ideas to implementation (1 Viewer)

[ashandlissy]

When the teacher taught about cathode ray oscilloscope and how a television tube operates i didnt actually understand a bit of the word he said.i checked out youtube but those videos were boring and difficult.i jus need to know basic principles of CRO and television tube.Anyhelp would be greatly appreciated.

 

[msum1uknow]

in cathode ray tube there are various roles of electrodes in the electrode gun,the deflectionplates and coils and fluoroscent screen.

 

[danjw]

in cathode ray tube there are various roles of electrodes in the electrode gun,the deflectionplates and coils and fluoroscent screen.

Trolling? LOL

Anyway try read through this and see if it helps http://www.hsc.csu.edu.au/physics/core/implementation/9_4_1/941net.html
If you have the jacaranda textbook that also covers the course in quite great detail so may be of help to you.
If you would like I'm happy to explain the concepts to you but am unable to right now as my time is limited.
Good luck!

 

[mirakon]

an electron is 'excited' when it reaches an energy threshold. That is, if you apply a certain amount of energy on an electron, it jumps to a higer orbital level in the atom. Its when the electron moves back, or is 'de-excited' that it releases a photon aka causes fluorescence.

crt televisions work by firing electrons at a screen. the electrons are fluorescent upon impact.

 

[sinophile]

an electron is 'excited' when it reaches an energy threshold. That is, if you apply a certain amount of energy on an electron, it jumps to a higer orbital level in the atom. Its when the electron moves back, or is 'de-excited' that it releases a photon aka causes fluorescence.

crt televisions work by firing electrons at a screen. the electrons are fluorescent upon impact.

yes, fluorescence occurs because it takes energy to excite the electron enough for it up jump a level, and when it gets tired and falls back down it releases the energy that made it jump up.

excite an electron enough, and it'll get ejected to 'orbit level infinity' i.e escape the pull of the atom's nucleus and never return.

 

[Fizzy_Cyst]

CRT TV:
• 3 seperate electron guns, one for each of the colours (Red, Green, Blue)
• TV's use electromagnetic deflection rather than electrostatic deflection as it is safer (does not require high voltage) and it has the ability to cover larger surface area
• Screen has three different types of coloured phosphors, each electron gun stimulates its corresponding phosphor (ie "Red" electron gun stimulates Red phosphors)
• Image is formed from two passes of an electron beam. Odd numbered lines first, followed by even lines.

Make sure you know what the electrodes in electron gun, deflection coils and fluorescent screen do.

CRO's
• Uses a cathode ray tube to display an input signal voltage as a waveform
o Voltmeters cannot measure small changing potential differences
o Many physical and biological phenomena can be converted to a voltage signal
o Useful in measuring how a quantity varies with time

• Oscilloscopes usually use electrostatic deflection

• In a CRO, a saw-tooth voltage is applied across the horizontal deflection plates.
o Causes spot to move across the screen at a constant speed
o Moves left to right
o Spot switches off when it reaches the right side of the screen
o Allows the creation of a constant time base

• Vertical deflection is provided by the input voltage, allowing voltage to be plotted as a function of time
o If input voltage varies from zero, the cathode ray is deflected upwards for positive polarity or downwards for negative polarity
o Vertical position changes in response to the input signal