TECHNES Encyclopedia Database

Nevertheless, this mechanism had a major defect: because the photoelectric cells were highly sensitive, the least variation in the light (a ray of sunlight, a lamp turned on, etc.) could cause the channel to change spontaneously.

To solve this problem, in 1956 a colleague of Polley’s, Richard Adler, designed the Space Command, which used ultrasounds; these are high-frequency waves imperceptible to the human ear. The only noise produced by the Space Command was the very distinctive sound of the buttons, which gave these remote controls the nickname “clickers.”