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USB-C charging law in the EU.

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nctnico:

--- Quote from: tooki on November 16, 2023, 08:00:24 am ---
--- 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.

--- End quote ---
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.

--- End quote ---
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).

--- End quote ---
The problem is that high current surges aren't a problem for batteries but a power supply typically doesn't like them. So you'd need a huge PSU to replaces the batteries of a cordless drill (for example). Somebody I know has experimented with this and his results wheren't stellar. If you want a corded power tool, buy a corded power tool.

Siwastaja:

--- Quote from: nctnico on November 16, 2023, 11:35:02 am ---The problem is that high current surges aren't a problem for batteries but a power supply typically doesn't like them. So you'd need a huge PSU to replaces the batteries of a cordless drill (for example). Somebody I know has experimented with this and his results wheren't stellar. If you want a corded power tool, buy a corded power tool.

--- End quote ---

I have used a cordless drill with a dead battery from a PSU in a pinch and can confirm that a 12V 30A Meanwell clone power supply (look at how big these are) was needed to be able to do anything and even that sagged (10A lab supply was tested first, totally unusable). And it was a supply capable of working in CC mode; those that fault out or enter hickup mode are unusable. A simple 18650 power cell easily puts out 30-40A of peak current. Many 18650 power cells are actually tested for a full continuous discharge cycle at as high as 25A; sure the cell temperature would be beyond 60degC at the end, but that's also why professional power tool chargers have battery cooling: they can bypass long cooldown waiting times.

wraper:

--- Quote from: tooki on November 16, 2023, 08:00:24 am ---
--- 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.

--- End quote ---
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.

--- End quote ---
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).

--- End quote ---
Then you will need very thick or very short wires to provide reasonably low voltage drop to not hinder performance. And again, PSU price will be prohibitive to the point of making no sense of using this contraption rather than just buying another tool that works from mains voltage natively.

coppice:

--- Quote from: Siwastaja on November 16, 2023, 07:05:05 am ---
--- 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.

--- End quote ---

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.

--- End quote ---
Big enough brush/commutator combinations will run for years without maintenance. The snag is people want their hand held power tools to be hand sized.

Siwastaja:

--- Quote from: coppice on November 16, 2023, 01:03:52 pm ---The snag is people want their hand held power tools to be hand sized.

--- End quote ---

Yeah. I think the biggest advantage in BLDC power tools was not efficiency or even performance increase, but it made those tools visibly smaller and lighter.

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