Pure maths, physics, logic (braingames.ru): non-trade-related brain games - page 96

[[Deleted]]

alsu: There are windings on the rotor and they are connected to electricity. They're not just for show.

The rotor is what turns. It's the stator, even though it's in the centre. Otherwise you would need brushes and a collector and that would make the design more complicated, more expensive and less reliable and durable.
You also have to consider the low power consumption and the high efficiency. That's what makes it work.

[Dmitry Fedoseev]

It seems to be an asynchronous motor. No commutators, no manifolds, no hall sensor either. The electronics just switch the coils, the field rotates pulling the permanent magnet rotor with it.

[[Deleted]]

Integer:
It seems to be an asynchronous motor. No commutators, no manifolds, no hall sensor either. The electronics just switch the coils, the field rotates pulling the permanent magnet rotor with it.

What do you mean you don't need it? It's not AC powered, it's 12 volt DC. The sensor is in the microcircuit and is switched by the magnetic field of the rotor. And the windings are supplied with alternating current by this.

[[Deleted]]

Integer:

If a direct current of 12 volts were applied to the stator windings, with the rotor spinning, the fan would jam instantly, its blades stopping instantly. This effect is used to brake asynchronous motors.

[Alexey Subbotin]

DmitriyN:

current is supplied where the windings are, otherwise there is no point in them.

What to twist it all the same, you can't do without switching the magnetic field, which means it won't work with permanent magnets - it will just get stuck at the nearest dead point, regardless of efficiency, whether it's 99.9999 percent, if the input is 0, then the output is 0 as well.

[Dmitry Fedoseev]

DmitriyN:
If a 12 volt DC current were applied to the stator windings, with the rotor spinning, the fan would jam instantly, its blades would stop instantly. This effect is used to brake asynchronous motors.

You are so amazingly persistent... But there were three (3) sentences in my post and you seem to have only read two, read the third one:)

[[Deleted]]

alsu:

Alsu, do you know what reedlocks are? What do magnets have to do with it? It has nothing to do with them. Note that the fan leads are shorted and at the end you can't see them at all. The whole secret is not in the reed, of course, but in the transistor on the board. This is the one that generates the current by cooling. Here, I found a schematic. You put a magnet close to the reed switch and the fan turns on. Simple as that.

[Alexey Subbotin]

Integer:

I think that only in modern Russia would put electronic circuits in case fans)). Bourgeois count well and design the simplest, otherwise the fan would not cost 100 rubles. This is why computer fans only use cheap brushless DC motors, which produce much less electromagnetic interference than asynchronous motors.

[Alexey Subbotin]

DmitriyN:
Alsu, do you know what reedlocks are? What do magnets have to do with it? It has nothing to do with them. Note that the fan leads are shorted and at the end you can't see them at all. The whole secret is not in the reed, of course, but in the transistor on the board. It's the one that generates the current by cooling. Here, I found a schematic. You put a magnet close to the reed switch and the fan turns on. Simple as that.

Yeah. If you put a battery in front of the wires and screw it on, it turns on too.

[Alexey Subbotin]

The pins on the diagram, by the way, are drawn for a reason