Found in Ferranti's 1968 documentation, this circuit uses a Darlington photo transistor to drive a 12V relay. The circuit can be implemented with modern equivalent components.
This circuit is from the 1983 Intersil Databook. The ADC0801 and 0804 are low-cost AD converters. They...
This circuit uses only two transistors, the first being low noise, being indicated for dynamic...
This circuit divides the frequency of a signal by two. The circuit is found in the May 1977 issue...