This circuit without sensors in series triggering an SCR was found in volume 5 of the 1995 Encyclopedia of Electronic Circuits. The circuit can have the number of sensors changed.
This circuit is a driver for R-2R network of AD converters. We found it in manufacturer...
This circuit was found in an American publication from the 60's. The transistor is made of...
This circuit produces an audio tone on the speaker or magnetic capsule. Rx must be such that added...