This series LED circuit was found in the February 1992 issue of Radio Electronics magazine. The effect's speed is dependent on C1 and adjusted by R3.
This circuit uses two sensors that are placed at the intersection of a miniature railway, causing...
This circuit with RIAA equalization is from 1985 US documentation. The circuit has a flat response...
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....