Design On Modula Test Power Supply Based On I~2C Bus

The test power supply of this research is an integrated power used in the emergency communication vehicle’s detection.There are two main purposes.One is to provide power for the cable conduction and insulation test.The second is to provide power for the computer, relays, sensors, integrated circuits and other devices. With the development of distributed power source technologies, the ever-growing capacity of power source in test system demands intelligent degree, security and reliability. The paper analyzes the working principle and characteristics of the switching power supply. According to the design requirements of the subject and in DC / DC switching power supply module unit as the research object,the paper presents a modular test power system. The system is based on a C8051F040 microcontroller as the core and use of the I~2 C bus to achieve digital control to five different output voltage power supply modules.When emergency communications vehicle’s power supply failure,the test power supply can quickly detect the fault excluded.It ensures the efficiency of emergency communications vehicles and improves its reliability.the main research works and innovations of the paper are as follows:1、On the basis of introducing the principles of test power supply system, the paper emphatically selects the major power stage circuit, discusses the major characteristic of phase-shifting full-bridge series resonance converter and analyzes the work principle of phase shift full bridge converter.2、Adopting C8051F040 of Cygnal series as host processors, I~2 C bus as a means for communication, a digital unit for the test power supply system is designed. This method makes simplify the control circuit part of the design, while improving the safety and reliability of the test power system.3 、 At last, the design scheme of a 220 V AC input and 5-way DC output power modularize power supply is introduced in detail including power factor correction design electromagnetic compatibility design, protection circuit design, emphasisly the current sharing control circuit design. I~2 C bus technology is used in the test power products, to achieve a combination of digital solutions of power modules, proposes a new design method.