Aircraft cockpit switch circuitry

摘要

A switch circuit for selectively driving a LED display at either a dim or bright intensity in response to varying input voltages is provided. The switch circuit includes a current regulator device which is responsive to a reference voltage and is coupled to a LED display device for supplying a first level of constant current therethrough so as to illuminate the display device at a dim intensity and for supplying a second level of constant current therethrough so as to illuminate the display device at a bright intensity. A controllable switching device is responsive to input voltages of a wide varying range for being selectively turned on and off and for generating the reference voltage.