This battery circuit provides a charging current of 500 mA depending on the solar panel. The switching circuit is from a National Semiconductor documentation from the 90s.
If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by...
This motor control using transistors was found in a recent English publication. The circuit is for...
In the figure we have an electronic toy organ that can both serve to amuse children as a basis for...