Smart Lead-acid Battery Detection System And Its Driving Power Supply Developed

Lead-acid batteries is widely used in modern electronic and communication equipment. On behalf of fragile electronic parts, it can be easily destroyed while not being noticed, so it is urgent for the society to develop an detecting equipment that can figure out the battery quality online in case of waste and accident. The detecting system make use of relativity between battery resistance and its quality. Meanwhile, designing a multiple-output low ripple switching power supply corresponding the high demand of this kind of detecting equipment is necessary. This thesis can be presented as follow:1. Researching and analysising the principle of lead-acid battery, figure out AC injection method in detecting system according to the feature of battery and low-ripple switching power supply according to the portability and stability.2. Intelligent detecting system is divided into 3 major modules: single-chip controlling module, current adjusting module and 2 step amplifying module. Controlling single-chip make use of model MSP430f169, its main function is: making use of DAC port to produce 1KHz sine wave signal, producing 8 way port choosing signal, testing the amplitude of sine wave signal, serial communicating with computer system; The function of current adjusting module is: amplifying circuit for tiny signal detection, band pass filter, 2 step amplifying device, dual-single polar conversion module, differential amplifier for testing voltage, analog switching module. The process of the design of whole hardware is simulating and experimenting.3. The multiple switching power supply can be also divided into 2 parts: Transformer and main electronic circuit. The construction of the power supply is fly-back TOP, the designing process of transformer combined AP traditional calculating method and designing software PI Transformer Designer, its magnetic core is EI28, the performance of the material is closed to PC40. The main electronic circuit has all the component of the power supply except for the transformer, including: input EMI filter, input AC rectifier module, stress buffer device, switching control chip and related circuit, out-put feed-back module and multiple-out put filter module.4. According to those rearch, a battery detecting system and the matching switching is finally made. The detecting system can dignify the tiny change of the resistance of simulaing wire, it can also specify precisly different resistance value of different battery in real situation. The matching switching power supply can work in situation of 220Vac±10%, its out-put voltage is seperated:+12V,-12V,+5V; the ripple is controlled in 0.5%.