DIY Samsung LM561C build

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VegasWinner

Well-Known Member
I got my sample roll of constant voltage samsung diodes and they look great. I have been in discussion with Roget and I am ordering both 3500k 90cri and 5000k 80cri in constant current format with 70led/m
 
Randomblame

Randomblame

Well-Known Member
ganglyguy420 said:
thanks for the info, would like comments but i think i haven't posted enough to get that option yet. I contacted a few suppliers on alibaba asking are your strips constant current? there looks like resistors inbetween the diodes. they reply: yes those are resistors to balance current between each diode. i thought resistors limit voltage?
Click to expand...
Yepp! They do both!
LED's are CC devices this means the current determines the voltage required. Increasing the current also increases the voltage.
The resistors limits the current, so that the LEDs get a constant voltage which fits to each string of 3 LED's on the strip!
This costs energy!
If you give 12V CV to a row of 3 LED's, they would burn instantly. The resistor limits the current so that from the 12v still about 8.5-9V arrive at the LEDs but with a constant current.(usually 65-150mA, depends on used resistors)
The advantage of such an arrangement is that the strips also run when some of the LEDs are defective. Only the affected string goes out, the rest continues to light. With CC strips (all LED's in series) the whole strip would be dead. Therefore, the hardstrips are usually arranged in series-parallel circuits, so that a large part continues, even if some LED's are affected. The remaining LED's gets only a little more current, because he splits between the remaining strings.
 
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ganglyguy420

ganglyguy420

Well-Known Member
Randomblame said:
Yepp! They do both!
LED's are CC devices this means the current determines the voltage required. Increasing the current also increases the voltage.
The resistors limits the current, so that the LEDs get a constant voltage which fits to each string of 3 LED's on the strip!
This costs energy!
If you give 12V CV to a row of 3 LED's, they would burn instantly. The resistor limits the current so that from the 12v still about 8.5-9V arrive at the LEDs but with a constant current.(usually 65-150mA, depends on used resistors)
The advantage of such an arrangement is that the strips also run when some of the LEDs are defective. Only the affected string goes out, the rest continues to light. With CC strips (all LED's in series) the whole strip would be dead. Therefore, the hardstrips are usually arranged in series-parallel circuits, so that a large part continues, even if some LED's are affected. The remaining LED's gets only a little more current, because he splits between the remaining strings.
Click to expand...
so are the led's on the strips in series & the led's on the H strips & Quantum boards in series parallel?
 
Randomblame

Randomblame

Well-Known Member
12v strips= 3 LED's in series + resistor, cuttable each 3 LED's
H-Series= 8 LED's in series, 6 strings in parallel, no resistor, not cuttable
QB 304's = 38 LED's in series, 8 strings in parallel, no resistor

They are usually configured to provide many possible driver solutions.
 
ganglyguy420

ganglyguy420

Well-Known Member
VegasWinner said:
strips also come in 24v and constant current and constant voltage
Click to expand...
Do you got a pic? im looking for somthing like that but all the ones i found have resistors between the diodes.
Randomblame said:
12v strips= 3 LED's in series + resistor, cuttable each 3 LED's
H-Series= 8 LED's in series, 6 strings in parallel, no resistor, not cuttable
QB 304's = 38 LED's in series, 8 strings in parallel, no resistor

They are usually configured to provide many possible driver solutions.
Click to expand...
you have an insane amount of knowledge seems like. my electronic knowledge is limited as of now but i hope im getting the jist of it. is this right? : if the diodes are are on a series* circuit its gonna need lots of resistors & therefor have more voltage drop? i just have to understand this 1 thing so i dont go buy a whole bunch 561's and find there not pushing the lumons like i want.
 
Baudelaire

Baudelaire

Well-Known Member
I need some advice from fellow stripheads here. Putting together a strip assembly that I would like to control with a switch the turns half the strips on, or all of the strips on. I believe the electrical nomenclature for the functionality I'm looking for is Off/A/A+B. I can find lots of Off/A/B switches, but nothing that's A+B (except a bunch off audio switches). Can anybody point me in the right direction, or help me better define what I need so I can refine my search?

-b420
 
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