This circuit was found in the February 1997 issue of Electronics Now magazine. The frequencies depend on the crystal and other tuned circuits.
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...