Jeff Liebermann wrote:> refills are commonly available and cheap. The printer cannibals sell > used parts and assemblies fairly cheap on eBay. Also, expertise is > more easily found: ><http://www.fixyourownprinter.com> > My favorite printer of the week is the HP 2300DN or DTN at between $90 > to $220 used depending on condition and options. Favorite feature is > double sided (duplex) printing.Problem with that is my location. Shipping anything from anywhere except China is too expensive to make it worth while. A $10 (postage included) Samsung feed roller is worth buying, a part that does not fit in an envelope and has to go in a USPS box costs 1/2 to 1/3 the cost of a cheap Samsung printer. UPS/DHL/FDEDX double or tripple that price. Also to be honest, the loss/theft rate from the US is too high to buy from unless it is via PayPal and eBay. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379 "Owning a smartphone: Technology's equivalent to learning to play chopsticks on the piano as a child and thinking you're a musician." (sent to me by a friend)
Using mobile phone as an internet radio
Started by ●October 2, 2012
Reply by ●October 4, 20122012-10-04
Reply by ●October 4, 20122012-10-04
On 10/04/2012 02:57 PM, George Herold wrote:> On Oct 4, 12:43 pm, Jeff Liebermann<je...@cruzio.com> wrote: >> On Thu, 04 Oct 2012 10:03:21 -0400, Phil Hobbs >> >> >> >> >> >> <pcdhSpamMeSensel...@electrooptical.net> wrote: >>> On 10/03/2012 09:41 PM, Jeff Liebermann wrote: >>>> On Wed, 03 Oct 2012 10:32:57 -0400, Phil Hobbs >>>> <pcdhSpamMeSensel...@electrooptical.net> wrote: >> >>>>> I don't know of any data that supports this common idea, but I'd be >>>>> interested in reading about it if anybody's actually done the experiment >>>>> carefully. >> >>>> It's an accelerated life test. The deration curve of the incandescent >>>> light bulb is well known and assumed to be >>>> (Vapplied/Vdesign)^-12 to ^-16 * Life at design voltage >>>> <http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/MC3...> >>>> See Fig 5 on Pg 5 for the graph. Nobody wants to wait 1000 hours for >>>> a bulb to blow. So, they increase the applied voltage, which >>>> dramatically decreases the lifetime down to reasonable test times. >>>> Using a rack of bulbs, they obtain an average (or median) lifetime at >>>> the higher voltage. Then, they work backwards on the curve to >>>> estimate what it would be at the design voltage. >> >>> You can't run an accelerated life test when the exponent isn't known >>> more accurately than 12 to 16. >> >> True, but I believe that's the range expected from different types of >> light bulbs (nitrogen filled, halogen, vaccuum), and not the range >> expected for a given device. I suspect that more accurate exponent >> value could be empirically determined for a given device, and later >> used only for that device. >> >>>> Yep. As I understand it (possible wrong), AC filaments break in the >>>> middle, mostly from vibration flexing. >> >>> I don't think so, because there's no mechanism for that, as I said. The >>> wire is fully annealed at all times, so there's no possibility of >>> progressive fatigue failure. >> >> <http://en.wikipedia.org/wiki/Incandescent_light_bulb#Reducing_filamen...> >> One of the problems of the standard electric light bulb is >> evaporation of the filament. Small variations in resistivity >> along the filament cause "hot spots" to form at points of >> higher resistivity; a variation of diameter of only 1% will >> cause a 25% reduction in service life. The hot spots evaporate >> faster than the rest of the filament, increasing resistance >> at that point a positive feedback that ends in the familiar >> tiny gap in an otherwise healthy-looking filament. >> >> Note the photo of the filament with a break in the middle. When I was >> quite young, I would break burnt out AC light bulbs to see what was >> inside. If the filament was intact, the break was always somewhere >> near the middle. If a piece broke off, one end of the broken piece >> was usually near the middle. In later years, I would look at the >> remains of DC panel lights (usually type 47 for old Motorola radios) >> and noted that the breaks were always near the supporting terminals, >> probably due to metal migration. >> >>>>> I suspect that the notion that cycling is hard on bulbs comes from the >>>>> way that the bulb often fails at turn-on, when the thinnest hot spot >>>>> vapourizes before the rest of the filament has a chance to come up to >>>>> temperature and reduce the inrush current. >> >>>> Yep. See my comments on the relatively high failure rate on the >>>> 40watt theater marquee lamps due to cycling. The same lamps in the >>>> lobby and foyer were not cycled and seemed to last forever. >> >>> I was actually disagreeing with you. There are lots of possible reasons >>> for the marquee lights failing prematurely. I'm not a tungsten expert >>> myself, so I'd be very interested in seeing actual data that shows a >>> dramatic shortening of life due to cycling. I'm not saying it's >>> impossible, just that I haven't seen any such data. >> >> So much for my anecdotal data. My theater marquee experience was in >> about 1966. The theater actually did keep records so that they could >> stock enough replacement bulbs, but I don't have copies of any of >> that. >> >> I tried Googling for similar repetative on-off tests and didn't find >> anything. If I have time, I'll try again. I must admit that the lack >> of test data does look suspicious. Perhaps sending the idea to >> Mythbusters and have them runs a test? >> >>> The filament isn't tungsten-plated, it's pure tungsten or a low alloy. >>> The brightness drop comes from tungsten condensing on the envelope. >> >> Oops. I thought it was plated. >> >>> And the connecting wire isn't plain steel, it's generally Dumet, >>> http://www.jlcelectromet.com/dumetwire.htm >> >>> which is a 42% Ni steel with OFHC copper or nickel plating. >> >>> You're making a lot of that up. I'd still like to see >>> carefully-collected data. >> >> No, not fabricated. It's my reliance on my memory in an area that I'm >> not familiar with. I tried Googling for the wire used, couldn't find >> much, and made a bad guess. The plating came from somehow getting >> thorium coated tungsten wire used in vacuum tubes mixed up with light >> bulbs. Sorry for the errors and muddle. >> >>> Cheers >>> Phil Hobbs >> >> -- >> Jeff Liebermann je...@cruzio.com >> 150 Felker St #D http://www.LearnByDestroying.com >> Santa Cruz CA 95060http://802.11junk.com >> Skype: JeffLiebermann AE6KS 831-336-2558- Hide quoted text - >> >> - Show quoted text - > > Hi Jeff, Phil. First I know nothing about incandescent bulbs. > But how about this as a model of why turning bulbs on and off might > cause them to fail sooner. > > 1.) I think we all observe that bulbs tend to blow when you turn them > on. > (unless you knock the lamp over or something.) > > 2.) I assume that the failure is mostly due to the thinner �hot spots� > on the filament. Thinner regions heat up faster (higher resistance > with equal current). > > 3.) Now even if the thinner region doesn�t blow, it still gets hotter > and loses a bit more tungsten than the rest of the filament. (For > that small amount of time that it�s turning on.) But still this means > that turning on the bulb causes the thin region to become a bit > thinner. > > And that�s it. Repeated on and off means that the thin region has a > higher average temperature than the thick part of the filament. It > evaporates faster and fails sooner. > > George H.If the effect is real, that sounds like a good candidate for a mechanism. Certainly you'd expect that to be important right near the end of the bulb's life, so maybe it's important throughout. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Reply by ●October 4, 20122012-10-04
On Thu, 4 Oct 2012 11:57:21 -0700 (PDT), George Herold <gherold@teachspin.com> wrote:>Hi Jeff, Phil. First I know nothing about incandescent bulbs.I'm still learning (mostly from my mistakes). I blundered across this video on tungsten filaments. <http://www.youtube.com/watch?v=DIGqBb3iZPo> 3:38 While it doesn't touch any of the issues previously mentioned, it does include some interesting info on how the filament is made and its structure. -- 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
Reply by ●October 4, 20122012-10-04
On 10/3/2012 2:01 AM, MikeS wrote:>> Using anything shortens it's working life. > > Seems to go against the whole ethos of exercising. Never get out of bed and > live forever ... > >If you were an android that may be true.
Reply by ●October 4, 20122012-10-04
In article <slrnk6ror4.jds.gsm@cable.mendelson.com>, Geoffrey S. Mendelson <gsm@mendelson.com> wrote:> Problem with that is my location. Shipping anything from anywhere except > China is too expensive to make it worth while. A $10 (postage included) > Samsung feed roller is worth buying, a part that does not fit in an > envelope and has to go in a USPS box costs 1/2 to 1/3 the cost of a > cheap Samsung printer. UPS/DHL/FDEDX double or tripple that price.> Also to be honest, the loss/theft rate from the US is too high to buy > from unless it is via PayPal and eBay.Couple of years back I needed a new element for my Pace SX80 desolder iron. Not one to be had in the UK. Got one from Pace US direct at not a bad price - but they charged 40 gbp for P&P by courier - wouldn't send it by post. So the delivered price was considerably more than the delivered price from a UK supplier. If it had been coming from Hong Kong or China, would have been less than half the price and free postage... There's lots of stuff I'd buy from the US if they would sort out their postal service. I get the impression as much is stolen as delivered. -- *Two wrongs are only the beginning * Dave Plowman dave@davenoise.co.uk London SW To e-mail, change noise into sound.
Reply by ●October 4, 20122012-10-04
On Oct 4, 4:28=A0pm, Phil Hobbs <pcdhSpamMeSensel...@electrooptical.net> wrote:> On 10/04/2012 02:57 PM, George Herold wrote: > > > > > > > On Oct 4, 12:43 pm, Jeff Liebermann<je...@cruzio.com> =A0wrote: > >> On Thu, 04 Oct 2012 10:03:21 -0400, Phil Hobbs > > >> <pcdhSpamMeSensel...@electrooptical.net> =A0wrote: > >>> On 10/03/2012 09:41 PM, Jeff Liebermann wrote: > >>>> On Wed, 03 Oct 2012 10:32:57 -0400, Phil Hobbs > >>>> <pcdhSpamMeSensel...@electrooptical.net> =A0 =A0wrote: > > >>>>> I don't know of any data that supports this common idea, but I'd be > >>>>> interested in reading about it if anybody's actually done the exper=iment> >>>>> carefully. > > >>>> It's an accelerated life test. =A0The deration curve of the incandes=cent> >>>> light bulb is well known and assumed to be > >>>> =A0 =A0 (Vapplied/Vdesign)^-12 to ^-16 * Life at design voltage > >>>> <http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/M=C3...>> >>>> See Fig 5 on Pg 5 for the graph. =A0Nobody wants to wait 1000 hours =for> >>>> a bulb to blow. =A0So, they increase the applied voltage, which > >>>> dramatically decreases the lifetime down to reasonable test times. > >>>> Using a rack of bulbs, they obtain an average (or median) lifetime a=t> >>>> the higher voltage. =A0Then, they work backwards on the curve to > >>>> estimate what it would be at the design voltage. > > >>> You can't run an accelerated life test when the exponent isn't known > >>> more accurately than 12 to 16. > > >> True, but I believe that's the range expected from different types of > >> light bulbs (nitrogen filled, halogen, vaccuum), and not the range > >> expected for a given device. =A0I suspect that more accurate exponent > >> value could be empirically determined for a given device, and later > >> used only for that device. > > >>>> Yep. =A0As I understand it (possible wrong), AC filaments break in t=he> >>>> middle, mostly from vibration flexing. > > >>> I don't think so, because there's no mechanism for that, as I said. ==A0The> >>> wire is fully annealed at all times, so there's no possibility of > >>> progressive fatigue failure. > > >> <http://en.wikipedia.org/wiki/Incandescent_light_bulb#Reducing_filamen=...>> >> =A0 =A0 One of the problems of the standard electric light bulb is > >> =A0 =A0 evaporation of the filament. Small variations in resistivity > >> =A0 =A0 along the filament cause "hot spots" to form at points of > >> =A0 =A0 higher resistivity; a variation of diameter of only 1% will > >> =A0 =A0 cause a 25% reduction in service life. The hot spots evaporate > >> =A0 =A0 faster than the rest of the filament, increasing resistance > >> =A0 =A0 at that point a positive feedback that ends in the familiar > >> =A0 =A0 tiny gap in an otherwise healthy-looking filament. > > >> Note the photo of the filament with a break in the middle. =A0When I w=as> >> quite young, I would break burnt out AC light bulbs to see what was > >> inside. =A0If the filament was intact, the break was always somewhere > >> near the middle. =A0If a piece broke off, one end of the broken piece > >> was usually near the middle. =A0In later years, I would look at the > >> remains of DC panel lights (usually type 47 for old Motorola radios) > >> and noted that the breaks were always near the supporting terminals, > >> probably due to metal migration. > > >>>>> I suspect that the notion that cycling is hard on bulbs comes from =the> >>>>> way that the bulb often fails at turn-on, when the thinnest hot spo=t> >>>>> vapourizes before the rest of the filament has a chance to come up =to> >>>>> temperature and reduce the inrush current. > > >>>> Yep. =A0See my comments on the relatively high failure rate on the > >>>> 40watt theater marquee lamps due to cycling. =A0The same lamps in th=e> >>>> lobby and foyer were not cycled and seemed to last forever. > > >>> I was actually disagreeing with you. =A0There are lots of possible re=asons> >>> for the marquee lights failing prematurely. =A0I'm not a tungsten exp=ert> >>> myself, so I'd be very interested in seeing actual data that shows a > >>> dramatic shortening of life due to cycling. =A0I'm not saying it's > >>> impossible, just that I haven't seen any such data. > > >> So much for my anecdotal data. =A0My theater marquee experience was in > >> about 1966. =A0The theater actually did keep records so that they coul=d> >> stock enough replacement bulbs, but I don't have copies of any of > >> that. > > >> I tried Googling for similar repetative on-off tests and didn't find > >> anything. =A0If I have time, I'll try again. =A0I must admit that the =lack> >> of test data does look suspicious. =A0Perhaps sending the idea to > >> Mythbusters and have them runs a test? > > >>> The filament isn't tungsten-plated, it's pure tungsten or a low alloy=.> >>> The brightness drop comes from tungsten condensing on the envelope. > > >> Oops. =A0I thought it was plated. > > >>> And the connecting wire isn't plain steel, it's generally Dumet, > >>>http://www.jlcelectromet.com/dumetwire.htm > > >>> which is a 42% Ni steel with OFHC copper or nickel plating. > > >>> You're making a lot of that up. =A0I'd still like to see > >>> carefully-collected data. > > >> No, not fabricated. =A0It's my reliance on my memory in an area that I='m> >> not familiar with. =A0I tried Googling for the wire used, couldn't fin=d> >> much, and made a bad guess. =A0The plating came from somehow getting > >> thorium coated tungsten wire used in vacuum tubes mixed up with light > >> bulbs. =A0Sorry for the errors and muddle. > > >>> Cheers > >>> Phil Hobbs > > >> -- > >> Jeff Liebermann =A0 =A0 je...@cruzio.com > >> 150 Felker St #D =A0 =A0http://www.LearnByDestroying.com > >> Santa Cruz CA 95060http://802.11junk.com > >> Skype: JeffLiebermann =A0 =A0 AE6KS =A0 =A0831-336-2558- Hide quoted t=ext -> > >> - Show quoted text - > > > Hi Jeff, Phil. =A0 First I know nothing about incandescent bulbs. > > But how about this as a model of why turning bulbs on and off might > > cause them to fail sooner. > > > 1.) I think we all observe that bulbs tend to blow when you turn them > > on. > > (unless you knock the lamp over or something.) > > > 2.) I assume that the failure is mostly due to the thinner =EF=BF=BDhot=spots=EF=BF=BD> > on the filament. =A0 Thinner regions heat up faster (higher resistance > > with equal current). > > > 3.) Now even if the thinner region doesn=EF=BF=BDt blow, it still gets =hotter> > and loses a bit more tungsten than the rest of the filament. =A0 (For > > that small amount of time that it=EF=BF=BDs turning on.) =A0But still t=his means> > that turning on the bulb causes the thin region to become a bit > > thinner. > > > And that=EF=BF=BDs it. =A0Repeated on and off means that the thin regio=n has a> > higher average temperature than the thick part of the filament. =A0It > > evaporates faster and fails sooner. > > > George H. > > If the effect is real, that sounds like a good candidate for a > mechanism. =A0 Certainly you'd expect that to be important right near the > end of the bulb's life, so maybe it's important throughout. > > Cheers > > Phil Hobbs > > -- > Dr Philip C D Hobbs > Principal Consultant > ElectroOptical Innovations LLC > Optics, Electro-optics, Photonics, Analog Electronics > > 160 North State Road #203 > Briarcliff Manor NY 10510 > > hobbs at electrooptical dot nethttp://electrooptical.net- Hide quoted tex=t -> > - Show quoted text -Yeah, I was thinking about this while splitting/stacking wood tonight. If the time to fail goes as some big power of the voltage (temperature), then during turn on, small diameter variations (or defects) get amplfied. A 'long life' 40 Watt bulb would fail almost as fast as a 100 W'er. (Of course I've got my 'lifetime supply' of 100W bulbs, and didn't budget any for research.) George H.
Reply by ●October 4, 20122012-10-04
On Oct 4, 5:05=A0pm, Jeff Liebermann <je...@cruzio.com> wrote:> On Thu, 4 Oct 2012 11:57:21 -0700 (PDT), George Herold > > <gher...@teachspin.com> wrote: > >Hi Jeff, Phil. =A0 First I know nothing about incandescent bulbs. > > I'm still learning (mostly from my mistakes).It's definitely my mistakes that have taught me the most. (my latest f-up had to do with short ultrasonic pulses, and 1/4 wavelength anti-reflection wave-plates...) I've no problem with your marquee story. Sometimes folk-tales about rocks falling from the sky are correct. The data point I offer to Phil is that bulbs fail when you turn them on. I see no reason why that can't be 'played backwards'. There most be some GE, Philips, (other) report that documents turn on failure. George H.> > I blundered across this video on tungsten filaments. > <http://www.youtube.com/watch?v=3DDIGqBb3iZPo> =A03:38 > While it doesn't touch any of the issues previously mentioned, it does > include some interesting info on how the filament is made and its > structure. > > -- > Jeff Liebermann =A0 =A0 je...@cruzio.com > 150 Felker St #D =A0 =A0http://www.LearnByDestroying.com > Santa Cruz CA 95060http://802.11junk.com > Skype: JeffLiebermann =A0 =A0 AE6KS =A0 =A0831-336-2558
Reply by ●October 4, 20122012-10-04
On Tue, 2 Oct 2012 22:21:26 +0100, "jim stone" <tgh6h56nzh@mail.invalid> wrote:>Not being able to find a small internet radio to buy we liked, we got mobile >phone with which we link with wi-fi to a modem router, and use it as an >internet radio. > >Keeping the phoned plugged into its charger all the time, we are using it to >play *all-day* background classical music through an amplifier and speakers.Several of my customers do exactly the same thing. Some play stored MP3/AAC music, while others stream from Pandora or Slacker. Most use an iPhone 3G, iPod Touch, or Droid A855 for the wi-fi connectivity. All have the phone plugged into a charger. No fatalities.>Since the phone has no 'moving parts' unlike a computer, we are wondering if >this continuous playing all day of the phone is going to shorten its working >life ?It won't hurt the phone in any way. However, the internal battery is another story. For Li-Ion, battery life is shortened when the battery is hot, and when it's left at full charge all the time. For details, see: <http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries> Most Li-ions are charged to 4.20V/cell and every reduction of 0.10V/cell is said to double cycle life. This is not much of a problem for easily replaceable inexpensive batteries, such as in the Droid A855, but might be an issue with the designed obsolescent iPhone series, where brain surgery is required to replace the battery. Apple has therefore wisely elected to charge their Li-Ion batteries to 4.1v or what I estimate to be 95% of full capacity. This greatly extends the battery life and will delay when you start cursing Apple products to about 3 years. <http://stephenwmoore.wordpress.com/2009/07/21/iphone-battery-life/> Someone mentioned having a phone with a dead wi-fi. I have two Apple 3G iPhones, both with intermittent wi-fi sections. If I turn the power off on the iPhone for a day, the iPhones will have a working wi-fi section for about 30 minutes. I also have a third working iPhone 3G, where the wi-fi has never failed. I've been inside trying to repair them, and failed. -- 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
Reply by ●October 5, 20122012-10-05
In article <de99517e-e5e1-4f9d-91e0- 412ab3171a05@o8g2000yqm.googlegroups.com>, George Herold wrote:> And that�s it. Repeated on and off means that the thin region has a > higher average temperature than the thick part of the filament. It > evaporates faster and fails sooner.Won't a thin region of a lamp filament have a higher temperature than the rest of it all the time, not just when the lamp is turning on? Rod. --
Reply by ●October 5, 20122012-10-05
On Oct 5, 6:20=A0am, Roderick Stewart <r...@escapetime.removethisbit.myzen.co.uk> wrote:> In article <de99517e-e5e1-4f9d-91e0- > > 412ab3171...@o8g2000yqm.googlegroups.com>, George Herold wrote: > > And that s it. =A0Repeated on and off means that the thin region has a > > higher average temperature than the thick part of the filament. =A0It > > evaporates faster and fails sooner. > > Won't a thin region of a lamp filament have a higher temperature than > the rest of it all the time, not just when the lamp is turning on? > > Rod. > --Hmm, sure, maybe... I really have no idea. But I can't remember ever seeing a bulb fail after being on for a while. (I'm sure it must happen.) They almost always go when you turn them on, from which I conclude that the turn on is more 'stressful'. Say does Don Klipstein still lurk here? He may have some info on turn- on failure. http://donklipstein.com/ George H.
