We found this circuit in the May 1996 Electronics Now magazine. The relay must have a voltage according to the circuit power supply and a trigger current of no more than 50 mA.
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...