sci.electronics.repair@googlegroups.com

Google Groups

N_Cook <diverse@tcp.co.uk>: May 09 11:25AM +0100 Trying to keep some 1960s junk going. Uses a long thin 1.5V motor so CD motors won't fit. A failed brush/contact. Before I randomly open another CD/cassette motor to rob a brush, anyone know the what the material is? All I've found so far is phosphor-bronze carriers with a brush insert, but the original is either 2 or 3 fingers conjoined, 2 on one side 3 on other side of the comutator, of a non-magnetic strip material, shiney material like tin, but obviously must have some spring and withstand spark errosion.

"pfjw@aol.com" <pfjw@aol.com>: May 09 04:42AM -0700 On Monday, May 9, 2016 at 6:25:34 AM UTC-4, N_Cook wrote: > Trying to keep some 1960s junk going. Uses a long thin 1.5V motor so CD > motors won't fit.   The brush material is graphite often with various admixtures depending on the application, voltage and other requirements. There are thousands of types and at least dozens of sources for specific brushes, including Amazon. Do a search for Aftermarket Motor Brushes.   I suggest you look for something close, and then careful application of a file or Dremel tool could do the rest. DO THIS AWAY from anything electrical as the carbon dust is very fine and very conductive. If done in doors, you will find that fine dust will travel many feet. Wear a particle mask as well, as it could also get into your lungs.   Peter Wieck Melrose Park, PA

N_Cook <diverse@tcp.co.uk>: May 09 12:57PM +0100 > I suggest you look for something close, and then careful application of a file or Dremel tool could do the rest. DO THIS AWAY from anything electrical as the carbon dust is very fine and very conductive. If done in doors, you will find that fine dust will travel many feet. Wear a particle mask as well, as it could also get into your lungs.   > Peter Wieck > Melrose Park, PA   That is the 3 motors I've broken into , the original has shim thick tiny fingers of metal, flexed against the comutator. Reminds me, last week, I was surprised to see 2 inch squares of gold leaf in a food supermarket. Apparently some people eat this stuff, 23 carat gold foil, 2 such squares per pack, thickness not stated, 3GBP

Clifford Heath <no.spam@please.net>: May 09 10:57PM +1000 On 09/05/16 21:57, N_Cook wrote: > Reminds me, last week, I was surprised to see 2 inch squares of gold > leaf in a food supermarket. Apparently some people eat this stuff, 23 > carat gold foil, 2 such squares per pack, thickness not stated, 3GBP   I think if you did the investigation you'd find that the folk why buy it are quite thick.

"pfjw@aol.com" <pfjw@aol.com>: May 09 08:40AM -0700 On Monday, May 9, 2016 at 7:57:50 AM UTC-4, N_Cook wrote:     > That is the 3 motors I've broken into , the original has shim thick > tiny fingers of metal, flexed against the comutator.   AH! that is an OLD Mabuchi-style hobby motor cheap as cheap can be.   Those fingers are spring bronze, very thin and relatively hard to duplicate as the bronze alloy is a delicate balance between being too hard and not having enough spring. Too hard would eat into the commutator, not hard enough would anneal and fail quickly.   http://www.mabuchi-motor.co.jp/en_US/technic/index.html   May be a link to some source for OEM parts.   Peter Wieck Melrose Park, PA

N_Cook <diverse@tcp.co.uk>: May 09 04:51PM +0100 > May be a link to some source for OEM parts.   > Peter Wieck > Melrose Park, PA   The metal is not any sort of yellow colour, tin/silvery colour throughout, so not a plating over bronze of any sort

ggherold@gmail.com: May 09 09:42AM -0700 On Monday, May 9, 2016 at 7:57:50 AM UTC-4, N_Cook wrote: > Reminds me, last week, I was surprised to see 2 inch squares of gold > leaf in a food supermarket. Apparently some people eat this stuff, 23 > carat gold foil, 2 such squares per pack, thickness not stated, 3GBP   I think gold leaf is used as a garnish on Indian sweets. https://en.wikipedia.org/wiki/Vark   Something like that.   George H.

avagadro7@gmail.com: May 08 06:28PM -0700 why are stereo equipment fuses glass tubes in cylindrical holders, auto fuses in vinyl holders fuses set in plastic cases with 2 connecting prongs out the bottom. ?????

ohger1s@gmail.com: May 08 06:48PM -0700 > why are stereo equipment fuses glass tubes in cylindrical holders, auto fuses in vinyl holders fuses set in plastic cases with 2 connecting prongs out the bottom. ?????   Because automobiles have a lot more fuses, and the color coded plastic fuses allow for a smaller denser fuse box as well as quickly identifying rating by color.

Clifford Heath <no.spam@please.net>: May 09 04:49PM +1000 > why are stereo equipment fuses glass tubes in cylindrical holders, auto fuses in vinyl holders fuses set in plastic cases with 2 connecting prongs out the bottom. ?????   Stereo equipment fuses generally blow at much lower currents, so use thinner wire that would corrode and reduce the rating. Plus they're often at mains voltage (or much higher than 12V) so a shield is a good idea.   Clifford Heath

Phil Allison <pallison49@gmail.com>: May 09 12:42AM -0700 > why are stereo equipment fuses glass tubes in cylindrical holders, > auto fuses in vinyl holders fuses set in plastic cases with 2 > connecting prongs out the bottom. ?????   ** Flat blade fuses and matching holders are relative new comers specifically designed for automotive and other 12V DC use - they have taken over in that job from glass tube fuses in the last decade or so.   Stereo equipment makers have no reason to change.       .... Phil

Bruce Esquibel <bje@ripco.com>: May 09 11:53AM > Because automobiles have a lot more fuses, and the color coded plastic > fuses allow for a smaller denser fuse box as well as quickly identifying > rating by color.     It wasn't always like that though, at one time the glass fuses in cars were standard. They weren't in cylindrical holders, they laid flat in a fuse block.   But you are correct about the count/density being a factor. I had a 1964 Buick which only had 8 or 9 fuses total. There just wasn't much in the electrical system to protect.   On the other extreme, like the 1997 Lincoln Mark VIII, there is something like 35 fuses for all the accessories. It's only about a 4"x4" square on the side of the dashboard, easy to get to, easy to examine.   35 glass fuses would take up a big chunk of real estate under the dash and would probably be a nightmare to access.   If you are asking why they don't use the colored plastic ones in the stereo hardware, I think the answer has to do with the difference of how a fuse behaves with 12v or 120v/240v passing through them.   The glass fuses usually vaporize when they blow, reducing the chance of an arc or flash to reseal the link. The 12v fuses just have a weak, short element that blows between two points.   I guess there is some possibility of the fuse "re-sealing" itself under certain circumstances (none of which I can think of).   -bruce bje@ripco.com

avagadro7@gmail.com: May 09 06:35AM -0700 https://goo.gl/xhrGmb   the 400 watt Kenwood amp mounted on the van's metal partition fuses with a blade type auto fuse.....on DC   on DC. My unconscious assumption was modern plastics were capable of AC 110V.   the air clearance in a glass fuse is prob commercially economic visavee capable plastics.   my designed in 1946 PV544's manual boasts a one page electric schematic. The 2008 Ford E250 runs 0ver 100 pages for 'problem solving' with equipment. IE poke meter into connector hole there >   bought an analyzer....

Jeff Liebermann <jeffl@cruzio.com>: May 09 08:52AM -0700 >why are stereo equipment fuses glass tubes in cylindrical holders, >auto fuses in vinyl holders fuses set in plastic cases with 2 >connecting prongs out the bottom. ?????   1. Glass and ceramic cylinderical fuses have the fuse wire soldered to the end caps. If you were to do the same thing using a plastic tube, the heat from the soldering operation will melt the plastic tube.   2. Automotive style plastic fuses, also known as blade or spade fuses, use a stamped fuse wire. You can only make a stamped wire so thin before it falls apart. The minimum value I could find for cartridge fuses is 0.080A. The minimum value I could find for automotive fuses is 1 amp: <http://www.littelfuse.com/products/fuses/automotive-passenger-car/blade-fuses.aspx> Speaker protection fuses need to be fairly low current: <http://www.barryrudolph.com/greg/fuse.html>   3. Glass and ceramic cylinderical fuses are typically rated at 117 and 230VAC insulation. Plastic automotive fuses are 32v and 58v. Note that it is possible to obtain UL listed blade fuses: <http://www.optifuse.com/blog/p100201.php> but not for use at 117/230VAC.   4. For stereo equipment, glass fuses can be chrome or gold plated to make them look "cool" and expensive. Same with gold and chrome plated cartridge fuse holders. Plastic fuses are comparatively ugly. <https://www.google.com/search?tbm=isch&q=gold+audio+fuse>   -- 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

Jeff Liebermann <jeffl@cruzio.com>: May 09 09:03AM -0700 On Mon, 09 May 2016 08:52:24 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:   >The minimum value I could find for cartridge fuses is 0.080A.   I didn't look hard enough. Make that 0.062A minimum in 3AG size: <http://www.littelfuse.com/products/fuses/cartridge-fuses/3ab_3ag-6_3x32mm-fuses/312.aspx> Note that it has a resistance of 24.7 ohms which much too high for many applications. There are also fuses on the list down to 0.010A, but they are listed as obsolete.   -- 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

Micky <NONONObobbyburns1111@gmail.com>: May 08 01:55PM -0400 On Fri, 06 May 2016 16:56:39 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:     >I had a good example of longevity. I had an SCO ODT 486DX2/66 server >running in my office 24x7 for about 15 years. I did manage to destroy >a few CPU and power supply fans (if it moves, it breaks), but most   Yes, I've noticed that. One time 40 years ago a neighbor asked me what kind of TV to buy, and I said, All I know is don't get mechanical tuning, get electronic. When I was over there next, it had a turret tuner**, but I kept my mouth shut. Why did they even ask me, I wondered.   **It was very easy to turn the knob, easier than any other that I've seen before or since. I think it was mechanical, unless there was for a while some sort of electronic channel selector that involved rotating a knob. ??   >largely a function of operating time. So, if your xmitter is full of >junk electrolytics, you might have more problems with continuous >operation.   Thanks. And thanks, Jur.

avagadro7@gmail.com: May 08 06:40PM -0700 SCOOP   http://www.nytimes.com/2016/05/08/science/just-how-much-power-do-your-electronics-use-when-they-are-off.html

Micky <NONONObobbyburns1111@gmail.com>: May 09 01:17AM -0400 >SCOOP   >http://www.nytimes.com/2016/05/08/science/just-how-much-power-do-your-electronics-use-when-they-are-off.html   Dang. We have to sent everyone in Niger an electric coffee pot so they can use more electricity.   I shouldn't sound sarcastic. For years I would tell people that with the power used to light up empty public washrooms in the US, we could power the country of Chad**.   But that's not funny anymore because Chad changed its name to Brian.   **I don't know if that was/is true, but I wouldn't be surprised.

Bob Engelhardt <BobEngelhardt@comcast.net>: May 09 09:54AM -0400 > SCOOP   > http://www.nytimes.com/2016/05/08/science/just-how-much-power-do-your-electronics-use-when-they-are-off.html   "About a quarter of all residential energy consumption is used on devices in idle power mode ..." If you exclude air conditioners, clothes dryers, and electric stoves.

"pfjw@aol.com" <pfjw@aol.com>: May 09 08:55AM -0700 On Monday, May 9, 2016 at 9:55:00 AM UTC-4, Bob Engelhardt wrote:   > "About a quarter of all residential energy consumption is used on > devices in idle power mode ..." If you exclude air conditioners, > clothes dryers, and electric stoves.   YIKES!   I could put everything on a power-strip and shut everything down dead when not in actual use. BUT:   a) I would have to reprogram the presets on two tuners. b) I would have to reset/reprogram the plasma TV from "sales-all-bright" mode to normal operating mode with each turn-on. c) I would have to re-sync the multi-device remote - about a 10 minute ordeal. d) I would have to reprogram the DVR. e) Reset the clocks on the stove & microwave. f) Let the vintage AR electronics and Dynaco PAT-5 "warm up" for about 15 seconds before allowing any sound through.   And, here is the grand total of the savings:   a) Two tuners "off": 3 watts b) Plasma TV: 5 watts c) DVR: 15 watts d) Stove & Microwave: 5 watts e) AR amp & Receiver: 6 watts f) PAT-5: 2 watts   36 watts. x 24 x 365 = 315,360/1000 = 315 kw. x $0.14 = $44.16/12 = $3.68 per month.   Most well designed switching power-supplies draw very little current when not in use. Vanishingly little.   Nor can we send our surplus power to Chad, as it happens.   Keep in mind that when we use devices such as a laptop or other battery- based items, the net use is pretty much the same whether we allow the battery to discharge between uses or not.   Peter Wieck Melrose Park, PA

ggherold@gmail.com: May 09 06:30AM -0700 On Saturday, May 7, 2016 at 8:18:08 AM UTC-4, jeanyves wrote: > http://kripton2035.free.fr/esr-repository.html   > --   > Jean-Yves.   (Nice link, thanks.) George H.

tomjenrobinson@gmail.com: May 08 02:02PM -0700 Hi you don't know me but I saw your Fred on Google and I think I may have what you're looking for this is the video player machine Sears Roebuck made before betamax came out the model number is 5285200204

Michael Black <et472@ncf.ca>: May 08 09:08PM -0400

Allodoxaphobia <knock_yourself_out@example.net>: May 09 02:38AM On Sun, 8 May 2016 21:08:27 -0400, Michael Black wrote:   > The only thing worse than people who reply to old threads is people who > don't even read the full thread before replying late, to even try to see > if the problem was solved.   Google Groopers -- bless their little hearts (and other little organs.)

avagadro7@gmail.com: May 08 06:43PM -0700 Any suggestions?   PMD 620 stayed black when slid on power   BLACK SCREEN   I said   YOU MOTHERFUCKER   3 times n put it back on the dash top.   45 minute later picked it up slid power on n there we were recording     EYEEYAHHAHAHHA YOU MOTHERFUCKER $300

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.