A CRT TV consumes more power when compared to LCD and LED because the CRT TV has a CRT Tube which uses a electron gun to beam the images onto the screen.
An LCD or LED TV uses Liquid Crystals and and LCD or LED bulbs to light the screen up.
While the CRT TV Tube is basically like a large light Bulb.
CRT Tubes use around 100 watts to as much as 200 watts per hour depending on how big the screen is.
For example I have 17" CRT monitor which uses around 100 watts while my larger LED monitor only uses around 40 watts of electricity.
The CRT stands for Cathode Ray Tube which again is like a large light bulb.
A CRT Tube works by electrically heating a tungsten coil which in turn heats a cathode in the rear of the CRT, causing it to emit electrons which are modulated and focused by electrodes.
The electrons are steered by deflection coils or plates, and an anode accelerates them towards the phosphor-coated screen, which generates light when hit by the electrons.
Before the invention of the integrated circuit, CRTs were thought of as the most complicated consumer electronics product.
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, the beams of which are manipulated to display images on a phosphorescent screen.
The images may represent electrical waveforms (oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena.
A CRT on a television set is commonly called a picture tube.
CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer.
In television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster.
In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and blue) with a video signal as a reference.
In modern CRT monitors and televisions the beams are bent by magnetic deflection, using a deflection yoke. Electrostatic deflection is commonly used in oscilloscopes.
The rear of a 14-inch color cathode-ray tube showing its deflection coils and electron guns
Typical 1950s United States monochrome television set
A CRT television filmed in slow motion.
A CRT is a glass envelope which is deep (i.e., long from front screen face to rear end), heavy, and fragile.
The interior is evacuated to approximately 0.01 pascals (9.9×10−8 atm) to 133 nanopascals (1.31×10−12 atm), to facilitate the free flight of electrons from the gun(s) to the tube's face without scattering due to collisions with air molecules.
As such, handling a CRT carries the risk of violent implosion that can hurl glass at great velocity.
The face is typically made of thick lead glass or special barium-strontium glass to be shatter-resistant and to block most X-ray emissions.
CRTs make up most of the weight of CRT TVs and computer monitors