This sequential circuit of LEDs was found in a Popular Electronics from the 90s. The circuit can be programmed and an adaptation consists of using optical couplers to drive power loads.
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...