- wire conductivity - 3 Updates
- Lithium powered things not charging? - 2 Updates
| gregz <zekor@comcast.net>: Jan 10 09:06AM > and twisted in a drill for easier handling. Quite manageable and extremely tough. > Peter Wieck > Melrose Park, PA Some notes on speaker wire. https://passlabs.com/press/speaker-cables-science-or-snake-oil Greg |
| jurb6006@gmail.com: Jan 10 03:35AM -0800 The page would not load for me, but I got this to say. I don't buy this snake oil shit. As long as the gauge is thick enough to allow good damping and not lose signal you are good to go. As far as I can tell, the best speaker wire would be solid, like Rpmex that is in a casing which will force the two leads to run parallel. Nelson Pass designs little three watt amplifiers n shit like that, there is no appreciable magnetic field. Audiophiles swear by them though. They also like single ended triode tube amps. This is where you take a 6L6 or 1 6550 per channel and rock the house with five watts. They replace perfectly good capacitors with super expensive ones which supposedly sound better. He is obviously pandering to those who do not know electronics. Float your scope and the DUT, put the scope probe across any coupling cap in there and if all you see is DC it is good enough for the job. Same with filters, if all you see is DC it is good enough. I mean they do the cap job on single ended amps. In some cases you might get a little more oomph out of a class AB amp upping the value of the main filters but you are not getting more power. All you get is more time at your dynamic headroom point before the voltages drop to the steady state power point. Same shit a few milliseconds later. I have indeed heard the difference when speaker wires are of insufficient gauge, but it was an extreme demonstration.. fifty feet of zip cord that was maybe 28 gauge or something. Not much fatter than telephone wire. |
| Ralph Mowery <rmowery28146@earthlink.net>: Jan 10 11:09AM -0500 In article <602f6567-bd60-4255-9fa1-88b73d2a4e98@googlegroups.com>, jurb6006@gmail.com says... > He is obviously pandering to those who do not know electronics. Float your scope and the DUT, put the scope probe across any coupling cap in there and if all you see is DC it is good enough for the job. Same with filters, if all you see is DC it is good enough. I mean they do the cap job on single ended amps. > In some cases you might get a little more oomph out of a class AB amp upping the value of the main filters but you are not getting more power. All you get is more time at your dynamic headroom point before the voltages drop to the steady state power point. Same shit a few milliseconds later. > I have indeed heard the difference when speaker wires are of insufficient gauge, but it was an extreme demonstration.. fifty feet of zip cord that was maybe 28 gauge or something. Not much fatter than telephone wire. When they can sell about 6 feet of wire to go from the equipment to a wall socket for over $ 100 , it proves they will buy most anything. That wire must be some oxygen free, special insulated wire or some such snake oil coated. There is no way the wire of the same gauge is going to be noticed when there is probaly over 50 feet of cheep wire from the socket to the breaker box of the house and hard telling how many miles of even cheaper made wire to the power company. |
| "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>: Jan 09 09:07PM "T i m" <news@spaced.me.uk> wrote in message news:2i327cpri8vc4hgb1bof0fghjafouoh7t1@4ax.com... > genuine Samsung one, they sent her a generic jobby (and only 650mA). > Along the way (and not helped by the charger thing) she's allowed it > to go flat and now it won't charge up again All the books are telling me that there's a critical minimum discharge voltage that going under damages the cell. Anything worth having should have a UVLO circuit to prevent that happening - I'd take it back and tell them its not fit for purpose. Refurbs usually only have 90 day warranty - so get your skates on. |
| T i m <news@spaced.me.uk>: Jan 10 11:47AM On Mon, 9 Jan 2017 21:07:14 -0000, "Benderthe.evilrobot" >> to go flat and now it won't charge up again >All the books are telling me that there's a critical minimum discharge >voltage that going under damages the cell. Agreed. >Anything worth having should have a UVLO circuit to prevent that happening - And most good devices do of course, however, they may only be protected from everyday full discharge conditions, not being left uncharged indefinitely (battery self discharge)? >I'd take it back and tell them its not fit for purpose. >Refurbs usually only have 90 day warranty - so get your skates on. That was the plan but there is now an update (and some egg on face). Recap: Daughter ordered the refurb Tab2 after my suggestion because of the cost, and there wasn't much about that was also 3/4G ready (and network unlocked). It arrived very quickly and when she unpacked it it *appeared* they had just sent the tablet, charging / data cable and the two pin Uk charger plug adaptor, not no charger itself. So, because it came with some initial charge she was able to play with it and confirmed it would do what she needed. It seemed to accept some charge using other USB chargers (we have many) and that was that. She didn't want to take it out till she had a decent case so put it to one side and ordered an Otterbox defender that took a while to go though. She mounted it in the case, tested that it still worked and put it aside again. In the meantime she had contacted the supplier re the missing charger and they quickly sent a generic (only 650mA, not the Samsung 2A) one though. I tried the charger but only saw the charging loop issue (and it was too flat to turn on by now) and no other charger seemed to make matters any better, including a genuine Samsung 2A one that came with a Samsung phone. Then I did some Googling and posted here, assuming the tablet had gone into what appears to be a known under voltage / loop state. I then contacted the supplier, went though what we had done so far and they emailed her a courier collection / returns document and I went to pack it all up ready for collection. As I picked up the Samsung box, I felt something moving inside that felt heavier than the Uk plug adaptor pins but when I opened it up there was nothing (other than said adaptor) to be seen, however, when I lifted up the blow moulded layer I found the genuine Samsung (5V 2A) charger underneath! So, I plugged it into the Tab and lo and behold it started charging properly <g> (the gold battery icon stayed on screen for a good time), however, the plug didn't seem to seat fully? Upon close inspection it looked like there was something laying across the bottom of the socket and I carefully removed it it appeared to be a 5mm length of softish plastic that could have come from the Otterbox or been there all the time (and part of the issue)? So, at this time we are keeping the tablet 'under observation' and will discharge it completely to make sure it continues to recover ok (although if it recovered from the previous depth of discharge there is no reason it shouldn't ... *unless* it's an intermittent problem. Anyway, I thought I'd relay what actually happened in case it helps anyone else and thanks to all who replied. ;-) Cheers, T i m |
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