- Rechargeable battery question - 3 Updates
- Heat sink grease - 1 Update
| "~misfit~" <shaun.at.pukekohe@gmail.com>: Apr 20 01:32AM +1200 Once upon a time on usenet John-Del wrote: > external charging as you suggest. I was just looking for an easier > way out (which is my defining personality trait...) > Thanks everyone. If it were mine I'd retro-fit a single battery made from lithium Ion cells with two buck converters to give your two supplies. -- Shaun. "Humans will have advanced a long, long way when religious belief has a cozy little classification in the DSM*." David Melville (in r.a.s.f1) (*Diagnostic and Statistical Manual of Mental Disorders) |
| John-Del <ohger1s@gmail.com>: Apr 19 06:47AM -0700 On Thursday, April 19, 2018 at 9:32:41 AM UTC-4, ~misfit~ wrote: > If it were mine I'd retro-fit a single battery made from lithium Ion cells > with two buck converters to give your two supplies. > -- The two supplies don't share a common ground. |
| Jeff Liebermann <jeffl@cruzio.com>: Apr 19 09:15AM -0700 >Turns out that hobby store brass sheet can be cut into battery tabs. >It welds very easily. I wouldn't use it for anything high current tho. You might want to try H-type nickel battery strips like this: <https://www.ebay.com/itm/183182559640> Ideally, you want mostly nickel strips, not nickel plated steel, but I've managed to make it work. I couldn't find any H-Type pure nickel strips on eBay. With an ordinary strip most of the current goes through the strip, with less current going through the stainless battery can. With an H-type strip, the electrodes straddle the slot. This increases the resistance of the strip as the current now needs to go around the slot. That results in a larger portion of the current going downward and through the battery can. I'm not sure using brass for electrodes is a great idea. I've never tried it. The resistivity of copper and brass are: copper 1.7*10^-8 ohm-meters brass 8.0*10^-8 ohm-meters making the resistance of identical wires roughly 4.7 times higher for brass. <http://www.radio-electronics.com/info/formulae/resistance/resistivity-table.php> If you look at photos of commercial spot welder electrode tips: <https://www.google.com/search?q=spot+welder+electrode+tips&tbm=isch> methinks you'll find that most of them are copper, not brass. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| "~misfit~" <shaun.at.pukekohe@gmail.com>: Apr 19 09:54PM +1200 > for example, I will take the old part and put it on top of the new > part so it spreads the force and isn't likely to break the case. > Squeeze the whole shebang until no more comes out. In my opinion you should never 'squeeze' it tighter than the clip / fastener is going to hold it. Otherwise you squeeze too much out and are left with voids. > leaving rather voids" > Hopefully those voids are where metal to metal contact was actually > achieved. They are usually under spring pressure. No such luck. They're usually where there was little contact. Metal-to-metal tends to stay that way duriung thermal cycling as long as pressure is constant. I've done a lot of work on laptops, a lot of them nasty to get into so it's best to do it right first time. I've also lapped more than my share of CPU 'spreaders' (IHSs) and (desktop machine) heatsink bases. -- Shaun. "Humans will have advanced a long, long way when religious belief has a cozy little classification in the DSM*." David Melville (in r.a.s.f1) (*Diagnostic and Statistical Manual of Mental Disorders) |
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