This circuit uses an optical coupler to indicate a phone call through a lamp. The circuit is from a Hands-On Electronics from the 90s. The lamp must be incandescent.
This is the conventional configuration of an astable multivibrator with operational, found in a...
This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for...
The Texas TL783 integrated circuit is a three-terminal high voltage regulator with a wide range of...