The speed indication of this circuit is made on an analog instrument. The circuit is used to count pulses (rpm) and was found in April 1976 Radio Electronics magazine.
This digital electronic dice was found in a 1977 magazine, but it can be easily assembled today, as...
The audio signal generated by the oscillator stage is amplified by an LM380 and reproduced with...
This circuit uses indicator lamps, as it was obtained from an American publication of the 90s. The...