This alarm with automatic shutoff was found in the April 1975 Radio Electronics magazine. The activation time is given by C1 and R3. The alarm uses series and parallel sensors.
This circuit is an excellent application for the PIC in audio, but the reader who intends to do...
To a 16-0hm load, this amplifier provides a power of 10 W. We found this circuit in a Motorola...
This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in...