Research On The High Voltage Discharge Power Supply System For Liquid Leak Detection Of Medical Bottle

In medicine industry, the sealability of medical bottle should be guaranteed strictly. Using high voltage discharge to detect the leakage condition of the medical bottle is a new detection method. This method takes use of the different electrical characteristics between the broken medical bottle and the good medical bottle to judge whether this medical bottle has the sealing problem by putting the bottle under the high voltage electrode and testing the discharge signal. This test method has the advantage of pollution free, high efficiency and high reliability but the research of this technology is still at the initial stage and no system theory has been formulated. This paper explored this method and developed the power supply system suitable for high voltage discharge detection based on the theoretical analysis. At first, the theory of using high voltage discharge to detect the leakage of the medical bottle was analyzed; meanwhile the developed power supply standard was confirmed. Furthermore, taking the ampoules for example, the frequency range of the power source was derived. Secondly, the high-frequency and high-voltage power source was designed, which was divided into the rectifier filter circuit, full-bridge isolation DC-DC convert circuit, full-bridge inverter resonance circuit and step-up transformer. In this part, the operating principle was analyzed and the main circuit as well as the control circuit was designed. Last but not least, the power system used DSP28335 for signal acquisition, A/D conversion and communication with PLC based on the MODBUS protocol. The manufactured high-voltage had the advantage of small volume, high efficiency and detecting the high-voltage discharge smoothly. The experiment on both the good and broken medical bottle confirmed the correctness of the detection method and effectiveness of the manufactured power source.