation energy. Input module 1 is the energy inlet and energy storage center of the system. Input module 1 includes a 24VDC input filter unit 6, which is used to connect to a stable external low-voltage DC power supply and filter out high-frequency ripple interference in the power grid through an EMI (electromagnetic interference) filter. The filter unit 6 is connected to a first energy storage unit 7 at its rear end. The first energy storage unit 7 is composed of multiple low ESR (equivalent series resistance) aluminum electrolytic capacitors or solid capacitors connected in parallel to form a huge charge pool, which is used to store the energy required for the main excitation and can provide a huge peak current at the moment of discharge.

[0018] Furthermore, as another embodiment of the present invention, in order to ensure the stability and safety of charging, the input module 1 may also be equipped with an independent charging management circuit, which can realize constant current charging of the first energy storage unit 7, and prevent the surge current at the moment of power-on from damaging the front-end circuit or affecting other devices.

[0019] Conversion module 2, connected to input module 1, is used to convert the stored DC power into high-frequency AC power and perform voltage boosting to output the adjustable main power voltage required to excite the sample; Furthermore, the conversion module 2 includes a push-pull MOSFET switching network 8, driven by the control module 3, which alternately turns on the DC power output from the first energy storage unit 7, converting it into a high-frequency AC square wave. This high-frequency AC square wave is then fed into the dual-plane transformer power conversion unit 9. Furthermore, the dual-plane transformer power conversion unit 9 adopts plane transformer technology, and its primary winding is connected to the push-pull MOSFET switching network 8; Furthermore, the dual-plane transformer power conversion unit 9 adopts a PSPS (primary-secondary-primary-secondary) cross-stacking structure. This structure can maximize the magnetic flux balance of the core, reduce leakage inductance, and improve the coupling coefficient, thereby efficiently boosting the high-frequency square wave voltage of the primary side. The output voltage of the conversion module 2 is controllable. It can reach 200VDC under no-load conditions, while under load (excitation electrode gap discharge), it can stably output 30-50VDC adjustable main power excitation energy according to the instructions of the control module 3.

[0020] Furthermore, as one embodiment of the present invention, the magnetic core of the dual-plane transformer power conversion unit 9 can be made of manganese-zinc ferrite PC95 with a turns ratio of 1:8. The windings can be made using a 2oz thick copper PCB etching process, and the leakage inductance is controlled between 0.1% and 1.5%. A dual complementary topology is adopted, that is, two plane transformers are symmetrically arranged, with the primary windings connected in series and the secondary windings connected in parallel, and they operate alternately at a switching frequency of 300kHz to cancel out the output ripple. The control module 3 connects to and controls the conversion module 2. The control module 3 uses a PLC controller 10 as the core control component. The PLC controller 10 has a built-in high-precision timer 11. The high-precision timer 11 can generate PWM signals with extremely high frequency and duty cycle accuracy to drive the push-pull MOSFET switching network 8 of the conversion module 2, thereby accurately controlling the output voltage. The high-precision timer is configured with a dead time of 56ns rise time delay and 52ns fall time delay, and the timer with an adjustable response time ≤0.3μs is used to generate a PWM signal with a frequency of 300kHz to control the main power conversion module. Furthermore, the PLC controller 10 also has an internally integrated ignition timing control unit 12, which is used to generate a precise ignition trigger signal and coordinate it precisely with the timing of the main power discharge to ensure that the main power energy can be injected in a timely and accurate manner at the moment the electrode gap is broken down, forming a stable excitation plasma; the ignition timing control unit 12 can use a TIM1 timer, configured in single-pulse mode, to generate an ignition control signal that is hardware synchronized with the main power drive signal, and output an ignition pulse width that is adjustable from 1 to 10 μs; The control module 3 also receives feedback signals from the protection module 5 and voltage and current sampling signals from the output terminal in real time, and adjusts the control strategy accordingly.

[0021] Ignition module 4, connected to input module 1 and controlled by control module 3, is used to generate a high voltage pulse to break down the excitation electrode gap; The ignition module 4 includes a 400VDC ignition power supply unit 13, which is electrically connected to the 24V output terminal of the input module 1. Through an internal DC-DC boost circuit, the 400VDC ignition power supply unit 13 can adopt a "Boost + voltage doubler rectification" topology, first boosting the 24VDC to 100VDC, and then obtaining a 400VDC high-voltage pulse through a two-stage voltage doubler circuit, which is stored in its equipped second energy storage unit 15 (usually a high-voltage capacitor). The energy required for ignition is pre-stored in the independent second energy storage unit 15. When ignition is needed, a strong current can be released instantaneously to generate a high-voltage pulse without drawing a large amount of current from the input module 1, thus avoiding voltage drop interference to the main power circuit during the ignition process. Furthermore, an ignition drive circuit 14 is provided between the ignition module 4 and the control module 3. When the ignition timing control unit 12 issues an ignition command, the ignition drive circuit 14 triggers a switching device (such as a silicon controlled rectifier or an IGBT (insulated gate bipolar transistor)) to instantly apply the 400VDC energy stored in the second energy storage unit 15 to the primary winding of the ignition coil (not shown in the figure) of the ignition module 4, thereby inducing a high voltage pulse of tens of thousands of volts in the secondary winding, breaking down the electrode gap. The ignition drive circuit can adopt an "optical isolation + totem pole amplification" architecture to receive the ignition timing control signal and drive the ignition power supply unit to work. Its transmission delay is ≤100ns, ensuring that the ignition response time is ≤10μs.

[0022] The protection module 5 is electrically connected to the conversion module 2, the ignition module 4 and the control module 3, and is used to monitor the system status in real time and quickly cut off the system in case of a fault. The protection module 5 monitors the working status of the conversion module 2, ignition module 4, and the entire system in real time (such as input overvoltage, input undervoltage, output overcurrent, module overheating, etc.) through voltage sensors, current sensors, and temperature sensors (not shown in the figure). Once any abnormality is detected, the protection module 5 will immediately send an interrupt signal to the control module 3. The control module 3 will then block the PWM drive signal and the ignition drive signal, quickly disconnecting the system to protect the core power devices and load safety.

[0023] Furthermore, the control module 3 can be configured with a dual closed-loop control strategy for voltage and current. Through feedback from the sampling and detection module, the voltage closed-loop strategy adopts a PID control algorithm to dynamically adjust the PWM duty cycle so that the load regulation rate of the main power conversion module is ≤0.4%. The current closed-loop strategy adopts amplitude limiting control, and automatically reduces the duty cycle to achieve overload protection when the output current exceeds a preset threshold.

[0024] Working Principle: In operation, after the system is powered on, the input module 1 connects to an external low-voltage DC power supply via the 24VDC input filter unit 6. The filtered DC power then charges the first energy storage unit 7 with a constant current through an independent charging management circuit until the first energy storage unit 7 stores sufficient excitation energy. Simultaneously, the 400VDC ignition power supply unit 13 in the ignition module 4 boosts the 24V DC power to 400VDC and charges the second energy storage unit 15, preparing for ignition. During this stage, the control module 3 completes initialization, setting the required excitation parameters (such as main power output voltage, discharge timing, etc.). When the spectrometer triggers the analysis command, the PLC controller 10 in the control module 3 sends an ignition trigger signal to the ignition module 4 through the ignition timing control unit 12 according to the preset ignition timing sequence. After being amplified by the ignition drive circuit 14, the trigger switch is turned on, instantly releasing the 400VDC high-voltage energy stored in the second energy storage unit 15 to the primary of the ignition coil. The secondary of the ignition coil induces a high-voltage pulse of tens of thousands of volts, which is applied to the excitation electrode gap of the spectrometer, causing it to break down instantly and forming the initial plasma channel. At the instant the electrode gap is broken down, the control module 3 immediately starts the main power output according to the precise timing preset by the ignition timing control unit 12. The PLC controller 10 generates a PWM drive signal through the high-precision timer 11, controlling the push-pull MOSFET switching network 8 in the conversion module 2 to alternately conduct in a high-frequency manner. The DC power stored in the first energy storage unit 7 is converted into a high-frequency square wave and sent to the dual-plane transformer power conversion unit 9 for boost conversion, outputting the preset main power excitation energy (usually adjustable from 30-50VDC under load).

[0025] During this process, control module 3 samples the output voltage and current in real time and executes a dual closed-loop control strategy for voltage and current. The outer voltage loop dynamically adjusts the PWM duty cycle through a PID algorithm to ensure that the output voltage remains highly stable when the discharge load fluctuates, with a load regulation rate ≤0.4%. The inner current loop monitors the output current in real time to prevent overcurrent. During the stable operation of the excitation source, the control module 3 continuously monitors the system status and adjusts the output parameters according to the preset excitation program. If multiple excitations or continuous analysis are required, the control module 3 can repeat the above ignition and main discharge process according to the set timing sequence to ensure the consistency and repeatability of each excitation. Throughout the operation, protection module 5 monitors the operating status of critical components in the system in real time using sensors such as voltage, current, and temperature. Upon detecting an anomaly (e.g., output overcurrent, overvoltage, module overheating, input undervoltage), protection module 5 immediately sends an interrupt signal to control module 3. Control module 3 then blocks all PWM drive signals and ignition drive signals, quickly cutting off the system output to protect power devices and the load. Once the fault is cleared, the system can resume normal operation.

[0026] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fully digital solid-state excitation light source for a spectrometer, characterized in that, include: Input module (1), which is used to provide a stable DC voltage and store the main excitation energy for subsequent circuits; The conversion module (2) is connected to the input module (1) and is used to convert the stored DC power into high-frequency AC power and perform voltage boosting to output the adjustable main power voltage required to excite the sample. Control module (3), which is connected to and controls conversion module (2), is used to generate drive signals; Ignition module (4), which is connected to the input module (1) and controlled by the control module (3), is used to generate a high voltage pulse to break down the excitation electrode gap; The protection module (5) is electrically connected to the conversion module (2), the ignition module (4) and the control module (3) and is used to monitor the system status in real time and quickly cut off the system in case of failure.

2. The all-digital solid state excitation light source for a spectrometer of claim 1, characterized in that, The input module (1) includes a 24VDC input filter unit (6) for connecting to low-voltage DC power and filtering out external ripple interference; the 24VDC input filter unit (6) is equipped with a first energy storage unit (7), which is composed of low ESR capacitors connected in parallel and is used to store the main excitation energy.

3. The all-digital solid state excitation light source for a spectrometer of claim 1, characterized by, The conversion module (2) includes a push-pull MOSFET switching network (8) for connecting to the first energy storage unit (7) and for converting DC power into a high-frequency square wave. The push-pull MOSFET switching network (8) is equipped with a dual-plane transformer power conversion unit (9), whose primary winding is connected to the MOSFET switching network for boosting the high-frequency square wave and outputting an adjustable main power excitation energy of 200VDC under no-load and 30-50VDC under load.

4. The all-digital solid state excitation light source for a spectrometer of claim 3, characterized in that, The dual-plane transformer power conversion unit (9) adopts a PSPS cross-stacking structure.

5. The all-digital solid state excitation light source for a spectrometer of claim 1, characterized by, The control module (3) includes a PLC controller (10) equipped with a high-precision timer (11).

6. The all-digital solid state excitation light source for a spectrometer of claim 5, characterized in that, The PLC controller (10) has an ignition timing control unit (12) built in.

7. The all-digital solid state excitation light source for a spectrometer of claim 1, characterized by, The ignition module (4) includes a 400VDC ignition power supply unit (13), and the 400VDC ignition source unit is electrically connected to the input module (1); an ignition drive circuit (14) is provided between the 400VDC ignition source unit and the control module (3).

8. The all-digital solid state excitation light source for a spectrometer of claim 7, characterized by, The ignition module (4) is equipped with a second energy storage unit (15).

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