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- We started the 100-foot long 10-foot wide deck high up in the California redwoods - 2 Updates
- "The Box" monitor speaker ... - 6 Updates
- Relay back emf protection - 2 Updates
- OT: Lockheed-Martin = saviour of the planet? - 3 Updates
- Can and LED floodlight possibly be as bright as a real floodlight? - 8 Updates
- GM OnStar fails where iPhone/iPad locates overturned car in ravine - 1 Update
- Electrical box ground wiring. - 3 Updates
| "Arfa Daily" <arfa.daily@ntlworld.com>: Oct 19 01:01AM +0100 > We don't actually know the distance because the hillside is steep, > so, you can't just run a 100-foot tape measure, but, it's less > than 100 feet by ten or twenty feet. The mind boggles ... With a design factor that important, wouldn't it make sense to use a laser measure ? These things are dirt cheap now, and accurate to better than a half metre. Even if you had to shin up that final tree and pin a white paper 'target' to the trunk ... Arfa |
| josephkk <joseph_barrett@sbcglobal.net>: Oct 23 06:23PM -0700 On Tue, 21 Oct 2014 20:10:10 +0000 (UTC), "Danny D." >That gives us 10,780 pounds of leeway for occupants. >But I plan to have most of the house weight supported by the redwoods, >not by the cable. I see a complete failure to account for wind loads. Wind loads on this tree house will be larger than the dead loads. Ask the owner to calculate the wind loads as well. ?-) |
| "Arfa Daily" <arfa.daily@ntlworld.com>: Oct 23 06:23PM +0100 Got an MA-120 powered monitor speaker from "The Box" (what a shit-street name for a company ...) in for repair. The output I.C is blown to pieces, but even before this happened, looks like it had had the legend ground off it. Anyone happen to know what it is ? TIA Arfa |
| "Gareth Magennis" <gareth.magennis@ntlworld.com>: Oct 23 08:01PM +0100 "Arfa Daily" wrote in message news:oQa2w.745511$ZX5.8075@fx32.am4... Got an MA-120 powered monitor speaker from "The Box" (what a shit-street name for a company ...) in for repair. The output I.C is blown to pieces, but even before this happened, looks like it had had the legend ground off it. Anyone happen to know what it is ? TIA Arfa What package is it, and is there a separate amp for the tweeter, or does it use a passive crossover? Gareth. |
| "Gareth Magennis" <gareth.magennis@ntlworld.com>: Oct 23 08:06PM +0100 "Gareth Magennis" wrote in message news:kgc2w.519718$XH2.158122@fx23.am4... "Arfa Daily" wrote in message news:oQa2w.745511$ZX5.8075@fx32.am4... Got an MA-120 powered monitor speaker from "The Box" (what a shit-street name for a company ...) in for repair. The output I.C is blown to pieces, but even before this happened, looks like it had had the legend ground off it. Anyone happen to know what it is ? TIA Arfa What package is it, and is there a separate amp for the tweeter, or does it use a passive crossover? http://uk.farnell.com/on-semiconductor/stk404-120n-e/amplifier-audio-class-ab-120w-sip/dp/2400415 Gareth. |
| N_Cook <diverse@tcp.co.uk>: Oct 23 09:08PM +0100 On 23/10/2014 18:23, Arfa Daily wrote: > is ? > TIA > Arfa Assuming no info out there. For such situations I determine which are the power rails and output and ground, "eductaed" guess the inputs , compensation, feedback etc. Put a sleeved splay-pinned TDA7293 in there and power up at half rail voltages and see what happens |
| "Gareth Magennis" <gareth.magennis@ntlworld.com>: Oct 23 09:41PM +0100 "N_Cook" wrote in message news:m2bn8e$rn1$1@dont-email.me... On 23/10/2014 18:23, Arfa Daily wrote: > is ? > TIA > Arfa Assuming no info out there. For such situations I determine which are the power rails and output and ground, "eductaed" guess the inputs , compensation, feedback etc. Put a sleeved splay-pinned TDA7293 in there and power up at half rail voltages and see what happens TDA7293 is a common part in these applications, but the Manufacturers spec of The Box's 120W RMS @ 4 ohms rules this out, being as the TDA is only 100W. Unless of course there is a separate 20W amp driving the tweeter. Or they are lying. Its probably a Chinese clone of an existing device, hence my Googling and finding the STK device. The weird thing is the STK is max rated at 6 ohms. Now, how many 6 ohm speakers are out there? Why would you produce such a device and rate it with that output parameter? (Mind you, I doubt this is the IC in question here, so this is kind of OT) Gareth. |
| "Arfa Daily" <arfa.daily@ntlworld.com>: Oct 24 01:26AM +0100 "Gareth Magennis" <gareth.magennis@ntlworld.com> wrote in message news:qKd2w.526388$_u1.307583@fx30.am4... > (Mind you, I doubt this is the IC in question here, so this is kind of OT) > Gareth. TDA7293 is indeed the correct package, so it might be. There is actually an electrolytic on the opposite end of the board that has also blown apart so badly that you can't see what value it originally was. The IC has burnt pins and print as it went up, and deposited a fair bit of soot around. I might get the IC out tomorrow and clean up a bit and see if it is actually going to be worth spending the time on. It is basically a piece of Chinese garbage, and probably not worth very much in the first place. It certainly isn't in very good condition, and doesn't look like it has been very well looked after, so it might be time to replace it anyway ... Arfa |
| bud-- <null@void.com>: Oct 23 01:53PM -0600 On 10/22/2014 3:23 PM, amdx wrote: >> 4. Diode > Slowest Opening. > Most damage to contacts. http://web.archive.org/web/20110104003731/http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3264.pdf |
| John Robertson <spam@flippers.com>: Oct 23 05:01PM -0700 On 10/23/2014, 12:53 PM, bud-- wrote: >> Slowest Opening. >> Most damage to contacts. > http://web.archive.org/web/20110104003731/http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3264.pdf This is very interesting, it raises points I had never considered such as the momentary current flow through the diode and coil, and how that can stress other parts. The two articles are good reading! It explains why (in my field of pinball repair) manufacturers stopped putting suppression diodes on the coils and instead put them in place to protect the driver devices (transistors/Mosfets, etc.). Thanks for bringing this topic up! Do note that both articles say you HAVE to protect the driver device from the back EMF!! John :-#)# -- (Please post followups or tech inquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| micky <NONONOmisc07@bigfoot.com>: Oct 18 06:24PM -0400 On Sat, 18 Oct 2014 18:56:20 +0800, "Mr. Man-wai Chang" >> as part of the fusion process,feeding directly into the grid, none of >> that messy Victorian steam and rotary generator stuff. >Would there be an emergence stop button that works? :) Of course there's an Emergency Stop button. It's right below the Open Door and Close Door buttons. |
| micky <NONONOmisc07@bigfoot.com>: Oct 18 09:31PM -0400 >If something is too good to be true ... >http://www.scientificamerican.com/article/lockheed-claims-breakthrough-on-fusion-energy1/ The problem is that for every million watts the fusion generates, it takes 1.6 million watts to retrieve the hydrogen fuel from its compounds. Also, Lockheed Martin was a misprint. It's Lockheed Morton, a guy I went to prep school with. |
| "Mr. Man-wai Chang" <toylet.toylet@gmail.com>: Oct 19 07:51PM +0800 On 19/10/14 9:31 AM, micky wrote: > compounds. > Also, Lockheed Martin was a misprint. It's Lockheed Morton, a guy I > went to prep school with. I have yet to see a blueprint that generates electricity from nuclear fusion. I would expect a fusion-powered steamer. :) -- @~@ Remain silent. Nothing from soldiers and magicians is real! / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (Fedora 19 i686) Linux 3.14.19-100.fc19.i686 ^ ^ 19:48:02 up 43 min 0 users load average: 0.00 0.01 0.05 不借貸! 不詐騙! 不援交! 不打交! 不打劫! 不自殺! 請考慮綜援 (CSSA): http://www.swd.gov.hk/tc/index/site_pubsvc/page_socsecu/sub_addressesa |
| Jerry Peters <jerry@example.invalid>: Oct 18 08:13PM > it might soften, warp, bend, buckle, or otherwise provide an excuse > for water to get to the steel. From there, it's only the anode rod > that protects the steel tank from corrosion. ALso plastic doesn't conduct heat all that well, leading to an inefficient WH. Also a gas HWH has a pretty powerful burner, mine's rated at 40,000 BTU/hour input. I suspect you suspicions about the plastic buckling/warping and separating from the steel tank are correct. |
| Jeff Liebermann <jeffl@cruzio.com>: Oct 18 01:56PM -0700 On Sat, 18 Oct 2014 20:13:17 +0000 (UTC), Jerry Peters >ALso plastic doesn't conduct heat all that well, leading to an >inefficient WH. Also a gas HWH has a pretty powerful burner, mine's >rated at 40,000 BTU/hour input. No, no. You don't want any thermal conduction through the plastic liner. The whole idea is to keep the heat inside the tank, not radiate or conduct it to the outside. That's why there's a mess of fiberglass insulation between the steel water tank and the outside cosmetic steel cover. Some people add an additional water heater insulating "jacket" on the outside of the heater. A thermal insulating plastic layer between the water and the steel tank should improve efficiency. An easy way to tell if your water heater is a piece of junk is to measure the case temperature of the water heater. Use a contact thermometer (Thermocouple or thermistor, not optical IR). It's probably the worst at the top of the heater. If the outer case is warmer than the ambient air, you're wasting energy heating that atmosphere instead of the water. Same with a refrigerator. If the case of the fridge is colder than ambient, you're cooling the kitchen. >I suspect you suspicions about the >plastic buckling/warping and separating from the steel tank are >correct. That was just a guess. I'm not so sure any more. The plastic liner and steel tank are both fairly flexible, so they can bend and bulge without breaking anything. You'll never see it because it all happens inside the tank. If they're glued together (bonded) properly, I don't think they will come apart. I was wondering why the water tank didn't have stiffening ribs, which would allow the use of thinner steel. I guess(tm) stiffening might interfere with the necessary flexing of the tank with temperature. It should also be possible to dope the alumina ceramic coating with something to help it match the coefficient of thermal expansion for the steel. Even so, stratification, and the difference between temperatures on both sides of the steel tank, will create enough of a temperature gradient to possibly microcrack the ceramic. Incidentally, it doesn't take much movement to wreck a ceramic coating. I had a nice ceramic coated steel tea kettle that I usually heat on the kitchen stove top to about 180C. One day, I stupidly put it directly on top of my wood burner running at about 300C. I compounded the error by boiling off all the water. My first indication of a problem was the sound of something like popcorn from inside the kettle. That was the inside coating flaking off and bouncing around. As I approached, a large piece of the outside coating flew off in my general direction. I had to use a broomstick to remove the kettle. I haven't calculated the differences in expansion, but for something as small as a kettle, it was much smaller than my predicted 1mm. -- 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 |
| Stormin Mormon <cayoung61@hotmail.com>: Oct 18 05:06PM -0400 On 10/18/2014 12:24 PM, Ian Malcolm wrote: > detected before significant electrolytic corrosion can occur. > Whoever first introduced vitreous enamel-lined mild steel hot water tanks > to the American market did you all a great disservice. Subject line change, no charge. |
| "Michael A. Terrell" <mike.terrell@earthlink.net>: Oct 18 05:55PM -0400 micky wrote: > use flexible and I didn't want zig-zag piping. ) And the front panels > were the same (although maybe they all use the same thermostats and > heaters.) Basically everything looks the same as the original. The Sears model number will tell you who made it. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge. |
| Jeff Liebermann <jeffl@cruzio.com>: Oct 18 06:23PM -0700 On Sat, 18 Oct 2014 17:55:41 -0400, "Michael A. Terrell" > The Sears model number will tell you who made it. There are numerous Sears manufacturers lists available online. Many have missing prefix numbers or only include specific classifications, such as power tools. If you can't find your model number prefix, just try a different list: <http://home.cogeco.ca/~gbishop/Public/SearsSourceCodes.htm> <http://vintagemachinery.org/craftsman/manufacturers.aspx?sort=1> <http://www.asecc.com/data/sears.html> On some serial numbers, you can extract the date of manufacture: <http://www.electrical-forensics.com/MajorAppliances/ApplianceManufacturers.html> <http://www.electrical-forensics.com> Incidentally, the above web site has some rather interesting photos of appliance related fires. For example, hot water heaters do NOT start fires: <http://www.electrical-forensics.com/Hotwater/HotWaterHeaters.html> and portable electric heater misuse hazards: <http://www.electrical-forensics.com/Heaters/ElectricHeaters.html> -- 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 <NONONOmisc07@bigfoot.com>: Oct 18 11:26PM -0400 On Sat, 18 Oct 2014 18:23:15 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote: ><http://home.cogeco.ca/~gbishop/Public/SearsSourceCodes.htm> ><http://vintagemachinery.org/craftsman/manufacturers.aspx?sort=1> ><http://www.asecc.com/data/sears.html> Well I went to all three pages, and searching on smith, none listed a.o.smith at all. But I remember the clincher reason I thought that's what it was. The first owner of the house left me the owners manual for the original water heater, by aosmith, and the manual was amost identical to the one that came with both of my Sears water heaters. Same text, same fonts, same graphics ><http://www.electrical-forensics.com/Hotwater/HotWaterHeaters.html> >and portable electric heater misuse hazards: ><http://www.electrical-forensics.com/Heaters/ElectricHeaters.html> I'll check these out. |
| Jeff Liebermann <jeffl@cruzio.com>: Oct 18 08:57PM -0700 On Sat, 18 Oct 2014 23:26:37 -0400, micky <NONONOmisc07@bigfoot.com> wrote: >><http://www.asecc.com/data/sears.html> >Well I went to all three pages, and searching on smith, none listed >a.o.smith at all. Yeah, I noticed that. However, it seems that Sears/Kenmore does sell AO Smith water heaters. Here's replacement parts for one AO Smith model from the Sears web site: <http://parts.sears.com/partsdirect/part-model/Aosmith-Parts/Water-heater-Parts/Model-ESM30/0002/1081000/50032737/00001> and Sears repair service for AO Smith products: <http://www.searshomeservices.com/aosmith-water-heater-repair> A clue might be that the Sears parts page shows the water heater by the AO Smith model number (ESM30) and not by the Sears style part number. The web page shows parts for 205 assorted AO Smith water heaters: <http://parts.sears.com/partsdirect/getProductType.pd?parentCategory=Plumbing&productType=Water-heater-Parts&sort=modelNumber&dir=asc&selectedBrand=Aosmith&page=1> none of which show a Sears style part number. >water heater, by aosmith, and the manual was amost identical to the one >that came with both of my Sears water heaters. Same text, same fonts, >same graphics AO Smith also posts some of their instruction manuals: <http://www.aosmithinternational.com/content/instruction-manuals> -- 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 |
| Stormin Mormon <cayoung61@hotmail.com>: Oct 19 07:31AM -0400 On 10/18/2014 11:26 PM, micky wrote: >> and portable electric heater misuse hazards: >> <http://www.electrical-forensics.com/Heaters/ElectricHeaters.html> > I'll check these out. The ones that are good enough to be as bright, can be twenty or thirty bucks per bulb. But, if it means not having to go 24 feet up, might be worth it. - . Christopher A. Young Learn about Jesus www.lds.org . |
| gregz <zekor@comcast.net>: Oct 19 05:47AM > Or, if the vehicle has a battery cut-out activated by a vehicle > upset.... > Jonesy First thing I thought, Gps antenna in ground. I guess the cell phone still had some service, and it's interesting that the on star seems to track you at intervals.still, on star seemed to save the day by recording accident. I keep meaning to shut mine off, and it's just one of my vehicles. Gets costly, or save the day ? Greg |
| Cydrome Leader <presence@MUNGEpanix.com>: Oct 23 05:32PM > The CPSC (and I believe the NEC) requires that any GFCI outlets which > don't have an actual ground, must be installed with a sticker which > says so, so that the user is aware that the ground prong is "open". Ok- that would make sense- as stupid as a sticker may be, you need something to indicate an abnormal condition. I've only see the industrial versions of these warning tags though- never seen one screwed into a wall in an old bathtoom, at least yet. |
| "David Farber" <farberbear.unspam@aol.com>: Oct 18 05:20PM -0700 Ron D. wrote: > When there is a threaded hole in the box that can accept a ground > screw, then other ways are possible. > So far, I've never tapped a ground hole. Hi Ron, I put a screw into the box and ran a wire from the screw to the GFCI's ground. But first I checked the line voltage with the neutral wire on the neutral side of the plug with a hair dryer running. Then I exchanged the neutral wire with the new ground wire and checked the voltage again with the hair dryer running. The voltages were exactly the same. That proved to me that the ground wire is making a good connection back to the service panel. Do you see an alternate explanation that would disprove my conclusion? Thanks for your reply. -- David Farber Los Osos, CA |
| bud-- <null@void.com>: Oct 23 01:46PM -0600 On 10/23/2014 1:26 AM, Michael A. Terrell wrote: >> different story. Anybody know what the NEC says about this? > The NEC requires the protected outlets be marked as non grounded. The > labels come with the GFCI. Trivial addition - downstream receptacles also need the "GFCI protected" label. As I think you have written, the NEC explicitly allows a (grounded) GFCI receptacle to be used on an ungrounded circuit, and allows grounded receptacles downstream, all with the label in your post. When used this way, ground terminals are not to be connected together. Ungrounded receptacles can also be used downstream. The ground terminal on a GFCI connects only to the ground contacts for what is plugged-in. There is no connection to the protection circuit. ============================== A few changes from the 2011 NEC If you are replacing a receptacle where it is now required to be tamper resistant (child proof), the replacement has to now be tamper resistant (most of a house). Same with weather-resistant. If you are extending an existing circuit in an area where AFCI protection is now required, the entire extension is required to be AFCI protected. (AFCI receptacles are now available.) If you are replacing an ordinary receptacle in an area where GFCI protection is now required, the new receptacle is required to be GFCI protected. (Several ways to do it.) If you are replacing an ordinary receptacle in an area where AFCI protection is now required, the new receptacle is required to be AFCI protected. (Also several ways to do it.) (Other than this, AFCI is intended to protect the branch circuit wiring in addition to the receptacle and what is plugged in.) |
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