This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in the 1994 National Semiconductor Linear Applications Handbook.
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...
This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The...