Have you wondered! How grinder rotates, How vehicles run, How mobile works?
In this modern world everything is possible. Television also plays a major role in our day today technology. One need not to go anywhere else in search of information. Television delivers/provides every information besides our feet. In such cases, almost all of us use TV remote to change channels but only a few may think how it works without any connection when we press the button. So let us see how it works.
In 1950, Zenith Radio Corporation developed the first wired remote intended to control a television. Later, in 1955 Eugene Polley introduced wireless remote control system. It works when a beam of light is passed onto one of four photoelectric cells in those remote. But it could not differentiate different light resources and passed all the lights. So in 1956, Robert Adler developed “Zenith Space Command” a wireless remote. It was mechanical and uses ultrasound to change the channel and volume. Each of the four bars emitted a different fundamental frequency with ultrasonic harmonics and circuits in the television detected these sounds and interpreted them as channel-up, channel-down, sound on/off and power-on/off.
WHAT ARE ELECTROMAGNETIC WAVES:
EM waves or electromagnetic waves are created as a result of vibrations between an electric field and a magnetic field. These waves especially infrared waves are used for wireless communication such as television, radio and so on..
How a television remote send signal to the receiver and how the receiver pick up the signal?
Here comes the play of wireless communication. The main technology used in remote control is infrared light. The signal between the remote control handset and the television consists of pulses of infrared light that requires line of sight to operate in television. When we remove the back cover of our remote, we may found a circuit board and a battery cell. These circuit boards which consists of integrated circuit called printed circuit or PBC(chip) are connected to battery.
COMPONENTS PRESENT INSIDE A REMOTE:
- a transistor (black, with three leads)
- a resonator (yellow) • two resistors (green) and
- a capacitor (dark blue).
- Next to the battery contacts there is a resistor (green) and a capacitor (tan disk).
When we press the button on the remote, it transfers those action into infrared light signals which are continuously received by TV. When the button is pressed, integrated circuit starts its function. It is detected by the chip and translates those units into digital data with different commands based on coding system. Data is stored in different addresses while pressing different buttons and the waves are passed according to it. i.e., the circuit is constructed to create a direct sequence for different buttons on your TV remote. Then the chip sends those signals to the transistor which amplifies the input signal and finally transmits to the TV receiver. TV receiver recognize frequency to differentiate the given command. Microchip reads the beam and tells the TV’s sensor what to do.
But you might have wondered that the channel might not change when you stand in between remote device and TV. This is because infrared rays travel only in straight direction and cannot pass through any object.
ADVANCEMENT AND FUTURE DEVELOPMENT:
It is also possible to develop touch screened remote with the help of modern technology. And these remote control systems can also be used in HVDC-plants, motor controls etc.,
Hope the above information might give you a better understanding about how remote functions with wireless communication technology.