Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The best four have a capacity down 14% from the good old days and the weakest pair are down 29%.
The camera uses 1.9 W, so a battery with 2.5 W·hr capacity should last 78 minutes, but about 400 mV of voltage depression causes the camera to give up before using its full capacity.
So they have a useful lifetime of maybe two years in our regular bike riding schedule and I should have bought replacements last year. I hope the next batch isn’t New Old Stock or recycled cells.
For unknown reasons, the handle on the porch screen door was installed less than one finger width from the frame, so I conjured a pair of plastic plates shifting it far enough to prevent finger pinches and avoid the screws for the outside handle:
Porch door handle repositioning
The original holes now have M4 threaded wood inserts and the holes in the ¼ inch acrylic have M4 heat-staked brass inserts, mostly because I had everything on hand.
This was part of a project to trim the bottom of the door to clear the porch floor boards, which evidently continued warping after they trimmed the door to fit:
Porch door trimming
That thin blue line suggests the highest part of the floor was once near the bottom of the picture, but it’s now the lowest part. The highest part is now near the hinge side near the top of the picture, firmly jamming the door in place.
The power supply converting the battery’s raw 6 V into whatever voltage is required by my troublesome SJCAM M50 trail camera failed, despite the replaced wire between the battery and the camera remaining intact. The camera continued to work with 5 V power supplied through its USB-C jack, so I think it can accomplish most of its goals with a USB battery pack nearby.
Unfortunately, the USB-C jack isn’t accessible with the case closed, so I decided to repurpose the battery compartment’s external 6 V input jack.
I removed the 000 (0 Ω) SMD “resistor” connecting the battery + terminal to the power supply circuitry and soldered one end of a wire to that pad:
SJCAM M50 – battery input pad
The adjacent 000 “resistor” connects the battery - input terminal to the circuit, so it remains in place.
The other end of the wire goes to the high side of the +5 V filter caps for the USB-C input:
SJCAM M50 – USB power input pad
The battery pack produced 6 V from two parallel-ish banks of four AA cells or an external source arriving through a 3.5 / 1.35 mm coaxial power plug, with a Schottky diode dropping 250 mV before reaching the BAT connector in the first picture. The camera seems happy to run from slightly under 5 V.
Unfortunately, “happy to run” means the camera remains in Setup mode, ready to dump its stored images through the USB port, and won’t take pictures regardless of the switch normally controlling such things. It seems I must either troubleshoot the switching regulator generating the internal power supply voltage(s)or junk the camera.
I’m not red-hot pleased with the several SJCAM cameras I’ve used, as they seem to feature under-designed durability for their intended use. The fact that SJCAM cameras seem to be on the better side of a bad lot is not comforting.
I did the probing & doodling during a Squidwrench remote meeting and was assured I would not regret directly applying five volts to the circuit, said with the intonation of this meme:
Last month it began to flicker and I eventually caught it in the act:
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
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
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.
That’s the gluing “fixture” with enough steel piled on the lid to keep it from moving and machinist vises pushing / holding the hinge fragments in place.
I used the same technique as before, with duct tape aligning the loose pieces and JB Plastic Bonder sticking them together:
Sears Humidifier – right hinge outboard
The other side of that hinge shows the broken section at the end of the molded void:
Sears Humidifier – right hinge inboard
The other hinge has a 3D printed replacement end:
Sears Humidifier – left hinge inboard
The other side shows there’s not much of the original hinge left:
Sears Humidifier – left hinge outboard
I very carefully installed the lid on the newly cleaned humidifier in the Basement Shop, where it flips up and down like anything.
At the start of this year’s humidification season, I will very carefully carry the lid up the basement stairs to the Sewing Room and we’ll see how long it survives in actual use.
One of the Dripworks Micro-flow valves in Mary’s garden blew a fan-shaped spray into the air when she turned the water on for the first time this season. Fortunately, the main valve is far away and she didn’t get hosed down.
The poor thing may have frozen and cracked during the winter. Seeing as how this would have been its fifth year in the garden, we can’t kvetch too much.
The Smell of Molten Projects in the Morning 