Building An LED Desk Lamp Need Some Advice

I'm building a stackable LED lamp as a project for my design class. This solidworks model shows a single cube of the lamp. This lamp consists of multiple stackable cubes. The cubes snap together magnetically and the more cubes you stack the brighter the lamp becomes. Each cube contains 2x CREE X-lamps which are heat sinked to the aluminum interior. Each cube should put out about 400 lumens and be dimmable to around 20 lumens. The lamp will run off AC power and I want to run it off a power supply like the one shown but I'm worried I might be overloading the power supply. Does anyone have an Idea how I could run 10 cubes (60 watts) simultaneously off a wall outlet without the need of a beefy power supply?


Cube with clear glass


Cube with frosted glass


Stackable in any direction


An example of the power supply I'm considering

Nibblonian Power Source!
No really if you want to run off AC look into the Seoul Semiconductor Acriche at zled.com.
If you can keep the magnetic connectors from being livewires at 110V.
It is a 110volt led.
Running each cube at 5W x 5W your pulling 2Amps at 3.7Volts or 1A at 7.2V. Stack and multiply the amps, you'll need a smart powerful wallwart. That all seems right to me. Direct Drive off a wall wart can work if your running 2 in series and you can switch your wallwart from 6v-7.5v giving you Low and Hi and theres no spikes. Cross your fingers there.

First, nice project. Interesting for sure.

My suggestion would be to do the best you can to estimate how many LEDs you are going to use for the project. This will be the key to your power solution. As stated above if each cube will be 2 x 3.7 = 7.4 volts. But now we are going to need more expertise. I assume as you "click" each unit together they will then be paralleled electrically.....unless you stack two units next to two units, then electrically you would have 2 serial by 2 parallel. Doing it this way should ease your electrical needs considerably as I understand it.....others will correct me (thankfully). So, you need to figure how high and how wide the best you can. That will give one of our experts the exact info to tell you what would be next.

Let's talk about dimming. May I suggest you look at the dimmers at www.theledlight.com. Here is the actual link, scroll down until you see the Zane Control Products dimmers.

http://www.theledlight.com/controls.html


You will notice they are set up for use with 12 Volts. I use these products alot for custom interior lighting using LED's in the home. Generally I use a cheap 12 volt DC power supply for any retailer on the web. You may have to build or purchase something to house the power supply and dimmer in, but you will end up with absolute beautiful execution electrically. You could for class, also use 12Volt batteries or a combination of batteries to get close to 12VDC if you do not have to run it for hours for class demonstration. That would save you a bunch of hassles.

Again, speaking from stupidity here, I did not particularly care for the dimming action when using a wall wort when I used the above dimmer. I chose instead the "real" product made for LEDs and didn't screw around. It's called a MicroDriver9.

http://www.ledsupply.com/ld-mdu9-sc-3570.php

For your purposes, it should make it simple and direct for you. Plug one of these into the wall, then take that output and use it to dim with the Zane product. Because it's constant current, you are jacking with it by then taking it's output and PWMing that to dim your LED's. This has caused my lower dimming to be kinda shakey. The far superior way is that "real" 12 volt power supply. No dimming problems here. I use PowerOne's regulated 12Volt DC power supplies. HEAVY, very heavy they are. PowerOne makes some really nice ones that will last you a lifetime (find one surplus...much cheaper and mine was still new in the box). So if you are going to keep this project and use it alot. Get a good power supply (maybe others can recommend something else), the Zane dimmer and you should be good to go.

Bob E.

Thanks for the info. I cant put in those high voltage 110 volt LEDs since someone could accidentally electrocute themselves at that voltage. I think I'm actually going to end up running 4x emitters in series for a total of 14.4 volts to reduce load on the power supply. I'm going to be running the 4 emitters at around 1.5 watts due to the smaller heat sink... I think that 12 volt power supply would be a great solution for this. Do you think it would be possible to use a potentiometer to dim with?

I have used that power supply to power 1 LED. it works fine actually!!! i have a 700ma power adapter like that and it works with 1 LED's no problem!

Your design is awesome! I would buy one of these (even though I'm sure it wouldn't be cheap). If you are making a demonstration model, and you're interested in selling as an object d'art let me know...

To be constructive: It seems to me you could just house the power supply inside the base block, provided you could provide enough thermal relief.

Actually I was thinking today about the whole transformer Idea and realized that no matter what the use of a transformer wouldn't be practical when marketed to consumers. Somone out there is gona get the bright idea of creating a whole wall of light up cubes and he will certainly blow the transformer once he plugs it in. Come to think about it, if some kid were to connect the positive and negative contacts with a spoon causing a short that would certainly blow the transformer too. I've also read those wall transformers are "energy vampires" and consume energy even on standby. That would completely defeat the purpose of having an efficient LED light source.
I'm now reconsidering using those Zpower LED's, which really complicates the design. one of the contacts will need to be insulated against spills and fingers. Infact the whole thing would need to be built fairly spill proof. Honestly it would be much easier for the purpose of my design class to simply use a wall transformer since it is a design class which focuses on aesthetics and not an engineering class. I'm kind of tempted to take the easy way out here but for the sake of intergrity I think I'm gona have to re design that central contact ring. Dang this might complicate the dimmer switch too... Im gonna have to look into AC dimmers now.

After thinking about your project more. You might be just as well to take one cube and make that the unlit or maybe pilot light only cube that has all the electronics junk in it.

Unfortunately, I see the same problem you talk about with the potential for short (accidentally or on purpose) with the (-) connection being out in the open. There has to be some sort of ultra small plug or something that can me put there and a simple rubber insert if it is not used to connect another cube.......just thinking out loud the best I can.

Keep up the supurb work. Great idea no matter how you finish it. But as you said, for commercial production, you will have to find something that will please the lawers.....I will continue the search for a plug for you.

Bob E.

jashhash said:

Cube with clear glass

Click to expand...

I absolutely adore it, hope you'll find a good power supply solution.

What about having the posts holding the windows be tubes that hold sockets which are covered? They each site ready to pass on wall voltage to the next cube, but you must pop off the cover to do so. Maybe have a circular connector with outside pins as hot and inside as ground. A gender changer connector would connect them. Each can then have its own low-power PSU inside.

Why not a P4? It would give you closer to 260 degree even output than the Crees.

You might also want to think about keying the cubes, so they line up to each other without effort.

:welcome:You just Necro'd your first thread and by that I mean its been dead for 7 years and you brought it back to life with a very on topic bit of info.
Just watch the post date in the headers, we can all do it when we get excited reading a thread and the neurons start strobing

Ah... now THAT'S a technique I haven't seen before from a spammer! That's part of SafetyBob's post from above with the links changed.

A crude, but interesting twist. Reported.

Yo Bimmer things changed in this thread since I replied trying to lead a wayward noob, so it was all a spammer link trap Oh Well can't help 'em all see the light
Enjoy the early summer with the top down