Here's a breakdown:
* Mechanical: They worked by sending physical, mechanical signals using sound waves or ultrasonic frequencies to actuate the TV's internal switches.
* Limited Functionality: These remotes primarily focused on channel selection and on/off functions. They didn't offer features like volume control, mute, or other advanced options.
* Often bulky: They were typically bulky and heavy due to the mechanical components inside.
* Line-of-sight: The remote needed to be pointed directly at the TV for the signal to work.
Notable examples:
* Zenith Space Command: This remote, introduced in 1956, is credited as the first widely available remote control for televisions. It used ultrasonic waves to change channels.
* Sylvania Flashmatic: This remote used a light beam to control the TV, offering a more reliable connection than earlier models.
While these mechanical remotes were the norm, early infrared remotes started appearing towards the late 1970s. These remotes were more compact and offered better reliability but were still considered a novelty compared to the popular mechanical models.
The 1970s saw the beginning of a transition from mechanical remotes to more advanced electronic ones, paving the way for the sophisticated remote controls we use today.