DIY LED driver for reef lighting

[der_wille_zur_macht]

Also, DWZM from the image of your CAT in page 23, it appears like you have the CAT slightly elevated so that only the Rear-protruding metallic base of the CAT is soldered to the Ground plane? or am i wrong?

That's just an optical illusion - the part is flat against the PCB. Along the very edge of the tab, there's a fillet of solder, but the part of the tab that's under the part is soldered down well, too. (I can verify this because I put vias in the middle of the pad, so I could check to make sure that the solder penetrated far enough to show up in the vias.)

 

[perikaruppan]

Oh Ok Thanks.

I also have those vias, so how do i solder the base of the CAT? can i apply solder to the Ground plane, place the CAT on top of it and use a the Soldering Rod to heat up the CAT TAB to heatup the solder below and get a proper solder?

 

[fstar25]

...you can stack a crapton of them on ...

That is hilarious. Please define the term "crapton" in a numerical sense.

I actually read this page, left the thread and had to come back and comment.

 

[perikaruppan]

forgot to read the earlier comment.. will do it that way... thanks a lot nathan

 

[der_wille_zur_macht]

That is hilarious. Please define the term "crapton" in a numerical sense.

I actually read this page, left the thread and had to come back and comment.

:lol: I'm glad someone's paying attention.

In this case, 40mA (Arduino pin current limit) / 30uA (draw on the EN pin) means 1 crapton = 1,333 of the drivers could be paralleled on a single Arduino pin. In other words, it's such an absurdly large number, we don't have to worry. I'd bet the practical limit would be much smaller than that, but even on my gigantic LED rig for my 360g I'm only going to have a dozen or two of these drivers on a single PWM signal and I'm not worried at all.

 

[perikaruppan]

finished the 6XCAT Single Sided board with the suggestions of DWZM of using jumpers!!!... and got it fabricated (test fabrication with no soldermask) and tested!!! and it worked wonderfully...

but just a small question - same problem that i faced with ZXLD..

using the Edision LEDs, 3.7V Vf, so 6 nos = 22.2V and i started with 23V... and current was only 530mA, used a 802 resistor where current needs to be 650mA. So increased to V, it took 24.9V to get to 640mA.. but then the IC started to get hot as there was more voltage drop!!!!! ... but the dimming worked perfectly with Ardunio... so that was not a problem...

any idea about this V/I problem? or it is not a problem?

 

[swimmer4uus]

DWZM, do you have any pictures of your prototype boards? I wanna compare and see if I'm going along the right lines.

 

[der_wille_zur_macht]

For the NCP3066 drivers? Sorry, I don't have anything besides what was posted earlier in the thread and I took the last one apart a few weeks ago to salvage for parts.

If it helps any, I used this part:

http://www.radioshack.com/product/index.jsp?productId=2103799

I ended up with around 4 jumpers per board. Basically I started by putting caps right next to pins they needed to be on, then I worked out from there. I jumpered the GND pin from the IC to an adjacent, empty row of pads on the other side of the board because there were so many GND connections.

 

[swimmer4uus]

For the NCP3066 drivers? Sorry, I don't have anything besides what was posted earlier in the thread and I took the last one apart a few weeks ago to salvage for parts.

If it helps any, I used this part:

http://www.radioshack.com/product/index.jsp?productId=2103799

I ended up with around 4 jumpers per board. Basically I started by putting caps right next to pins they needed to be on, then I worked out from there. I jumpered the GND pin from the IC to an adjacent, empty row of pads on the other side of the board because there were so many GND connections.

Dang!!! I figured I'd have a couple jumpers.

 

[swimmer4uus]

So I'm putting together my first NCP3066 based driver. It's buck topology but I figured posting here would be better than starting a new thread. I'm looking for some input from you guys that have designed and put together your boards.

For reference here's my schematic:

This is where I am so far. I have yet to solder up anything. A couple questions I have: does the polarity of these parts matter? I know the diode does, but not sure on the others. If it does, which way should I position them? Also, am I positioning the NCP3066 right? I've looked at the data sheets on the pin locations, then the excel build sheet has the chip opposite than the pictures in the data file. Anything pop up that's obvious to the EE's or anyone else that's done this?

And here's the closest picture I can get of the Inductor. It has 4 pins, and I have no clue how to solder/connect this bad boy.

 

[MuckTown]

dwzm: Just ordered my boards from seeedstudio. Took a look at your BOM and it does not have a ID number for the headers. I looked them up on mouser but wasn't sure about which I should get. I think I remember your headers have screws to secure the wires. It wasn't clear on mouser if screws are used for wire.

 

[ackerman]

here u go

http://www.mouser.com/Search/ProductDetail.aspx?R=1984659virtualkey65100000virtualkey651-1984659

http://www.mouser.com/Search/ProductDetail.aspx?R=1984785virtualkey65100000virtualkey651-1984785

 

[kcress]

does the polarity of these parts matter?

You bet! Those are polarized capacitors. The line down the side goes to the negative side of the circuit. In this case the GND line.

And here's the closest picture I can get of the Inductor. It has 4 pins, and I have no clue how to solder/connect this bad boy.

The inductor should only have two leads. More of them are generally just dummy pins that help mechanically hold the inductor down. You need to determine which two are actually hooked to the inductor. You should be able to probe them all with an ohmmeter and figure out which two they are.

 

[swimmer4uus]

Thanks kcress. After posting I read a little on polarity of the components, but you just confirmed it for me. Good thing I haven't soldered yet.

 

[der_wille_zur_macht]

here u go

http://www.mouser.com/Search/ProductDetail.aspx?R=1984659virtualkey65100000virtualkey651-1984659

http://www.mouser.com/Search/ProductDetail.aspx?R=1984785virtualkey65100000virtualkey651-1984785

Those will definitely work, I think those are the actual parts I'm using. On the BOM, I didn't put part numbers because I felt that headers were a matter of personal preference. I probably should have at least listed those as options.

 

[swimmer4uus]

Here it is.

So tell me what you guys think about my soldering skills. Very rough, but gets the job done.

I haven't been able to find reasonably costly values for my resistors. I just don't feel like paying 12 bucks for resistors. Anyone know of a different combo or something for a total of 133 mOhm?

 

[TheFishMan65]

Anything in series to add up to 133. So a 100 and a 33. 4 at 33. etc.

 

[gringabot]

Hi Guys,
Really impressed with the work thats being done on drivers , i'm particularly interested in the driver that uses the cat4101 and have a question about the 5vin , is the 5v line from an arduino ample for say 6 of the cat4101's or would it be better to use a separate 5v supply

Thanks

 

[truebeliever71]

North East Group buy.

North East Group buy.

I'm going to be placing a order for the PCBs for the CAT4101 driver and was wondering if anyone else in the New York state/upper PA area would like to go in on them. I will need 6 boards and there's min. order of 10.

I'll be placing the order Thursday April 22.

 

[ackerman]

I just got mine yesterday says 10 but they shipped out 12 of them.