S3 telecommunications hw for 3.3 & 3.4

Hello S3!

Here is your homework exercise on telecommunications.  I would like you to put the answers to each of these questions in your blue homework jotter and hand it in to me no later than Tuesday 14th September.  You will not receive credit for doing the homework if your jotter is handed in after this deadline.

Use the calendar on the right to check for any important dates (HW deadlines, assessments, parent evenings) during your Standard Grade course.  There is a podcast button under the calendar that will help you to subscribe to all future hw and answers on iTunes.  Just ask if you need help with that.

S3 how a TV 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.

S3 how a TV 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.