Found in 1968 Mullard documentation, this circuit uses period components. The transistors are matched pairs and the sensor is an Indian photocell of the time.
This circuit uses a large surface diode to detect radiation (alpha and beta particles, in addition to...
This preamplifier for the phonographic capsule was obtained in an Argentine publication from 1973....
This circuit is from a 1993 publication and can be implemented with any optical isolator that has...