When I signed up for distance education a decade or two ago they wouldn’t let me use my normal username ‘jj5’ (from memory at three characters it was too short) so I had to pick something else on the spot while I was signing up and in the heat of the moment I picked ‘sixsigma’, mostly as a bit of a joke.
In statistics sigma is the standard deviation, and six sigma with regard to a normal distribution is six standard deviations from the norm which is very very unlikely. It was just me being cute and not particularly humble but at the same time just tongue in cheek.
Anyway. The thing is that I think very very unlikely events/things are cool. Because when they happen they shake everything up. And today a very very unlikely thing happened to me, which in my whole life has never happened before, and will probably never happen ever again:
Today one of the blisters in the blister pack that my medicine comes in didn’t have a tablet in it!
Old Book: Industrial Electronics Reference Book by Electronics Engineers of the Westinghouse Electric Corporation published 1948 with 680 pages.
Today we teardown a homemade continuity tester which I put together for use before I had a multimeter, so that was in the early days of my new lab, circa August 2021.
While I was preparing the links for this blog post I discovered that the plastic case I used for the continuity tester was the HB5610 Black Hand-held Electronic Enclosure from Jaycar. I purchased one of these for AU$9.95 back in August 2021, which was around the time that I made this continuity tester.
I subsequently purchased a ten pack of similar plastic cases from AliExpress for AU$64.55 (inc shipping) in March 2022. I went to find the AliExpress listing so I could link you to it, but it’s an old listing and has been taken down. I did search for an equivalent product but didn’t find what I was looking for. The dimensions are roughly 70mm x 135mm x 24mm and there is a facility for 2x AA batteries built in.
What I say in the video about active vs passive piezoelectric buzzers is correct. The active buzzer will do the buzzing for you, all you need to do is supply some power. The passive buzzer will need an input signal in addition to power, so some sort of oscillator if you want to generate a tone.
I knocked up a schematic for this continuity tester, something like this:
I’m gonna try getting some PCBs made for this circuit from PCBWay, because I’m still trying to learn everything I can about that process!
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I found myself over here today: Timeline of human evolution. It’s striking how recent most of the things we take for normal are, and how different things used to be. I wonder what our future is?
A while back now I had the good fortune to pick up Silicon Chip‘s library of old books. I didn’t get *all* of them, but I did get quite a lot.
I was thinking that as part of my In The Lab With Jay Jay videos, in future, I will tell you about one of these old books during the introduction to the video.
