This circuit is from a 1968 documentation. It makes use of thermistors (NTC) to indicate overheating of charged batteries. Modern equivalent components can be used.
This low-power intercom can be powered by solar cells. The circuit is two-way, with an integrated of the...
The advantage of this circuit lies in the fact that it does not need a negative source to generate...
The circuit shown in the figure can be used on a data transfer bus using an appropriate family...