Diy Led Rig

[StandbySetting]

Wiring in series would mean that I would need to find a 3V power supply though wouldn't it? If I remember my physics rightly.

 

[Ps3Steveo]

Providing your not drawing more current than is available parallel is always the best bet really.

 

[SuperColey1]

Read the original thread guys. the one where Imade mine. The LED experts all said ALWAYS wire high power LEDs in series and not parralel. I don't know the reasoning but read the thread and those of you with electrical knowledge will be able to say. Suffice to say I followed their advice and wired mine into 5 series of lights. You will need to follow both of these thread because I used both of them for advice:

http/www.fishforums.net/index.php?/topic/264895-diy-whole-tank-led-lighting-retrofit/

http/ukaps.org/forum/viewtopic.php?f=50&t=3687&start=50

As for fault finding. Do it properly in the firs tplace Not one fault on mine since it was completed in Jan 2009 (2 years and 7 months agooooo.......

Andy

 

[StandbySetting]

Both very interesting reads, presumably if I found a computer cooling fan that runs at 24V and draws 700mA of current I could add that in parallel with the LED's? I shouldn't need to use one but just in case would I be fine to do so?

 

[SuperColey1]

No idea. lol. If you use proper heatsinking and there is anough room inside the unit and it is well vented I doubt you will need fans. Mine haven't been turned on since a couple of months after I started using it. They run hot but proper heatsinking does the job fine

Andy

 

[StandbySetting]

That was meant to read parallel lol, thanks Andy.

 

[Ps3Steveo]

Maybe it's due to the type of LEDs, can't say I ever used them before bit I'm sure they must come with some specs.

 

[SuperColey1]

Just looking through the first of those 2 threads I found this:

Treating each LED as an individual would be a poor way of doing this. You'd need a driver for every LED! Highest efficiency (cost and power) is obtained from switching CC drivers and chains of LEDs in series. That way you'll get better brightness matching too.

I remember that during the research and build those who joined the thread without reading the whole thing would jump in with 'parralel' etc.

I don't think it is to do with the type of LED. It is to do with efficiency. Meaning if you are going to do an LED rig with the intention of reducing consumption, then try and do it to run as efficiently as possible.

Anyways. That was what I was advised to do so that is what I did.

Andy

 

[Ps3Steveo]

Strange as I wouldnt be to bothered about efficiency if its only running from a step down PSU. There would be more chance of having LED's with different levels of brightness in series than in parallel. But like I say maybe due to the drivers being designed to cope with that problem they suggest that as its possible and reduces power consumed by the LED's. There must be a limited amount of LED's that you can run from each driver in series then.

 

[Ps3Steveo]

Lol sorry just looked at specs and realised that the current drawn would be greater if wired in parallel and would need a bigger driver lol.

 

[Gavo]

With DC voltage systems, volt drops very fast so with parallel you may notice the last lamp dimmer than the 1st

I would stick to series so all the lamps are the same brightness.

 

[Ps3Steveo]

Lol I work with DC 12v all day and it takes around 30m of cable length to see a drop of 0.5v, I work in security and we measure volt drop on every system and at 1amp at the psu we see hardly any volt drops over long cable distances so 700mA won't be to different.

 

[Gavo]

The guy is using a cheap driver thats pushed near the limit with the leds and mentioned a scalextric transformer, depending on the efficiency of the driver (and reading the wrong calculations in the thread) this may be overloaded and the voltage will drop.

It looks like he is using at most about 0.25mm cable, taking into consideration heat factors and 3W bulbs I would think there would be a noticeable dip in the light at the end of the circuit if in parallel (having done it myself).

So I sugested using a series circuit.

Its not like he is using 2.5mm T+E and a high quality transformer is it.

 

[Ps3Steveo]

Lol no but connecting in parallel will mean pushing the driver beyonds it's limits anyway so if you did the same I'm not suprised an led was dimmer. There will be no volt drop over 12inches of cable no matter how you wire it and the cable being used should always be thick enough to cope with the current being used.

 

[StandbySetting]

Andy do you know approximately how hot the LED's and heat sinks are likely to get? This is how I've mounted the heat sinks so far, PS3Steveo has suggest using some form of metal insulation between the heatsinks and wood.