Under this name, Radioelectronics magazine published in the January 1974 issue a light exposure meter for photographers. The circuit used general-purpose transistors and a FET, with an LDR sensor.
This circuit was found in a 1977 Radio Shack documentation. The unijunction transistor can be...
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We...
This circuit offers excellent sound quality for headphones of 150 ohms or more. The circuit was...