Nice Ive been looking for legitimate high cri strips for awhile. Ive found some real high end ones that have a rosy warm tint and high cri but with a price to match. Does anyone know if the warm version of these are yellowish or rosy?
Hey that’s an excellent video, thanks for sharing!
I have talked to the vendor and he is very kind. I asked for the real measurements of these strips and he sent me the warm light led measurements and the daylight led measurements. Results seem great! I am really happy with the price if these results are true:
still the voltage on an end of a strip is always lower as where the cennection is
using 19V PWM is just stupid, as the current is well over the rated with a tint shift
I have done 120LED/m 5070 stips with connections on both ends and 2m lenght, there is a decent voltage drop of about 1.5V in the middle
Lexel, good point. I am still learning about this so let me see if I understand it correctly: using 19V on a 24V setup will increase the current thought the Leds (as the resistance will not change) causing the tint shift, right? What would happen with the opposite? Powering a 24V with 30V for example. The current would decrease? and it would also cause color tint shift?
Let me ask you something about the tint shift in another situation if I wanted a really low output from these lights (I know I can always use PWM at the stated voltage, but for the sake of theory): what happened if I power a 12V led strip with a 5V powerbank? The current would increase until the USB reach its max current. And that is probably too low. These leds would run with less current, would they also have tint shift (or would they turn on at all)?
The second situation would be the follolwing: powering a 12V led strip with a limited current 12V power supply. The leds would be less bright and less color accurate?
Powering 12V strip the safe way is 100% current no PWN,
then measure on the strips input voltage where the leads are soldered and adjust the PSU voltage till it reaches 12V, maybe a few 0.1V more
Depending on current, gauge and length of the cables this may be 12.5-13.5V
if he is using 19V thats just stupid pulsing the LEDs current likely over their specs
19V on a 12V strip is killing them - no matter if he is using PWM or not.
19V on a 24V Strip will barely light the LEDs up and they will pretty much live forever
12V Stripe on 5V Powerbank doesn’t work - 3 LEDs in series need ~7-8V to light up a tiny bit.
Wow their WW 3000k actually has a negative DUV value and 93.53 R9!!! I’ve been searching for good led strips for my home decor and all the Amazon ones I bought have very yellowish/greenish tint. I would love to buy a 3000k one but they only sell NW 4000k-4500k and CW 5500k-6000k.
Well, guys, he actually connected 2x12V LED strips in series, then to reduce heat output and boost efficiency, he put 19v instead of a 24V power supply. Then he uses PWM to reduce power even further.
He wouldn’t be that dumb to power a single LED strip with 19V+PWM. That is why he put 2 in series. Watch the whole video, and you will understand.
I understood that but, at first, I though Lexel had not. I was going to explain this to him, but then I tried to think.
He stated:
Undervoltaging means more current (since the resistance does not change), right? As he stated, more current = color shift.
So, I think he meant undervoltaging a 24V LED system to 19V means more current, so tint shift. Did I understand right?
Undervolting means less current - until the LEDs don’t light up at all.
The forward voltage of every LED gets less if you lower the current - and vice versa.
Visualisation:
The more current you want, the more voltage you need
The more voltage you want, the more current you need
So, if you give the LED which this graph is about exactly 3V, it will draw ~75mA. It is impossible to run this LED with 3V and 300mA.
24V LED-Stripe on a 19V Power Supply means lower current, therefore a tint shift.
PWM dimming doesn’t affect the tint as hard as dimming via current does, but it does.
Understood, thanks for the nice explanation and graph! I was stuck with Ohm law, U=Ri but apparently the resistance of the LEDs are not constant.
But aren’t these leds connected with a much higher resistor in the strips? I thought that this much higher (and fixed) resistance is the one who will determine the current through the strip?
Found another 90CRI strip. I asked for the 3000k version and they showed me a test report showing x=0.4275 and y=0.3814, which calculates into a DUV of –0.008, which is very nicely rosy! Perfect for the living room or bedroom use!