How does a remote control work?

In summary, different types of remote controls use different techniques to send a signal to their respective devices. TV remote controls use an infrared LED that turns on and off at a 44kHz rate, while garage door and car remotes use a radio signal. Each type of remote control has a unique sequence of turning the carrier on and off to send a specific message. The codes used by garage door and car remotes are only used once to prevent theft. Taking apart a remote can provide a better understanding of how it works.
  • #1
bluemoonKY
131
16
I'm specifically interested in television remote controls, garage door opener remote controls, and car door remote controls.

I know that the remote control must send a signal somehow to the television, garage door, or car door respectively. But what type of signal does each type of remote control signal? I mean, is it a radio wave or what?
 
Engineering news on Phys.org
  • #3
Different ones use different techniques. TV remote controls are fairly fun and straight forward. They typically switch an infrared LED on and off at a 44kHz rate. A receiver in the TV picks up infrared and is tuned to 44kHz.
The 44khz signal is called a carrier. Using it helps the TV distinguish the difference between steady sources of light, like sunlight, and the remote.
To get message across, the carrier is turned of and on in a sequence that's unique to the TV brand and function.
Garage doors and cars do the same thing with a radio signal (the carrier), but most of these remotes only use each code once and then move to another code in a very long list. The opener or car only uses each code once, and then rejects it from there on. This keeps thieves from using a receiver to steal the code and reuse it.

Left over remotes are pretty common. I really encourage you to take one apart to look at. You'll find a little LED in the TV/VCR/Cable remotes, and a loop in car remotes that is used as an antenna.

-Mike
 

1. How does a remote control communicate with the device it is controlling?

A remote control uses infrared or radio frequency signals to communicate with the device it is controlling. These signals are sent from the remote control to the device, which receives and interprets them to carry out the desired function.

2. How does a remote control send different commands to a device?

A remote control has buttons or controls that are programmed to send specific signals to the device. These signals are unique and correspond to different functions or commands, which are then translated by the device's receiver to perform the desired action.

3. What powers a remote control?

Most remote controls are powered by batteries, which provide the necessary electricity for the device to function. Some remote controls may also have rechargeable batteries or be powered by a small solar panel.

4. How does a remote control stay connected to the device it is controlling?

A remote control stays connected to the device it is controlling through a wireless connection. This can be through infrared signals, which require a direct line of sight between the remote and the device, or radio frequency signals, which do not require a direct line of sight and can work from a distance.

5. Can a remote control work with any device?

No, a remote control can only work with devices that are specifically designed to be compatible with it. This is because each remote control sends unique signals that are programmed to work with a specific device's receiver. However, some universal remote controls can be programmed to work with multiple devices from different brands.

Similar threads

  • Electrical Engineering
Replies
12
Views
1K
  • Electrical Engineering
Replies
4
Views
1K
Replies
13
Views
3K
Replies
31
Views
2K
Replies
3
Views
3K
  • Electrical Engineering
Replies
17
Views
2K
  • Electrical Engineering
Replies
3
Views
825
  • Electrical Engineering
Replies
25
Views
2K
  • Special and General Relativity
Replies
23
Views
786
  • Electrical Engineering
Replies
2
Views
2K
Back
Top