That’s how. [via Reddit]
now that, may be the most humble and useful use of an animated gif yet. (now do low end (pop loose) rice cooker)
Having disassembled a variety of these suckers, I’m more interested in a detailed discussion of how the typical “flat plate AC motor” inside them works. From the standpoint of designing my own. Even a good name to shove into Bing would be nice.
For those that have no idea what I’m talking about (sizes vary, naturally):
Picture a four-inch by four-inch stack of 1/16th inch iron plates that ends up 1 inch high. They have a large hole drilled through the entire stack, roughly one inch diameter. That hole is the central axis of the fan, and is very nearly filled by a magnets-and-iron cylinder on the main shaft. The side view of the cylinder is much like a barber pole in the arrangements of magnets and iron. There’s also a thick copper tube wrapped around (and through) one side of the plates. The only other electrical component is a transformer between wall AC and the copper windings.
These suckers are obviously dirt cheap given how often they show up. But they always seem to fail in the bearings supporting the central cylinder. The cylinder moves off the center and starts ‘binding’, then the wiring overheats somewhere and you have another piece of junk. I’ve never had success “just replacing the bearings”, because placement is quite crucial and there are never any arrangements for adjustments.
The bearings are the -only- wear point, and they’re often complete drek. I’ve seen just straight brass bushings used, for instance. But now I have an entire box of the central cylinders to use … and stymied on how -exactly- the plates and windings are working.
What you’re looking at is called a “shaded-pole motor”
Wiki page and everything. Excellent. Thank you very much.
An Oscillating fan is anoying at best and tortuous to deal with at worst.
I find them to cause more discomfort than they “cure”.
Oh that seel so……. Oh its back …….. then you fix the thing so the torture ends.
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