This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in the 1994 National Semiconductor Linear Applications Handbook.
This micro FM transmitter or wireless FM microphone makes use of a ceramic capsule as a microphone or...
The voltage of 30 V indicated in this project, shown in the figure depends on the diac used. It...
This circuit is intended to drive bistable relays and can be used as a shield for...