An Experiment With L E D Lighting

[Crossy]

OK, I'm bored, so I'll post the route I took to having my lounge, bathroom and bedroom fully illuminated with LED lights.

A company I'm associated make and import LED lamps, these are mostly intended as replacements for the small halogen spotlights and work well in this application. A 3W LED produces about as much light as a 20W halogen and has the advantage of being available in many colours, some are even able to change colour in use

This company also make LED 'fluorescent' tubes that are a direct replacement for conventional tubes (just remove the starter) they don't however make the circular tubes used in Thai ceiling fittings, this is the problem

Soooo, what to do?

Whilst browsing eBay I spotted a Hong Kong company selling power LEDs and ended up buying a load of 1W white and warm white devices, they look like this.

Note that they are mounted on a handy metal back plate for easy handling, about US$0.5 each.

A different company sell various varieties of LED driver modules, you can't just hook LEDs up to power (even low voltage DC) as they require a constant-current drive or they fry very quickly. I got a bag of these 3W 85-230V drivers, each will drive three of the 1W LEDS. US$2 each.

The LEDs were assembled into 3W rosettes, and each rosette hooked to a driver

Obviously, we can't have this hanging in mid air, and only 3W is not enough light anyway. I reckoned that the bathroom needed about 9W (it's got a 10W CFL at present) so three of these setups are needed.

A conventional bathroom fitting provides a home, it came from our local Mom and Pop electrical shop

after stripping out the lampholder it looks like this

Three of the 3W assemblies were installed

The LEDS do get warm and need heatsinking, they are attached to the metal fitting back using double-side heatsink tape (silver loaded epoxy would be cheaper), get both from The OverClock Shop. A dab of silicon holds the electronic modules and stops the wiring flapping around.

Apply power and, ta-da

The LEDs are VERY bright point sources, so a diffuser is required, that's why I got the fitting with a translucent white cover

OK, so the whole lot cost about US$25, rather more than a conventional setup, but it only uses about 11W and the LEDs should last 50,000 hours (that's nearly 6 years of illumination 24/7).

Flushed with success, I made two fittings for the lounge

One of these contains 20 1W LEDS with a 20w driver module, the other has 21 LEDs with seven of the little drivers shown above, both work well. My only reservation is that the warm-white LEDs are rather more yellow than I'd like, might try substituting a few white LEDs.

With LED modules of up to 100W (yes 100 Watts) readily available LED lights are definitely of age.

Use a long strip of small LEDS for accent lighting in that flashy ceiling, maintenance free and cheap to run, add an RGB controller and you have infinitely variable colour to suit your mood

[GungaDin]

Good for outdoor security lighting?

[Daffy D]

Thanks Crossy for the interesting and detailed post.

I'm always interested in new innovations, it was my hobby in a former life, always experimenting and trying something new

Shall keep your ideas in mind for a future time

[Crossy]

Good for outdoor security lighting?

Absolutely, we're looking at LED floodlights for billboards. Long life and low power consumption compared with halogen.

The big issue at present is availability of suitable light fittings. The manufacturers are taking the piss on price at present, OK the LED modules are not cheap, but to try and charge US$200 for a floodlight (without the LED or driver) is just taking the Michael

[bankruatsteve]

Interesting and from what I've seen on TV, the LED lighting will probably be the future standard. But, what is the pro/con from the flourecent? Do you know or have link for that?

[thatguy]

Very cool. I assume these drivers knock the voltage way down. AC or DC ?

[wpcoe]

Are LED lights easily dimmable?

[Crossy]

Are LED lights easily dimmable?

Those little electronic drivers are not dimmable since they give constant current from 85-230v input.

However, if you drive the LEDs off a variable current DC source they will dim right down to zero with no colour change.

Some useful information here AV02_0532EN.pdf

[Tywais]

Are LED lights easily dimmable?

I've designed a few LED controllers for our facility. A couple of multi-mode flashers, sequencers (running lights). The dimmer can be done two different ways. 1st as Crossy mentioned a variable current source (have also designed one of those and is fairly trivial circuit) or PWM (pulse width modulation) which is the most efficient way as there is very little power loss in the switching mosfet.

[wpcoe]

Are LED lights easily dimmable?

I've designed a few LED controllers for our facility. A couple of multi-mode flashers, sequencers (running lights). The dimmer can be done two different ways. 1st as Crossy mentioned a variable current source (have also designed one of those and is fairly trivial circuit) or PWM (pulse width modulation) which is the most efficient way as there is very little power loss in the switching mosfet.

So, uhm, consumer dimmers are a ways down the road yet? For that matter, are consumer LED light fixtures available yet?

[jackr]

Nice one Crossy. LEDs are the way forwards and would eventually like the whole house sorted.

Know of a supplier in Muang Thai that doesn't charge exorbitant baht for manufactured LED fittings?

[Crossy]

Right now LED lamps are very new technology in Thailand and as such attract scarily premium pricing

There are a number of sellers on eBay, mostly in HongKong, that will ship to Thailand. Sadly much of the stuff available is total crap from China and careful selection is required, particularly, those lamps using lots of small LEDs aren't worth a light

Several sellers have 3W and 5W downlighters and spotlamps using 3 LEDs, these I would consider the minimum power for any useful lighting (sorry forum rules preclude me pointing at particular sellers or products).

Whilst LEDs are more efficient than other types I think the claims are often over rated. IMHO you should use 80-90% of whatever CFL would be adequate in your application. My home-built 20W ceiling fittings give subjectively about the same light level as the 34W circular fluorescents with conventional ballasts they replace, the 9W fitting in the bathroom appears brighter than the 10W CFL it replaced.

[johng]

This company also make LED 'fluorescent' tubes that are a direct replacement for conventional tubes (just remove the starter)

Crossy can you provide some more info on these replacement tubes please.

As long as they aren't too expensive I would like to replace all my fourescent bulbs with LED's

[chrgrims]

Great thread. Thanks Crossy.

[Tywais]

LED lighting has quite a few companies producing them. Below gives you an idea of what is available and can be done with them. Of course what is available in Thailand is a different story.

http://www.besthomeledlighting.com/all_led_bulbs

http://www.ledlightbulb.net/

http://www.fun-led-light.com/led-home-lighting.html

http://www.ledtek.com.cn/english/

http://www.eartheasy.com/live_energyeff_lighting.htm

http://www.gelighting.com/na/

http://www.besthomeledlighting.com/

http://www.theledlight.com/

[Crossy]

Crossy can you provide some more info on these replacement tubes please.

As long as they aren't too expensive I would like to replace all my fourescent bulbs with LED's

I'll check again on Monday, but IIRC they are definitely heading for the 'too expensive' box at around 2500-3000 Baht for the 4 foot version

Prices can only come down, remember how expensive CFLs were when they first appeared.

[jackr]

Several sellers have 3W and 5W downlighters and spotlamps using 3 LEDs, these I would consider the minimum power for any useful lighting (sorry forum rules preclude me pointing at particular sellers or products).

Whilst LEDs are more efficient than other types I think the claims are often over rated. IMHO you should use 80-90% of whatever CFL would be adequate in your application. My home-built 20W ceiling fittings give subjectively about the same light level as the 34W circular fluorescents with conventional ballasts they replace, the 9W fitting in the bathroom appears brighter than the 10W CFL it replaced.

I dunno; bunged a 1-watter in place of a 5-watt low energy and it threw off similar lumens, albeit at a tighter angle. The 12-volters work really well for low lighting on trees in the garden though. Sourced some 3-watters in CM couple weeks ago but they're talking over a grand a pop and their strip lights with colour change were around 4k.

[CDNinKS]

Found this company in one of the house magazines:

Megaman

[Crossy]

A useful effect which I've not really verified is that the lack of UV emissions from these lights means they don't attract insects. Bad for the geckos good for us

[david96]

Yes LED lighting is the future but at present they are too expensive and the payback time would be too long.

However once the major lamp manufacturers (eg Philips, Osram etc) start making them in commercial quantities the price should drop to match the standard 36W 1200mm along with all the other industry standard fluoresent lamps.

My estimate would be 10 years before they become commercially viable.

What is the lumen output of these currently available 36W tube LED replacements?

[chrgrims]

i would pay extra to get the non-uv function.

[Tywais]

What is the lumen output of these currently available 36W tube LED replacements?

Here is an LED fixture released in 2007 that shows 1000 Lumens output, or 75 lumens per watt. physorg

Another site showing comparisons > Efficient LED Home Light Bulbs

Some comparison intensities.

* 32 watt T8 fluorescent--85 to 95 lumens/watt

* standard F40T12 cool white fluorescent--60-65 lumens/watt

* compact fluorescents--low 30's to low 60's lumens per watt, usually 48-60

* UPDATE 12-2006 -- The newest white LEDs shipping from manufacturers in 2006 are approaching the efficiency of compact fluorescents, into the 50-60 lumens/watt range. At this time, however, there are no RE lighting products that use these new LEDs, and they remain extremely expensive. Manufacturer's research labs are also reporting new white LEDs that approach the 80+ lumens/watt of T8 fluorescents. However, these products are not shipping yet.

* T3 tubular halogen--20 lumens/watt

* white LED--15-19 lumens/watt

* standard 100 watt incandescent--17 lumens/watt

* incandescent night light bulb (7w)--6 lumens/watt

* incandescent flashlight bulbs--dismal, less than 6 lumens/watt

Source

Of course things have improved significantly in the 4 years that comparison list was produced.

[Crossy]

Here is an LED fixture released in 2007 that shows 1000 Lumens output, or 75 lumens per watt. physorg

The tubes here http://www.ledlightbulb.net/store/index.ph...amp;cPath=37_40 are showing similar efficiencies, I would hope that the latest hi-tech units would be better than these made in China units.

[david96]

Here from the Philips catalogue are the current outputs of 36W 1200mm tubes.

TLD 36/830 3350 lumen output warm white 3000K

TLD 36/840 3350 lumen output cool white 4000K

TLD 36/850 3250 lumen output daylight 5000K

TLD 36/865 3250 lumen output cool daylight.6500K

K is the colour temperature.

840 is used for general lighting.Average tube life 13000hours on a 3 hour switching cycle.

A pack of 25 costs about 75 Dollars AUD. compare that with one 36W LED tube.

[Crossy]

I have no means of measuring the light output of the LED units. The illumination is subjectively similar (not helped by the warm-white LEDs being very yellow).

What I CAN measure is power input (using my Kill-A-Watt):-

Original 32W circular fluorescent, conventional ballast, input power 47W

Home brew 20W LED light (20 x 1Watt warm-white LEDs), input power 24W

So if nothing else I'm reducing my lighting power consumption by 49%.

Pay back on power saved (not that I'm really interested, this is after all an experiment) about 4.3 years assuming 6 hours a day usage. I would not expect to replace the LED unit for at least 15-20 years. It's important to note that this is against component costs only, my time for assembling the units is free.

EDIT A VERY rough check with my camera exposure meter indicates that the LEDs are actually about 1/3 stop brighter So in reality pretty much the same output.

[thedivezone]

Thanks to this thread and this other one : http://www.thaivisa.com/forum/Solar-Garden...ng-t321066.html I also felt inspired to try my hand at solar panels and LED lighting.

Years ago i'd brought back a 14W solar panel from Germany which i'd intended to use to light up a street sign for a business that never took off. Having found myself with excess time on my hands due to lack of employment i set about putting it to an alternative use.

Thanks to poster jackr at the other thread i found out about these 12V/1W LEd lights which i got at KeeHin in Phuket for 80 Baht:

which install nicely into an old Halogen bulb housing :

The biggest problem was finding a light-sensitive switch, that switches the lights on at nightfall and turns them back off again at dawn. This i found at conrad.de, an electronic mail-order shop in Germany and it came as a DIY kit to solder together .

Ideally this should be a switch that turns the power off if the battery voltage drops below a certain level, but i haven't found that one yet.

Now it's simply a matter of sticking the solar panel on the roof:

vaguely pointing in a southerly direction, and wiring it all together (apologies to the sparkies for the shoddy wiring):

Solar charge controller on the right, light-sensitive switch on the left, light dependant resistor (LDR) sticking through the plastic box at the top :

And voila :

I didn't tally it up exactly, but incl. the solar panel (about 109 Euro if i remember correctly) it all came to appr 8000 Baht. I could probably run a 10 W bulb for gazillions of hours on the grid for that money, but it wouldn't be quite the same, would it ?

[bkkbill]

I didn't tally it up exactly, but incl. the solar panel (about 109 Euro if i remember correctly) it all came to appr 8000 Baht. I could probably run a 10 W bulb for gazillions of hours on the grid for that money, but it wouldn't be quite the same, would it ?

How true if we did all things on a cost return base it would be a very sad world. Oh maybe not quite a gazillon years.

[zzdocxx]

Crossy you're a stud, what can I say?

Bravo!

[david96]

LED fittings are available for downlight replacements. See Pierlite LED Firefly, available in surface mounting or flush fitting. Have a 3W LED, complete with flex and plug, 50000hour lamp life.

Self contained emergency luminaire using LEDs instead of the 10W halogens are available

from Davis Lighting.

Exit luminaires may be the next after the cold cathode lamps which are a major improvement

over the standard fluoresent tube.

[Crossy]

The arrival of my tools and test kit from the UK (including my Lux-meter) means I now have some quantitative measurements:-

Two measurements were taken:-

a. 1 Metre below the centre of the fitting

b. 1 Metre below the centre of the fitting and off-axis by 1m (to get an idea of beam width).

Results.

...................................... On Axis Off axis

34W circular fluorescent:- 360 Lux 190 Lux

21W warm white LED:-.... 300 Lux 194 Lux

21W white LED:-............. 384 Lux 165 lux

9W white LED:-............... 260 Lux 88 Lux