Led lamp - won't work in cold enviroment

[Gabriel]

Have this led lamp that works perfect fine in room temperature but wont light up outside in cold winter.

Is this because of the startup capacitor is not made for cold enviroments ? startup cap are su'scon - see picture second last picture.

Link to manufacturer site - Cob Led 50W

[stj]

Re: Led lamp - won't work in cold enviroment

you probably answered your own question.
the problem is electrolytics hate cold.
you may have to increase the value.

[Gabriel]

Re: Led lamp - won't work in cold enviroment

Thanks for your answer - Are both the 47uF 50V and the 33uF 50V caps considered startup caps ?

[stj]

Re: Led lamp - won't work in cold enviroment

i dont know - your the one with the board!

i cant see a controller in the foto's - got any foto's of the other side?

[Gabriel]

Re: Led lamp - won't work in cold enviroment

I got a few pictures of the underside - looks like the 8 pin so on the primary side is marked F52966 but I can't be sure.

[budm]

Re: Led lamp - won't work in cold enviroment

ESR goes up when temperature goes down, and ESR goes down when temperature goes up.
Caps are cheap, I would just recap it with good caps.
There are two small caps (start/run caps) in the primary side close to Q1.

[stj]

Re: Led lamp - won't work in cold enviroment

what's your night-time outside temps at the moment?

[Gabriel]

Re: Led lamp - won't work in cold enviroment

I guess average at -2C to -5C, sometimes around 7.

One of the lamps was dead at -1C or perhaps -2C.

[stj]

Re: Led lamp - won't work in cold enviroment

yea, your gonna have problems i think.
maybe you can use something other than electrolytics.

[SteveNielsen]

Re: Led lamp - won't work in cold enviroment

How about some insulation in the box?

[stj]

Re: Led lamp - won't work in cold enviroment

that only slows temperature differences, it will probably equalise outdoors even with insulation.

[SteveNielsen]

Re: Led lamp - won't work in cold enviroment

The PSU might produce enought heat that it could be worth a try anyway.

[Gabriel]

Re: Led lamp - won't work in cold enviroment

They are normally stored in cold car or cold storage containers so I guess insulating them wont work.
I did have a look at fm datasheet and see they are rated for -40 to +105, I will try to recap one of the laps to see if cold start behavior changes.

[kc8adu]

Re: Led lamp - won't work in cold enviroment

are these new or have they been in use and just started doing this?

[stj]

Re: Led lamp - won't work in cold enviroment

you should probably do a FULL recap, because if the others dont work, you could damage the led.

[Gabriel]

Re: Led lamp - won't work in cold enviroment

are these new or have they been in use and just started doing this?

Me and a friend found 15 lamps in a retailers dump, they all look pretty brand new with almost no scratches or other damages. All these lamps more or less have the same cold start problem but work perfectly fine indoors.

you should probably do a FULL recap, because if the others dont work, you could damage the led.

Yes, I will do a full recap on one of the lamps to see if it helps - the other lamps are not really in use.

Of all laps we found one one of them had a electric failure but it was also the only lamp that had a different revision board and also a different led driver.

[ben7]

Re: Led lamp - won't work in cold enviroment

Some sort of ceramic capacitor might help with the high ESR at low temp problem.

[Behemot]

Re: Led lamp - won't work in cold enviroment

Those suscons seem like SK, general purpose. Just use quality low-ESR caps, the ESR should be than similar to warm SKs even while being cold.

[kc8adu]

Re: Led lamp - won't work in cold enviroment

if that is like one my neighbor put up last summer the caps are baked.
his is a dim blue now.several rows of leds are out too.it runs too hot to touch.

[stj]

Re: Led lamp - won't work in cold enviroment

always going to be a problem regulating temps in outdoor equipment.
unless you make cold-weather & hot-weather versions.