This circuit is from an article about operations in a Radio Electronics magazine from around 1968. The transistors are types of the time and the power is not the greatest.
In the figure we have the way to connect solar cells in series in order to increase their voltage. The...
The sensor in this circuit is an LDR and the potentiometer serves to control the sensitivity...
This circuit is used to match a high impedance input source with a low impedance output device...