Re: [CAD_CAM_EDM_DRO] Re: shielding for steppers

In a message dated 24-Nov-01 04:26:07 Central Standard Time, cncnut@...
writes:

> Why, oh why don't motor manufacturer provide screw terminals on the
> motor for cable connection? <<

Peter: They DO on some size-42 and HUGE size-72! Even a 1/2" NPT hole for
screwing-in a Sealtight connector! BIG stuff!

>
> PS What is TTL? <<

Oh, goodie! An "electronics question" even stoopid-I can answer! TTL stands
for "Transistor-[to-]Transistor Logic". That is the "old term" for what is
now mostly referred to as "bipolar logic". Nevermind the triviata of
difference between the two terms meaning the "same" thing (which is not truly
accurate!), but that is now considered a "past generation" of
logic-circuitry. Logic circuitry? I mean the "schematics" of the
micro-silicon stuff on a "chip" down inside an "integrated circuit". (If you
have never popped one or several apart (especially a "dead" microprocessor
IC, or the like) and gawked at it under a 50-power microscope, you have
missed one of the mind-bending pleasures of late-20th C. life!)

"TTL" means the signals in a "logic chip circuit" and between those in
separate IC's pass from Transistor to Transistor, with nothing "in-between"
like diodes, resistors, or capacitors, as is generally the case in audio or
video circuitry, or older "logic". See "RTL". Summa us OLD guys got our
tiny feet wet in "logic" with RTL. Ran on a pair of D cells for hours!
Yeah, there WAS "three-volt logic" before the current Super-Speed logic
craze! It coupled IC's and the transistors inside 'em together via
Resistors. It was "slow" (couple megahurtz, max.) by today's gigem-hurtz
standards, but entertained us hardware-geeks in the mid-sixties, it did!

Shall I go on? "MOS" means Metal Oxide Semiconductor, and "FET" means Field
Effect Transistor (those two are kinda the "same thing", only not; like
above!). CMOS? ComplimentaryMOS. That means you have a Totem Pole of N-
and P- MOS transistors in a "stack", with the DC connected to flow through
BOTH of 'em, depending on whether the "logic state" is "one" or "zero".
Aren't you excited you asked??? If you REALLY wanna know more, and become a
wizard, find Don Lancaster's "CookBook" series in a library or bookstore.
TTL CookBook, and CMOS CookBook. The two most-practical-useful geekery-books
ever printed!

Sorry... I was havin' fun! But all that is real and true! Jan
Rowland


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