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 1-transistor reflex receiver was found in a 1963 publication. The coil is for the mid wave...
Found in a European magazine from the 90s, this circuit emits beeps that are several seconds apart to...
This interface or shield circuit for instrumentation was obtained in a publication from the 90's....