This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in the 1994 National Semiconductor Linear Applications Handbook.
This circuit allows the "recovery" of weak signals recorded on tape that correspond to programs. The...
This circuit uses two JFET such as the BF244 or BF245 and has an excellent gain with small...
This simple motor control for alternating current with triac was obtained in a European...