Tag Archives: science channel

How do modern Vending Machines know what coins You put in? Science, Technology & Curiosity 23 MAR 2016

How do modern vending machines know what coins you’ve inserted? Well, according to this fantastic CG animated segment from the Science Channel, current day vending machines make use of a combination of light sensors to accurately measure the size of the coin being dropped in, and electromagnets to determine the metal type of the coin rolling past. Together this information provides the onboard computer with enough information to make a pretty accurate guess as to what coins have been inserted, allowing it to then calculate and distribute change if necessary.

A bonus for anyone who has ever had a fight with a vending machine before, modern machines detect whether or not an item has dropped into the retrieval chute by means of light beams – and if nothing has indeed dropped down, the computer simply tries again! (That would have saved me a LOT of frustration in my university days!)

Very clever.

vending machines

Related Link: Science Channel

How Does the Cue Ball Stay Separated from the Colour Balls? Science, Technology & Curiosity 17 MAR 2016

I enjoy the odd game of pool every now and then, and if you are the same, then you have undoubtedly at least once given thought as to how the white cue ball remains separated from the colour balls when it drops down a pocket.

As it turns out, the answer is quite a simple trick. Magnets.

Essentially the cue ball contains metal, which then thanks to the pull of a large magnet along the unseen ball tracks beneath the table, is thrown down its own special track each and every time it rumbles down a table pocket.

The Science Channel details this clever trick in their wonderfully animated explanation video:


colour balls for a game of pool

Related Link: Science Channel