wiring cobs parallel

C

churchhaze

Well-Known Member
Growmau5 said:
@Airwalker16 funny timing. Im actually working on a video discussing that topic.
Parallel wiring cobs using:
-fuses
-current limiting resistors
-how to build a current mirror

The premise is: "someone" is on a restricted budget. They need light now, but dont want to piss their limited funds away on some china shit. So they buy a heatsink that can handle some serious juice, one COB, and one driver.
As their budget increases, or they save up, they add a second cob & heatsink for the same dissipation, but driving up efficiency, then a 3rd and so on.
Im basing it off of the ICEled cooler and this driver (for demonstration purposes): I guess ill have to see if the iceled ULTRA can handle a 3590@ 2.3 amps, lol. :fire:

View attachment 3787184
Click to expand...
Did you figure out how many volts the current limiting resistor or the current mirror drops? Those will both reduce efficiency by a lot. Assuming 1ohm resistors and 1.4A per string, that's 1.96W lost per resistor. Vce on a BJT or Vds on a mosfet is not going to be negligible either. Then there's generating the reference current...
 
Last edited:
CobKits

CobKits

Well-Known Member
Growmau5 said:
I guess ill have to see if the iceled ULTRA can handle a 3590@ 2.3 amps, lol.
Click to expand...
it can, with ease. ive run 100V chips at 3A all day long on those and thats not even topping out the 200W dissipation the sink is rated for. CXB is cake even out to 3.6A

looking forward to your vid, as always!
 
Last edited:
V

voon

Well-Known Member
I have a question about the benefits of serial wiring using constant current dirver .. how regulation works at HLG-Xxh-cXx version ,, A ,, .. I was confused from the diagram in pdf .. but according to information acts to regulate the internal potentiometer ,, A ,, reduction current 50 to 100%, it means that the power reduction of current and increasing the efficiency COB? .. How is it with the version ,, B ,, 3v1 dimming control .. .. 10-100% reduced power of voltage and efficiency of the COB remains the same, it does not change?
 
V

voon

Well-Known Member
just out of curiosity .. Today I tried Parallel wiring 7.5V driver for 13x CPUs Intel and active coolers whole system power consumption is only 5W of total .. I think very interesting .. no disadvantage for Actively cooling, only hope that the not stop work coolers for sometimes .. but I use for CLU048_1212 @ 500 mA .. only 8W heat and passive cooling would be survive probably.. Information about values listed on the plate on coolers must be exaggerated and fictitious (7x 0.6A + 6x 0.17A) X 7.5V = 39,15W vs. measured me 5W only .!
 
CobKits

CobKits

Well-Known Member
voon said:
I have a question about the benefits of serial wiring using constant current dirver .. how regulation works at HLG-Xxh-cXx version ,, A ,, .. I was confused from the diagram in pdf .. but according to information acts to regulate the internal potentiometer ,, A ,, reduction current 50 to 100%, it means that the power reduction of current and increasing the efficiency COB? .. How is it with the version ,, B ,, 3v1 dimming control .. .. 10-100% reduced power of voltage and efficiency of the COB remains the same, it does not change?
Click to expand...
cob efficiency is only related to the current you feed it, not how the driver makes that current. driver efficiency needs to be considered separately but most operate at 90-95% no matter what you do so its less of a consideration
 
CobKits

CobKits

Well-Known Member
voon said:
just out of curiosity .. Today I tried Parallel wiring 7.5V driver for 13x CPUs Intel and active coolers whole system power consumption is only 5W of total .. I think very interesting .. no disadvantage for Actively cooling, only hope that the not stop work coolers for sometimes .. but I use for CLU048_1212 @ 500 mA .. only 8W heat and passive cooling would be survive probably.. Information about values listed on the plate on coolers must be exaggerated and fictitious (7x 0.6A + 6x 0.17A) X 7.5V = 39,15W vs. measured me 5W only .!
Click to expand...
what power are you feeding it? fans will run at lower voltage at a lower speed. hook up one instead of 5 and measure volts and mA
 
V

voon

Well-Known Member
CobKits said:
what power are you feeding it?
Click to expand...
Run at 7.5V.. label on CPU 12V, 0.6A by Delta elec , 0.17A by Foxconn and 0.28A by Nidec.. i know as work coolers,that i give them less voltage ,they running speed lowly .. but P=IxU = 39W not 5W measured me.. I trying run them on 12V,9V,7.5V,4.5V.. they work right on each voltage ..slowly and slowly. I think that 5V maybe too .less cooling efficiency
 
V

voon

Well-Known Member
CobKits said:
cob efficiency is only related to the current you feed it, not how the driver makes that current. driver efficiency needs to be considered separately but most operate at 90-95% no matter what you do so its less of a consideration
Click to expand...
I understand you.. I know as you think that..probably I expressed faintly .. I thought it will increase the efficiency of the COB, when I will regulate per ,, A ,, driver version and COB run on less power, because I will feed less current .. but version ,, B, with 3in1 dimmer will work equally or will regulate the exercise of a less voltage and efficiency not change?
 
CobKits

CobKits

Well-Known Member
3 in 1 just means 3 ways to dim
-resistance
-DC voltage signal
-PWM

all ways to signal the driver. dimming is done the same regardless of how you tell it to do it. the same 90-93% driver efficiency is maintained, and of course if you reduce the current per cob, that efficiency per watt will rise.

same with A. A and B dimmed the same will be equally as efficient
 
V

voon

Well-Known Member
Sorry, probably you don't understand me .. I don't think efficiency by the total load of driver , but regulation methods inside driver .. Is it the difference between A and B version? .. datasheet HLG-120H-C700 is mentioned regulation 350-700mA possible for only ,, A ,, .. 107-215V is range control for ,,B,, version? .. i understood that the regulation ,, B ,, works actuation voltage range .. So you're saying that they both versions regulates the input current to the COB therefore effciency / watt
 
CobKits

CobKits

Well-Known Member
correct. you can crank voltage all the way up on any power supply but current dictates how hard a cob will run. both A and B dim current to control cob power, and in a given size, both A and B are equally efficient at the same current/wattage
 
You must log in or register to reply here.
Top