If you revamp and update this device, you could submit it to the Design Gadget Freak column. We pay $500 for complete Gadget Freak entries. If you're interested, send me a note at email@example.com and I'll send along the details.
Nowadays, I would update the power supply with a voltage regulator IC and update the op amp, but I think you'll like the simplicity. Hint: two precision thermistors, a 25-turn pot and a voltage comparator op amp.
I grew up on Popular Electronics. Every project was very well documented with schematics and wiring diagrams and parts lists. I seem to see too many of these GF articles not even up to the standards of PE in the good old days - 50's and 60's.
This column needs to be presented with better editing. I agree that many of these GF cases are incomplete and have indecipherable or incorrect schematics and incomplete parts lists like this one and dead end links. Even Design News has had too many errors lately.
I know the audience is full of engineers but who needs to have work so hard to read the article? When these projects are presented with a half baked presentation it is disrespectful to the author and to the readers. And a pain in the @ss to read. It takes the fun out of it.
So PLEASE put a little time into editing and put everything, photos, schematics, BOM's etc into the article on the same page or have links that work.
I found that a far simpler means of solar water heating was to submerge a black plastic sheet in the pool when it was not in use. The sheet did ned to be well below the surface, so as to heat a larger volume of water, it could even be on the bottom, out of the way. It was not hard to remove for serious pool use, and it consumed no energy, and it was very cheap.
Most gadget freak write-ups, it appears to me, are incomplete in one way or another. The result is that the missing order number for the dual temperature controller is to be expected. Just attempt to find a circuit, or some other critical build information. Usually some vital information is missing. That is what to expect.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
The IEEE Computer Society has named the top 10 trends for 2014. You can expect the convergence of cloud computing and mobile devices, advances in health care data and devices, as well as privacy issues in social media to make the headlines. And 3D printing came out of nowhere to make a big splash.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.