The main feature of this circuit found in an old American publication is that it is powered by the very signal it converts. The transistors are of the time and can be replaced by current types.
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...