Author Topic: The Dubai Lamp  (Read 14249 times)

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Offline amykTopic starter

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Re: The Dubai Lamp
« Reply #50 on: April 19, 2022, 12:37:52 am »
That is very odd. Why would Philips decide to design and use a more complex driver circuit, which has the same ~0.5PF as the cap dropper/post-regulator in the original Dubai Lamp, instead of simply giving the original one even better LED filaments --- or just selling that one as-is?

 

Offline BrokenYugo

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Re: The Dubai Lamp
« Reply #51 on: April 19, 2022, 12:44:51 am »
That is very odd. Why would Philips decide to design and use a more complex driver circuit, which has the same ~0.5PF as the cap dropper/post-regulator in the original Dubai Lamp, instead of simply giving the original one even better LED filaments --- or just selling that one as-is?

Perhaps a 120V version is planned? I don't think enough dropper cap would fit in the screw base of a 120V version of the Dubai schematic.
 

Offline Gyro

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Re: The Dubai Lamp
« Reply #52 on: April 19, 2022, 01:15:58 pm »
Clive made some interesting comments about colour temperature and tint - 3000k and maybe a slightly greenish tint. Maybe the price (apart from cost) you have to pay for ultimate efficiency.
Best Regards, Chris
 

Offline BrokenYugo

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Re: The Dubai Lamp
« Reply #53 on: April 19, 2022, 06:32:12 pm »
Yes, the higher CRI phosphors are less efficient, especially at lower color temp, I also think the bulb makers are that much more stingy with the more costly high CRI LEDs and drive them that much harder. I was recently given a new production high CRI 2700k GE bulb that is rated 10 watts for a whole 800 lumens, and the case isn't even quite the full A19 diameter, they put off good light, but for how long?

« Last Edit: April 19, 2022, 06:34:12 pm by BrokenYugo »
 
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Offline mikerj

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Re: The Dubai Lamp
« Reply #54 on: April 19, 2022, 09:20:18 pm »
That is very odd. Why would Philips decide to design and use a more complex driver circuit, which has the same ~0.5PF as the cap dropper/post-regulator in the original Dubai Lamp, instead of simply giving the original one even better LED filaments --- or just selling that one as-is?

The buck regulator will give flicker free lighting, the same cannot be said for the simple capacitor dropper designs.
 
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Offline thm_w

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Re: The Dubai Lamp
« Reply #55 on: April 20, 2022, 12:11:49 am »
That is very odd. Why would Philips decide to design and use a more complex driver circuit, which has the same ~0.5PF as the cap dropper/post-regulator in the original Dubai Lamp, instead of simply giving the original one even better LED filaments --- or just selling that one as-is?

The buck regulator will give flicker free lighting, the same cannot be said for the simple capacitor dropper designs.

The dubai lamp was not a simple capacitive dropper though, to refresh your memory:
https://youtu.be/klaJqofCsu4?t=1265
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Offline mikerj

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Re: The Dubai Lamp
« Reply #56 on: April 20, 2022, 01:27:43 pm »
I suppose the buck will be more efficient than the linear regulator.
 

Online MK14

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Re: The Dubai Lamp
« Reply #57 on: April 20, 2022, 02:23:44 pm »
I suppose the buck will be more efficient than the linear regulator.

But also, assuming they are serious/honest/realistic about the 50,000 hour (burn) life. It helps keep the heat (hence lowers component temperature) dissipation down, possibly widens the range of (mains) input voltages the bulb(s) can support, and could reduce warranty claims (early failure).

The lamps are potentially worth the £12 (as BigClive mentions), because they are, (apparently) flicker free, very minimalistic energy consumption, very long lamp burn life, great for places where it needs to be on most of the time (e.g. some hall ways), and difficult/hazardous lamp locations. Such as high up on buildings.

I hope in the coming future, other suppliers (in addition to John Lewis), will stock those bulbs in the UK. Also, I hope the higher (equivalent) wattage versions, namely 75 watt and 100 watt versions, will also become available (UK). As 60 watts (equivalent) ones, are not necessarily bright enough, for all lighting needs.

I'm sort of stating the obvious here. But the current climate of sky high energy prices, and huge interest in big energy savings/efficiencies, would seem to make these new ultra efficient LED bulbs, suited for the big time, mass-market. So I hope Philips do market/sell/stock them, much more widely, than they currently seem to be. I.e. More retailers, advertising, bigger range (40W, 60W, 75W, 100W in UK), and possibly reduce the price, as £12, is rather pricey for LED bulbs.
« Last Edit: April 20, 2022, 02:42:29 pm by MK14 »
 

Offline cdev

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Re: The Dubai Lamp
« Reply #58 on: April 21, 2022, 06:11:28 pm »
In high wage areas I bet long life lower energy bulbs would pay for their higher cost.

If they needed far less frequent replacement, for  example..
"What the large print giveth, the small print taketh away."
 

Offline james_s

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Re: The Dubai Lamp
« Reply #59 on: April 21, 2022, 06:14:32 pm »
The wages are irrelevant, high efficiency lamps do pay for themselves. Even compared to the CFLs they replaced and even with the cheap electricity I have here the early LED bulbs I paid $40 each for paid for themselves in energy savings. Somebody who is very poor may not be able to afford the initial outlay for the efficient lamps but if they could scrape up the money they would pay for themselves in the long run.
« Last Edit: April 21, 2022, 08:45:14 pm by james_s »
 
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Offline Marco

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Re: The Dubai Lamp
« Reply #60 on: April 21, 2022, 08:37:45 pm »
That is very odd. Why would Philips decide to design and use a more complex driver circuit, which has the same ~0.5PF as the cap dropper/post-regulator in the original Dubai Lamp, instead of simply giving the original one even better LED filaments --- or just selling that one as-is?
The combination of low flicker, small capacitor and high efficiency might not have been possible without a buck regulator.

A resistive regulator will have to burn the ripple on the capacitor.
 

Offline james_s

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Re: The Dubai Lamp
« Reply #61 on: April 21, 2022, 08:46:34 pm »
The lack of flicker is a huge issue for me, I'm very sensitive to flicker. I typically buy a sample lamp to play with before I buy more of them to put into use and I reject lamps that have line frequency flicker.
 
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Offline cdev

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Re: The Dubai Lamp
« Reply #62 on: May 06, 2022, 01:52:36 am »
Me too.. I can see the flicker.. A lot, and it bugs me. I can tell lamps apart by flicker level.
"What the large print giveth, the small print taketh away."
 


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