This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two 9 V batteries since it requires a symmetrical source.
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...