1. You could cut the panel out of the lid and glue in a window if you wanted to keep them waterproof 🙂

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2. Stop with the Links . . . they don't work. There, I saved you and anyone else, some time.

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3. Man those prices are coming up! Don't know if I would pay 8 bucks for one of those.

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4. Who doesn't have a vice for outdoor action?

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5. The squiggly pcb trace is because most of the Chinese people designing these things have little idea what they’re doing. They just randomly copy other designs until they get something that sort of works and put it on eBay, Ali express, etc. There are all sorts of examples of things that make no sense to a real engineer but end up in Chinese products out of pure ignorance.

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6. It seems a typo – 100mA instead of 100A. The meandering trace is most likely a fuse.

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7. Cut out the rectangle in the battery box lid, along that recess and put in a piece of thin plexiglass. Now you can see the cells and you don't have that unsightly uncovered button and it's wires and hot glue blob.

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8. Way back in the day, 1984ish, we used an arbor press to install IDC connectors. A vise works just as well.

   To get the precision spacing you need, design a board with 2 headers at the correct spacing then solder the headers in. Put a connector on each, lay the ribbon cable on top the fit it in a vise or use an arbor press or even a drill press (pillar drill). The connectors don’t take much force but do need to be pressed squarely or they will break. Our cable assemblies didn’t use the extra part yours have. It provides strain relief to keep the wires seated in the forks, I think you can skip using that part.

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9. I have a dual voltage (±5) power supply with similar tracks to those going from the full bridge rectifier to the input caps of the 7×05 voltage regulators. Not sure of their purpose there either.

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10. I assume the wiggily tracks are to keep the resistors heat off the transistor. Transistors can cause thermal runaway conditions if you don't consider such things.

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11. Wiggly line impedance matching? Or inductor.

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12. If I remember making up ribbon cables correctly, the connector design is very annoying as the clip is designed with the cable looping back through, so you don’t get a straight run from connector to connector..if you don’t do it that way ten the clips don’t work. Alternatively you can cut some very small sections of ribbon cable to keep the clips in place.

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13. Julian – do you ever get worried to opening packages from China that may contain insets. I do sometimes question it.

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14. dute, in the SECOND when you touch the capacitors contacts and say "ofcourse, there is nothing in there" i remembered my old middle school teacher, who taught us work with low voltage devices, as we was young students, we cant work with electricity in circuits, so he must come and touch live parts as proof, that its without power, one day he probably forgot secure the switch and touch live part, get hit pretty hard by 250v and walk away with "wtf i was sure i switch it off", EVERY time, when i hear "feel free to touch is, its turn off" i remember that day, even if its over 30 years ago

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15. Late watching this, Julian. Really enjoyed it – Thank you.

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