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USB-C charging law in the EU.

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coppice:

--- Quote from: wraper on November 15, 2023, 11:27:08 pm ---
--- Quote from: SiliconWizard on November 15, 2023, 10:10:47 pm ---When it does, either you feel like renovating the motor by changing the brushes yourself (as long as you can find the parts), or you throw it away as finding the motor itself as a spare part is even less likely. Brushless motors have much, much longer lifetime.

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If you replace brushes timely, brushed motor can last a very long time. In better tools, brushes usually have a wear protection, they electrically disconnect when become worn out to prevent motor damage. As of DIY use, they'll last forever. The downside of BLDC is that it can accumulate magnetic dust and shavings.

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50 years ago a good brushed motor lasted a very long time. Now its not just the brushes that wear. In a lot of motors the commutator wears a lot, too. I think with all the higher end motors going brushless, brushed motors have been driven into a super low cost space where quality can't be maintained.

nctnico:

--- Quote from: SiliconWizard on November 15, 2023, 10:10:47 pm ---Yep. And while efficiency per se is not that much different as you pointed out, a brushed motor will by design wear out much faster. When it does, either you feel like renovating the motor by changing the brushes yourself (as long as you can find the parts), or you throw it away as finding the motor itself as a spare part is even less likely. Brushless motors have much, much longer lifetime.

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For as long as the electronics keep working... Brushes are just a mechanical part and likely you can source ones that will fit even if the original ones are no longer available. Then again, I have never had to replace brushes in any tool used around the house. I did buy brushes for a Makita reciprocating saw which was worn more than I initially hoped for. Turns out the brushes didn't need replacing. Only some bearings and a seal.

Siwastaja:

--- Quote from: SiliconWizard on November 15, 2023, 10:10:47 pm ---Yep. And while efficiency per se is not that much different as you pointed out, a brushed motor will by design wear out much faster. When it does, either you feel like renovating the motor by changing the brushes yourself (as long as you can find the parts), or you throw it away as finding the motor itself as a spare part is even less likely. Brushless motors have much, much longer lifetime.

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Not all brushed motors wear up quickly, it's again a design decision. Larger brush area not only increase efficiency by decreasing current density, but slows down the wear. High-quality brushed motor power tools easily lasted years of daily professional use while cheap ones fail in worst cases in just few hours. Similarly, some brushed EV traction motors were good for easily 150 000 kilometers before brush swaps.

tooki:

--- Quote from: wraper on November 15, 2023, 09:04:41 am ---
--- Quote from: tooki on November 15, 2023, 08:42:08 am ---It’d certainly be trivial for the manufacturers to make an AC-powered dummy battery, akin to what’s common in cameras.

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That PSU most likely will be more expensive than AC powered tool, and likely oversized quite a bit to have enough power. I doubt you want something like 0.5-1.5kW PSU attached to the tool. Somewhat reasonable only for low power tools.

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I suggested looking to the ones on cameras: the actual SMPS doesn’t fit into the battery compartment, so the power brick is connected via a cable so that the camera stays compact (= existing accessories will still fit).

David Hess:

--- Quote from: wraper on November 15, 2023, 08:38:31 pm ---Cordless drills usually are more like electric screwdrivers that can also drill. So RPM will be like a half of an average mains powered drill that has higher RPM and no torque adjustment, so not suitable for screws. And again, cordless tools, especially cheap usually have brushed motor. BLDC is usually used in better tools. Often basically the same model comes in both variants with some performance advantage in BLDC version.
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Many of Milwaukee's M12 tools come in brushed and brushless versions, with the later offering noticeably higher performance.  I started with their brushed M12 drill but found it to be underpowered in some applications, so picked up the brushless version.  I am not sure why this is the case since both use electronic control and rely on the same batteries, but I suspect one significant difference is simply the effective number of poles in the motor.  4-pole brushed motors are only common with starter motors, so 3-pole brushless motors will have a natural power advantage over common 2-pole brushed motors.

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