This 100 MHz bridge circuit was found in an American 1970s documentation. The supply voltages are not indicated, nor are the tubes.
The relationship of values between R1 and R2 determines the reference voltage for this circuit that...
Presence Detector (CB18741E) The original name of this project found in documentation from the 90s...
This circuit locks when the sensors are opened. The relay can be 6 or 12 V depending on the power...