| Page 1 of 2 | 1 | 2 |
|
|
LED wattage
Can I take it that where a lamp or shade states a maximum wattage,
this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? |
LED wattage
On 12/03/2018 18:50, Scott wrote:
Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? Remember that LEDs don't like the bases containing the electronics to get too warm (this will shorten the life). The devil is in the detail. |
LED wattage
In article ,
newshound writes: On 12/03/2018 18:50, Scott wrote: Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? Remember that LEDs don't like the bases containing the electronics to get too warm (this will shorten the life). The devil is in the detail. To a first approximation, if it's rated 100W filament lamp, it will be suitable for 100W equivalent CFL or LED, even though these actual wattages are very different. However, it depands entirely on the ventilatiom, and if you are happy for a shortened lamp life, which is a comprise I'll often take. -- Andrew Gabriel [email address is not usable -- followup in the newsgroup] |
LED wattage
Scott explained :
Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? An LED is very susceptible to damage from its own heat build up, much less of an issue is likely heat damage to the shade it is in. If the shade allows good airflow and cooling of the LED, likely it will not be a problem. |
LED wattage
On Monday, 12 March 2018 20:06:40 UTC, Andrew Gabriel wrote:
In article , newshound writes: On 12/03/2018 18:50, Scott wrote: Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs yes and any LED will be okay (on the basis that LEDs use so much less power), no. LEDs are not heat tolerant. or is the light intensity likely to be an issue liable to cause fading? you jest Remember that LEDs don't like the bases containing the electronics to get too warm (this will shorten the life). The devil is in the detail. To a first approximation, if it's rated 100W filament lamp, it will be suitable for 100W equivalent CFL or LED, even though these actual wattages are very different. However, it depands entirely on the ventilatiom, and if you are happy for a shortened lamp life, which is a comprise I'll often take. Any LED is fine if the fitting is open & well vented. In a closed fitting, LEDs of same light output have a greatly reduced life due to overheating. NT |
LED wattage
On Mon, 12 Mar 2018 21:36:41 +0000, Harry Bloomfield wrote:
Scott explained : Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? An LED is very susceptible to damage from its own heat build up, much less of an issue is likely heat damage to the shade it is in. If the shade allows good airflow and cooling of the LED, likely it will not be a problem. That nicely sums up the issue. The incandescent lamp wattage rating for any given lamp shade or luminaire is based on how much heat it can safely handle. Incandescent lamps run at much higher temperatures than any LED can survive (150 to 200 deg C ). The problem with LEDs is that the LEDs themselves and any fancy electronic ballasts have a maximum junction temperature rating of 125 deg C meaning the whole lamp must be kept a good 30 to 50 deg cooler to establish the required temperature gradient between ambient and the solid state device junction temperatures within (LEDS and switching transistors and diodes) to dissipate the heat generated by these devices. The older, less efficient 81 LPW LED lamps were limited to the equivalent American based 806 Lm 60W rating and even these only met their claimed 25,000 hours life rating in open reasonably ventilated shades/ luminaires. Now, it is possible to upgrade those 810 Lumens lamps with the 100W 1500Lm LED equivalent 12W 125 LPW lamps in those very same luminaires because they produce slightly less *waste* heat than the earlier 810 Lumens 10W LED lamps did, meaning they will run just as cool, if not slightly cooler, despite consuming an extra 2 watts for almost double the light output. The main benefit of yet higher efficiency LED lamps is not the power savings they offer but the fact that they can be fitted into almost every standard luminaire or lamp shade with almost no regard to the issue of overheating that afflicted the early low efficiency LED lamps. Most of the energy savings to be made with lighting were achieved with the CFL generation of energy efficient lamps. Upgrading a houseful of CFLs to today's modern 125LPW LED lamps will offer a vanishingly small reduction in the overall domestic electricity bill. -- Johnny B Good |
LED wattage
I'd imagine that depends on the quality of the shade. Don't you think shades
are the most pointless things every invented? After all you go for more efficient lighting solutions yet try to block some of the light with a shade. I propose nice to look at sockets and lamps instead. Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! "Scott" wrote in message ... Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? |
LED wattage
On Tuesday, 13 March 2018 08:11:10 UTC, Brian Gaff wrote:
I'd imagine that depends on the quality of the shade. Don't you think shades are the most pointless things every invented? After all you go for more efficient lighting solutions yet try to block some of the light with a shade. I propose nice to look at sockets and lamps instead. Brian Trouble there is that they aren't very nice to look at, and if you can look at them then they aren't bright enough to illuminate a large area very well. I thought the idea of a shade was so that yuo couldn;t see a really bright bulb and that the light got diffucused by the shade which could also add a bit of colour. |
LED wattage
|
LED wattage
On Tue, 13 Mar 2018 02:49:55 GMT, Johnny B Good
wrote: On Mon, 12 Mar 2018 21:36:41 +0000, Harry Bloomfield wrote: Scott explained : Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? An LED is very susceptible to damage from its own heat build up, much less of an issue is likely heat damage to the shade it is in. If the shade allows good airflow and cooling of the LED, likely it will not be a problem. That nicely sums up the issue. The incandescent lamp wattage rating for any given lamp shade or luminaire is based on how much heat it can safely handle. Incandescent lamps run at much higher temperatures than any LED can survive (150 to 200 deg C ). The problem with LEDs is that the LEDs themselves and any fancy electronic ballasts have a maximum junction temperature rating of 125 deg C meaning the whole lamp must be kept a good 30 to 50 deg cooler to establish the required temperature gradient between ambient and the solid state device junction temperatures within (LEDS and switching transistors and diodes) to dissipate the heat generated by these devices. The older, less efficient 81 LPW LED lamps were limited to the equivalent American based 806 Lm 60W rating and even these only met their claimed 25,000 hours life rating in open reasonably ventilated shades/ luminaires. Now, it is possible to upgrade those 810 Lumens lamps with the 100W 1500Lm LED equivalent 12W 125 LPW lamps in those very same luminaires because they produce slightly less *waste* heat than the earlier 810 Lumens 10W LED lamps did, meaning they will run just as cool, if not slightly cooler, despite consuming an extra 2 watts for almost double the light output. Very good points. I shall buy Philips and not one from the pound shop. The main benefit of yet higher efficiency LED lamps is not the power savings they offer but the fact that they can be fitted into almost every standard luminaire or lamp shade with almost no regard to the issue of overheating that afflicted the early low efficiency LED lamps. And instant start and arguably better colour rendition. Most of the energy savings to be made with lighting were achieved with the CFL generation of energy efficient lamps. Upgrading a houseful of CFLs to today's modern 125LPW LED lamps will offer a vanishingly small reduction in the overall domestic electricity bill. |
LED wattage
In article ,
Johnny B Good wrote: Most of the energy savings to be made with lighting were achieved with the CFL generation of energy efficient lamps. Upgrading a houseful of CFLs to today's modern 125LPW LED lamps will offer a vanishingly small reduction in the overall domestic electricity bill. Oddly, visited a pal's flat where he'd done just that. And the LEDs he'd used - probably the cheapest he could find - made it seem like being out on a miserable cloudy winter's day. Very depressing. -- *Yes, I am an agent of Satan, but my duties are largely ceremonial Dave Plowman London SW To e-mail, change noise into sound. |
LED wattage
wrote in message
... Any LED is fine if the fitting is open & well vented. In a closed fitting, LEDs of same light output have a greatly reduced life due to overheating. I have a Philips Hue bulb in the light beside my bed: a bare fitting in a table lamp, with no shade. The light part of the bulb gets barely warm. The base gets fairly hot: it's bareable for 10 seconds but after that it starts to become a bit too hot to tolerate. And that's with no shade around it, so best-case cooling. It's rated 10 W / 70 mA / 810 lumen. And that's for maximum brightness at a fairly neutral white. |
LED wattage
On 13/03/2018 12:00, NY wrote:
wrote in message ... Any LED is fine if the fitting is open & well vented. In a closed fitting, LEDs of same light output have a greatly reduced life due to overheating. I have a Philips Hue bulb in the light beside my bed: a bare fitting in a table lamp, with no shade. The light part of the bulb gets barely warm. The base gets fairly hot: it's bareable for 10 seconds but after that it starts to become a bit too hot to tolerate. And that's with no shade around it, so best-case cooling. Some shades help cooling by creating convection like chimneys do. |
LED wattage
"whisky-dave" wrote in message
... On Tuesday, 13 March 2018 08:11:10 UTC, Brian Gaff wrote: I'd imagine that depends on the quality of the shade. Don't you think shades are the most pointless things every invented? After all you go for more efficient lighting solutions yet try to block some of the light with a shade. I propose nice to look at sockets and lamps instead. Brian Trouble there is that they aren't very nice to look at, and if you can look at them then they aren't bright enough to illuminate a large area very well. I thought the idea of a shade was so that yuo couldn;t see a really bright bulb and that the light got diffucused by the shade which could also add a bit of colour. Exactly. The purpose of a (translucent) shade is to increase the effective size of the illuminated area (and maybe to direct the light a bit more from being omnidirectional) so it's more diffuse and less of a point source. That's why in the days of tungsten bulbs, they started frosting the inside of the glass so the whole bulb was a uniform brightness and you didn't get a thin filament of brightness which tended to leave more of an after-image on the retina if you happened to look at the bulb. |
LED wattage
On Tuesday, 13 March 2018 12:07:35 UTC, NY wrote:
"whisky-dave" wrote in message ... On Tuesday, 13 March 2018 08:11:10 UTC, Brian Gaff wrote: I'd imagine that depends on the quality of the shade. Don't you think shades are the most pointless things every invented? After all you go for more efficient lighting solutions yet try to block some of the light with a shade. I propose nice to look at sockets and lamps instead. Brian Trouble there is that they aren't very nice to look at, and if you can look at them then they aren't bright enough to illuminate a large area very well. I thought the idea of a shade was so that yuo couldn;t see a really bright bulb and that the light got diffucused by the shade which could also add a bit of colour. Exactly. The purpose of a (translucent) shade is to increase the effective size of the illuminated area (and maybe to direct the light a bit more from being omnidirectional) so it's more diffuse and less of a point source. That's why in the days of tungsten bulbs, they started frosting the inside of the glass so the whole bulb was a uniform brightness and you didn't get a thin filament of brightness which tended to leave more of an after-image on the retina if you happened to look at the bulb. And this is where LEDs are really bad in spotlights you end up with a bright spot on the wall, OK if that's what yuo want but most want even illumination throught the room. |
LED wattage
On Tuesday, 13 March 2018 12:06:23 UTC, dennis@home wrote:
On 13/03/2018 12:00, NY wrote: tabbypurr wrote in message ... Any LED is fine if the fitting is open & well vented. In a closed fitting, LEDs of same light output have a greatly reduced life due to overheating. I have a Philips Hue bulb in the light beside my bed: a bare fitting in a table lamp, with no shade. The light part of the bulb gets barely warm. The base gets fairly hot: it's bareable for 10 seconds but after that it starts to become a bit too hot to tolerate. And that's with no shade around it, so best-case cooling. Some shades help cooling by creating convection like chimneys do. very few |
LED wattage
On 13/03/18 10:27, Scott wrote:
Very helpful. Mind is in a globe (bathroom light) but it is quite a big globe. I won't go overboard with output.. Short engineering dissertaion on heat dissipation. What kills incandescent lamps is "hours on". What kills lampshades is peak temperature. That why they have lamp wattage ratings. 90% of an inmcandescent is heat so to a first approximation a '60W lampshade' can take 60W of heat in its middle without going brown or catching fire.. What kills LEDs is the product of life and of temperature. The hotter they run the shorter they run. However most LED *CHIPS* will stand to run at 100C or more. What this means is that *NO* LED is going to scorch that lampshade. To get 60W of heat you probably need 80W of LED, and that probably will not fit in the lampshade. And would blind you! I've just grabbed a candle LED that is about 40W equivalent, and its about 40C. That is par for the envelope of a LED bulb. Ergo the only critical factor is whether the lampshade will overheat the LED. Frankly if it's designed for an incandescent the answer is hell no!. I've even put LEDS in enclosed cooker hoods and fully enclosed luminaires and they have been FINE. For several YEARS. As usual tabbypurr is pontificating from limited armchair theory and zero real understanding. -- €œBut what a weak barrier is truth when it stands in the way of an hypothesis!€ Mary Wollstonecraft |
LED wattage
On Tuesday, 13 March 2018 12:40:55 UTC, The Natural Philosopher wrote:
On 13/03/18 10:27, Scott wrote: Very helpful. Mind is in a globe (bathroom light) but it is quite a big globe. I won't go overboard with output.. Short engineering dissertaion on heat dissipation. What kills incandescent lamps is "hours on". What kills lampshades is peak temperature. That why they have lamp wattage ratings. 90% of an inmcandescent is heat so to a first approximation a '60W lampshade' can take 60W of heat in its middle without going brown or catching fire.. What kills LEDs is the product of life and of temperature. The hotter they run the shorter they run. However most LED *CHIPS* will stand to run at 100C or more. What this means is that *NO* LED is going to scorch that lampshade. To get 60W of heat you probably need 80W of LED, and that probably will not fit in the lampshade. And would blind you! I've just grabbed a candle LED that is about 40W equivalent, and its about 40C. That is par for the envelope of a LED bulb. Ergo the only critical factor is whether the lampshade will overheat the LED. so far so good Frankly if it's designed for an incandescent the answer is hell no!. I've even put LEDS in enclosed cooker hoods and fully enclosed luminaires and they have been FINE. For several YEARS. yes, with limited use. You've got 15k or 25k hour life lamps, a year on 24/7 is only 8760rs. If you're willing to live with much reduced life, great, go for it. As usual tabbypurr is pontificating from limited armchair theory and zero real understanding. whoosh. NT |
LED wattage
On Tuesday, 13 March 2018 12:28:26 UTC, wrote:
On Tuesday, 13 March 2018 12:06:23 UTC, dennis@home wrote: On 13/03/2018 12:00, NY wrote: tabbypurr wrote in message ... Any LED is fine if the fitting is open & well vented. In a closed fitting, LEDs of same light output have a greatly reduced life due to overheating. I have a Philips Hue bulb in the light beside my bed: a bare fitting in a table lamp, with no shade. The light part of the bulb gets barely warm. The base gets fairly hot: it's bareable for 10 seconds but after that it starts to become a bit too hot to tolerate. And that's with no shade around it, so best-case cooling. Some shades help cooling by creating convection like chimneys do. very few I look cool in shades :-D |
LED wattage
|
LED wattage
In article ,
whisky-dave wrote: On Tuesday, 13 March 2018 08:11:10 UTC, Brian Gaff wrote: I'd imagine that depends on the quality of the shade. Don't you think shades are the most pointless things every invented? After all you go for more efficient lighting solutions yet try to block some of the light with a shade. I propose nice to look at sockets and lamps instead. Brian Trouble there is that they aren't very nice to look at, and if you can look at them then they aren't bright enough to illuminate a large area very well. I thought the idea of a shade was so that yuo couldn;t see a really bright bulb and that the light got diffucused by the shade which could also add a bit of colour. the original reason for calling them "shades" was that they shaded certian places from the light. Sometimes they act as diffusers, too. -- from KT24 in Surrey, England |
LED wattage
On 13/03/18 12:40, The Natural Philosopher wrote:
On 13/03/18 10:27, Scott wrote: Very helpful.Â* Mind is in a globe (bathroom light) but it is quite a big globe.Â* I won't go overboard with output.. Short engineering dissertaion on heat dissipation. What kills incandescent lamps is "hours on". What kills lampshades is peak temperature. That why they have lamp wattage ratings. 90% of an inmcandescent is heat so to a first approximation a '60W lampshade' can take 60W of heat in its middle without going brown or catching fire.. What kills LEDs is the product of life and of temperature. The hotter they run the shorter they run. However most LED *CHIPS* will stand to run at 100C or more. What this means is that *NO* LED is going to scorch that lampshade. To get 60W ofÂ* heat you probably need 80W of LED, and that probably will not fit in the lampshade. And would blind you! And don't forget LED "filament" strings with no PSU - there you should be limited only to the led operation temperature without any problems with silicon or capacitors not liking the heat. On an aside, the only issue I've had with "filament" LEDs is that different batches can dim at different rates on an LED dimmer (ie full on all looks the same, but right down at the "just glowing" stage, one set can be literally "just" glowing and the other can be quite a bit brighter. But overall, they look pleasant and the simplicity seems to help - I have had almost no failures compared to lots of failures of PSU based lamps in a similar time frame (couple of years). But to be fair, this problem seems to abate with larger lamps - my R63's are going strong after 2-3 years with zero failures. |
LED wattage
On Tue, 13 Mar 2018 12:00:12 -0000, NY wrote:
wrote in message ... Any LED is fine if the fitting is open & well vented. In a closed fitting, LEDs of same light output have a greatly reduced life due to overheating. I have a Philips Hue bulb in the light beside my bed: a bare fitting in a table lamp, with no shade. The light part of the bulb gets barely warm. The base gets fairly hot: it's bareable for 10 seconds but after that it starts to become a bit too hot to tolerate. And that's with no shade around it, so best-case cooling. It's rated 10 W / 70 mA / 810 lumen. And that's for maximum brightness at a fairly neutral white. That's a fairly inefficient lamp - or the glowing bit is very efficient and the electronics aren't. I noticed (couple of years ago) that Ikea's LED lamps, even base down, were hot enough to burn within a few seconds. I've some here that get up to about 40 - 50 deg. eventually, even in a shade. -- Peter. The gods will stay away whilst religions hold sway |
LED wattage
On Tuesday, 13 March 2018 13:28:19 UTC, The Natural Philosopher wrote:
On 13/03/18 13:04, tabbypurr wrote: yes, with limited use. You've got 15k or 25k hour life lamps, a year on 24/7 is only 8760rs. If you're willing to live with much reduced life, great, go for it. Golly. A mixture of actual SUMS and hand wavey phrases like 'a greatly reduced life' showing the total incomprehsnion of reality by 'tabbypurr' By the way, its 24x7. not 24/7 The LEDS are ALREADY in a totally enclosed container. The light bulb. Anything outside of that short of sticking them inside a polystyrene foam box is going to make the square root of sweet fanny adam's difference. I see you've resorted to bullsht. Life's too short. Bye. |
LED wattage
|
LED wattage
On 13/03/2018 12:19, whisky-dave wrote:
And this is where LEDs are really bad in spotlights you end up with a bright spot on the wall, OK if that's what yuo want but most want even illumination throught the room. A spotlight is supposed to produce a bright spot. If you don't want one then don't use a spotlight. |
LED wattage
On Tuesday, 13 March 2018 15:46:46 UTC, wrote:
On Tuesday, 13 March 2018 13:28:19 UTC, The Natural Philosopher wrote: On 13/03/18 13:04, tabbypurr wrote: yes, with limited use. You've got 15k or 25k hour life lamps, a year on 24/7 is only 8760rs. If you're willing to live with much reduced life, great, go for it. Golly. A mixture of actual SUMS and hand wavey phrases like 'a greatly reduced life' showing the total incomprehsnion of reality by 'tabbypurr' By the way, its 24x7. not 24/7 The LEDS are ALREADY in a totally enclosed container. The light bulb. Anything outside of that short of sticking them inside a polystyrene foam box is going to make the square root of sweet fanny adam's difference. I see you've resorted to bullsht. Life's too short. Bye. But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. |
LED wattage
On 14/03/18 09:54, whisky-dave wrote:
But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. |
LED wattage
On Wednesday, 14 March 2018 10:18:33 UTC, Tim Watts wrote:
On 14/03/18 09:54, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. They canlt easily be dimmed, they are crap, they flicker and don't last anywhere near as long as stated. |
LED wattage
On 14/03/18 11:07, whisky-dave wrote:
On Wednesday, 14 March 2018 10:18:33 UTC, Tim Watts wrote: On 14/03/18 09:54, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. They canlt easily be dimmed, they are crap, they flicker and don't last anywhere near as long as stated. That's not been my experience - the filament candles I have dim very well. The only problem (as mentioned a few posts back) is that the cut off point varies between batches (diode forward voltage variances I guess) so you can either get one set cutting out whilst the other is glowing or the other set brighter whilst the first is glowing. |
LED wattage
On Mon, 12 Mar 2018 18:50:43 +0000, Scott
wrote: Can I take it that where a lamp or shade states a maximum wattage, this is for incandescent bulbs and any LED will be okay (on the basis that LEDs use so much less power), or is the light intensity likely to be an issue liable to cause fading? As a development in this sage, I tried to buy three e14 to b22 converters to allow me a better choice of bulbs. The order is shown as 'awaiting fulfillment', the phone number on the website is invalid, HMRC say the VAT number is now deregistered and TrustPilot reviews are nearly all one star - terrible. Has anyone encountered Easybulb / Gigateq LImited in Manchester? And yes, I know I should have done this research earlier - caveat emptor. |
LED wattage
On 14/03/18 11:07, whisky-dave wrote:
On Wednesday, 14 March 2018 10:18:33 UTC, Tim Watts wrote: On 14/03/18 09:54, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. They canlt easily be dimmed, they are crap, they flicker and don't last anywhere near as long as stated. They can easily be dimmed, and tehy wont flicker any more than a fluorescent does. -- You can get much farther with a kind word and a gun than you can with a kind word alone. Al Capone |
LED wattage
On Wednesday, 14 March 2018 09:54:42 UTC, whisky-dave wrote:
But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. The heat comes from the LED, it doesn't get transferred to the LED. |
LED wattage
On Wednesday, 14 March 2018 11:07:31 UTC, whisky-dave wrote:
On Wednesday, 14 March 2018 10:18:33 UTC, Tim Watts wrote: Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. They canlt easily be dimmed, they are crap, they flicker and don't last anywhere near as long as stated. more cobblers |
LED wattage
wrote in message
... On Wednesday, 14 March 2018 09:54:42 UTC, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. The heat comes from the LED, it doesn't get transferred to the LED. Ah, is the heat mainly from the LEDs rather than the PSU? |
LED wattage
"whisky-dave" wrote in message
... On Wednesday, 14 March 2018 10:18:33 UTC, Tim Watts wrote: On 14/03/18 09:54, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. They canlt easily be dimmed, they are crap, they flicker and don't last anywhere near as long as stated. They can be dimmed very easily using their own built-in control logic (but not too effectively by using an external triac dimmer) - all that is required is a constant-frequency square wave with a variable mark:space ratio. The problem is that they tend to be clocked at a relatively low speed, so as you decrease the M:S ratio, the flicker on moving objects becomes very noticeable. I've seen some 7-segment LED displays on cookers which were clocked at main frequency, and that was *horrible* if your eye panned over something moving and you saw multiple copies of the time in your field of view. Likewise for the "red man" on the switch box of a Pelican crossing as you are driving past. |
LED wattage
On Wednesday, 14 March 2018 14:32:48 UTC, wrote:
On Wednesday, 14 March 2018 09:54:42 UTC, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. The heat comes from the LED, it doesn't get transferred to the LED. NO it doesn't. |
LED wattage
On Wednesday, 14 March 2018 14:47:42 UTC, NY wrote:
wrote in message ... On Wednesday, 14 March 2018 09:54:42 UTC, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. The heat comes from the LED, it doesn't get transferred to the LED. Ah, is the heat mainly from the LEDs rather than the PSU? You can tell where the heat comes from by touching the bulb mount. |
LED wattage
On Wednesday, 14 March 2018 15:05:51 UTC, NY wrote:
"whisky-dave" wrote in message ... On Wednesday, 14 March 2018 10:18:33 UTC, Tim Watts wrote: On 14/03/18 09:54, whisky-dave wrote: But it is true the problem with LED lightbulbs is that they do get very hot at the base as that's where the SMPS are but the heat can be transfered to the actual LEDs which don;t like being hot. The life of the lamps might well be UP TO 15K hours but they are very liklely to fail long before that due to temperature as the 15K hours refers to an LED used within the specs and even then it doesn't mean it will last 15,000 hours. Not all LED lamps have much in the way of PSUs :) https://youtu.be/ReO9D1E8XqI?t=9m2s Basically a bridge and 3 passives. They canlt easily be dimmed, they are crap, they flicker and don't last anywhere near as long as stated. They can be dimmed very easily using their own built-in control logic what built in control logic ? How do they dim rising or falling or just increased resistance ? (but not too effectively by using an external triac dimmer) - all that is required is a constant-frequency square wave with a variable mark:space ratio. The problem is that they tend to be clocked at a relatively low speed, so as you decrease the M:S ratio, the flicker on moving objects becomes very noticeable. Yes I know, but of course others have said there's no flicker. I've seen some 7-segment LED displays on cookers which were clocked at main frequency, and that was *horrible* if your eye panned over something moving and you saw multiple copies of the time in your field of view. Likewise for the "red man" on the switch box of a Pelican crossing as you are driving past. We have bench PSUs here that do the same but that is because of multiplexing displays and nothing to do with mains frequency. |
| All times are GMT +1. The time now is 06:28 AM. |
|
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter