We found this circuit in the July 1992 issue of Radio Electronics magazine. An optical system produces the light beam that, when interrupted, triggers the alarm. The sensitivity is adjusted by R4.
This sensitive field strength meter was found in 1993 documentation. The instrument may be the...
This circuit was found in a 1967 General Electric manual. It is intended for the control of high...
The figure shows how to vary the output voltage of a 7812 regulator between 12 V and 2 V less than...