2007年E题 开关稳压电源本系统以C8051F020为核心，电压可预置，步进电压为1V，输出电压范围为30V到36V，输出电流为0-2A。可显示预置电压，实测电压，实测电流，实测效率。该系统主要由最小单片机系统，PWM信号控制芯开关稳压电源??山东大学 周勇 宁金龙 赵立歧?摘要本系统以C8051F020为核心，电压可预置，步进电压为1V，输出电压范围为30V到36V，输出电流为0-2A。可显示预置电压，实测电压，实测电流，实测效率。该系统主要由最小单片机系统，PWM信号控制芯片TL494，开关电源升压主回路，A/D以及D/A组成。系统通过键盘预置电压值送给TL494形成闭环反馈回路，采样康铜丝上的电压间接推算出电流并显示。本系统具有调整速度快，精度高，电压调整率低，负载调整率低，效率高，无需另加辅助电源板，输出纹波小等优点。关键词：C8051F020；TL494；开关电源；boost电路。ABSTRACTFor this system to C8051F020 core voltage can be preset, stepping voltage of 1V output voltage range of 30V to 36V, output current is 0-2A. That preset voltage can be measured voltage, current measurement, the measured efficiency. The system mainly by the smallest SCM system, TL494 chip PWM control signal, the main boost switching power supply circuit, A / D and D / A component. Through the keyboard preset voltage TL494 gave a closed-loop feedback loop, sampling the voltage copper wire Kang indirectly current and projected that. The system has adjusted speed