How the First Wireless Television Remote Control Works

Robert Adler's 1957 invention of the Space Command remote, which used ultrasonic sound waves to control television functions without wires or batteries.

What it covers

The patent describes a remote control system that uses ultrasonic sound pulses to trigger specific functions on a television set. The remote contains mechanical hammers that strike aluminum rods of different lengths when a button is pressed, creating high-frequency sound waves above the range of human hearing. A microphone on the television receiver captures these specific frequencies, which are then converted into electrical signals to perform actions like changing channels or adjusting volume.

What it doesn't cover

• —Does not cover infrared (IR) remote controls, which use light pulses rather than sound waves.
• —Does not cover Bluetooth or Wi-Fi based remote controls.
• —Does not cover systems that require a direct electrical wire connection between the remote and the TV.
• —Does not cover digital signal processing or complex data transmission protocols.

The clever bit

By using mechanical sound generation, the remote required no batteries, making it a truly self-contained, maintenance-free device that lasted for decades.

Why it matters

This invention effectively launched the modern era of television convenience, allowing viewers to control their sets from across the room. It solved the problem of the 'Space Command' predecessor, which used light and caused accidental channel changes from sunlight, by moving to sound frequencies that were less prone to environmental interference.

Real-world examples

• 1.Zenith Space Command 400 remote control
• 2.Early ultrasonic TV tuning systems