This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an amplifier stage. The circuit has a 500 mV output.
This 1964 Electronic Design circuit uses a photo-FET as a sensor. The component is rare today. |...
This circuit is from an 80's documentation. The transistor can be any general purpose PNP and the...
This circuit was found in a 90s Electronics Now. The maximum current is 1.5 A, given by the...