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.

Get to know the Texas Instruments TPS7A92 (ART333aE)
The Texas Instruments TPS7A92 integrated circuit consists of a low-voltage (LDO) linear voltage...
Test circuit for transistors as oscillators (CB3915E)
This circuit checks the oscillation capacity of a transistor. The circuit can be used with fixed...
Coded Switch using Reed Switches (CB3974E)
This circuit is from a1970 documentation. R1 may have 10k and P1 47k. The transistors can be BC558...