Development Of The Switching Power Charger

Now, the finished Switching Power Charger has many disadvantages. For example , it can only work in the mode of stabilized voltage or stabilized voltage and current limiting ; when charge to the lead-acid battery group ,it has only the single way of charging that the output voltage is constant, this is not beneficial to the use and life-span of the lead-acid battery; the Switching Power Charger is not be convenient for computer monitoring. To supply these gaps, we adopt MCS-51 microcontroller for the control of stabilized voltage and stabilized current. Accordingly, we can realize charging the lead-acid battery group automatically and monitoring the Switching Power Charger by computer.This paper studied the basic principle of Switching Power Supply and the technology of Pulse Width Modulation ( PWM ) , determined to adopt Pulse Width Modulator SG3525 to produce PWM control signal; studied the working principle of IGBT, the structural and control principle of Intelligent Power Module( IPM ), designed the external drive circuit, protection circuit and buffer( absorption) circuit of IPM, realized using IPM to replace IGBT as the master switching device; also discussed the charging method of lead-acid battery ,including the conventional charging method and the technology of quick charge.This paper designed a Switching Power Charger control system that using IPM to replace IGBT as the master switching device, adopting SG3525 to produce PWM control signal with the core of MCS-51 microcontroller. The system realized the detection and simultaneous display for the output voltage and current of Switching Power Supply .It can control stabilized voltage, stabilized current and switch automatically. It also can control the time of stabilized voltage and stabilized current very conveniently by timing .So it can realize for automatic charge and intelligent protection of lead-acid battery group. Besides, The system realized the communication between MCS-51 microcontroller and personal computer.Practical long time operation shows that the system has good technical performance and high reliability. It works stably and can be operated conveniently .So ,this has reached the expected goal.