Standard 1 MHz Oscillator (CB9653E)

We found this circuit in an old American documentation. Transistors can be modern equivalents.

Wiper Water Sensor (CB4968E)
The purpose of this circuit is to sense the water level in the windshield wiper reservoir. The circuit...
Relay for photodiode (CB21735E)
We found this circuit in Popular Electronics from January/February 1969. The circuit must be...
CMOS Optical Interface (CB18264E)
This circuit shows how to interface a CMOS circuit with a microcontroller or other circuit using an...