1 - 5 of 32 Posts

#### jeffkrol

· Registered
Joined
·
13,387 Posts
Thanks.. The Razor is unexpectedly low in PAR...
Best guess is the ind. diodes are set to only output 150mA

Out of curiosity can you see the resistor number on the RayII and the ps voltage?

The 2 tight rows vs 3 spread rows makes more of a difference than I would have thought..

#### jeffkrol

· Registered
Joined
·
13,387 Posts
I corrected myself.. not sure what I was looking at at first. My post was edited..

#### jeffkrol

· Registered
Joined
·
13,387 Posts
Great write up. I have the Razor and Stingray over my 30" and I confirm your results, Low light at best!
combined that is a bit of an interpretation.. Adding the PAR pushes it above "at best"..

#### jeffkrol

· Registered
Joined
·
13,387 Posts
All the resistors on the Razor board show "180"

The Ray2 is the earlier one with the PS integrated and the stupidly short power cord.
Thanks yea I saw the 180 (18Ohm) from the photo.
That is where this came from
Best guess is the ind. diodes are set to only output 150mA
R = (VDC – 3 x VF) / IF = (24 – 6 x 3) / 0.35 = 17.1Ω (ohms)
And, the power that the resistor has to dissipate is given by:
P = V x I = 6 x 0.35 = 2.1W (watts)
(12- 3 x 3.4)/.150 = 12 Ohms.. but I'm guessing on the V(f) snd current draw at it..
Most run in this area..which is close to .5W..

http://electronics.stackexchange.co...specced-values-and-real-values-for-led-strips

for fun on how to increase your output (and overheat) your LED strip light..
Hint: replace ps w/ one larger in voltage than you have..

note though 150mA is pretty well on the top level for .5W LED's.

https://d114hh0cykhyb0.cloudfront.net/pdfs/spmwht5225d5waq0s0.pdf
http://www.homeled69.com/faq_17.html

#### jeffkrol

· Registered
Joined
·
13,387 Posts
I've got a 15v power supply on the bench looking for a home!
If the output is OK, well there are some tweaks to lower the voltage a bit..

Using some power diodes will drop the voltage, or even some of those cheap flea bay boards.
In a small silicon diode at rated currents, the voltage drop is about 0.6 to 0.7 volts
Take 3 or 4..
You probably don't want 15V.. Anything over 14 may significantly shorten it's lifespan.

I didn't go further than 14.21v (I originally didn't want to go past 13.8v, but oh well). You can see that I cycled through the voltages at a faster rate near the higher voltages, because I was too scared to damage the LED strip. At 14v it dwarfed the luminous flux outputted by 25m of RGB led strips that were in the room, that's for sure Sasha Dec 20 '12 at 10:37

Then again a PWM dimmer would work as well.. The diodes can take short bursts of high current.. http://electronics.stackexchange.co...real-values-for-led-strips#comment98393_51778

1 - 5 of 32 Posts