I like taking things apart. Or putting them together. New piece of furniture from IKEA is like a small Christmas. It’s something different than programming, yet very similar, at least for me, in how the brain processes the (dis)assembling. Already as a child in school I liked learning how everyday objects work.
But there’s a small difference in understanding the concept and really seeing the real – production level quality design – device. Because for production level quality you need to work out all the corner cases here and there, understand i.e. real forces applied and so on.
So when I realized my 4 dollar relay is broken I decided to take it apart (irreversibly 😉), to see how the real relay looks inside. The idea is simple. You have some spring keeping the two contacts from touching and a coil that eventually pulls them together, if there’s juice flowing through it.
Here are some picture (excuse my sloppy soldering job):
To my surprise even the real life “implementation” of relay (alright, this is a cheap 4 dollar relay, not rated for high current, precise switching times, etc.) is pretty much the same as the basic concept. There’s a coil, some contacts and one of them is on a preloaded piece of metal acting as a spring.
Can’t be any simpler. How cool is that?