13A / USB socket power drain?

[Tim Watts]

Yeah - that worked well with my wife's Samsung S2. I had to take that to bits and replace the lower board...

[Adrian]

I think he meant that sod's law says you always start by going the wrong direction.

[Dave Liquorice]

Assuming you are delivering a significant amount of power. No current, no volt drop. B-) But I agree it doesn't take much resistance to drop a 5 V supply 0.25 V and out of the USB tolerance.

There will still be (or should be!) the filter components I suspect they make more contribution the idle state current draw than the SMPSU.

Agree, though I can't really see these things being that useful. Especially when you can get wall warts with multiple outputs and some being capable of several amps. eg: the PortaPow Crystal, four outputs just over 4 A available either to a single port or shared.

[Hanny Z]

Much more often it?s the two little prongs on the plug on the end of the cable that fails and is very cheaply and easily replaced.

[Dave Liquorice]

eh? You guess the orientation and line it up. It's only when it won't fit that you find you have it wrong and have to flip it 180 degrees,

[Andy Burns]

Except I would expect the idle chargers to be taking under 10mW rather than 1W, have you felt one that's not supplying power? None of mine from the last 5 years are at all warm, so it's more like 2MW rather than 200MW.

[Andy Burns]

Imagine a single charger for your laptop, tablet, phone, e-reader.

Shame thunderbolt displays aren't common on PCs, I think you can get a converged USB3/thunderbolt port that can do either, maybe miniDP can be done over USB3 and we can have laptops with only USB and Gigabit ports...

[Andy Burns]

Adrian wrote:*

No you start with it right, except it feels a bit wrong, so you turn it over, then you know it's *really wrong, so you turn it again knowing it's now right you give it more of a shove ...

[tabbypurr]

5.25v to 4.75v is 0.5v drop. 44mV drop per m at 1A for 1mm2 permits 11m of 1mm2, 16m of 1.5mm2 or 27m of 2.5mm2. That's plenty for a room size run - w ith the psu in the middle you get twice that run length. Make it a figure o f 8 ring and you can go further. So distance / design needs to be considere d but is not a problem.

NT

[tabbypurr]

f 1mm2, 16m of 1.5mm2 or 27m of 2.5mm2. That's plenty for a room size run - with the psu in the middle you get twice that run length. Make it a figure of 8 ring and you can go further. So distance / design needs to be conside red but is not a problem.

Use 2.5mm2 with CPC connected to neutral wire and you can run a total of 14

0m length circuit in a figure of 8 ring configuration with the PSU halfway along. Limited, everything is, but its more than enough.

NT

[Adam Funk]

...more than once...

[Hanny Z]

That?s 360, not 270.

[Dave Liquorice]

tolerance.

A piddly little 5 W. I have a Raspberry Pi and USB HD that pulls about the best part of 3 A on start up and sits at about 0.75 A. That's just one device. I plug my phone into this distribution to charge that'll pull another amp, tablet 2 A... Oh look we are at nearly 4 A without really trying, this household still has two more phones that could be plugged in...

This is with fairly old kit not more recent stuff that'll charge at 3 A given the chance. IMHO any 5 V distribution needs to handle 10 A or more without the volts dropping out of spec at any outlet. So that impressive sounding 27 m of 2.5 mm^2 @ 1 A, suddenly becomes 2.7 m @

10 A.

You also assumed that the PSU output voltage was 5.25 V, (the upper limit) and that it was perfectly regulated and didn't drop under load.

[Dave Liquorice]

That just shows that the heat loss input can be dissipated without much rise in temperature. I bet if you looked at 'em with a thermal image camera they would be "warm". I think 10 mW is rather too low but 1 W high, 100 mW? and thus 20 MW of grid "wasted".

[Graham.]

Type "B" have 4 possible ways when you're doung it by feel alone.

Oh, and a type "A" fits rather convincingly into a RJ45 socket but DAMHIKT.

[Graham.]

Only if you keep rotating it in the same direction. Like SWMBO and curly telephone handset cables that resemble the structure of DNA.

[Tim Watts]

I bet you are so glad *cordless* housephones are the norm!

[tabbypurr]

Maybe you missed the 2nd post. With a figure of 8 ring topology using 2.5mm^2 T&E you get a distribution distance of 140m at 1A, or 14m at 10A from one single psu. Should be enough for most living rooms.

The 5.25v regulated psu was a design choice not an assumption.

NT

[tabbypurr]

14m is for one psu & 2.5mm^2 T&E, if that's not enough with 2 psus you get 28m at 10A.

NT

[tabbypurr]

Nope, overlooked something! With 2 psus you can get 3x the total length, ie 42m at 10A.

NT