Found in an Electronics World of 1969, this circuit causes a light bulb to flash along with the audio signal applied to the input. The circuit only works with incandescent lamps. C can be 47 nF to 220 nF.
This circuit was obtained in a 1974 documentation. It shows how to use a JFET as a low intensity...
Schmitt Triggers convert a signal of any waveshape in square signals or pulses. The circuit shown...
This circuit was found in a 1992 publication. The critical component is the photodiode, but...