A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer
A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer
A display apparatus having a pair of polarizers with an optical rotator therebetween, one of the polarizers being a variable polarizer which is independently operated to alternate between substantially orthogonal states of polarization and cause the display to rapidly alternate between
An image altering apparatus which provides confidential viewing of a video display by means of time multiplexing the fundamental display image with a color-inverted image thereof on a pixel-by-pixel basis. Electronic circuitry and/or software are utilized to modify the fundamental image
An image altering apparatus which provides confidential viewing of a video display by means of time multiplexing the fundamental display image with a color-inverted image thereof on a pixel-by-pixel basis. Electronic circuitry and/or software are utilized to modify the fundamental image