A Quest for KISS
I will never forget the lesson Don Colvin, a Designer and Manufacturer of Electronic Devices taught me. It was his collection of products designed to restrict unauthorized toll calls, which was a note worthy problem of the day.
Some of the devices Don had purchased for study looked like full blown micro computers of the day with specialized tone decoder boards hanging off the bus using phase lock loops ICs and other neat and expensive stuff. A power supply and steady state fan, blinking lights, and a terminal and keyboard to program it..
At the end of looking at more than a half dozen solutions, Don produced his own product, it was a circuit board just a little bigger than a 20 pin PIC processor with a few external components, and it was telephone line powered! Furthermore, you could program it right from the phone, and hide it neatly inside a phone jack, or near anywhere you wanted to put it.
How could I ever forget! It was a lesson as memorable as getting into the high voltage section of an old TV set! Don had spent his time researching how to build a KISS product. He expanded the market to folks who wanted to protect a single phone in their apartment!
Certainly you understand if you can make a product with the same functionality for one dollar that your competitor makes for $100, your competitor will soon realize he has a large marketing problem.
So today, I’m spending time researching a way to detect whether I have about 4-20 amps of current, (more or less is good). 120-240 VAC 50-60hz flowing on typical insulated 10-12 gauge wire with a motor or pure resistance load at the far end.
All I need is a yes or no.. and I don’t even need a quick yes or no. certainly it would be nice if we could attach our inexpensive current sensor without lifting a wire from a terminal block, but we can’t have everything.. or can we?
So of course, I Google (logic level current sensor) and similar, I finally arrive at this page:
I look at the unit price even at 1000 units, and I ask… are you kidding?
And here’s that neat little led on my water heater, one for the top element, one for the bottom element and powered directly from that mini transformer!
Yes, that’s an LED, and if we can light this led directly from that little coil, there’s little doubt we can use an opto isolator and give ourselves a clean logic level change into the input pin of a PIC, or maybe an 8 pin Atmel?
You might ask why we bother? My answer is we are unwittingly doing all we can to raise the price of energy, and we’ll need smarter products. WE need to know when they are mal functioning early as possible.
Consider this water heater, what if we took the design one step further and warned when one of the elements was burned out?
There are other things far more difficult to detect than a water heater we normally have good access to.., we could use a tiny micro to monitor patterns of use and alarm when anomalies pattern.
If you have an idea or source, please let me know, no way GE paid more than a dollar or two for these, and it sur would be fun to find some at surplus prices..
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