Watch Loupe

This morning my new eyeglasses arrived, they are these ones from AliExpress: Watch Loupe Glasses Magnifying Repair Tool Loop Magnifiers Watchmaker Jewelry Jewelers Magnifier Foreye Convenient Professional.

Rather than do an unboxing video I thought I’d just write it up in this blog post.

There’s a headband type thing that comes with them that looks rather cheap and flimsy (it is), but it’s actually quite functional and practical.

The 20X magnification is my fav, and I might even see if I can get something with higher magnification one day.

John's new eyeglasses

The headband that goes with the eyeglasses

The Problems of Philosophy, further reading

At the end of The Problems of Philosophy, Bertrand Russell says:

The student who wishes to acquire an elementary knowledge of
philosophy will find it both easier and more profitable to read some
of the works of the great philosophers than to attempt to derive an
all-round view from handbooks. The following are specially

AliExpress diodes

I ordered a bunch of SMD diodes from AliExpress (nine different types), and nine packages arrived, but they weren’t labeled. I tested everything to infer what I got, and they didn’t ship me what I ordered. My notes are here and the video of me doing all this is here.

I kept a note of the seller and will try to not order from them again. In the mean time I think I have filed the components that did arrive in the correct drawer.

Below are two happy snaps from this project. I guess on the bright side I got some practice doing SMD soldering and using my signal generator and my scope.

Oh, and I added a new item to my debugging notes, viz “is it plugged into the right socket?” (I had my output cable on the signal generator plugged into the wrong BNC connector on the device, that took some figuring out…)

John's test rig

John's test rig, labeled

Switching diodes and rectifying diodes

I had an envelope full of SMD diodes arrive today. Three different types in three different sizes, so nine bundles. Unlabeled!

I’m not sure what they were thinking at the shop. I got them from here.

I managed to figure out that the ones marked ‘S4’ were the Schottky diodes (1N5819WS). I think the ones labeled ‘T4’ are the switching diodes (1N4148WS) and the ones labeled ‘T7’ and ‘A7’ are the rectifying diodes (1N4007), but I’m not sure of that yet.

I asked ChatGPT for help and it explained how I can devise a test circuit, so that’s on my TODO list for tomorrow.