Building New Panels - Sharing the Process

[rrog]

Schroomie- Thanks, but no, I cannot read schematics. As I've clearly illustrated in this thread, I'm a complete electronic idiot. I can follow only dummied down directions and please don't take that kinda time. I liked the idea because I plan to make 5 more panels, each requiring 5 drivers...

I don't need dimming, and my drivers are dim-able. So maybe that added to my cost / complexity.

 

[luvdemshrooms]

If you truly were a complete electronics idiot, your light would not have lit.

 

[rrog]

Maybe I'm not complete. I'm an incomplete electronics idiot.

Do you have a pic of the guts inside your driver?

 

[luvdemshrooms]

I do now.

The PCB is something we use for another application. That's why some of the components look a "tad" oversize.

All the components used are available in through hole versions except for the 8 lead SOIC (chip) which is hidden in the pic. Adapter boards are available so it can be used with no problems.

 

[rives]

LDM, you are using one large supply and then feeding each string with the pictured driver?

 

[rrog]

Well, hell- I've done the fuses, MOV's and Zeners once. If there was just one driver that I built per unit, that's a big deal all the way around!! No one makes these boards for sale as a kit?

 

[luvdemshrooms]

LDM, you are using one large supply and then feeding each string with the pictured driver?

One string of 20 LED's running off one driver powered by 115vac.

The current set resistor is just visible in the pic with the designator "R5". A potentiometer could be used there if desired.

 

[luvdemshrooms]

Not including the enclosure or the PCB, there are roughly $15 bucks worth of components.

 

[rrog]

Is it possible to build one of these to replace the 5 drivers in my current build? Again, I'm looking at 25 drivers currently (ha). Is this PCB readily accessible to a consumer like me?

Rives- I have to again thank you for all your help looking up all the details of my build. I will definitely build more of these with some improvements, but wouldn't have done this first one without your steady encouragement. Sincerely I thank you.

 

[luvdemshrooms]

This is a proprietary PCB but there are prototyping PCB's available that will do the job. The PCB in the pic was designed for surface mount components and to run 6 XML's. As I'm running more I had to substitute components of a more "robust" nature. Hence the "home made" look.

I know they'll run 20 LED's per driver. They should have no trouble doing 25.

What did you pay for your drivers?

 

[rrog]

$50. Again, they are dim-able, and maybe I could find other drivers. I like the size and output, so would build 5 for my new med-compliant room.

 

[rives]

Rrog, if you've decided on the driver that you want, you should check out bulk pricing through Alibaba. Onlinecomponents.com also has amazing pricing if it is an item that they stock, and they appear to be willing to bring in inventory if given some notice.

 

[hempfield]

Piece of cake. While I'm using a PCB for a base, and as such many surface mount components, the same thing could be built with through hole components and a perf board.

When I have a few minutes I could put together a parts list for you.

Can you read/follow a schematic?

Can you share this with us ? I mean the schematic of the circuit, the components you have used and so on. Building a high efficiency switching driver is not so easy and can be quite tricky to tune up without proper equipment (scope, frequency meter, etc),

Cheers !

 

[Weezard]

You lot work too hard and pay too much.

You lot work too hard and pay too much.

Or,
You can go minimalist
Here's a KISS regulator.

This drives a string of Blue leds,
And I use 2 more for the strings of red.



A very simple formula finds a resistor value for your desired current.
A 1.1 ohm resistor will give you 1 ampere of current.
And only consume 1 Watt doing so.
The LM 317, 3 terminal regulators sell for about 40 cents ea.

And you don't need a circuit board.
Just solder the resistor to the "Adj, and the output pin and feed the leds from the Adj. pin and you're done.

You want simple and inexpensive?
Just ask a guy who's lazy and cheap.

Aloha,

Weeze

 

[hempfield]

The problems with current limiting circuits is that the input voltage should not exceed to much the voltage drop on the led chain, because the bigger the difference, the lower the efficiency (the voltage difference is converted on power dissipated/lost on the regulator) . LM317 has a maximum working current of 1.5Amps and a voltage drop of at least 1.25V . For leds which require a higher current a MOSFET transistor can be used (as I explained on the romanian section : https://www.icmag.com/ic/showthread.php?p=5669918#post5669918).

But it would be quite interesting to try switching drivers, that offer high efficiency despite the number of leds connected on the output.

 

[rrog]

... So is this do-able or no?

 

[luvdemshrooms]

I'm in discussions with my partner as to the possibilities/ramifications of selling these. Either as a kit or semi-kit.

As I pointed out earlier, the PCB's were not originally designed for the components I'm using. One component in particular (the driver SOIC) is not available in through hole, which means an adapter board would be needed for most people.

You can probably see in the pic that there's a screw/nut securing a component to the case. That Mosfet was originally a surface mount part. It ran a bit hot so I soldered on a through hole Mosfet and attached it to the aluminum enclosure. It's things like that which we are talking about. Do we provide an enclosure? Do we spec that an aluminum enclosure is used? How do we handle warranty issues? They could be easily dimmed by adding a potentiometer in along side the current sense resistor. Do we point that out in the instructions we would need to provide?

Or, when all is said and done do I just share the schematic and BOM?

We're talking about this but it won't be an overnight decision.

 

[rrog]

I would think the further you were from a completed driver, the less liability. Please keep us posted.

 

[GuFF]

Hey RROG have you considered using a power-loss relay like what Rives did on his Hybrid unit? Shuts the driver down if the fan fails.

I'd like to set one up on mine.

 

[rrog]

I had thought about that, but with this being my first project of this type, I didn't do this.