Category: Office Tech

I have aways sort of vaguely assumed that at some point in my youth I must have sat in a class in which the teacher made a potato battery and used it to light up a light bulb.  Recently I got it into my head that it might be interesting to reconstruct that old classroom demonstration.  But events of the past few days, recounted in this blog article, make me think that the old classroom demonstration must have never actually happened.  I must have just read about it in books and I must have sort of assumed that you could do, in real life, anything that is described in a book.  After many false starts, I did eventually manage to light up a light with a potato battery.  Continue reading “quantum physics and potato batteries”

Loyal readers will recall that recently I did a large number of test welds to measure welding currents generated by my new inexpensive stick welder (blog article).  I had been using my smart phone to log real-time current measurements via Bluetooth from a clamp-on DC ammeter (blog article).  Part way through the large number of test welds, I was astonished to see that my smart phone had powered itself down.  I tapped the power button and coaxed the phone back to life and completed my current logging activities, and eventually figured out why the phone had so mysteriously and abruptly powered itself off.  A tiny bit of hot steel from one of my test welds had flown several feet and had landed on the glass screen of the phone, and had melted a small crater in the glass.  You can see the crater, which is less than one-fourth of a millimeter in diameter, in the photomicrograph above.  After about a day, cracks had traveled from this crater across the full expanse of the glass.  I realized I would need to learn how to replace the screen.  This blog article describes it.  Continue reading “Replacing a screen of a smart phone”

As we know, the “springing forward” of clocks for Daylight Saving Time happens at about 2AM. This “radio controlled” wristwatch does the DST adjustments automatically. I happened to be awake when it happened just now, and you can see a video recording of the automatic adjustment carried out by this wristwatch.

Continue reading “Watch an automatic time change!”

 

This blog article talks about using an automation controller to keep a server room from getting too hot.  Continue reading “Cooling a server room”

The implicit promise made by the maker of an RCA cable is that its center conductor is shielded by its outer conductor.  I have, however, been astonished in recent times to see that many RCA cables are not shielded at all.  Continue reading “Shielded and yet not shielded”

It will be recalled (blog article) that I had recently started getting familiar with an inexpensive inverter welder.  What became pretty clear early on is that the number in the display does not match the number of amperes of welding current delivered to the welding rod. Alert reader Dave posted a comment:

Can you accurately anticipate what amperage to expect given the readout on the machines as a ratio to the readings you have gotten on the ammeter? Perhaps this is an opportunity to do some more experimentation…

Prompted by alert reader Dave, I did some more measurements.  Here are the results.

Continue reading “Welding current redux”

(followup:  I have now measured more welding currents — blog article)

It will be recalled (blog article) that I recently took a stick-welding course.  I also recently purchased an inexpensive inverter-type welding machine (shown at right), and a neighbor of mine also purchased an inexpensive inverter-type welding machine.

Each welding machine has a rotary knob for picking the welding current.  And each welding machine has a three-digit numerical display.  The question that arose for my neighbor and me was, can we safely assume that the number in the display will be the number of amperes of actual welding current?  The answer turned out to be “no”.  Continue reading “Measuring welding currents”

Readers of this blog are already aware that I enjoyed the movie Glass Onion (blog article), from writer/director Rian Johnson.   At about the time that Glass Onion became available for streaming, it came out that Johnson had just gotten done creating, writing, and directing a ten-episode television series Poker Face (Wikipedia article).  I have greatly enjoyed all five episodes of Poker Face that have aired thus far.

Which brings us to episode four of Poker Face, entitled Rest in Metal.  This episode has a plot element called a “Death Capacitor”.  Which is what I will now discuss. Continue reading “Death capacitors”

The executive summary for this blog article is that ethernet is faster than 5-gigahertz wifi, and 5-gigahertz wifi is faster than 2.4-gigahertz wifi. (I imagine that most readers of this blog already expected this to be the case.) Continue reading “Choosing a LAN type”

It turns out that anybody who wants to, can publish things on SSRN (Wikipedia article).  SSRN, it will be recalled, is an initialism for Social Science Research Network (web site).  To test this out, I created an account at SSRN and uploaded The Fool’s Errand that is DOCX.  You can see it here:  https://ssrn.com/abstract=4346907.  This blog article describes the process and the results.  Continue reading “Publishing things on SSRN!”