This circuit uses a 555 (according to the diagram) to generate 50 ms tone bursts at a frequency of 1.5 kHz. The circuit is from an 80's Electronic Design.
This circuit is intended for monitoring an environment. It fires a relay with a sound, but only if...
Found in Popular Electronics from the 90s, this circuit generates signals in a frequency range set to...
This simple circuit was suggested by the Electronics Handbook Volume XIII 1993. LED D1 emits light for...