A long time ago I had a lot of fun building electronic gadgets. There were many articles about
building all sorts of fun things, up to and including computers. I had a lot of fun assembling
Heathkit stuff. My first Heathkit computer had an awesome 30 MB hard disk. Most of the kits
they were selling at the time had only two small floppies.
Disappointing that there is so little about hobby electronics on the Internet.
What started me off on this rant was getting up in the dark, and having triac controlled light switch
because of hysteresis coming on bright enough to be unpleasant to my dark-adapted eyes.
I'll bet few members know what a triac is, or what hysteresis is. The dictionary isn't much help,
it doesn't even list "triac", and its definition of hysteresis doesn't help in understanding the
problem with the light. And I've forgotten too much to explain it well, even if I had ability to draw
diagrqram in this post.
hysteresis
n.
5ModL < Gr hystercsis, a deficiency < hysterein, to be behind, come short < hysteros, later, behind < IE *udteros, compar. of base *ud3, up > OUT6 Physics a lag of effect when the forces acting on a body are changed, as a lag in magnetization (magnetic hysteresis) of a ferromagnetic substance when the magnetizing force is changed
hys#ter[et$ic 73et4ik8
adj.

One year we had a young woman who was getting a singing group together for the Ithaca Festival. She picked up singers from many local groups, but, since she didn't want female tenors, she had to make the female tenors into altos. This left her with a fairly small tenor section, so she had some of us baritones switch to tenor. I was one of her ad hoc tenors but I had to switch to falsetto for some of the higher passages. In the process I noticed that my crossover point was higher on the way up than it was on the way down. That is, while I could sing up to (say) a middle C in chest voice before I had to switch to falsetto, if I were in falsetto, I could make it down to maybe an A below middle C before I had to switch back to chest voice. I commented to her that I had hysteresis in my voice. When she said that she didn't understand what I meant (I am used to this which is why I indulge so often in exegesis) someone else commented that I meant that when I was singing my throat heated up.

Dear Faldage: at least it wasn't your "womb wandering" which was ancient theory of
causation of "hysteria" in emotionally disturbed women.

Yeah, I was trying to figure out where uteruses came into this. I still can't figure out the connection between hysteresis and wombs. Apropos of hysteria, I suggested to my sister that if women could be described as hysterical, with that particular organ being to blame, then perhaps men who are being unreasonable (they can be, you know. I have one at home and have to deal with this) can be described as testical.

I'm sure I could comment on hysteresis under normal circumstances (since it's an oft-used word in physics) but I've now realized the whole "how to write the number one" discussion on Q&A has about worn-out my explaining circuits for the day. Maybe tomorrow, if no one else can help you out, Dr. Bill.

testical.

Or either scrotal, one. Or testy?

I went bartlebying after the relation betwixt hysteresis and hysteria and it seems it ain't there. The Greek words are husteros and hustera, respectively. The one means late and the other womb.

Dear b8rdfeed: men may be irritable and impatient = "testy" but that seems to be a problem
with their "tête" not their testicles.

Dear Bean: I'm sure you could explain the problem with the dimmer switch better than I could.

testy
adj.
3ti[er, 3ti[est 5ME testif < Anglo-Fr < OFr teste, the head < L testa: see TEST16 irritable; touchy; peevish
tes4ti[ly
adv.
tes4ti[ness
n.

Disappointing that there is so little about hobby electronics on the Internet.

You surprise me, Dr. Bill. I found several hundred pages on various subjects of electrics and electronics. Here's but one of them:

http://www.amasci.com/amateur/elehob.html

Several Universities have educational web pages on basic through advanced electronics. Most of the necessary components can be bought easily or rehashed from old household items.

I look forward to my retirement in 2033 when I can find the time to try some of this out....

WW, I love your mind!

Dear Rubrick: YOUR URL is far better than any I could find. But I challenge you to find
in your site a diagram of a dimmer switch, showing a triac, and an explanation of
hysteresis. I am quite sure many members of AWADtalk have such dimmer switches, but
no idea how they work.

Quite a challenge, Dr. Bill. Give me five minutes.

Here's the diagram of the dimmer switch (including the TRIAC) http://www.geocities.com/tjacodesign/dimmer/dimmer.html

and here's the explanation of hysteresis: http://www.lassp.cornell.edu/sethna/hysteresis/WhatIsHysteresis.html

3:47 (!)

Dear Rubrick: Joke on me. I searched again, and had happy thought to search for "dimmer switch"
and found a site describing a triac, and showing a circuit.
http://www.howstuffworks.com/dimmer-switch3.htm
My faith in Internet is restored; thanks to your demonstration that my previous search was not
properly conceived. Bill

a rope with some slag in it one which you jerk, and the energy of the jerk works through the slag, and then the object attached at the other end finally moves?

From the Dictionary of English slang:

Slag: Noun. 1. A prostitute or promiscuous woman. Derog.

They told us about standing Waves on a transmission line in electronics school in the Navy, but this is something else altogether different.

I liked Rubrick's link explaining hysteresis. It does a good job of explaining it. A "hysteresis loop" is what I was thinking of when I first read it, where if you perform an action, and the perform its opposite, you don't end up where you started, because of hysteresis.

Imagine dragging a reasonably obedient dog around by a 6' leash, and that you start with the dog 6' to your left. First you walk him 20 feet to the right. This means, because of the leash, he's only moved 14 feet to the right. Then you go back to where you started, 20 feet to the left. Buddy the dog is still going to be 6' to your right when you finish, because his rule is "always walk behind my owner at the full length of the leash". So although you have taken yourself exactly back to where you started, because of some lag in the system (where the system = you + Buddy the dog), the whole thing is not quite back to its initial state.

And of course, you can think of ways to imagine this problem where you do both end up in the original state, but there are also many starting points, combined with the "lag" produced by the rope and the fact that this obedient little dog only trails behind you , where you don't both end up in the same position. Does that make sense?

Slag used to be of considerable value in the old days when limestone was added to charge
of an iron smelting furnace. The slag could be ground and used as very serviceable cement,
in spite of its unattractive color. With the new basic oxygen process, I don't know what
the slag is like.
Damned if I can think of a way that slag should become slang for sex industry person.

Yes, things are getting pretty slack around here.

Dear Rubrick: my search was slack, yours was slick. My congratulations and gratitude, Sir.