Replacing a screen of a smart phone

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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”

Welding current redux

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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”

Measuring welding currents

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(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”

Death capacitors

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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”

Publishing things on SSRN!

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:  This blog article describes the process and the results.  Continue reading “Publishing things on SSRN!”