The High-Voltage Power Supply Of Aerial Gamma Spectrometry Survey System

As the heart of electronic equipment, the power supply provides a stable work environment for them. However, about 60% of malfunctions are owing to power supply. With the continuous development of electronic technology, the requirement for power supply is also rising, which draws more and more attention to the designs and researches on it.Traditional DC high voltage power supply uses the linear power supply technology, which is bulky and restricted structurally, weakening the overall efficiency of power and making the performance general. Therefore, with the progress and development of the switching power supply, most of the DC powers tend to use switching power supply technology, which has become the mainstream design in power industry because of its advantages that the linear power supply can not match. The switching power supply technology brings the benefits of small size, light weight, higher efficiency and better performance to DC voltage power supply.This article derives from the National 863 Program-"Investigation of Airborne Gamma Spectrometry System Development"(2006AA06A207), taking the power supply of airborne gamma spectrometer as the object of study, and presenting the development process of DC high voltage power supply in airborne gamma spectrometer as well as the realization of control circuit.The main achievements of this paper are as follows:(1) Based on the analysis of designing theory of high voltage power supply system, and combined with the actual situation of this project, this thesis focuses on the key technologies of the realization of the high voltage power supply, the mechanism of the high-frequency PWM square wave and the principle of realizing parallel load resonant circuit.(2) Choosing TL494 as the system PWM Generation Module, this paper designs and debugs TL494 peripheral circuit, and achieves the output of TL494 adjustable square wave by optimized control model, and thus control the conduction of the switching valve.(3) To reduce the high voltage power loss and improve the efficiency of power supply, the paper designs an effective and reasonable resonant inverter circuit and a soft switch technology.(4) This thesis designs the main circuit of the airborne gamma spectrometer high voltage DC working power supply, and expounds the circuit's main functional module based on the analysis of the composition and realization theory of the power system structure. Besides, the relevant parameters were also calculated and designed.(5) The application of integrating Single Chip Microcomputer with analog circuit control technology ensures that the system not only owns a strong maneuverability but also a high reliability.Through the above studies, this paper applies switching power supply techniques in high voltage power supply design, which achieves a high frequency high voltage power supply, and greatly reduces the volume and weight of the power supply, improves its stability and efficiency as well. After commissioning, the design obtains the following achievements: the high-voltage output ranges from 0V to 1500V adjustable, the ripple is less than 300mV, the switching frequency is 20 kHz, basically meeting the expected research results, which plays a positive role in promoting research and design of high voltage power supply in future.