One of my favorite show from the early days of Discovery Channel was a British import called
Secret Life of Machines hosted by tinkerer Tim Hunkin. If you haven't seen it, it was a British TV series that explores how things work in a wonderfully oddball way.
Well, come to find out Hunkin is still around. He has his own YouTube channel and is producing new "Secret Life of... " content..
https://www.youtube.com/user/timhunkin1His explanations are broadly overarching but they serve perfectly well to get general points across. He's still as delightfully oddball as ever, albeit with a bit less hair and a few more wrinkles. Hunkin's dry delivery, hands on approach, and occasional intellectual "wink and nudge" to the viewer make the overall presentation a decently enjoyable and educational way to spend 30 to 45 minutes. He even has the original shows remastered and posted to the channel.
Brad