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DIY LED lighting?

Garuf said:
Cheers for the link Zig, that works out at about £30 more expensive than my proposed DIY. Have you contacted the seller to know about the waiting list times or anything like that?
Since you first posted them there's been no new news at all.
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The guy in fish street speaks english his name is Eric just give him an email if you need to know anything in particular, AFAIK waiting time is about a month for the newer G2 models, shipping is a rip but you can choose Airmail (cheaper)and they upgrade you to UPS, just wanna check UPS dont hit you for automatic import duty in the UK.
 
I had that with some teeshirts, ended up paying £8 for the teeshirts and £30 postage fines! 🙄 I dread to think what it'd be on a luminaire?!
 
Could someone please advise me on how PWM Dimming works and if there any plug and play dimming units of this kind on the market.

Cheers Gordon
 
Hi Gordon
BINKSY1973 said:
Could someone please advise me on how PWM Dimming works
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PWM stands for Pulse Width Modulation.
On a DC circuit (which is what LED's are), PWM varies the length of time that full power is applied to the LED.
If you had a 5 volt power supply and you used a bog standard switch to turn it on, you would have 5 volts all of the time and therefore 100% output from the lamp.
PWM works by switching the power on and off very rapidly.
Imagine you had a one second period divided into ten segments. To get 50% output from the lamp you would turn it on in the first tenth, off in the second tenth and on again in the third tenth and so on. The net effect is the lamps would only appear to glow at 50% brightness as the power is only applied 50% of the time. To get 20% brightness you would turn it on for the first tenth, off for the next four tenths, back on for one tenth and off for the next four tenths etc.
That's the basics, but PWM controllers usually work in millisecond (one thousandth of a second) or less, so you can have infinitely variable light levels.
(I use PWM controllers at work and they switch at an astonishing 3000 times a second :shock: ).
Why do the lamps not flicker, I hear you ask.
The human eye cannot detect any flicker at these high rates of switching. A classic example of this is your domestic light bulb. That's only switching on and off 50 times a second (50 Hertz), and to you it looks like it's on all the time, so we have no hope of detecting flicker on something that's switching on and off thousands of times a second.
That's about as basic as I could make the explanation of a complex subject, so I hope that helps.

BINKSY1973 said:
if there any plug and play dimming units of this kind on the market.
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I'm not sure if there are any plug and play units available on the market just yet as I have not researched this, but I would say that if the LED lighting takes off, they will be off the shelf in the not too distant future.
 
Very interesting link Tonser. Had I not already finished my LED project I would look into those led strips some more.

BINKSY1973 said:
Could someone please advise me on how PWM Dimming works and if there any plug and play dimming units of this kind on the market.

Cheers Gordon
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Ceejay explained it well. I studied this for a few months last year and couldnt for the life of me find any PWM products which I could adapt to my led lighting to simulate sunrise/sunset moonrise/moonset so I ended up figuring out how to do it myself.

There is a link to my project in my sig but if you would like more detailed info on how I did it just msg me. Once the proramming is done it is a very simple circuit.
 
Im working on a DIY led light bar for my 1ft cube. Ill let you guys know how it goes.
 
Check these out, they run very hot mind you and need a lot of power but then they are tiny and each one gives about 8 watts in one direction. Full info and drivers available here.
http://www.rapidonline.com/Electron...onics/Power-LEDs/Linear-high-power-LEDs/81569

dont be fooled by the colour, they really are very intense white at 6500K, you cant look at them.
Im using some now, need to go on an aluminium plate though or they overheat.
jason
 
Sorry I have taken so long guys but finally I got the lux meter out and tested it on a 3w led.

1/2 foot away from led: 3000+ lux (meter doesnt go above 3000)

1 foot away: 1800+

1 & 1/2 foot: 800

2 foot: 475

I don't know what the angle of this particular led is but I would guess 80-90 degrees. For every 1/2 a foot to the side from 1 & 1/2 foot down the lux would roughly 1/2 in intensity.

Hope this helps 😀
 
Hi

After reading most of this post i decide to try do DIY led light for my tank but i have few questions first

Is better to do this in one strip or two?

Any good shop which sell lumilux led for good price ?

How many high output leds i need for my 2ft tank and which one to choose

Where can i get some nice looking case with heatsink to hide all the leds and all cables
 
Not been on the forums much for a long while but thought I would belatedly 'butt in' on a few additions to this thread 😉

Tonser said:
I just thought I'd resurrect his thread, as I'm thinking of converting my old luminaire to led's. Are your setups still going strong Andy ? Anything you would have done differently in retrospect ?
Also, do you have a link to the seller on ebay who you used ? The earlier links have now expired.
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Yes the unit is now 15 months old and still running perfectly. No LEDs been changed at all. Very satisfied

I wouldn't change anything but I would add something. A mirrored diffuser like the grids you have on office flourescents. Why? Because the unit is above my eyeline when I sit down to watch TV and the glare is a bit annoying. These are damned bright beasties. I will get off the sofa and see if I can find one eventually 🙂

The seller I used for the LEDs and heatsinks is this one:
http://cgi.ebay.co.uk/20pcs-3W-Whit...emQQptZLH_DefaultDomain_0?hash=item35a7fd7809


zig said:
Don't know where Andy is, AWOL the last month or so, maybe he will pop back in soon and share his wisdom.

Another thing you will quickly realise is that It works out more expensive than you think, an equivelant T5 setup could be cheaper. Personally though I am just going to treat it as a project so although cost is a factor its not the overiding one for me anyway.
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Alas I got pretty bored with almost everything mid last year especially the forums. Hardly use the PC these days 🙂 I'll check this thread for a few days though.

On the cost aspect yes...to DIY my unit was about £110. The T5 equivalent would be about £50 however I am using less wattage and the LEDs should last for 7 years at least whereas T5 tubes would need changing every 3 or so years. Over that time frame I will save substantially. Maybe even cost half as much total when the 7 years are up!!!!

FishBeast said:
I am new to the DIY LED thing but I have been looking into it based in luminems.
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Aaargh Pet hate to the extreme. Forget Lumens. Absolutley no use to us for our needs. They tell you how bright the light looks to us!! not how much light they are outputting. Plants do not have eyes therefore they do not care about brightness however they do care about how much light there is.

As an example. To match a 250W MH for Lumens you would need approx 300+W of LEDs. However when tested the original 75W solaris LED unit showed 85% as much PAR as a 250W MH!!! Yes 30% wattage = 85% PAR. Sound extreme? The same tests showed that it was 110% PUR!!!! The 75W LED unit had higher Useable light than the 250W MH. This is why Lumens gets people off on the wrong way of thinking.

alzak said:
1-Is better to do this in one strip or two?
2-Any good shop which sell lumilux led for good price ?
3-How many high output leds i need for my 2ft tank and which one to choose
4-Where can i get some nice looking case with heatsink to hide all the leds and all cables
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1-Neither!!! Forget about traditional strips like tubes. With LEDs think more of a matrix or grid pattern. The spread is key. Work out how many LEDs to use and then divide the hood into a grid with the LEDs equally spaced to gain the best spread of light.

2-See link at the top for cheap lumilux (probably copies but they are what I used)

3 - I would suggest for a medium light tank then aim for about the 1W per gallon region. For a higher light tank towards 1.5WPG. I would suggest that a good grid will need about 2 thirds wattage of a T5 setup to out perform it.

4 - I made a wooden luminaire with the same footprint as the tank. Heatsinks are sold by the same seller in the link above and a standard 'zip cable tidy is all I use. The type you use on computer cables. Poundland sell them, tesco sell them etc.

I also read in one of the posts above about lenses. When the LEDs are used for reef setups they are using 3 to 4 times the amount we would need therefore they are closer together and they focus each one down. If we try and do that then because we are spacing ours a lot further apart then you will see 'beams' of light in the water. Not desirable. Your typical lambertian die LED (half sphere in shape) will be a 120º output meaning it will emit light down and sideways. Let it do that. It spreads the light more equally. No visible beams and a good even light to your plants 🙂

AC
 
Thanks for your reply and thoughts Andy.

Unfortunately I'm at a bit of a standstill with this as I took the plunge 7 weeks ago and ordered some bits to experiment with from Ledrise.com and they keep sending emails detailing further delays to the products I've ordered. I've demanded cancellation of the order and a full refund, but have yet to get it 🙁

Tony
 
About to order mine, awaiting an email just clearing up what drivers I need and then I'm on the way. I'll be using 3 strings of 7, and a lumo for my nano.

I'm struggling with getting suitable power sources though. They seem few and far between and if I'm honest I don't really know what I'm hunting for.
 
Garuf said:
About to order mine, awaiting an email just clearing up what drivers I need and then I'm on the way. I'll be using 3 strings of 7, and a lumo for my nano.

I'm struggling with getting suitable power sources though. They seem few and far between and if I'm honest I don't really know what I'm hunting for.
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If you are running 3 strings of 7 x 3W then a 24V source is what you need for each string. If you are going the pcb route (no idea on how they work 😉 ) then you would need a 72V source.

Maybe someone with electrical knowledge can confirm if these are viable. Laptop power supplies etc.:

24V:
http://cgi.ebay.co.uk/Laptop-Power-...Computing_LaptopAccess_RL?hash=item23067ea7b1

AC
 
Thanks, Andy. Yeah I was thinking of going for stings of 9 but I don't know if that'd be plant destroying territory, from our private messages it seems most likely.

I still want to go down the PCI route but I'd like individually on/off on a timer and I don't think that's possible within easy electronics. Of course you could add switches but that's not on a timer. Possibly you could use 555 timers but I don't really remember how they work.
 
I also read in one of the posts above about lenses. When the LEDs are used for reef setups they are using 3 to 4 times the amount we would need therefore they are closer together and they focus each one down. If we try and do that then because we are spacing ours a lot further apart then you will see 'beams' of light in the water. Not desirable. Your typical lambertian die LED (half sphere in shape) will be a 120º output meaning it will emit light down and sideways. Let it do that. It spreads the light more equally. No visible beams and a good even light to your plants
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Remember me saying this? Yes me 😉 Whilst I still believe it to be true I have used lenses in the MkII version of my luminaire. I'll add updates of this soon. Looks the business 🙂 More like a super hi tec piece of cool decor than a practical part 🙂

I was thinking of going for stings of 9 but I don't know if that'd be plant destroying territory, from our private messages it seems most likely.
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Garuf I don't think it would be plant destroying however it would mean that you needed a driver for 9. The reason I stated 7 is that you can run 7 at almost max off the 24V drivers but 9 would hardly light up 🙂

I have strings of 3 because I am using 12V adaptors to enable me to split the timings of each string of 3. My cabinet has 1 extension, plugged into it's own wall socket, solely devoted to the lights. It has 6 of those mini timers (the smaller mechanical ones) with 6 of the 12V adaptors. Those who worry about overloading should understand that each string is barely pulling any current in comparison to most household units. Think more about the extension pulling probably less than most people's sole light which of course in a lot of cases is then plugged into an extension along with their other equipment. I then do have 1 more timer and adaptor for the fans plugged into the main extension lead which has filter and heater too.

AC
 
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