Category: Telecommunications
S3 homework solutions
I have recorded some short videos to help you review your recent homework exercise. Here is the answer to part (a) of the data logger question.
You can download a copy of any of these homework video files using the download link under each post.
How a TV set works – part 3
The site I have been using throughout the television section of the course is here.
The shadow mask makes sure that electrons fired from the filament responsible for each colour of sub-pixel do not hit the wrong phosphor dots, e.g. electrons sent by the “green” gun do not reach the phosphor dots that glow red or blue. This animation shows how the shadow mask works.
Remember: electrons do not have a colour. Colour is only produced when electrons collide with phosphor paint.
How a TV set works – part 1
Here is a short video clip showing how an image can be built up on a TV screen, one line at a time. In a real TV set, the beam moves much more quickly (about 7000 m/s!) across the screen and 25 complete images are shown each second.
raster scan from mr mackenzie on Vimeo.
Remember that in a real TV set, the beam does not scan its way back up the screen but takes a “flyback” from the bottom right to the top left corner to start on the next image.
total internal reflection
Here is a short video showing some examples of total internal reflection.
3.4 Telecommunications HW
Here is your homework exercise based on the telecommunications work we have covered in class. Click on the download link to get your copy.
Homework jotters must be handed in by next Monday (19th).





