The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • HQ Sixteen: Chin Light Failure

    The COB LED module I stuck under the HQ Sixteen’s chin worked well at first:

    HQ Sixteen Chin Light - results
    HQ Sixteen Chin Light – results

    Last month it began to flicker and I eventually caught it in the act:

    HQ Sixteen Chin Light - first failure
    HQ Sixteen Chin Light – first failure

    That’s taken with the phone’s selfie camera from the quilt’s viewpoint, which is much too close for the camera’s focus, but you get the general idea.

    Pulling it off, putting it on the bench, applying 12 V, and letting it heat up produced this:

    HQ Sixteen Chin Light - hot failure
    HQ Sixteen Chin Light – hot failure

    That’s with the voltage backed off to 8 V to avoid burning out the exposure.

    Letting it cool a bit:

    HQ Sixteen Chin Light - cool failure
    HQ Sixteen Chin Light – cool failure

    You may recall I stuck the aluminum backing plate to the HQ Sixteen’s case aluminum body with some heatsink tape and the thing ran just warm to the touch, so I suspect the initial failure had little-or-nothing to do with overheating and a lot to do with buying stuff from eBay.

    That suspicion is supported by having two more of those in the drawer with their failed chips circled.

    So a better design is in order …