DIY LED Build help

[Rybren]

I decided to try messing around with a DIY Strip Light build. As t was more of a learning exercise, I used cheapie Ebay parts.

I am using 9 x 3W blue (460-465nm)C Forward Voltage:3.6V~3.8V Forward Current:700mA,

9 x 3W Royal blue (445-455nm)C Forward Voltage:3.6V~3.8V Forward Current: 700mA

and a driver with these specs:

Input Voltage: AC85-277V 50/60Hz
Output Voltage: DC36-60V
Output Current: 600mA ±5%
can work for 12-18pcs 3W led chip n series connection


I mounted the LEDs and wired everything up. Before powering anything on, I used a MM to check across all solder joints to ensure that the LEDs would light and checked for grounding issues between the stars and heatsink. Everything seemed to be good.

When I powered up the fixture, all of the leds would flash on and off. I went back and rechecked the soldering and grounding, and everything looks good.

Any ideas what might be at play here?

Thanks

 

[tgp4274]

how many did you wire in series?? sounds like you may be over loading the driver.....
from what you put down as the driver you should only wire say 12 leds in a row...

 

[Rybren]

Thanks

The driver is supposed to handle 12 to 18 LEDs. I went for the max - 18.

Forward voltage on the LEDs is 3.6 to 3.8. With 18 LEDs that should work out to a max of whoops, too much!

Guess I should have done the math first.

Slowly shrinks away in shame...

 

[tgp4274]

lol its ok..
I never try to max out any thing electric I always try n shoot for the lower end so as to not overwork the part..
good luck n hope ya get it

 

[Rybren]

Okay, so I removed 1 LED from the string and it works perfectly. Measured the current across a 1 Ohm 5W resistor and it's sitting at about 590ma. Interestingly enough, the driver specs above say 600ma, but the driver that they sent is marked as 650ma.

Thank for the help!

Cheers

 

[jstec]

I just did this myself and it didn't give me the output I was looking for. If I wanted it to work if have to add more then the five strips (three blue,two white) and I had already put so much time into it that I said screw it went on Amazon and bought a light half off. Post up some pictures if u get it going I'd love to see it!

 

[mark sid tottle]

Easiest way to make sure not over loading the driver, is multiple the number of leds by there voltage(18×3.8v=68.4v). That way you will be able see if you have added to many leds in one string.

 

[Rybren]

Easiest way to make sure not over loading the driver, is multiple the number of leds by there voltage(18×3.8v=68.4v). That way you will be able see if you have added to many leds in one string.

Where were you this morning BEFORE I soldered 18 together?

I actually knew enough to do this, I just got fixated on the 12-18 3W description and wasn't paying attention.

 

[mark sid tottle]

Where were you this morning BEFORE I soldered 18 together?

I actually knew enough to do this, I just got fixated on the 12-18 3W description and wasn't paying attention.

Lol halfway on the other sid of the world lol. If you need anymore help just ask. I've built my own leds so know how much of a pain it can be.
Have a look at https://www.reef2reef.com/forums/do-yourself-diy/177634-my-do-yourself-light-emitting-diodes-build-using-arduino-controller.html

 

[Rybren]

Thanks for the offer. I will have a read through your thread.

Cheers