Abstract: An electronic circuit for use in a monocular night vision device for electronically controlling a plurality of components within the device, the device having an objective lens assembly for receiving low intensity light, a variable gain image intensifier tube having a user adjustable variable gain controller external to the tube for adjusting the light intensity level of a visible output image, a single eyepiece lens assembly for viewing the output image from the image intensifier assembly; and a non-metallic housing comprising an upper housing for receiving the objective lens assembly, image intensifier assembly, and eyepiece lens assembly, and a lower housing containing a battery cavity for receiving batteries to power the device. The housing aligns the objective lens assembly with the image intensifier assembly and the eyepiece lens assembly along an optical axis wherein the upper and lower housing are coupled to one another along the optical axis.

Abstract: The photocathode of an image intensifier is pulsed ON and OFF at a rate determined by a thyristor or SCR having the anode to cathode path coupled to the photocathode and the gate electrode triggered by a variable resistor, capacitor (RC) circuit to cause the photocathode to draw or conduct current only during the OFF interval of the SCR. During the ON interval of the SCR, the photocathode is OFF or non-conducting, wherein the controlled image intensifier tube exhibits a relatively constant resolution over a wide range of input light input values as from 10.sup.-6 to 10.sup.1 foot-candles.