Published in Popular Electronics with the curious name of Obnoxious Noisemaker, this 1968 circuit generates random sounds that are reproduced on a loudspeaker. The power transistor can be a BD136.
This circuit from an old documentation includes the power supply for the 117 V power grid. It can be...
The frequency of this circuit is approximately 1 Hz. Whenever the output is at low level, the LED...
This circuit has been found in an old documentation and therefore uses a lamp as an indicator. In a...