【Jiyican Contest】

1. Engineering principle: The first step is to use silicon photovoltaic cells to collect optical signals and then convert them into electrical signals to output current, and then use an I/U converter to convert the current into voltage. The second step will be divided into three branches. The first is to extract the DC signal. The intensity of the DC signal is considered to be the light intensity. The second step is to extract the power frequency signal and design a frequency and amplitude identification circuit to identify the frequency and amplitude. The power frequency signal is 220 and the signal frequency of the power supply is 50HZ. Then extract the high-frequency signal and identify the frequency amplitude of the high-frequency signal. Finally, the extracted signal is transmitted to the microcontroller for processing.

2. Function: (1) Reduce the harm of light to vision (2) Provide friendly reminders on light intensity (3) Provide brightness reminders

3. Working conditions: Test in a place with light exposure, and use an oscilloscope to observe the waveform for measurement.

4. Test parameters: DC signal, power frequency signal frequency and amplitude, high frequency signal frequency and amplitude