This circuit was found in Analog Devices documentation from the 90's. The integrated circuit used is from the time. The circuit is for HDTV signals. of the time.
This code switch only activates a relay when the right sequence of buttons is pressed. The circuit...
This current-limited variable power supply was found in 1977 book. The diodes are according to...
This circuit for measuring bridges was found in American documentation from the 60's. Transistors are...