Using 555 integrated circuits, this alarm circuit was found in a 90s American documentation. The signal must be applied to a good audio amplifier.
This circuit consists of a rearrangement of the previous circuit also using 4 relays. We found this...
This circuit limits the intensity of an audio signal from a control voltage. The circuit is from a...
This limiting circuit or Clipper was found in a 1977 documentation. The circuit uses only passive...