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by theamk 501 days ago
It is less and less likely... motor-based clocks are a thing of the past; hand appliances (like mixers and blenders) use either DC or universal motors to allow speed control. Even refrigerators feature "variable speed motors" nowadays, which means they are frequency-independent.

I think fans will likely be the last devices which care about frequency.. but new ones are often 12V/24V-based, with a little step-down modules.
4 comments
quickthrowman 501 days ago
Most commercial AC fan and pump motors are already powered by variable frequency drives, and a lot of newer residential appliances have EC motors to allow for speed control.

I’m seeing more and more EC motors in commercial applications, for things like 2-3 HP fam motors and pumps.

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satiric 501 days ago
What about dryer motors? I mean, I don't much care what rpm the dryer runs at, but it should change speed with the grid frequency right?
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bluGill 501 days ago
Modern dryiers are generaly run on a phase converter so while the motor is ac the frequency is controlled by a computer.
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kencausey 501 days ago
I wonder if resistive heating devices like ovens which have a tuned temperature component would become systematically less accurate if the frequency changed significantly.
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smallmancontrov 501 days ago
Nah, the thermal time constant is a low-pass filter on the order of .01Hz, all of the line frequencies in this thread are waaaay higher than the control loop bandwidth. The loop would never notice the substitution.

You might be able to trip up a fancy soldering iron where loop bandwidth is intentionally maximized, but I still suspect the first thing to go would be the magnetics on anything with a transformer.

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exmadscientist 501 days ago
> first thing to go would be the magnetics

Yes, but not for the reason you'd think: 50 Hz magnetics have to be physically larger to work (peak flux density for a given current is higher), and magnetics are so big and heavy that they're not designed with much margin. So 60 Hz transformers will often not work at all at 50 Hz, and 50 Hz transformers will sometimes perform pretty badly at 60 Hz (though also sometimes going this direction works fine).

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creeble 501 days ago
True for consumers (houses), not true for industrial applications where motors are in the >100HP range.
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bluGill 501 days ago
Fans because a furnace only needs two speeds at most.
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