This circuit was found in the March 1997 Electronics Now magazine. It uses a common analog indicator and the transistor is a general purpose one.
This circuit comes from a Gernsback Publications of the 90s. The circuit uses a general-purpose transistor as...
Found in an Elektor from the 90's, this double door-bell drive circuit switches a relay by...
The oscillator shown generates a rectangular output signal at a frequency of 5 MHz, determined by the...