Exploration of Low-Power Solutions for High-Voltage Power Supplies in Exposure Machines

In industries such as semiconductor manufacturing, printed circuit board (PCB) production, and flat-panel display fabrication, exposure machines are critical equipment. Their core light sources—such as ultra-high-pressure mercury lamps—require stable and reliable high-voltage power supplies for operation. Traditional high-voltage power supplies suffer from issues like high power consumption, significant heat generation, and low efficiency. With increasing demands for energy conservation and environmental protection, exploring low-power solutions for high-voltage power supplies in exposure machines is of great practical importance. This article discusses the technical principles, implementation paths, and application advantages of low-power design for high-voltage power supplies.
Technical Principles of Low-Power Design
The core of low-power design for high-voltage power supplies in exposure machines lies in optimizing the energy conversion path and reducing unnecessary losses. Traditional linear voltage regulation circuits endure high voltage differences, resulting in substantial thermal dissipation. Modern solutions adopt switching mode power supply (SMPS) technology combined with intelligent control strategies to achieve high-efficiency conversion.
An effective technical approach is a combination of a startup circuit and a feedback power supply circuit. During the system startup phase, the high voltage initially powers the drive circuit through current-limiting methods such as an RC circuit. Once the magnetron or lamp operates normally, the alternating current signal generated is rectified to provide feedback power to the drive circuit, while the startup circuit is cut off. This significantly shortens the conduction time of the high-voltage step-down circuit, fundamentally reducing power consumption and heat generation.
Key Implementation Solutions
1.  Intelligent Switching of Power Supply Path: By introducing switching elements (e.g., MOSFETs) and supplementing with voltage detection and judgment circuits, the load voltage is monitored in real time. The switch conducts during startup and promptly turns off after completion, with feedback energy sustaining system operation. This design minimizes the heating time of the startup resistor, significantly enhancing safety and efficiency.
2.  Efficient Voltage Regulation Control: Abandoning traditional high-power-consumption linear voltage regulation devices (e.g., Zener diodes), an active voltage regulation circuit based on a hysteresis comparator and MOSFET is adopted. This solution enables more precise voltage control, avoiding device damage due to inaccurate current control, thereby improving system reliability.
3.  Soft-Switching and Resonant Technologies: Applying quasi-resonant operation and valley switching technology in power converters. By allowing the switch to turn on at the lowest voltage point (valley), switching losses and electromagnetic interference (EMI) are effectively reduced. This is particularly effective for energy savings in high-voltage conversion scenarios.
4.  Standby Power Management: When the exposure machine is on standby, the high-voltage light source is inactive, but some circuits still require power. Using zero-standby-power chip technology, power supply to optocouplers and synchronous rectifiers can be cut off via protocol control, reducing system standby power consumption to the milliwatt level (e.g., <5mW), meeting stringent energy efficiency standards.
Application Advantages and Challenges
Applying the aforementioned low-power solutions to high-voltage power supplies in exposure machines offers obvious advantages:
•   Significant Energy Savings and Reduced Consumption: Efficient energy conversion and intelligent power management directly reduce electricity consumption, aligning with green manufacturing requirements.
•   Improved System Reliability: Reduced power consumption means less heat generation, alleviating the impact of thermal stress on component lifespan and enhancing overall machine reliability and stability.
•   Enhanced Safety: Low heat characteristics reduce the risk of equipment overheating, ensuring safe production.
However, some challenges remain:
•   Increased Design Complexity: Intelligent switching, feedback control, and other functions require more precise circuit design and control algorithms.
•   Cost Considerations: High-performance switching devices and control chips may increase initial costs, requiring a balance against long-term energy-saving benefits.
Conclusion
The trend toward low-power consumption in high-voltage power supplies for exposure machines is an inevitable technological development. Through innovative circuit topologies (e.g., startup-feedback switching), adoption of advanced control strategies (e.g., quasi-resonant operation, intelligent voltage regulation), and enhanced standby management, the high power consumption issues of traditional solutions can be effectively addressed. These technical solutions are not only applicable to exposure machines but also hold significant reference value for other industrial equipment requiring high-voltage power supply. Future research could further explore the application of wide-bandgap semiconductor devices (e.g., SiC, GaN) in high-voltage, high-frequency power supplies to achieve even higher efficiency and power density.