TV Remote Controls. TV remote controls have been around since 1950. Zenith was the first company to market this product. This remote control was wired to the TV. You could change channels, turn the sound on and off and also turn the TV on and off. You could not adjust the volume up or down.
In 1955, Zenith introduced Ultra Sound. This TV remote control was a box that could generate sounds just above the range of human hearing (30 to 50 kilo cycles). Because it was above 30 kilo cycles, no one could hear it. The TV had a microphone that could pick up these frequencies and the circuits that processed them. If you pressed the "ON" button, it would generate a frequency and the TV would decode it and turn the TV on. This was limited to only four or five keys. Ultra Sound was in production for over twenty five years.
In 1975, the infra-red TV remote control began to take over. In 1980, almost everything was using infra-red. These remote controls would send an infra-red signal to the TV. Infra-red is very programable, but it can not got through walls or floors and has a range of about three to eight meters. With infra-red, the sky is the limit for the number buttons on the remote. Today, we still use infra-red today on most of our remote controls. Some remotes use radio frequencies, but this method is more expensive to manufacture. We offer TV remote controls for most major brands.
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