This differential amplifier, found in a 1964 Electronic Design, has a gain of 30. The setting can be applied to modern equivalent transistors.
This simple circuit can be used in a robot that follows the light directly feeding a small motor....
We found this circuit in Radio Electronics magazine from May 1962. The circuit uses rectifier...
We found this circuit in Mullard's 1960s transistor manual. The circuit oscillates at 800 Hz, the...