Quote:
Originally Posted by E350
And BTW, screw the microprocessor controlled new style electric blanket controllers and go with a simple rheostat DC controller. Because if it weren't for a lifetime warranty from a company that cares, Lands' End, my home use ~$250 120v AC electric blanket would be worthless.
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Well if you are looking to limit your power usage then you would not want a rheostat. When you reduce the output of the blanket, that power is consumed by the rheostat. The microprocessor unit will most likely implement some form of PWM to control the output. We will essentially be turning the it on and off in rapid succession, the duty cycle (time on versus time off) will determine output. So if we wanted it set low, we would be consuming far less power.
Quote:
Originally Posted by E350
Since we're drifting away from the OP anyway I'd be curious from an electronics POV why a MSW source would fry microprocessors. With today's glut of these types devices its something we all need to know more about.
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So I suspect in most cases it not the microprocessors itself but the supporting logic, not that it matters.
DaveB was pretty much on track when he brought up Harmonics. Noise is something we worry about in every electronic design, you can specialize and be a signal integrity. There are all sorts of rules, and design guides to minimize or reduce noise. In all those cases you would expect to start out with a clean power source.
There is the difference in a MSW and PSW. The PSW is similar to what comes out of your wall. In reality the MSW is a modified Square Wave.
The first thing that you might not see work on device would be a timer or clock, since the sine wave was at 60 Hz it was relatively easy to track the zero crossover point for a timer. Using a MSW as you input would throw that off, a clock on your microwave would be a good example if you left it in running on your inverter.
The other main thing is power, I guess I would liken the power output of the MSW to running your tools off of 200 ft of 16 gauge extension cords, sure it may run, does not mean it is running good or that you are not putting extra stress on it. A simple test would be to make a bag of microwave popcorn in your microwave. Use the same time settings running through shorepower and a MSW. I expect that you will see a difference in how much of the popcorn actually pops using the MSW.
Typically MSW will boast of a higher efficiency factor in their power conversion. But that is just stating cost of the conversion, and doesn't take into the actual reduced about. You may have a MSW that boast of 90% efficiency, but when compared to the PSW that is listed at 85% it still uses more power overall.
I expect that many things that were listed as not working on MSW now work only because of the better design in the power brick.
I have had a MSW for 11 + years, and only have one device that didn't work for me. (But I really don't run much on the inverter). I am currently switching to a Pure sine wave unit, but I would say that decision was weighed more with the built in charger section than the inverter part.
-greg