Brian Hoskins

Hi everyone,

Thought I'd share a recent experience with an infra-red lamp I bought from China (got it through Ebay). I bought the item so that I could take down my 500W flood lamp which was irritating the neighbours. The new infra red lamp would be just the ticket, because it would illuminate my drive enough for the camera to pick out detail just fine.

I switched it on, and was pleased to see that it worked. I've got a SONY camcorder that does night-shot so I thought I'd spend a couple of minutes testing it out with that. 5 minutes or so later, I noticed an entire half of the lamp wasn't working. Then I smelled burning electronics. I took the thing apart, and you wouldn't believe it - 2 resistors (they look like 1/4 watts... maybe 1/2 watt at a push) running 140 Infra Red LEDs. Just how long did the designer of this lamp expect it to last?? Both resistors were charcoal. I'll have to make my own circuit for it now. No doubt the LED array will be the next to go, since they've wired chains of LEDs in parallel.

Brian

crusty

so did you have to use your own PS or did one come with it? did you overjuice it? I would think if ya put enough of them in a series you wouldn't even need a resistor with the right amount of juicey juice.

Brian Hoskins

Are you calling me an amateur?

...ok I am an amateur. But no I didn't "over juice it". It requires a 12V D.C. PSU capable of supplying 1.5A. So I used my bench power supply. I understand that some will be connected in series, but these in turn must be connected in parallel to other groups of series LEDs. And they're driving all of this with 2 puny resistors. Something not quite right there I'm sure!!!

Brian

Brian Hoskins

Besides, if they're driving them in groups of series LEDs connected in parallel with other groups of series LEDs, what happens when one LED goes faulty? That means the entire row of series LEDs go out, and so the current is then distributed amongst the remaining LEDs. One of those will feel the stress of that until it too burns out, taking with it another row of LEDs and the current is then redistributed amongst the rest. And so on and so on until the lamp doesn't work anymore.

Brian

Nigel Goodwin

I can spot your mistake(s) right there - you bought from China (land of crooks and dodgy deals) and you bought from Ebay (also full of crooks and dodgy deals). Doubly bad!.

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Styx

doesn't that cancel out and make a good \o/

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Hero999

Make them in to 20 chains of 7 LEDs and run them from a 12V 500mA wallwart.

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wmmullaney

I agree, my brother bought an mp3 player from China via Ebay, worked for a month then broke.

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Brian Hoskins

A mistake I don't intend to make again I can assure you.

Brian

eblc1388

Easier said than done.

Avoiding all things that come with the "Made in China" label?

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L.Chung

Brian Hoskins

Well not so much that I guess. Really it's all about adhering to the famous saying, "If it sounds too good to be true... it is"

Brian

crusty

soooo sorry i might have referenced you at all as a amateur, if you knew what you was doing then i presume you wouldn't need a thread on the subject.

Nigel Goodwin

Wouldn't help much anyway, there's a LOT of stuff actually made in China that's not labelled as such - for example Roberts Radios - because they fit the radio in the case in the UK it has a 'Made in the UK' label, but the radio part is just bought from China!.

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RODALCO

What was the sellers feedback rating ?

You certainly have to give him a minus for that piece of junk he sold you.

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Brian Hoskins

I was a little unfortunate there. The lamp did initially work, so I left him positive feedback. Just minutes later it went faulty, but I had already left my feedback so unfortunately he got away with it!

Brian