Arduino Controlled Dishwasher
neonsquirt.com
neonsquirt.com
I wonder if he think his little project was worth not buying the $150 replacement part? Clearly it was a lot of fun.
(They also have an interesting bit of poor design that has caused them to leak out water onto my floor after a plastic part broke. Sigh.)
There are high end brands who have a guarantee of more than 10 years, but they're expensive and the cost per year comes about the same as the cheap ones.
One particular case was the refrigerator. No matter how much we cleaned it it smelled like mildew. As it turned out not only were the door seals bad, the internal liner was breaking down and the foam insulation had degraded. Replacing it with an A+++ rated model was the best thing to happen to us. Not only was it quieter, it only runs 1-2x per day, has more internal storage, and it cut the electric bill by 20%. This thing will pay for itself in 2 years with the electric bill savings only.
There are many things to be said about making old devices work again but sometimes you have to ask if it's really worth it. I'm pretty certain that old refrigerator pump would have ran for another 20 years.
But in bigger companies, there's the issue of standardisation: A company policy might mandate that all test-automation has to be done with LabView, so even a simple "dishwasher complexity" device might be implemented on a dedicated PC because it's just cheaper to shell out the $1000 for hardware than to re-train engineers to do Arduino on a $20 board.
Or some other company (possibly more industrial automation inclinded) might do everything with Siemens-S7 controllers.
This is why in reality you often see things setup with the apparently wrong tool for the job, but limiting the number of choices might make (business) sense.
The lifetime of the solid-state-relay will be reduced if you don't use the proper subber circuits (see for example the S202S02F datasheet found as the first google hit).
A old-school mechanical relay might be a better fit.
To drive mechanical relays, the ULN2003 is a very handy part. It's 7 transistors + freewheeling diodes + resistors in one 16pin DIP.
Thanks for pointing out the snubber circuit. I hadn't noticed and am about to build a project with the S202. :-)