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Dafydd Wynn Williams **
Joined: 19 Feb 2020 Posts: 97 Location: 3 miles south of Bangor North Wales
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Posted: Wed Nov 03, 2021 13:34 Post subject: LEDs |
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One for the Electronics Boffins out there :-
Several aspects of LEDs puzzle me
1. Whilst it is essential for LEDs connected to DC to be connected 'the right way round', domestic LED lamps ( AC bayonet fitting) not so. Or is it that they light on and off 50 times a sec?
2. LEDs are rated in lumens, but especially with hand torch manufacturers, the lumens claims are wildly different for the same class of LED?
3. I have fitted a pair of '55W' DRLs to my TLc, which are superb, but both run happily from a 2Amp fuse!
4. The packaging of Osram 921 DWP-02B wedge LEDs for reversing light use have confusing info, described as 1.4 W, 2W and 2.9W. (no lumens) Which figure is definitive?
Shead some light please. (sorry)
Dafydd WW |
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Posted: Wed Nov 03, 2021 13:34 Post subject: Google Ads keep this community free to join! |
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Tractionman ******
Joined: 07 Apr 2007 Posts: 821 Location: Bournemouth, Dorset
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Posted: Wed Nov 03, 2021 14:38 Post subject: |
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Cant help with technical info on those points Dafydd, except the last one, - f'kin bright !!
Seriously though, as they are all wattage figures, and you have the same led bulbs as per previous post that are rectangular in shape, maybe the wattage on the bigger flat sides are one figure, the wattage on the narrower flat sides are another, and the one on the end is yet another.
3 different facets, 3 different figures/brightness output. Just a guess. |
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Dafydd Wynn Williams **
Joined: 19 Feb 2020 Posts: 97 Location: 3 miles south of Bangor North Wales
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Posted: Fri Nov 05, 2021 18:35 Post subject: |
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Come on you Electronics Boffins, how about some thoughts on my post on LEDs please.
Dafydd WW |
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Tractionman ******
Joined: 07 Apr 2007 Posts: 821 Location: Bournemouth, Dorset
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Posted: Fri Nov 05, 2021 18:52 Post subject: |
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LEDs run cooler, consume less power so dont require heavy guage cable or fuses. You could phone a friend ? 🤐 |
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karl2000 ****
Joined: 25 Apr 2021 Posts: 318 Location: North West
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Posted: Fri Nov 05, 2021 19:19 Post subject: |
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50/50 |
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Tractionman ******
Joined: 07 Apr 2007 Posts: 821 Location: Bournemouth, Dorset
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Posted: Fri Nov 05, 2021 20:04 Post subject: |
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🤣🤣 |
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karl2000 ****
Joined: 25 Apr 2021 Posts: 318 Location: North West
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Posted: Fri Nov 05, 2021 20:39 Post subject: Re: LEDs |
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Hi Dafydd,
Dafydd Wynn Williams wrote: |
One for the Electronics Boffins out there :-
Several aspects of LEDs puzzle me
1. Whilst it is essential for LEDs connected to DC to be connected 'the right way round', domestic LED lamps ( AC bayonet fitting) not so. Or is it that they light on and off 50 times a sec?
2. LEDs are rated in lumens, but especially with hand torch manufacturers, the lumens claims are wildly different for the same class of LED?
3. I have fitted a pair of '55W' DRLs to my TLc, which are superb, but both run happily from a 2Amp fuse!
4. The packaging of Osram 921 DWP-02B wedge LEDs for reversing light use have confusing info, described as 1.4 W, 2W and 2.9W. (no lumens) Which figure is definitive?
Shead some light please. (sorry)
Dafydd WW |
1. Normal incandescent light bulbs and domestic lighting circuits dont really care which is + and which is -. You can put a normal bayonet bulb in either way around, so there is probably some magic in the led bulbs to compensate for that, as that what people expect. I've seen a few ceiling roses which have + and - wired incorrectly (switched) and the lights still work.
2. My understanding is that all light is rated in lumens - it is a measure of the light. With the old bulbs the wattage was used as an indication of the light, but because LED's use much less current (and therefore consume less power / wattage) the wattage isn't very useful. You will find charts about that will let you convert a lumens rating to old incandescent wattage, which is all most people understand. (I want a 100W bulb in my light for example!)
3. Because the 55W DRL's probably arent really using 55W of power if they are LEDs. They are probably *equivalent* to a halogen bulb at 55W. Power = Voltage X Current (P=VI) So the maximum power you could be consuming on a 2 Amp fuse on a 12 V circuit is 12*2 = 24W. So your LED's must use less than that, probably a lot lot less!
4. Not a clue about their packaging I;m afraid. But a lot of LED bulbs are sold with halogen W equivalents so that people know which is the right brightness for their car - eg the sidelights want W5W,, but the LED's wont really use 5 watts. Maybe put connect a multimeter in-line in a test circuit and see what they really pull!
I'm sure someone will correct some of the above and provide better answers, but thats my two penneth! |
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karl2000 ****
Joined: 25 Apr 2021 Posts: 318 Location: North West
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Posted: Fri Nov 05, 2021 22:51 Post subject: Re: LEDs |
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Dafydd Wynn Williams wrote: |
4. The packaging of Osram 921 DWP-02B wedge LEDs for reversing light use have confusing info, described as 1.4 W, 2W and 2.9W. (no lumens) Which figure is definitive?
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Hi Dafydd,
I''m not sure where you are seeing those numbers on the 921 packaging - is there any way you can show us?
https://www.performancebulbs.co.uk/osr921dwp-02b-osram-ledriving-sl-w16w-cool-white-bulbs-12v-1.4w-(wedge-921-21w)-921dwp-02b.html
These are the 921 DWP-02B bulbs and you can see pictures of the packaging on this site.
On the front of the packet, it says W2.1x9.5d. That is the dimensions of the wedge base of the bulb. W means wedge, the base is 2.1mm wide and it's 9.5mm long. D means double connection (2 wires) which means one filament in the bulb.
On the back of the packet, it says:
W2.1x9.5d (again)
12V | 2W - the LED bulb actually draws a max of 2 watts
Canbus Compatible 21W - the bulb is equivalent to an old fashioned halogen 21W bulb.
Hopefully that makes sense! If your bulb packet is totally different let us know! |
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Tractionman ******
Joined: 07 Apr 2007 Posts: 821 Location: Bournemouth, Dorset
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Posted: Sat Nov 06, 2021 10:20 Post subject: |
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OSRAM reverse light bulbs Dafydd ?? The ones we gave you info on are SAMSUNG multi led and super bright ! 😮 |
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Dafydd Wynn Williams **
Joined: 19 Feb 2020 Posts: 97 Location: 3 miles south of Bangor North Wales
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Posted: Sat Nov 06, 2021 14:05 Post subject: |
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Thanks Karl, your interpretation of the packaging card, is helpful and I now know I was taking the wedge dimensions as performance figure, thanks for putting me right.
TM, I bought my LEDs using Karl's reference - https://e bay.co.uk/itm/313443534850 from e bay, whch came up as Osram. Are the ones you have fitted (Toshiba??) a better performance?
Dafydd WW |
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Dafydd Wynn Williams **
Joined: 19 Feb 2020 Posts: 97 Location: 3 miles south of Bangor North Wales
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Posted: Sat Nov 06, 2021 14:09 Post subject: |
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Sorry TM, I should have said SAMSUNG.
Dafydd WW |
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karl2000 ****
Joined: 25 Apr 2021 Posts: 318 Location: North West
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Posted: Sat Nov 06, 2021 14:53 Post subject: |
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Hi Dafydd,
Sorry for the confusion - my original suggestion of Osrams for the reverse lights was superseded when TM suggested the SAMSUNG ones.
I'd already ordered the Osrams but the Samsung ones looked much better with more LED's and when I saw TM's photos of the bulbs in action I ordered the Samsungs and fitted those.
So, another upgrade for your list - at least you can change the bulbs in 30 seconds now ) |
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Tractionman ******
Joined: 07 Apr 2007 Posts: 821 Location: Bournemouth, Dorset
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Posted: Sat Nov 06, 2021 19:57 Post subject: |
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👍👍 |
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Dafydd Wynn Williams **
Joined: 19 Feb 2020 Posts: 97 Location: 3 miles south of Bangor North Wales
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Posted: Wed Nov 10, 2021 18:26 Post subject: |
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Like Karl, having accepted TM's glowing report of the SAMSUNG LEDs, although having bought and fitted he Osram LEDs I too ordered a pair of the SAMSUNG LEDS.
I now have a SAMSUNG LED (£10.06 a pair)in the RH reversing light and an Osram in the LH light, (£14 + a pair)!
The difference in brightness/illumination is marginal, if any, in favour of the SAMSUNG. The SAMSUNGs came loose & without any manufacturers packaging or markings.
I will leave things as they are and see which lasts longest.
The improvement in illumination is remarkable over the original bulbs and well worth the cost.
Dafydd WW |
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TONYCY11 ****
Joined: 05 Jun 2012 Posts: 409 Location: CYPRUS
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Posted: Wed Nov 10, 2021 19:00 Post subject: |
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The Osram leds are made by Osram hence the official packaging the Samsung ones are usually made by individual electronic led bulb manufacturers USING Samsung led chips , hence no official Samsung manufactures packaging . |
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