This circuit makes use of an optical coupler to isolate the telephone line. The circuit is from 1970s documentation. The components admit equivalents.
This integrated circuit is recommended as a standard amplifier in sound equipment, TV sets,...
This circuit is from a 1975 Miniwatts magazine, therefore using Philips components from that time,...
We found this circuit in a 1995 publication. It makes use of infrared LEDs of the type existing at...