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Jeff Liebermann <jeffl@cruzio.com>: May 30 10:36AM -0700 On Thu, 30 May 2019 05:59:08 -0700 (PDT), Tim R <timothy42b@aol.com> wrote:   >It's probably worse than with CFLs because of the concentrated area >where the heat is produced, right?   Maybe. LED's are certainly more efficient. Lumens/watt LED 100 CFL 60 Incandescent 16 For equal amounts of light output (lumens), a CFL lamp takes 1.7 times as much power to produce that light as does an LED. That's a big difference, but not as spectacular as the 6.3 times jump from incandescent to LED.   You're concerned about "heat" with measured in Joules where 1 joule = 1 watt/second What I think you want is the final operating temperature of the device to make sure that it doesn't melt plastic, degrade the LED's, destroy electronic components, or set fire to the vicinity. The final temperature has many parameters, most of which are NOT the same for LED and CFL. For radiation loss, the surface area of a CFL lamp is larger than the equivalent LED, and is therefore a more efficient heat radiator. While the LED might waste fewer watts than the CFL light heating up the room, the CFL will remove the heat from the lamp more efficiently because it has a larger surface area. The LED compensates for its smaller size by using aluminum heat sinks, while the CFL has a larger thermal mass by using ceramics. Lots of other differences making a general conclusion rather difficult.   >What isn't obvious to me, having looked at the internals, is why the >orientation would have more than a trivial effect. That heat looks >pretty trapped no matter where the base faces.   Also maybe. The various lamps will move heat using conduction, radiation, and convection. All three mechanisms are involved in determining the final temperature of a lamp. In a light fixture, the ability of move air through the fixture to remove the heat via convective air currents is restricted. Without air flow the temperature of the lamp will rise. If the air flow is uneven, there will be hot spots on the lamp surface. Some lamps are more tolerant to heating than others. My plastic case MR16 LED lamp was probably the least tolerant. High temperature halogen incandescent lamps are quite happy at much higher temperatures. LEDs lose half their light output going from room temp (25C) to operating temperature (100C) <https://www.lrc.rpi.edu/programs/nlpip/lightinganswers/led/heat.asp> which is why LED heat sinks are much better and larger than CFL which can tolerate higher temperatures.     -- 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

"pfjw@aol.com" <peterwieck33@gmail.com>: Jun 02 02:26PM -0700 They are found in both our houses. That you wish to make a virtue of ignorance is what is funny in a sad sort of way.   Peter Wieck Melrose Park, PA

Lucifer <LuciferMorningstar@bigpond.com>: Jun 03 03:17PM +1000 On Sun, 2 Jun 2019 14:26:16 -0700 (PDT), "pfjw@aol.com"   >They are found in both our houses. That you wish to make a virtue of >ignorance is what is funny in a sad sort of way.   To whom are you replying and about what?

tabbypurr@gmail.com: Jun 03 02:17AM -0700 On Monday, 3 June 2019 06:17:03 UTC+1, Lucifer wrote:   > To whom are you replying and about what?   > >Peter Wieck > >Melrose Park, PA   probably me. By stating that something exists, when I merely claimed the norm [in the UK] was something else. From a guy that thinks the SMPSU produces more heat than it's load. And that it's the ballast or control unit that determines a LED's spectral output. Let it go.     NT

Cursitor Doom <curd@notformail.com>: Jun 02 11:48PM I didn't know people still do this...   https://www.youtube.com/watch?v=dRI0ZLTP6_0

tabbypurr@gmail.com: Jun 03 02:14AM -0700 On Monday, 3 June 2019 00:48:36 UTC+1, Cursitor Doom wrote: > I didn't know people still do this...   > https://www.youtube.com/watch?v=dRI0ZLTP6_0   not many do. I've seen homemade tubes of all types & CRTs too     NT

Pat <forums@greensdomain.com>: Jun 02 12:56PM -0400 On Sun, 2 Jun 2019 15:57:22 -0000 (UTC), Cursitor Doom >wave rectifying tube/valve? Is it normal for them to become too hot to >touch after only a minute or two? >I'm talking specifically about the 5Y3GT in this context.   Vacuum Tubes (Valves) work by heating the cathode to "boil off" electrons. The 5Y3 has a 5v filament that draws 2 Amps. So that's 10 watts even without any current flowing in the plate circuit. So, yes, I would expect it to get hot quickly.

Cursitor Doom <curd@notformail.com>: Jun 02 05:12PM Thanks, guys. They'd juxtaposed it with a VR150 which quickly reached a similar temperature due to its proximity. I just thought that was a rotten layout, but clearly it's not a concern in that case.       -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

Fred McKenzie <fmmck@aol.com>: Jun 02 01:21PM -0400 In article <qd0rl2$qaj$6@dont-email.me>, > wave rectifying tube/valve? Is it normal for them to become too hot to > touch after only a minute or two? > I'm talking specifically about the 5Y3GT in this context.   Voltage drop times current, filament (cathode) to plate, plus voltage times current across filament. Never measured temperature, but energy has to go somewhere. Gets hot, radiates.   Fred

Fred McKenzie <fmmck@aol.com>: Jun 02 01:25PM -0400 In article <qd101u$qaj$10@dont-email.me>,   > Thanks, guys. They'd juxtaposed it with a VR150 which quickly reached a > similar temperature due to its proximity. I just thought that was a > rotten layout, but clearly it's not a concern in that case.   Its not proximity. Voltage times current. Gets hot.   Fred

Ralph Mowery <rmowery28146@earthlink.net>: Jun 02 01:31PM -0400 In article <cpv7fehagjbe95m4g57hl0vplumcge63s3@4ax.com>, forums@greensdomain.com says... > electrons. The 5Y3 has a 5v filament that draws 2 Amps. So that's 10 > watts even without any current flowing in the plate circuit. So, yes, > I would expect it to get hot quickly.   That is not even counting on power flowing in the tube as you mentioned.   With out looking it up, I would expect the tube to drop around 20 or more volts. So at 100 ma and 20 volts, that is another 2 watts to add to the 10 watts of just the filament.   Even some of the smaller glas tubes can get hot enough you can not pull them out after short time unless you have asbestos fingers.

Jeff Liebermann <jeffl@cruzio.com>: Jun 02 12:29PM -0700 On Sun, 02 Jun 2019 12:56:58 -0400, Pat <forums@greensdomain.com> wrote:   >electrons. The 5Y3 has a 5v filament that draws 2 Amps. So that's 10 >watts even without any current flowing in the plate circuit. So, yes, >I would expect it to get hot quickly.   Ah yes, but you can get far more efficient Sovtek 5Y3GT tubes (thermionic valves): <https://shop.ehx.com/item/5y3gt/tubes-vacuum-sovtek/> which features a filament that draws only 2mA +/- 0.2mA 5V or 10 milliwatts.   I like the description on the data sheet: <https://shop.ehx.com/catalog/addimages/5y3gt-sovtek.pdf> MINIATURE DOUBLE ANODE KENOTRON IN GLASS DESIGN WITH OXIDE-COATED INDIRECTLY HEATED CATHODE INTENDED FOR RECTIFICATION OF COMMERCIAL-FREQUENCY ALTERNATING CURRENT. That explains why one gets frequent commercials on TV sets that use Sovtek 5Y3GT kenotrons.     -- 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

Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Jun 02 11:40PM +0200 On 02.06.19 17:57, Cursitor Doom wrote: > wave rectifying tube/valve? Is it normal for them to become too hot to > touch after only a minute or two? > I'm talking specifically about the 5Y3GT in this context.   Draw a lot of current and you get a lot of heat.   Dont want the heat? lower the current, or use bigger components and cooling.

Cursitor Doom <curd@notformail.com>: Jun 02 09:48PM On Sun, 02 Jun 2019 13:21:58 -0400, Fred McKenzie wrote:   > Voltage drop times current, filament (cathode) to plate, plus voltage > times current across filament. Never measured temperature, but energy > has to go somewhere. Gets hot, radiates.   Er, yes. That wasn't quite what I meant, but never mind. My fault for not being clear enough having re-read it.         -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

Cursitor Doom <curd@notformail.com>: Jun 02 11:54PM On Sun, 02 Jun 2019 23:40:29 +0200, Sjouke Burry wrote:   > Draw a lot of current and you get a lot of heat.   > Dont want the heat? > lower the current, or use bigger components and cooling.   Thank you, Captain Obvious. I can't see what was so misleading about the wording in my original question that's causing some folks to misinterpret it. Anyway, the first two respondents told me all I wanted to know so many thanks to them and their excellent comprehension skills.         -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

Lucifer <LuciferMorningstar@bigpond.com>: Jun 03 03:12PM +1000 On Sun, 02 Jun 2019 12:29:53 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:   > CURRENT. >That explains why one gets frequent commercials on TV sets that use >Sovtek 5Y3GT kenotrons.   What about cold cathode tubes?

Boris Mohar <borism_void_@sympatico.ca>: Jun 03 03:30AM -0400 On Sun, 2 Jun 2019 15:57:22 -0000 (UTC), Cursitor Doom <curd@notformail.com> wrote:   >wave rectifying tube/valve? Is it normal for them to become too hot to >touch after only a minute or two? >I'm talking specifically about the 5Y3GT in this context.     I melted solder on top of 5Y3GT     Regards,   Boris Mohar   Got Knock? - see: Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca   void _-void-_ in the obvious place     --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

adrian@poppyrecords.invalid.invalid (Adrian Tuddenham): Jun 03 09:26AM +0100 > Draw a lot of current and you get a lot of heat.   > Dont want the heat? > lower the current, or use bigger components and cooling.   Just a little nit-pick here:   You will get exactly the same quantity of heat (energy) if you use bigger components and cooling - but you will get it at a lower temperature.   This leads to the curious situation that if you need to dissipate a lot of energy, it should be possible to do it in a smaller space by using valves rather than by using transistors which have to run at lower temperatures.     -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk

Arie de Muynck <no.spam@no.spam.org>: Jun 03 11:07AM +0200 On 2019-06-02 21:29, Jeff Liebermann wrote: > CURRENT. > That explains why one gets frequent commercials on TV sets that use > Sovtek 5Y3GT kenotrons.   Fortunately the datasheet really specifies 2A not 2mA. I was already imagining a fake tube with 2x 1N4007 inside, and a 2mA LED to 'light up' the cathode...   Arie

micky <NONONOmisc07@bigfoot.com>: Jun 02 06:10PM -0400 In alt.home.repair, on Mon, 3 Jun 2019 04:03:38 +1000, "Rod Speed"   >You don't have to do leds that way, its easy to have a constant >current linear supply. How easy it is to find something in the >specs on ebay or amazon tho is harder to say but they do exist.   You've gotten too technical for me. Maybe people in the group I added can tell me where to buy what you're suggesting.

"Rod Speed" <rod.speed.aaa@gmail.com>: Jun 03 09:18AM +1000 "micky" <NONONOmisc07@bigfoot.com> wrote in message news:39i8fepibbfteglk7m8pp278dmdgkcc1sf@4ax.com... >>specs on ebay or amazon tho is harder to say but they do exist.   > You've gotten too technical for me. Maybe people in the group I added > can tell me where to buy what you're suggesting.   Quite a few sold everywhere are like that.   I use Philips Hues which likely are fine but that system is very expensive for just the one led light.

Peeler <troll@trap.invalid>: Jun 03 01:46AM +0200 On Mon, 3 Jun 2019 09:18:13 +1000, cantankerous trolling geezer Rodent Speed, the auto-contradicting senile sociopath, blabbered, again:     > I use Philips Hues   I told you already several times, you can shove your Philips Hues up yours, senile Ozzie pest!   -- FredXX to Rot Speed: "You are still an idiot and an embarrassment to your country. No wonder we shipped the likes of you out of the British Isles. Perhaps stupidity and criminality is inherited after all?" Message-ID: <plbf76$gfl$1@dont-email.me>

bitrex <user@example.net>: May 30 04:07PM -0400 A guy on social media (natch) who had a faulty Korg Oasys ($8000 synthesizer) trying to DIY repair the switching power supply, and posted photos of himself having extracted the fucking primary-side PFC boost filter cap, 470uF 450 volts, having convinced himself this was the faulty part because it didn't read exactly 470uF on a DMM.

John Robertson <spam@flippers.com>: May 30 05:21PM -0700 On 2019/05/30 1:07 p.m., bitrex wrote: > photos of himself having extracted the fucking primary-side PFC boost > filter cap, 470uF 450 volts, having convinced himself this was the > faulty part because it didn't read exactly 470uF on a DMM.   And the technician who finally is called in to fix this will have to deal with all sorts of the cheap owner's crappy work including broken traces, ripped out feed through holes...   John :-#(#

KenW <ken1943@invalid.net>: Jun 02 10:56AM -0600 On Sun, 2 Jun 2019 15:57:22 -0000 (UTC), Cursitor Doom >wave rectifying tube/valve? Is it normal for them to become too hot to >touch after only a minute or two? >I'm talking specifically about the 5Y3GT in this context.   Ever hear of "hot as hell" ? They can get so hot you can't touch them unless turned off.

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