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 has a thermal chamber that acts as a stabilizer, compensating for the ambient...
We found this voltage multiplier circuit in a Radio Electronics magazine from December 1991. The...
This circuit is a handset receiver that picks up the signal emitted by a coil under the rug or...