Found in an American publication of 1968, this circuit makes use of a pilot light of the time. It can be replaced with LED with appropriate series resistor. Transistors may be modern equivalents.
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...