Some LED Calaculation Required?

[nick703]

Ok
1) i have a smd LED 3030 6V of forward volatge and 1 watt power rating and also 60 watt Constant current LED Driver.

2) Total Led is 60 and Every 10 x 6 Led series and parallel (10 in series and 6 series line is connected parallel)connection use for street light.

In my constant current led driver 700 mA output volatge i have measure is 112V.

so My question is My led blink and after 2 to 5 sec Led is Burn.

What should i do to do not burn led?

 

[KlausST]

Hi,

What should i do to do not burn led?

Simple answer: drive it within it´s specifications. Thus usually a datasheet is needed.

But the (raw) calculation is not difficult:
1W @ 6V gives about 160mA
so if the driver gives 700mA you need to parallel 5 LEDs (strings) to get a LED current below 160mA.
700mA / 5 = 140mA

if you connect 6 (strings) in parallel you are on the safe side. Then you have 10 in series, making 10 x 6V = 60V total voltage.

Now you say you measure 112V. Here I see the problem. This is too much.

This means either your LED specification is not correct or the LED driver specification is not correct, or the LED driver is defective.

--> post the LED datasheet and a photo of your LEDs including connections
--> post the LED driver datasheet and a photo of your LED driver

Not to the problem related:
If all LEDs are from the same production batch I see no problem, but to be on the safe side I´d add a series resitor of 20 Ohms 1W in series with each string. This ensures better current distribution and more equal LED brightness.

Klaus

 

[nick703]

Hey klausST,

Thanks for your reply but actually i don't have a datasheet of LED driver.
Actually i want to design with this Voltage rating and also i don't know about LED Driver current I assume it be 700mA may be higher.
I only know the driver rating is 60Watt and no load condition votage is 112V.

And i use led datasheet is

https://www.indiamart.com/proddetail/3030-smd-led-1-watt-11439846097.html

i think the voltage range of Constant current LED Driver is 90 to 120V .

 

[KlausST]

Hi,

i don't have a datasheet of LED driver.

If you want a reliably working circuit you first need reliable specifiactions.
Without datasheet --> do your own trial and fail. Nobody else can really help..

You can´t calculate with "I assume" and "I think the voltage...".

Your link is no datasheet .. it´s just an advertising page --> no reliable specifications.

Unreliable informations will result in unreliable operation.

Klaus

 

[nick703]

Yes you are right Brother.

I am going with my trail and error method because My Led Driver specification is not mentioned in cover. so i have to use with 112 V output .

Thanks for your Reply.

 

[Audioguru]

1W is a lot of heat in a tiny little LED.
1W is the maximum allowed if it is cooled properly.
If you do not cool the LEDs properly then of course they will burn.

 

[KlausST]

Hi,

Very good point, Audioguru.

So indeed even if the current stays within the specified range, one need to keep the temperature in the specified range, too.

Still the doubtful 112V....

Klaus