This circuit uses a contactor having been found in a 1987 publication. More modern equivalent devices may be used. The circuit has neon indicator lamps.
In the figure below we have the way to connect solar cells in parallel to charge a battery in an...
We found this parallel regulator in a 1973 publication. Transistors admit equivalents and the...
This circuit can be found elsewhere on this site as part of alarms or sirens. The circuit given is...