Available for free is this classic British engineering show about the inner workings of technology.
Back in the late 80's early 90's this show ran on channel 4 hosted by Tim Hunkin and Rex Garrod. It is one of those sciencey things I remember fondly from my youth and it stands up well even today.
It's a funny and interesting look at how things work with lots of demos made by Hunkin and Garrod to show the principle of things.