Found in documentation from the 1980s, this circuit can have several adaptations to use modern transistors and LEDs instead of the lamp. The power supply voltage can also be changed.
Found in a 1967 General Electric documentation this circuit uses unijunction transistors that may...
This tunnel diode circuit was found in American documentation from 1966. The tunnel diode is the...
Used by radio amateurs to accompany telegraphic transmissions, this circuit generates an audio...