This circuit provides a signal when dialing occurs. The circuit is powered by the telephone line voltage itself. We found it in an old documentation.
This circuit is ideal for the design of interfaces and shields, as it allows total isolation of...
Found in a 1968 EEE, this circuit accepts frequencies from 1 to 1000 Hz and control voltages from 0.1 to...
Found in a 1970 EEE this circuit emulates a zener diode whose voltage can be set to R2. Power...