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.

Crystal Controlled Oscillator (CB6186E)
This circuit is from Signetics' 80s documentation. The circuit generates 100 kHz signals according...
VHF Transmitter (CB1564E )
The small transmitter shown in the figure can generate signals in the range of 50 MHz to 200 MHz....
1 kHz oscillator (CB6909E)
This oscillator produces a modulated signal using a unijunction transistor. We found it in an...