Group Actions
Engagement
  • Author Author: Gough Lui
  • Date Created: Date Created
  • Views 2384 views
  • Likes 5 likes
  • Comments 20 comments
Related
Recommended

Click MR16 LED Globe Failure Post-Mortem

Gough Lui

One of my regular blog readers submitted an LED globe for post-mortem analysis, having failed well before the expected lifetime. I take a look inside, determine the configuration and analyze the relatively "anonymous" product which seems to show several design shortcomings which I discuss and think might be relevant to other readers at the element14 community.

 

The article is posted at http://goughlui.com/2016/06/01/failed-click-ltmr5w3k-5w-led-mr16-replacement-globe/

 

What really gets me is that many products are still designed using multiple-parallel LEDs without any current balancing mechanisms (e.g. remember emitter feedback resistors when paralleling BJTs?) and that leads to potential for a single string to be overstressed continually, fail early, and begin the cascade of failure as other LEDs are forced to soak up current in excess of their ratings, and operate in less efficient regimes resulting in greater heat production and degradation of the semiconductor material. Of course, if you went all-series, you would have an all or nothing situation and require higher voltage driver electronics, but I personally would gravitate to this arrangement for reliability reasons, or go with multiple independent channels if reliability is demanded.

 

Any comments, or stories related to LED globes or LED light designs are very much welcome.

 

- Gough

Parents

  • Hi Gough,

    I am hoping that they do as good of a job figuring out what went wrong with me when I stop ticking as you performed on the LED globe. This is a great learning experience to follow your dis-assembly and analysis of the light.

    I am glad that you are bringing some of these links to your web site onto the Forum.

    John

  • in reply to jw0752

    Love the humour - although I am still trying to find the right level of balance. I find that when I post them around the community, I get the valuable discussion and feedback that I don't otherwise get when it's just sitting on my site, but at the same point in time, I feel a bit guilty of spamming links and I'm sure some people might not appreciate it as much as if the content was posted here directly. But since the content itself is not "directly" involved with element14 equipment, I'm a bit torn between the two, but I suspect if I just use my own "blog" area here, I might not cop as much scorn image.

     

    - Gough

  • in reply to Gough Lui

    We have absolutely no problem with you or anyone else posting links to blogs on external sites, as long as:

     

    • It's of interest to engineers
    • It's not spam

     

    Obviously we'd rather you blogged here, but we're aware that's not always practical, you might already have a blog before you came here, or you might have incentives to blog elsewhere, or just prefer the experience elsewhere. And should you have a blog elsewhere, we have no problem with you linking to it.

     

    Our primary goal is to encourage discussion of electronics and engineering in general, and you linking to your blogs does exactly that. So stop worrying about scorn from us and get posting! image

     

    I think it's a given as well that on your external blog you might occasionally mention some of our competition, and that's fine too, as long as it's sensible and not blatant promotion.

Comment
  • in reply to Gough Lui

    We have absolutely no problem with you or anyone else posting links to blogs on external sites, as long as:

     

    • It's of interest to engineers
    • It's not spam

     

    Obviously we'd rather you blogged here, but we're aware that's not always practical, you might already have a blog before you came here, or you might have incentives to blog elsewhere, or just prefer the experience elsewhere. And should you have a blog elsewhere, we have no problem with you linking to it.

     

    Our primary goal is to encourage discussion of electronics and engineering in general, and you linking to your blogs does exactly that. So stop worrying about scorn from us and get posting! image

     

    I think it's a given as well that on your external blog you might occasionally mention some of our competition, and that's fine too, as long as it's sensible and not blatant promotion.

Children