This circuit was obtained from a 1967 GE SCR manual. It is intended for controlling relays responding to a decrease or increase in temperature.
We found this circuit in Ferranti's 1974 transistor manual. Transistors are general-purpose types...
This circuit for a receiver was found in an English documentation from 1963. The transistor is made of...
We found this oscillator in a publication for radio amateurs from the 70s. The circuit generates...