How Do Infrared Remote Control Toys Work?
At face value Infrared (or IR) Remote Controlled Toys aren’t much different from radio controlled toys in regards to how they operate. You press a button on the remote and the toy responds…simple. Also, some IR toys are designed to look like the big boy radio control models. However, what’s unique about them is what goes on behind the scenes. The manner in which the remote control communicates with the receiver in the toy is the key difference.
Unlike radio control, infrared has no use for an antenna to communicate. The antenna is eliminated from the controller and the toy making it an ideal choice for toddlers because for toddlers the antenna poses a potential hazard. Therefore, IR RC’s are ideal for toddlers as well as children. Instead of antennae, an infrared remote system utilizes a beam of light as a means of communication. With an LED (Light Emitting Diode) located on the front end of the remote and its counterpart, a photodiode detector located on the toy, communication is possible. The toys remote controller sends signals by way of a beam of light (also known as the carrier) which is emitted from the LED, much like how your TV remote communicates with your Television. The IR remote control does this by generating pulses of infrared light by way of the LED that carries specific binary codes or data strings. These pulse codes correspond to specific commands such as:
· Stop, etc.
The IR receiver in the toy extracts the binary data codes from the pulses of light and then finally carries out these commands.
The basic principal at work in an IR remote control system sometimes referred to as Beam Technology, is the use of light to carry signals between a remote control and the device it's managing. IR remotes function by modulating (turning on and off in rapid succession) an infrared light source. The rate of modulation is called the carrier frequency. The reason for this is to provide a better transmission system, therefore allowing the IR controller and receiver to operate within noisy environments with respect to light. An IR receiver for any given remote is tuned to the carrier frequency of its specific remote and therefore will not see or acknowledge any other remote tuned to a different carrier frequency. For example, with respect to home audio and video components, this is the reason why your DVD remote does not operate your TV, or your TV remote will not operate your DVD.
The Infrared light is invisible to the naked eye. Its wavelength is too long for the human eye to detect. An infrared light beam however could be seen with the aid of a camera such as a camcorder or cell phone camera. In some cases IR controlled devices are equipped with a “telltale sign” which is a little red light that flashes to indicate a received carrier from the IR remote. Infrared light is in the invisible lower portion of the electromagnetic spectrum as depicted in the diagram below.
Although Infrared remotes have been around for 25 years, unlike the Radio Control controllers they have their inherent limitations due to the nature of infrared light. Infrared remote controls have the range of roughly 30 feet or less. Infrared also requires a line-of-site method of operation. In other words, the LED on the remote control has to be pointing in the direction of the IR receiver in order for the signal to be received. The signal cannot penetrate walls nor can it turn corners, even the human body becomes an obstacle. However in some cases if the signal is strong enough, IR can be reflected or bounced off light colored walls, white walls being the more reliable. Other forms of interference are from sunlight, fluorescent bulbs and any other IR device transmitting in close proximity. To help avoid interference from other sources of IR remotes operating nearby, the light from the IR remote is modulated at a frequency that is not present in sunlight. And the receiver only responds to that modulated frequency with the help of filters that block out IR light at any other frequency. With these measures all working together, interference is cut down a great deal.
Just like the big boy radio control models, Infrared Remote Control toys are available as Cars, Trucks, Helicopters and even Robots. They come in many different shapes, sizes and colors. Infrared Remote Control Toys are very simple to operate and for this reason RC toys are great for children of all ages. They are fun and are an ideal motivator for getting the kids away from the Television and video games for hours.