DIY led not all lights lighting up

[r6justin]

have a pair of Mean Well ELN-60-48D's each running 16 LED's from rapidled
driver 1 powering 16 CREE XT-E Royal Blue LED (works fine)
driver 2 powering 4 CREE XT-E Royal Blue LED and 12 CREE XT-E Royal Blue LED

I have about 5 led's on the board not lighting up. work fine if testing but not when all plugged together. they're the furthest from the ends also. Thought it was because overdriving but each are 2.9v and the 48v driver can handle 16.5 of these. Also have srv2 fully up as is 1300ma and these led's can handle up to 1500ma

Have meanwell's setup just testing using 3v for voltage and not connected to my apex yet.

Am I missing anything? maybe short in my wiring?

 

[Khemul]

Also have srv2 fully up as is 1300ma and these led's can handle up to 1500ma

Did you check the actual current reading, or just turn the SRV2 all the way up? 1300ma isn't necessarily the maximum setting for the SRV2 on these drivers. It is the maximum they are rated to safely run at, but they can go a bit higher. One of mine hit 1900ma one time while I was adjusting the current.

 

[oreo57]

Did you check the actual current reading, or just turn the SRV2 all the way up? 1300ma isn't necessarily the maximum setting for the SRV2 on these drivers. It is the maximum they are rated to safely run at, but they can go a bit higher. One of mine hit 1900ma one time while I was adjusting the current.

Check w/ a VOM to see if you are bridging any contacts to the heat sink.. Both the plus and minus side..

 

[Fish Stix]

If it were me I would unplug the LEDs and use the battery tester to test each led and make sure they are all still firing and none went out for any reason...if all are firing reconnect + to - and make sure there is a plug on the last led closing the loop. 16 xte at 1300 is more than I felt comfortable powering with that driver I only put 12 xte on a meanwell 48d...

Plus I'm curious how you worded it... "Powering 4 and 12?" It makes me wonder how you have it set up, that you would not just say 16....

 

[sleepydoc]

Shouldn't be too tough to debug. If some of the LEDs are lighting, there is power/current running to at least part of the string.

1. Verify that all LEDs are working (sounds like you've done this)
2. Verify that the driver is capable of running the string or LEDs you want. i.e. can supply the necessary current and voltage based on the LEDs specs. (I assume you've done this)
3. Assuming 1 and 2 are OK, grab your volt meter and start checking voltages. Start with the voltage between the two contacts of the driver. Now move the positive test probe down the line of the LEDs and check the voltage across each one.

If all except the last 3 in the series light there is either a short in them or a short to ground as Oreo suggested.

Another way to check is to unplug the driver and use an ohm meter and measure the resistance between the heat sink and each of the LED contacts.

 

[zachts]

You MOST CERTAINLY have at least two shorted points on the string, more if the ones that are out are not all in a row. Use your meter and do a short test to the heatsink on ALL solder points and then fix the faulty ones. Problem solved! A few are not lighting because the current is taking the path of least resistance into the heatsink rather than thru the leds which are in fact a diode and by nature resist current flow.'

Recheck and clean up all your solder joints so no bare wire or solder is touching or near the edge of the star chips.

 

[rwb500]

show us a picture of the circuit and which ones are/aren't working. you also might have soldered the wrong pads on some of them so the current is skipping them.

 

[sleepydoc]

a short in one of the LED's would expain that LED not lighting up, but if multiple LEDs at the end of the circuit are failing it's most likely a short to the heat sink. I assume your driver is grounded with the heat sink - what happens if you take it off so it is electrically isolated. (or so both of them are electrically isolated)?

 

[ghellin]

I see problems!

2.9vf is @ 350mA, at 1300mA they drop 3.3V totaling 52.8V Big problem!

Did you use a multimeter to confirm 1.3A or are you guessing. I have worked with dozens of ELN's and they all can and do go higher than 1.3A when the SVR2 is cranked up.

14 Cree LEDs is about the max you want on an ELN driver.

 

[ghellin]

Did you check the actual current reading, or just turn the SRV2 all the way up? 1300ma isn't necessarily the maximum setting for the SRV2 on these drivers. It is the maximum they are rated to safely run at, but they can go a bit higher. One of mine hit 1900ma one time while I was adjusting the current.

Yup!

 

[oreo57]

I see problems!

2.9vf is @ 350mA, at 1300mA they drop 3.3V totaling 52.8V Big problem!

Did you use a multimeter to confirm 1.3A or are you guessing. I have worked with dozens of ELN's and they all can and do go higher than 1.3A when the SVR2 is cranked up.

14 Cree LEDs is about the max you want on an ELN driver.

@3V the CREEs are @ slightly over 600mA....

I do see that they are err.. "out of balance"..
But considering this:

driver 1 powering 16 CREE XT-E Royal Blue LED (works fine)
driver 2 powering 4 CREE XT-E Royal Blue LED and 12 CREE XT-E Royal Blue LED

Since some light , closest to driver (shortest run) it seems to imply a loss of voltage causing the downstream LED's to not hit their minimum V(f)

I do agree that they need to shorten the strings..to 14.........


Meanwell goes up to 52.8V....per spec sheet...........http://www.meanwell.com/search/eln-60/ELN-60-spec.pdf

Anyways, they are running at the limits of the driver....

 

[ghellin]

Forward voltage (@ 350 mA, 85 °C) V 2.85 From the data Sheet. Always look at the datasheet.

 

[ghellin]

You can also Tweak the SVR1 but with the level of knowledge here it's best not to go above 48v. To go beyond that you should know what you are doing :0

 

[ghellin]

have a pair of Mean Well ELN-60-48D's each running 16 LED's from rapidled
driver 1 powering 16 CREE XT-E Royal Blue LED (works fine)
driver 2 powering 4 CREE XT-E Royal Blue LED and 12 CREE XT-E Royal Blue LED

I assume you are running XT-E's and something else?

 

[oreo57]

dupe

 

[oreo57]

Something is amiss...

I used 3V because that would be about a rough minimum based on 48/16= 3V
Either way they are probably not getting 1300mA out, unless the max voltage was increased w/ the pot though it is theoretically possible based on the driver specs....Though obviously there could be a lot variation/driver variation ect...

What CREE says..and you, and I agree

Typical forward voltage @ 350 mA, 85°C (V) 2.85

Point is it is "possibly" and probably not a driver error. Swapping drivers would be diagnostic though..

Taking the end diode (or 2) "off line" would also be a good troubleshooting procedure.
Don't think it matters much.. o/p seems to have left the building..
At 48V it should be enough to light all the diodes, though not at a high current..