Found in a 90’s Radio Electronics, this circuit uses a component from the time, difficult to find today. It generates 12 tones in different octaves.
This circuit was found in a 1998 documentation and its purpose is to automate controls by timing its...
This circuit is from a 1977 Radio Shack documentation. It produces a modulated sound of good...
This second-order filter was found in old American documentation and can be applied to other...