This is the traditional voltage follower configuration with the 741 operational amplifier. The circuit is from 1976 documentation and the power supply must be symmetrical from 6 to 15 V.
With this circuit, an external circuit can be controlled by turning it on or off and reversing it (if...
The battery is charged by the photocell that keeps the low consumption beacon in the dark. The...
This circuit with 4 transistors can receive signals in 6 shortwave bands. The circuit is from a...