On Sunday, 26 January 2020 17:37:29 UTC, Johnny B Good wrote:
On Sun, 26 Jan 2020 12:33:25 +0000, Chris Hogg wrote:

On Sun, 26 Jan 2020 03:52:27 -0800 (PST), harry
wrote:

====snip====

The activity series. The further they are apart, the faster any
reaction.

https://en.wikipedia.org/wiki/
Reactivity_series#Comparison_with_standard_electro de_potentials

From school chemistry of sixty years ago: Kate Now Can Make All Zebras
File Slowly Past Her Clucking Hens After All

Potassium, Sodium (Na), Calcium, Magnesium, Aluminium, Zinc, Iron (Fe),
Tin (Sn), Lead (Pb), Hydrogen, Copper (Cu), Mercury (Hg), Silver (Ag),
gold (Au).

The earlier ones in the sequence dissolve before the later ones.

It's extraordinary how these meaningless phrases stick in the mind, even
after all this time.

That's the whole point - they're meant to be easier to remember
mnemonics.

I taught myself the resistor colour code during my very early teens
(perhaps just before - it WAS a long time ago now) by simply using the
actual colour sequence of "Black, brown, red, orange, yellow, green,
blue, violet, grey, white." for the 0 to 9 digit sequence. It was only a
decade or so later that I was taught the (NOW!) non PC mnemonic[1] of:

"Black boys rape our young girls but virgins go without." which I was
only able to recall with the aid of the (by then) well ingrained colour
sequence I'd taught myself years earlier - I was using actual knowledge
of the colour code as an aid to remembering a mnemonic intended as an
aide mémoire for recalling the colour code sequence!

These days, after over half a century, I'm glad I bothered to learn that
non PC mnemonic since it provided a sanity check for my recollection of
the colour code sequence when I resumed my interest in DIY electronics
projects nearly two years ago after a quarter of a century break - "Use
it or lose it!" is ever so applicable in this case.

Another phrase I can't forget (I don't think this is a mnemonic so much
as a reminder to be careful) is the "Electrician's Litany" of:

"Ashes to ashes, dust to dust, positive to negative, **** or bust!"

that I heard one of our EL&P engineers utter. I'd heard it perhaps just
two or three times but an amusing enough 'ditty' for me to take the
trouble to remember it - I was more easily amused back then.

[1] I'd heard or read of other less non PC colour code mnemonics since
then but one mnemonic was all I needed or ever wanted. Any others would
have just confused things and be counterproductive to their intended
purpose.


Resistor colours.
Richard Of York Gave Battle In Vain