EEVblog Electronics Community Forum
EEVblog => EEVblog Specific => Topic started by: EEVblog on March 29, 2015, 06:42:40 am
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A quick rant on T4 fluorescent tubes, and a small upgrade to replace a T4 tube with a LED strip.
Previous video on LED lighting Dave's back deck:
https://www.youtube.com/watch?v=GkVRX3h_A30 (https://www.youtube.com/watch?v=GkVRX3h_A30)
EEVblog #728 - T4 LED Lighting (https://www.youtube.com/watch?v=_UFT-mjyhG0#ws)
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I believe T4 was specifically designed for non-standard length applications. Mostly decorative things, with interestingly shaped tubes. They only needed to standardise the ends, so people could mass produce standard connectors.
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A T4 that lasted 12 years, and the lamp actually died and not the ballast. You must not use it at all much, they typically only do 2 years before the lamp goes low mercury and glows pink or dim, or the ballast detonates.
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A T4 that lasted 12 years, and the lamp actually died and not the ballast. You must not use it at all much
Before Sagan came along, hardly used this bathroom at all.
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Antarctic themed bathroom. Who wants to guess about the closet under the stairs. I wanna see the Marty room.
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Hi Dave, try http://www.linedict.com/ (http://www.linedict.com/) for translating the chinese symbols. (With all these cheap chinese stuff, demo boards with the user manual in engrish, and the component descriptions in these funny simbols, linedict was great help to me)
The first symbol is a 3, and the last one in brackets is the symbol for comfort (maybe wavelength?) The other are unclear even on a 1080p resolution. So maybe 30W warm white?
BTW it looks even cooler so that the individual leds are showing. Countdown till SWMBO says it is too dim :)
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Not too bad this time. Only noticed it on a few occasions.
That will be the YT recoding, brainfarting on the fast changing data and saying "ah bugger it I will use a larger macroblock till i get an Iframe" to reduce data rate.
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Does the power supply have any compliance such as UL or VDE?
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I can only add (repeat) I only see it on recent EEVBLOG videos. Not on any other recent video on over a dozen other channels I subscribe too and have watched in the past week or two. I don't see it on HD EEVBlog videos.
So if it is YT then I can't see the reason it seems to only affect the EEVBlog.
I've changed nothing. Exact same way I'e shot, edited, rendered, transcoded and uploaded my video for a long time now.
Other people have reported it's happening on other channels, so it's almost certainly not me.
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That will be the YT recoding, brainfarting on the fast changing data and saying "ah bugger it I will use a larger macroblock till i get an Iframe" to reduce data rate.
Iframe? You mean key frame? If Dave's Handbreak script doesn't specify the use of key frames, that might be something to look into. Personally, I'm still wondering why Dave standardizes on 25/50 FPS and not 30/60 considering that most LCD screens today run on 60 FPS, which should give less temporal aliasing. I could understand it if a video contains mainly footage from a camera that can only output 25 FPS, but otherwise, :-//
I wonder if this issue could be related to that too. Perhaps the encoder isn't really optimized for 25 FPS, and gets confused and has to compensate by adding/removing a frame every now and then to keep a constant fame rate, and does this badly. Just a thought. This could be thoroughly tested. First by uploading the SAME video export again and seeing if the same glitch occurs at the same places, as a reference to rule out that it isn't completely random. Then uploading a 30 FPS export and see if the glitch occurs there. And all the while of course confirming that the glitch isn't in the uploaded file.
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(https://www.eevblog.com/forum/blog/eevblog-728-t4-led-lighting/?action=dlattach;attach=144196;image)
That's a gorgeous brown wire color on the output. I really like the reddish tone in that brown color. And that really really dark blue color is something else... :-DD
Maybe this is not a pure oversight by the manufacturer, and it refers to where you are supposed to connect the negative and positive wires. But, are there any common standards for LED wiring that dictate blue and brown for negative and positive? :-//
I would have liked some more playing around with these. You should have bought one or a couple more and maybe...
* Compared the light output, voltage output, and power draw over the full specified voltage range.
* Tested the primary/secondary isolation with your isolation tester.
* And of course, a teardown to see exactly how crap it is inside! Could you feel from the outside that it was potted for example? IP67 pass, or IP67 my ass?
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IP67 when enclosed in an appropriate IP67 rated fitting............ Otherwise IP00.
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did it pass 'the she who has to obeyed' test ?
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did it pass 'the she who has to obeyed' test ?
Happy wife :-+
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Personally, I'm still wondering why Dave standardizes on 25/50 FPS and not 30/60
My main camera is 25/50fps
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Personally, I'm still wondering why Dave standardizes on 25/50 FPS and not 30/60
My main camera is 25/50fps
It seems it's not unusual for cameras to be locked to 25/50 or 30/60. I recently bought an FZ1000 4K bridge camera and I was a little surprised that it has two models depending on the region it's purchased in, and it appears locked. While these cameras still support localised legacy standard composite SD outputs, this may remain the case for a while. It'll be a compromise between the cost of providing multistandard and the perceived value to the customer of what could be considered an edge case
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Why did you have to fix the light at the lab?
Is there a "Don't fiddle at home" agreement?
I'm glad that you got an good WAF at yout work.
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Dave,
Your rant about non standard lengths of these T4 tubes is not correct!
The numeral in T4 , T5, T8,... always denotes the tubes diameter in unity of 1/8 inch, and the length varies for ALL of these different types - also in a standardized manner - over the wattage.
Physical background: the diameter will determine the current density, the length determines the overall burn-voltage, and so the wattage.
Therefore, the length should be correlated to wattage in a proportional manner.
Therefore you would have had to buy exactly the same diameter AND wattage as replacement as the old one, or you may also use a different diameter, after you had a quick look into the wattage vs. length tables.
Maybe, you were a victim of an incomplete WIKIPEDIA entry in the English version.
The German version has a good overview and description on this subject, just look at the tables here: http://de.wikipedia.org/wiki/Leuchtstofflampe (http://de.wikipedia.org/wiki/Leuchtstofflampe)
Translations:
Durchmesser = diameter
Sockel = socket
Länge = length
Leistung = wattage
PS : Anyhow, it is an interesting video, because I also were not aware of that problem; and I also want to replace fluorescent lamps and "energy saving " ones by LEDs in the future.
Frank
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Why did you have to fix the light at the lab?
a) Ran out of solder, heatshrink, and double sided tape at home, home lab is practically non-existent now.
b) Had to shoot a mailbag with Sagan anyway (addressed to him)
c) SWMBO was busy. Translation: go away and play with Sagan
d) Thought I might as well shoot a quick video about it while I was there.
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"Nice" power supply you got for those LED's. Cable color instructions are all wrong and that CE marking is most likely "China Export." I would also eat my hat if that thing is really IP67 rated.
It would be really nice to see a teardown of that supply!
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Your rant about non standard lengths of these T4 tubes is not correct!
The numeral in T4 , T5, T8,... always denotes the tubes diameter in unity of 1/8 inch, and the length varies for ALL of these different types - also in a standardized manner - over the wattage.
Then please explain:
- why no one sells T4 tubes to match the length I had - anywhere online that I could find, even overseas.
- Hardly any local lighting or hardware stores carry practically any T4 tubes spare, and the rare one that did had every size but mine (close though).
- No one makes T4 LED replacement tubes, yet they do for the other sizes that do have standardised lengths.
- Why many sites (inc wikipedia) confirm that there is no standard, and that it basically what I found when I searched.
Perhaps in Germany, but elsewhere there doesn't seem to be any standard.
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High efficiency LED power supply? 170V x 0.53A = 90.1W or 265V x 0.13A = 34.45W so power draw could be anywhere from 34.5W to 90.1W - hardly high efficiency when 10W is output to the LEDs!!
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Iframe? You mean key frame? If Dave's Handbreak script doesn't specify the use of key frames, that might be something to look into.
"Key frames" is a term in animation. The animator draws (or models, whatever) key frames at specific instants and the animation system "tweens" from one to another. (In cel animation the tweening process is done by animators' assistants.) Terms related to "key" are common in production, like key grip, chroma key, etc.
Video codecs use temporal coding to reduce the average data rate, while allowing both detail and fast motion to be preserved. They do this by assigning frames to different types: the frames with the most detail are called the I-frames. I is for "intracoded", meaning they are complete pictures, no temporal data. In between I-frames the codec uses P-frames, which describe movement in terms of distance from the last I-frame, and B-frames, which interpolate movement between I- or P-frames. P is for "predictive" and B is for "bidirectional". I-frames take much more bandwidth than the other types, about 3x each P-frame and 15x each B-frame, so to keep the average data rate low they are spaced far apart.
The encoder needs to decide which frames should be I-coded, based on movement and detail in the scene. Just adding more I-frames won't necessarily remove artifacts, because each I-frame increases the bandwidth requirement. In order to meet the data rate target the encoder would need to increase the compression level (by dropping more DCT coefficients). The trick is to choose the proper frames for I-coding.
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I just watched the video using a non flash or HTML based player, using the H.264 based player in Mplayer. No artefacting visible, so the YT video is fine, and the browser or app based players ( which probably are using a browser based rendering in any case) are the things creating the artefacting. Totem 2.30.2, and GStreamer 0.10.28, yes it is not the most modern, and still no artefacts visible in VLC either.
Geez, 140M for a 11 minute video.....Dave, I think we can lay this one to rest.....
As to T4 being hard to get that is true, as most stores and wholesalers will not stock a lamp that is cheap ( under $5 each) but with a minimum buy of a case of 25, that might sell one a year or less. With small power tubes you get a lot of size variations, and even more colour temperatures and colours, so to keep a case of each will mean a lot of shelf space in use, for something that both is fragile and very slow moving.
If I encounter any T4 or smaller ( or T5 which does eat the ballast and the tube at the same time) I will look at getting LED strip to replace it. If you want more light add extra strips next to each other, you can put 3 strips in the same place as a T5 on the cover, and get about the same light output. RGB strips are nice there as well, and you can also get 24V RGB strips, which are slightly more efficient and also have a cheap controller available. I am using some old ones on 12V, just had to do some slight bodge wiring to split it into 2 3 LED strings.
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The first symbol is a 3, and the last one in brackets is the symbol for comfort (maybe wavelength?) The other are unclear even on a 1080p resolution. So maybe 30W warm white?
I'll give a try at the characters in Japanese (most of them match the traditional Chinese ones anyway):
1: 3 - this is easy
2: (game of) go ? - but the character seems a variation of the most common form, so maybe just a name?
http://www.edrdg.org/jmdictdb/cgi-bin/entr.py?svc=jmdict&sid=&q=1270870 (http://www.edrdg.org/jmdictdb/cgi-bin/entr.py?svc=jmdict&sid=&q=1270870)
3: color
http://www.edrdg.org/jmdictdb/cgi-bin/entr.py?svc=jmdict&sid=&q=1357600 (http://www.edrdg.org/jmdictdb/cgi-bin/entr.py?svc=jmdict&sid=&q=1357600)
4: white
http://www.edrdg.org/jmdictdb/cgi-bin/entr.py?svc=jmdict&sid=&q=2751410 (http://www.edrdg.org/jmdictdb/cgi-bin/entr.py?svc=jmdict&sid=&q=2751410)
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It would have been worthwhile to have opened the power supply to see what was in it. The CE marking means nothing. The power supply in the video is not C-Tick compliant. And you cannot trust that the wiring is UL approved self extinguishing type in case of fire. There does not seem to be any link to this DYOU brand on the web. Maybe DYOU means Do You Own Underwriting ^-^.
An electrician I know who installs LED lights told me there are a lot of drivers around which produce excessive RF EMI. No compliance, no nothing. He only uses those from a reputable wholesaler in Melbourne who imports quality approved drivers which are also RF quiet. More expensive than eBay crap, but money well spent.
A mate of mine had a Hoo Flung Dung brand bathroom fan which caught fire, causing $20,000 worth of damage. It was a sobering experience for him. Even though all this crap is made in China, at least a genuine well known brand there is some level of quality and safety.
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Your rant about non standard lengths of these T4 tubes is not correct!
The numeral in T4 , T5, T8,... always denotes the tubes diameter in unity of 1/8 inch, and the length varies for ALL of these different types - also in a standardized manner - over the wattage.
Then please explain:
- why no one sells T4 tubes to match the length I had - anywhere online that I could find, even overseas.
- Hardly any local lighting or hardware stores carry practically any T4 tubes spare, and the rare one that did had every size but mine (close though).
- No one makes T4 LED replacement tubes, yet they do for the other sizes that do have standardised lengths.
- Why many sites (inc wikipedia) confirm that there is no standard, and that it basically what I found when I searched.
Perhaps in Germany, but elsewhere there doesn't seem to be any standard.
Sorry for that , Dave!
In EU, there obviously exists a standard / norm , i.e DIN EN 60081.
I assume, that on other continents, there also exist corresponding standards, even in Australia. :-//
The Chinese manufacturers may well stick to these definitions also.
I append a diagram about my assumption, and it turns out to be correct, there's a linear dependency between length and wattage for the T4 tube.
Only complication visible in this diagram, is the different efficiency of the gas filling, as there exist also e.g. HE and HO types, High Efficiency and High Output types, that alters the current density for the same diameter, obviously.
So you can not only select by diameter / wattage.
But I assume, that the absolute length of the tube is given on the package.. so when dealing with the replacement of an FL, you definitely have to measure the length of your old tube.
Maybe the bathroom lamp manufacturer used a no name lamp manufacturer, which did not obey any standards..
Please specify, which exact length your old tube has.. maybe there's a replacement from German company OSRAM, which would fit, even in LED replacement.
Again, thanks for illuminating that problem!
Frank
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http://www.boondaburra.com/ (http://www.boondaburra.com/)
Check out the antartic theme bathroom that seems to annoy Dave ;D
I'd be more annoyed at that hideous 80's style it used to have when you got the house. God... :palm: Wooden toilet seats :palm:
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Personally, I'm still wondering why Dave standardizes on 25/50 FPS and not 30/60
My main camera is 25/50fps
It seems it's not unusual for cameras to be locked to 25/50 or 30/60.
Yep. I have a big beef with that.
I live in Europe which is a "50Hz PAL" zone, but ... if I want to make youtube videos I really ought to have a 60Hz camera.
Should be no problem these days, right? But there's no way to do it. There's no way to buy a "60Hz" camera over here. The only way I could get one would be to buy it on eBay or something and then I'd have to pay more for it, worry about warranties, etc.
Basically I'm doomed to produce 50Hz videos for a 60Hz medium unless I take that extra risk.
I'm betting the internals of the 60/60Hz cameras are identical, it's just a firmware thing. Why this stupid limitation?
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Personally, I'm still wondering why Dave standardizes on 25/50 FPS and not 30/60
My main camera is 25/50fps
It seems it's not unusual for cameras to be locked to 25/50 or 30/60.
Yep. I have a big beef with that.
I live in Europe which is a "50Hz PAL" zone, but ... if I want to make youtube videos I really ought to have a 60Hz camera.
Should be no problem these days, right? But there's no way to do it. There's no way to buy a "60Hz" camera over here. The only way I could get one would be to buy it on eBay or something and then I'd have to pay more for it, worry about warranties, etc.
Basically I'm doomed to produce 50Hz videos for a 60Hz medium unless I take that extra risk.
I'm betting the internals of the 60/60Hz cameras are identical, it's just a firmware thing. Why this stupid limitation?
I am not sure it's completely down to technology, although the nuances of supporting both PAL and NTSC is non trivial, although I would think that nowadays supporting either is rather quaint. I am wondering if it is also to do with legacy import taxation in some legislatures?
During the PAL/SECAM/NTSC battle fifty or sixty years ago, many countries chose their own standards often based on protectionism for their home industries, and imports were taxed accordingly. There are also several PAL based standards as a result.
In the EU for example, there are different duty rates for camcorders compared to cameras, a camcorder defined for tax purposes arbitrarily as being able to record a single segment of over 30 minutes or so. This is still a limitation in some cameras. There is also a different tax on camcorders to video recorders and that's why camcorders tend not to have external video in.
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Many modern cameras the frame rate is adjustable in the service menu to suit a region. That way during manufacture they simply do the programming in bulk per region. It might be a customer accessible menu or a service menu that is in the service manual. Google the model and service manual and have a look to see if you are lucky.
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He only uses those from a reputable wholesaler in Melbourne who imports quality approved drivers which are also RF quiet. More expensive than eBay crap, but money well spent.
Not necessaraly so much more expensive. E.g. the Meanwell LPH-18-12 is under 8EUR has real EC and you get a data sheet which promises safety standards as TUV EN60950-1,TUV EN61347-1,EN61347-2-13, IP67 approved; design referred to UL1310 Class2, CAN/CSA No.223-M91;
EMC immunity compliant to EN61000-4-2,3,4,5,6,8,11, EN55024, light industry level, criteria A; EMC emission compliance to EN55022 (CISPR22),Class BEN61000-3-2 ClassA, EN61000-3-3
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who is the manufacturer of your variable frequency power supply?
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who is the manufacturer of your variable frequency power supply?
Absopulse VFC500. Teardown here:
https://www.youtube.com/watch?v=DihpIvK1fdo (https://www.youtube.com/watch?v=DihpIvK1fdo)
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Many modern cameras the frame rate is adjustable in the service menu to suit a region. That way during manufacture they simply do the programming in bulk per region. It might be a customer accessible menu or a service menu that is in the service manual. Google the model and service manual and have a look to see if you are lucky.
Nope. I've googled everything imaginable and can't find anything.
FWIW it's a Canon Legria HF G25.
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who is the manufacturer of your variable frequency power supply?
Absopulse VFC500. Teardown here:
https://www.youtube.com/watch?v=DihpIvK1fdo (https://www.youtube.com/watch?v=DihpIvK1fdo)
Thanks for the info, I must have missed that video
That seems to be a very nice piece of equipment
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Then your SOL, unless you can find the model that uses the same electronics but has the 60FPS firmware enabled for US sale. Pity the Canon hack kit does not work on video cameras.
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Then your SOL, unless you can find the model that uses the same electronics but has the 60FPS firmware enabled for US sale. Pity the Canon hack kit does not work on video cameras.
I wonder if there's a jumper on the PCB...
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Sorry for that , Dave!
In EU, there obviously exists a standard / norm , i.e DIN EN 60081.
I assume, that on other continents, there also exist corresponding standards, even in Australia. :-//
Not sure whether DIN EN 60081 covers T4 tubes, but even if it does the reality is that there are a lot of T4 tubes used/manufactured with proprietary lengths. Even with such a DIN standard, German online shops selling T4 tubes very often warn explicitly about proprietary T4 tube lengths. Example quote from lampenwelt.de (in German language): "Hinweis: Bei diesen T4 Leuchtmitteln gibt es häufig Sonderleuchtmittel mit gleicher Leistung aber unterschiedlichen Abmessungen."...
With regard to length-wattage relationship you might very well be correct, but it does not always help. An example:
T4 18W, 470mm
T4 18W, 485mm
Well, i guess you see the problem... Unless manufacturers provide accurate wattage numbers like 18.123W, you will have to deal with tubes that are of different, albeit similar length and same power ratings...
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Any update on SWMBO's verdict? I think the look is cool (no pun intended) but I guess it depends on if its bright enough. I usually find flouro's too bright in bathrooms so maybe you'll be OK.
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who is the manufacturer of your variable frequency power supply?
Absopulse
http://www.absopulse.com/ (http://www.absopulse.com/)
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Any update on SWMBO's verdict?
:-+
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who is the manufacturer of your variable frequency power supply?
Absopulse
http://www.absopulse.com/ (http://www.absopulse.com/)
Thank you.
I watched your video on this great instrument. I had not seen this before. Thanks for such a great introduction to instruments.
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I just had this idea... Posted to the YouTube video, but felt a picture would say it a thousand times better than words...
Basically, a thought on how one might fit two lengths of LED strips with the addition of two standoffs and a piece of plexi.
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I just had this idea... Posted to the YouTube video, but felt a picture would say it a thousand times better than words...
Basically, a thought on how one might fit two lengths of LED strips with the addition of two standoffs and a piece of plexi.
It's much easier than that, just put them both on an angle, in a triangle spape, one angled down, one angled up.
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It's much easier than that, just put them both on an angle, in a triangle shape, one angled down, one angled up.
That is true, if you have a triangular surface to mount them to. Just saying that a pair of standoffs and a strip of plexi is rather easy to come by though, with minimal effort. If you've got something triangular to use... Go for it (if you need more light that is).
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I wonder, can a second strip be attached to the top piece of glass (the panel that faces the ceiling)?
Due the height, it will not be noticed, and it will allow you to double the light.
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(https://www.eevblog.com/forum/blog/eevblog-728-t4-led-lighting/?action=dlattach;attach=144196;image)
That's a gorgeous brown wire color on the output. I really like the reddish tone in that brown color. And that really really dark blue color is something else... :-DD
LOL! I noticed the same thing (I haven't gotten further in this thread so maybe it was addressed).
I was somewhat disappointed that a) Dave didn't mention this and b) He chose a shit Chinese PSU for this application. I realize he probably bought it just to get it working and not to do a teardown, and that a teardown of a potted item is likely to be destructive, but I really wonder what is inside that driver?
Perhaps I am paranoid but I don't like using no-name non-certified parts in line voltage applications in a home for obvious reasons.
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For what it is worth, if you need a quick pin extender you can always simply get a molex connector off a junk computer PSU, pop out the pins, chop off the crimped part, slip them over the ends of the tube pins, and add whatever length of solid copper wire you need to make them fit.
Also you can so the same thing, except instead of using large copper wire you can solder a computer IDC/Dupont header pin on the end of it and have a convenient breadboard "hands free" DMM probe holder
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I did not see any ground leads on the supply or inside the lamp fitting, this would be a requirement if your bathroom circuits are protected with an ELCB.
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That would be on the part left dangling on the wall. The unit splits in 2 parts with 4 screws holding it together. While there is no earth bonding wire from a dedicated post joining the 2 halves, the mirror itself and most of the acessible parts are either glass or acrylic.
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Whoa whoa whoa, are you certified electrician Dave? You have to know what youre doing before you go mucking about with mains devices!
What do you think it is, America, where homeowners are allowed to change their own wall outlets willy-nilly? :-DD ;)
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He only uses those from a reputable wholesaler in Melbourne who imports quality approved drivers which are also RF quiet. More expensive than eBay crap, but money well spent.
Not necessaraly so much more expensive. E.g. the Meanwell LPH-18-12 is under 8EUR has real EC and you get a data sheet which promises safety standards as TUV EN60950-1,TUV EN61347-1,EN61347-2-13, IP67 approved; design referred to UL1310 Class2, CAN/CSA No.223-M91;
EMC immunity compliant to EN61000-4-2,3,4,5,6,8,11, EN55024, light industry level, criteria A; EMC emission compliance to EN55022 (CISPR22),Class BEN61000-3-2 ClassA, EN61000-3-3
I had a Meanwell 48V PSU go *BANG!* when it was just lying idle on a bench powered with a normal load. A filter cap had exploded for no apparent reason. At least Meanwell meant well. I mean, lets face it, they mean well.
Even so, Meanwell are not too bad at the low end. I would trust Meanwell over Yoo Kat Dung brand any day. Especially in the home.
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It's got a CE mark, so that means its good, right? :)
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I did not see any ground leads on the supply or inside the lamp fitting, this would be a requirement if your bathroom circuits are protected with an ELCB.
Yeah saw the same thing, would always do that in a bathroom esp with chinese PSU. :P
Although the fixture is hanging outside reach it is good practice, but I do not know what the australian rules are in this case.
Concerning T4, never before heard of it, T5 is pretty much the standard here and you can see that there is less and less supply (and demand) now led is gaining ground.
And still the TCO, Lumens/Watt and lifetime of TL's is still pretty competitive with 20000 hours lifetime for the TL tube itself and 80000 hours for the electronic driver (or iron copper ballast if you wish) and only €2,50 for a replacement tube LED is way way more expensive.
The lifetime of the tube is influenced by how many start/stops you make but the same is true for the led electronics ;)
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It's got a CE mark, so that means its good, right? :)
It is as good as oval-shaped circles. :)
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I wonder, can a second strip be attached to the top piece of glass (the panel that faces the ceiling)?
I ALWAYS over engineer stuff... That is such a perfectly simple a solution. :-+
What do you think it is, America, where homeowners are allowed to change their own wall outlets willy-nilly? :-DD ;)
But I like my willy-nilly outlets! I even take the time to do it RIGHT, unlike the almost half my fellow 'Muricans that get it right by the simple sheer probability of getting the hot and neutral right 50% of the time... The other outlier are the ones who screw up so bad they catch shit on fire or blow a box, or make a live ground, or some other horrifying deathtrap! |O