Question - Dealextreme driver for household lighting...

[Stillphoto]

As always figured I'd ask here before pulling the trigger. I've got a little dx order going and i saw some parts that made me go oooh. Now I need to know from the wizards here if it will all jive together.

The parts are :
housing:
http://www.dealextreme.com/details.dx/sku.13741

Driver:
http://www.dealextreme.com/details.dx/sku.13552
I plan on sheathing it in some heatshrink to make sure nothing shorts out against the inside of the housing.


Led will be a warm white high cri seoul from mouser.

I figure for around $15 total (with led) it's an interesting / somewhat simple way to get into a decent colored led replacement bulb.

Seems like a viable driver, am I wrong?:tinfoil:

 

[Stillphoto]

Anyone? Oh well, I'll order it and if stuff gets fried, it gets fried right?

 

[brickbat]

Yeah... Looks like a nice driver to me too. I was gonna complain about it's lack of a housing, but for $3, seems like a good deal.

And, thanks a bunch for the Mouser tip. I didn't realize they carried SSC warm LEDs. Which device did you select? The N42182L-S2, by chance?

 

[Ken_McE]

Looks like a winning combo.

 

[CM]

Let us know how it turns out. I've got a few home projects that these would work with.

 

[X_Marine]

Looks line a nice mount for the money.
Not sure on the output of the driver.

Let us know what you think.
Thanks
X/BillyD..

 

[FrontRanger]

Driver:
http://www.dealextreme.com/details.dx/sku.13552
I plan on sheathing it in some heatshrink to make sure nothing shorts out against the inside of the housing.

...

Seems like a viable driver, am I wrong?:tinfoil:

One thing I noticed about its 3*1W brother was that one reviewer reported 43% efficiency. Not good, but perhaps tolerable for your application?

You may have already noticed this, but I wanted to mention it because the reviewer for the 1*3W version you linked reports "It uses a little over 2 watts of power ". This is not possible, since the power dissipated in the load already exceeds 2W! (655 mA current onto a Cree Q5 or SSC P4).

Let us know how it works!

 

[brickbat]

...one reviewer reported 43% efficiency... .

That reviewer apparently made a common mistake in calculating the input power. In an AC circuit power is not V * A. It's V * A * PF; and he didn't measure the power factor. I suspect these supplies are more than 43% efficient...

 

[Stillphoto]

Should be getting the stuff any day now, I'll do my best to keep everyone posted...Whats the efficiency of a standard incandescent bulb? Just for conversation's sake.

 

[FrontRanger]

That reviewer apparently made a common mistake in calculating the input power. In an AC circuit power is not V * A. It's V * A * PF; and he didn't measure the power factor. I suspect these supplies are more than 43% efficient...

Possibly. If the input impedance at 60 Hz is primarily resistive rather than reactive (when properly loaded with the LEDs), then he'd be almost right. If not, the the efficiency would indeed be higher than he calculated, as you say.

 

[nein166]

Sorry I missed this thread. I built this light a month ago, and used a Q5 but the Hi CRI sounds better.

I wrapped the driver with electrical tape.
Lots of space in the threaded end of the housing, and you need to epoxy it to the heatsink IIRC

The optic isn't great but maybe the SSC is better suited than the Cree.
I took the optic out and use it as a flood spot.

The GU10 housings work great with XR-E so I'm happier with those.

 

[Stillphoto]

Ok here's where I'll need your help, 4 wires on the driver, pretty easy when it comes to + and - for the led, they're marked on the board.

No clue which of the remaining 2 white wires gets soldered to their respective places on the bulb socket. Picture to follow

 

[smflorkey]

No clue which of the remaining 2 white wires gets soldered to their respective places on the bulb socket. Picture to follow

Since you're connecting them to 110VAC, there is no polarity. It doesn't matter which of them is connected to the center and which to the screw shell -- at least in terms of connecting power to the circuit. You might consider potential paths to a short circuit in that shell to help you pick the wires and how you will attach this driver to a suitable heat sink.

Hope that helps,
Steve

 

[nein166]

Since you're connecting them to 110VAC, there is no polarity. It doesn't matter which of them is connected to the center and which to the screw shell -- at least in terms of connecting power to the circuit. You might consider potential paths to a short circuit in that shell to help you pick the wires and how you will attach this driver to a suitable heat sink.

Hope that helps,
Steve

Ditto as above
Pink and White wires are for + and - LED (pink=+)

I remember a center hole and a plastic disc around isolating it from the metal screw. I soldered the other white wire to the top edge of the screw, I did it on the outside and had the bare wire jamb the screw to the white plastic(bulkhead) between screw and heatsink. Also I potted the driver with epoxy. The epoxy is needed to hold screws and bulkhead together.

 

[Stillphoto]

Awesome, I love the no-polarity issue.

Yeah looks like I really do need to epoxy the whole thing together, since the screws are useless. I'm most familiar with standard Devcon epoxy. While mechanically that should be a sound adhesive, I'm guessing it might not do so well as a thermal/heatsinking type epoxy. Would that be a correct assumption?

Is it me, or will I have to epoxy it before I even get to test it?

 

[nein166]

Is it me, or will I have to epoxy it before I even get to test it?

You could cut a power cord and wire nut it up to the driver
But..
Yes its nessecary to epoxy it up as an assembly first.
I used a 5min Devcon and haven't noticed a problem to pot the driver.
The LED star is better suited to Arctic Silver since it can be screwed down.
I stuck the optic on a SSC P4 and got a much better beam, its going to look cool... erm warm.

 

[Stillphoto]

Ok I plan on completing the build tomorrow. I had previously used some heat-shrink on the circuit board. Should I cut that off if I'm going to pot the board in epoxy anyways?

I'm re-using a lumileds star to mount my ssc p4...took off the old led, cleaned off the thermal crud that isolated the led from the star and made sure the seoul would fit properly. I have a little bit of some thermal epoxy, I figure that should work fine for attaching the led to the star.

Do I need to use a bunch on the rear or the star as well? I figure if for some reason the circuit is no good I'd like to be able to salvage the led/star.

 

[nein166]

It'll be needed for permanent installation. If you leave enough wire to lift the star and put the epoxy in later you can test it and still recover the star. Just don't run it for too long with out the star epoxied to the heatsink. Use those screws to hold the star down in the meantime.

 

[spencer]

Instead of epoxying the star to the heatsink you could use thermal grease/paste (what is used between your CPU and heatsink in your computer). You should be able to get this at any local computer store.