DIY LED driver for reef lighting

[der_wille_zur_macht]

Finally sent away my order for the LM3409 board I talked about a few pages ago. Will let everyone know when they're built.

 

[O2Surplus]

DWZM-

Have you found any other Mosfets with low Rds, that are rated for 48 volt/ 5amp operation. I'd like to build a driver with those specs as the Maximum. Any info is appreciated.

 

[der_wille_zur_macht]

Just had a look and I see no obvious silver bullet, but I might be missing some components.

Specs you need:

If we cap power dissipation in the transistor at 3w (random value) we need Rds under .12 ohm.

48v plus a bit of headroom, say 55v or higher

Qg under 30 nC

Some possibilities:

http://www.fairchildsemi.com/ds/FD/FDD5614P.pdf

http://www.onsemi.com/pub_link/Collateral/NTB5605P-D.PDF

http://www.irf.com/product-info/datasheets/data/irfr5505gpbf.pdf

For reference this is what I use at 28v and ~3A max:

http://www.mouser.com/Search/ProductDetail.aspx?R=FDD4685virtualkey51210000virtualkey512-FDD4685

 

[terahz]

I'm using FQD17P06TM.

 

[O2Surplus]

Hey DWZM, TeraHz

Thanks for the info- I'll give one of those Mosfets a try. I'd seen a couple of those after searching DigiKey, but I had doubts as to them being correct for my application.I'm noob when it comes to selecting parts based on some of the more esoteric design parameters eg.. Qg, Rds, and so on. It's been 15 years since my electronic engineering classes and I'm afraid V over I x R is about all I can remember. Thanks Again:lolspin:

 

[rrasco]

Did anybody ever get any of these PCBs printed? I am close to ordering all the parts for my build, I was planning to use the CAT4101 layout x18 to power three 36 LED pendants. I wasn't sure if anybody had extra boards or if anybody was interested in going in on a batch of boards. If not I may have extras printed for any takers that are interested later on.

 

[TheFishMan65]

rrasco, I have PMed you.

 

[lomo]

I have one question about this drivers.
Is it possible to build them on breadboard? Not for long term use, but for testing purposes.

 

[O2Surplus]

I have one question about this drivers.
Is it possible to build them on breadboard? Not for long term use, but for testing purposes.

I don't think the LM3409 or the CAT4101 are available in a "through-hole" package, so that may make them tough to test on a bread board. You may be able to find small "break-out" boards that you can solder the chips to, that will allow you to wire them into your circuit. "Schmart Boards" should have something that will work with these chips. All the other components should be available in a "through-hole package. Here's a link to the "Schmart Boards"
http://www.schmartboard.com/index.asp?page=products

 

[der_wille_zur_macht]

kcress or some of the other "real" EEs might dispute or clarify this, but I would be nervous about testing on a breadboard if you're going much outside the norm for these drivers, since board layout and package choices for individual components can alter performance. And if you're not going well outside the norm, then why do you need to test? Just build on one of the established PCBs.

 

[rrasco]

Where is everyone getting their terminal blocks?

 

[der_wille_zur_macht]

Mouser, for the little green 3.5mm screw blocks seen in the photos. Phoenix is the manufacturer, they make a bunch of different form factors - vertical, horizontal, etc - if you drill through the search function you can get what you want.

They seem a bit pricey at first I've priced them elsewhere at typical bargain sources (hobby vendors, eBay) and I haven't really found anything cheaper.

 

[rrasco]

I was overwhelmed by the number of styles and variances, and there was certainly sticker shock at first. I think I found what I was looking for and at a fair price.

Mouser Part #: 651-1984659

 

[rrasco]

I'm going to get some of the triple separate cat4101 boards printed, I wanted to make sure I had the latest design before I sent it off though. I downloaded it from the hpled google code library: http://code.google.com/p/hpled/downloads/list

I'm currently trying to make gerber files, so if anybody has those for this board they could just send me, that would be awesome.

 

[der_wille_zur_macht]

If you want a 6 position horizontal terminal, that's fine.

The file you linked is the most up to date version of that particular design.

If you struggle with gerbers, PM me your email address and I will email them to you.

 

[rrasco]

Thanks. Yes, I need 6 position terminals.

I figured out the gerber stuff. The only concern I have is verifying the gerber files in ViewPlot. The first time I created gerber files, I used SparkFun's cam file and 2 4 number format (as their tutorial instructed me to do), but I noticed iTead has their own cam file and I have to use 2 3 as the number format for the holes to line up. Is that correct?

 

[kcress]

They seem a bit pricey at first I've priced them elsewhere at typical bargain sources (hobby vendors, eBay) and I haven't really found anything cheaper.

Two points.
1) Depending on the current rating identical looking Phoenix connectors can be about half the price. Our drivers can use the absolute lowest rated ones.

2) Check Jameco. The last bag of three hundred I purchased was cheaper there.

 

[TheFishMan65]

You might check future electronics also. I know they have had the Cheapest CAT4101 $1.92 today ($1.80 for 10+).

 

[rrasco]

You might check future electronics also. I know they have had the Cheapest CAT4101 $1.92 today ($1.80 for 10+).

Figures, I just ordered 25 @ $2.59/ea from Mouser :angryfire: Of course, what's $20 at this point...

 

[pandimus]

a buddy just put me on to a really cool search engine. octopart.com they search all the companys for electronics and give you the lowest part.