Optical sensor for PC (CB20548E)

This circuit was found in a PC documentation from 1996. It can be used as a shield with modern microcontrollers.

Symmetrical Power Supply 1 A (CB1192E)
This power supply may have 5, 6, 9 or 12 V outputs depending on the 78XX and 79XX series...
Telephone Amplifier (CB24504E)
This simple amplifier uses a microphone attached to the telephone. The 3-transistor circuit was...
Half Wave Fast Rectifier (CB5160E)
This 80's circuit can be made with current comparators. Rectification accuracy is 1% DC up to 100...