一款用UC3842计的电动车充电器工作原理分析.docxVIP

At present, the County personnel totaled 93,000 people, is three times times of 2010. Review the work of the past five years, the County formed to encourage innovation, innovation, participation in innovative atmosphere, a large number of innovations emerging high-level personnel leading the increasingly strong role; innovative idea further innovations gradually expanded from economic to social governance, public safety, intelligence and other areas of urban construction, innovation and talent support becomes increasingly important. Of hard work, the county levels to cherish, continue to consolidate, improve and, for the future development, to remain sober-minded, scientific foresight, courage to play. Under the influence of complicated international and domestic situation, the domestic economic situation, and General Secretary of stability, but downward pressure on large trend of differentiation and deepening of structural adjustment sums up the current situation. From Dongping actual see, Thirteen-Five during, County faced stable economic growth, and deepening structure adjustment of double task, both faced with economic total small, and per capita level low, and industry structure not reasonable, and economic development way extensive, basic situation, more has industry cluster early now prototype, and Park hosted capacity constantly enhanced, and resources traffic location advantage increasingly appeared, and cadres masses innovation venture passion ?一款用UC3842设计的电动车充电器工作原理分析（附图）：? ?? ?? ???? ? UC3842工作原理：? ? 该电路的电源部分使用单端式脉宽调制型开关电源，脉宽调制IC使用的是UC3842。UC3842是一种电流型脉宽控制器，它可以直接驱动MOS管、IGBT等，适合于制作单端电路。? ? 220V整流滤波后的约300V直流电压经电阻R1降压后加到UC3842的供电端（7端），为UC3842提供启动电压，UC3842内部设有欠压锁定电路，其开启和关闭阈值分别为16V和10V。在开启之前，UC3842消耗的电流在1mA以内。启动正常工作后，它的消耗电流约为15mA。反馈绕组为其提供维持正常工作电压。由于漏感等原因，开关电源在每个开关周期有很大的开关尖峰，即使在占空比很小时，辅助电压也不能降到足够低，所以辅助电源的整流二极管上串一个电阻（R3），它和C9形成RC滤波，滤掉开通瞬间的尖峰。 接在4脚的R5、C6决定了开关电源的工作频率。计算公式为：Fosc (kHz) = 1.72 / (RT (k) × CT (uf))，此电路的工作频率为40KHz。? ?过载和短路保护，通过在开关管的源极串一个电阻（R