New style Samsung LM561C Board

ichabod crane

Well-Known Member
Running at the same current is not the same as running them at the same *efficacy*.
I stand by my statement that running the 301B at the same current as the 561C does not equate to running half the number of diodes. If you run the diodes at the same current there is no gain of 50% less diodes needed.
 

Aolelon

Well-Known Member
Your numbers are wrong. You are not running at the same current.

I dont know how to get a screen shot here but mine are totally different. When run at .125 amps I show the 561C with 288 diodes running almost the same as 273 301B diodes.

At .150 amps the 561C with 288 runs close to the 301B with 273 diodes.

And at 288 diodes again for the 561C the 301B needs 271 diodes when run at .175 amps.

All these numbers are with in a few lumens of each at the numbers. These are 3000K S6 and SK flux, 80 CRI, VF AY. The same as you listed.
My numbers are wrong? I didnt post any numbers
 

Stephenj37826

Well-Known Member
I stand by my statement that running the 301B at the same current as the 561C does not equate to running half the number of diodes. If you run the diodes at the same current there is no gain of 50% less diodes needed.
Of course. Running them at the same current/wattage and running half as many leds for the same output would actually be impossible. The 301b would need to be around 115% efficient to do that. Generally there are a couple of ways to increase efficiency. Better leds (lm301b) or reduce the current you are running the leds(by using more leds and driving them softer) that was what I am referring to.
 

nfhiggs

Well-Known Member
I stand by my statement that running the 301B at the same current as the 561C does not equate to running half the number of diodes. If you run the diodes at the same current there is no gain of 50% less diodes needed.
That was not the claim that was made:

"You would need 2x as many 561C to match the efficacy." was the statement Stephen made.

As the simulator clearly shows running them at the same efficacy requires considerably fewer of the 301B diodes to produce the same output. Not quite half, but pretty damn close when you use real world temperatures of 60C or so.
 

ichabod crane

Well-Known Member
That was not the claim that was made:

"You would need 2x as many 561C to match the efficacy." was the statement Stephen made.

As the simulator clearly shows running them at the same efficacy requires considerably fewer of the 301B diodes to produce the same output. Not quite half, but pretty damn close when you use real world temperatures of 60C or so.
Hey why dont you go back and read were I said that we were comparing two different things?
 
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wietefras

Well-Known Member
In the end the thing that really matters is price. If you can buy a led strip with 288 LM561C SMDs for $50 vs a board with identical performance but then from 185 LM301B for $75, then who cares about the efficacy of the individual SMD's? Either you keep the money in your pocket, or you could buy more strips and get a higher efficacy.

BTW I wouldn't trust that simulator too much. Especially not using LM301B data. 4000K and 5000K numbers are identical and 3500K numbers are way too high (look more like 4000K). If they are screwed up that much, who knows what else they got wrong.
 

Stephenj37826

Well-Known Member
In the end the thing that really matters is price. If you can buy a led strip with 288 LM561C SMDs for $50 vs a board with identical performance but then from 185 LM301B for $75, then who cares about the efficacy of the individual SMD's? Either you keep the money in your pocket, or you could buy more strips and get a higher efficacy.

BTW I wouldn't trust that simulator too much. Especially not using LM301B data. 4000K and 5000K numbers are identical and 3500K numbers are way too high (look more like 4000K). If they are screwed up that much, who knows what else they got wrong.
The numbers I was originally talking about where from test data directly from Samsung themselves. Unfortunately, we can't share internal stuff but the future is bright(Pun Intended). As I have stated our price for the QB288 will be the same with V2 using 301B.
 

nfhiggs

Well-Known Member
The numbers I was originally talking about where from test data directly from Samsung themselves. Unfortunately, we can't share internal stuff but the future is bright(Pun Intended). As I have stated our price for the QB288 will be the same with V2 using 301B.
Are you going to make 301B versions of the other layouts such as the QB132 and the QB96?
 

skoomd

Well-Known Member
What about the QB120, are you going to make more of them, with any diode?
I have the drivers sitting for months now.
I hope so. i would like to see a few tweaks to some of the QB designs. But the QB120 and QB132 are REALLY nice if you cover your canopy with them. My biggest gripe is with the QB288/304. They're too small for how much light they output. You could theoretically cover your entire canopy with qb288s, but your wallet wont like that.

The QB120/132 are about twice as big as the QB288/304 yet output half as much light. That's a good thing. But I feel the QB288/304 should use the same ideology and spread the diodes out a lot more. They could be like 18"x12" or something and would be a superior board for sure.
 
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