The 3V DC source is supposed to be the solar cell (part no. 6SCB7); the potentiometer directly next to it represents the light exposure on the solar cell. The other potentiometer can be adjusted to change the circuit’s sensitivity to light. The other DC source, at 3.7V, is the rechargeable battery (part no. 6SCB4)
Please note that when building this, you don’t need the potentiometer on the right (as it will hinder the solar cell’s use), and that the solar cell is connected to the →CH (charge) pin on B4, NOT THE DISCHARGE (<—DIS) PIN!
Also, use a resistance of 200k ohms instead of the 50k fixed-value resistor.
