Found in a 1967 General Electric documentation this circuit uses unijunction transistors that may be equivalent to those indicated. The number of stages can be modified.
E) This audio filter was found in the August 1993 issue of Radio Electronics magazine. It cuts low...
This defrost alarm starts from an interesting idea. A small magnet on an ice stone is trapped at the...
This circuit was obtained from a Linear Technology manual from the 1990s. The components may have...