This circuit was found in a PE Hobbyst Handbook of 1989. It uses a black light fluorescent of the time. Small fluorescent black light from 1 to 4 W can be used.
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...