| Microwave detectors as a kind of portable devices, like laptop, MP4and other portable devices, also faces the power supply problem. The unique working environment of microwave detectors decided the highly dependence of power supply system, In many places not accessible to the grid battery as a power supply system is especially important. Battery as a power supply of mobile electronic equipment, environmental protection, energy saving, light is the trend of its development.Based on the variety of various charging methods, protection circuit, DC/DC circuit, control chips, the analysis of the working principle, design of a lithium battery charge discharge system. First of all, through the study of charging method and comparative analysis, the charging curve combined with lithium battery charging mode, Design the first constant current charging and then constant voltage charging mode. At the beginning of the charging according to the battery status to decide whether to increase a trickle charge.Different from the other design,the Constant current and constant voltage as well as the trickle charging circuit is design in advance.When charging began, the controller monitors the battery voltage, temperature and other parameters, determine the choice of charging.according to the state of the battery. Secondly design of protection circuit for the charge and discharge process of lithium battery pack, and conducted a simulation on part of the circuit. Thirdly, to choose a Buck converter for the principle of integration of the voltage converter chip, design of wide input discharge plate multi-channel output voltage range.further, to the switching circuit, to achieve power adapter and lithium battery-powered switch freely. Finally, select the FPGA as the control system,and designed with minimal its system circuit.After the completion of the project design, and after the debugging of system, each part can work normally, thus this is a successful completion of the design of a portable power supply system. |
PDF Full Text Request