This is my circuit which charges the supercapacitors. The problem with the circuit is the minimum input voltage require to get 3.3 volts output. Once the input voltage goes below the certain level ( i guess ~4.2 volts ) then breakout board does not give 3.3 volts as an output. As per the circuit, I do need 3.3 volts constant.
Should I use boost converter from 2.7 volts to 3.3 volts?
Please give some suggestions of IC or circuits.
This project is about powering few LEDs (let's say 3 LEDs) with the solar panel. LED specs are 2.6 volts and 2 mA. The solar panel could be of any voltage and dimension. I prefer to use 5, 6 or, 9 volts small panels. I used LDR to sense the presence of the light with the LM393 comparator and TI SPST switch IC for switching. My original goal is to be able to use it for a long time at least 16-18 hours. Thus, I used super caps to store energy.
Temperature range: -20 to 52 deg C
LED: 2.65 volts and 2 mA datasheet
Solar PV source power: 0.6 W Amazon
desired load power: 0.02 W
work time: 24 hours (after 'power-bank' is fully charged and LEDs are triggered by the sensor)
sensor: LDR (I would love to use other sensors like current as LDR could give false detection with some occlusion)
project time: 30 days