The Design Of High-voltage Power System For Capillary Electrophoresis

As an effective way of biological components analysis, Microchip Capillary electrophoresis has been widely used in biotechnology, clinical medicine, environmental protection and so on. In the analysis of capillary electrophoresis, high voltage must be threw in the pools of biochip, and their voltages and polarities can be controlled in order to achieve the sample injection and separation. As a result, the stability and switching speed of high-voltage power supply output play an important role in electrophoresis precision and accuracy. The traditional high-voltage power supplies are not only large, unstable in output, but also should be controlled by computer in Capillary Electrophoresis. Therefore, this paper which based on single-chip and high-voltage modules carries out the research of intelligent high-voltage power system for CE.In this paper, power supply system of three high-voltage output was designed whose core was single-chip AT89S52 .Three high-voltage modules were the main circuit to produce high voltage. Three output voltages were achieved from 0 to 5k and the current was less than 0.25mA. The Cathode and the Ground of second voltage can be switched. As the core of high-voltage power supply system, single-chip AT89S52 completed regulation of output of high-voltage modules, output display , communication with the photon counter or PC, and set the over-voltage, short circuit protection was set. In Electrodes switching Circuit, four high-voltage relays which were drove by Single-chip through the optocoupler made double throw switch. The circuit not only switched faster, but also has safe and reliable characteristics. The injection voltage, separation voltage, injection time, separation of time can be set through LCD and keyboard. The system completed the settings automatically which reduced the man-made factors and ensure the accuracy of the analysis. In addition, for different models and different structure of the single-chip capillary electrophoresis, this article designed the experimental sample frame in order to impose voltage to the pools.Compared with the original high-voltage power supply of laboratory, the power system not only reduced the size greatly, but also output steadily, drifted small, electrodes switching quickly, and can operate independently, met the requirements of CE.