This circuit, found in a 1958 magazine, is for reference only, since the components are not easy to find today. The transistors are germanium types and power supply is made by common cells.
We found this circuit in a 1986 Elettronica Pratica magazine, but the components used are common. As...
We got this circuit from Radio Electronics from July 1990. The circuit mimics the sound of the red...
This circuit interrupts the power supply when grounding is missing. The circuit is from an old...