Suggested for the control of photographic enlargers, this 1967 General Electric circuit uses still common components. The circuit directly controls a lamp for exposing negatives.
This circuit is used in transceivers, enabling input selection by diode switching through polarity...
This configuration was found in an American publication from the 90s. Operators admit equivalents just...
This circuit was found in an Italian magazine Elettronica Prática of 1977. The transistors can be...