This circuit is almost same with 5V regulated solar power supply circuit. The different with circuit before is using diode 1N4148 and resistor that is parallel with solar panel. This is the figure of the circuit.
The oscillator will turn off when the output from the solar panel is above 1.3v and although the circuit does not shut down to zero current, it consumes about 3 mA, while the shut-off circuit takes about 1mA. On a bright day, the solar panel delivers 20mA to the battery, so the overall net charging current is about 15mA max. This means any data logging circuit or transmitter connected to the supply will only work at night.
To go over the purpose of the automatic section again: The automatic components turn off the 5v section so the battery can charge and store enough energy to operate a transmitter during the night hours, when it will be needed.
The oscillator will turn off when the output from the solar panel is above 1.3v and although the circuit does not shut down to zero current, it consumes about 3 mA, while the shut-off circuit takes about 1mA. On a bright day, the solar panel delivers 20mA to the battery, so the overall net charging current is about 15mA max. This means any data logging circuit or transmitter connected to the supply will only work at night.
To go over the purpose of the automatic section again: The automatic components turn off the 5v section so the battery can charge and store enough energy to operate a transmitter during the night hours, when it will be needed.
