Found in the July 1994 Electronics Now magazine, this circuit drives a relay up to 12 V depending on the power supply. The transistor can be general purpose.
We found this circuit in a 1995 documentation. It is a two-channel preamplifier for supplying a...
In the figure we have the way to connect solar cells in series in order to increase their voltage. The...
This circuit is from the 1990 Motorola Data Databook. The circuit can be implemented with...