本专利提出了一种照相曝光时间的控制电路。它由第一集成电路、开关电路和第二集成电路组成,其中第一集成电路包括一个光电元件和一个为产生光电元件光照表征电压的电容器。开关电路包括一个半导体元件,它的作用是当第一集成电路达到开关电路的触发电平时,起一个开关的作用。 This patent proposes a control circuit of photographic exposure time. It consists of a first integrated circuit, a switching circuit and a second integrated circuit, wherein the first integrated circuit comprises a photovoltaic element and a capacitor for characterizing the voltage of the photovoltaic element for generating light. The switching circuit includes a semiconductor element which functions as a switch when the first integrated circuit reaches the trigger level of the switching circuit.