Why is NS +12V regulator marked LM2940CT -12 ?

N

N_Cook

Guest
not printed as LM2940CT /12 say.
Any other awkward ones like that, hopefully to lodge in memory, or just a NS
thing.
Not being familiar with that range the 9 in the type number triggers a
mental connection with 79 series negative regs
 
On Apr 2, 8:26 am, "N_Cook" <dive...@tcp.co.uk> wrote:
not printed as LM2940CT /12 say.
Any other awkward ones like that, hopefully to lodge in memory, or just a NS
thing.
Not being familiar with that range the 9 in the type number triggers a
mental connection with 79 series negative regs
Click to expand...
Uh, because that is the part number?
The LM2940 family are low drop out POSITIVE regulators with the
voltage shown as a suffix.
Sure, the 79xx series were the negative regulators of the early
series, but before that they had other numbers such as LM340 [I
think].
Surely you cannot expect that they will avoid vaguely similar numbers
to old devices just because someone MIGHT confuse them for a much
older device numbering? It is also not National's fault that the dash
and the minus sign happen to look very similar.

Neil S.
 
On Fri, 2 Apr 2010 16:26:31 +0100, "N_Cook" <diverse@tcp.co.uk> wrote:

not printed as LM2940CT /12 say.
Any other awkward ones like that, hopefully to lodge in memory, or just a NS
thing.
Not being familiar with that range the 9 in the type number triggers a
mental connection with 79 series negative regs
Click to expand...
Because sometime, back in the days when electricity was being
discovered, decided to recycle the "hyphen" as a "minus" sign, under
the assumption that a "hyphen" would never be used in electronics, and
a "minus" would never be used in typography. The "hyphen" always
appends or prepends a letter, while the "minus" always prepends a
number. That actually worked quite well, until the invention of
electronic part numbers, causing problems as you have noticed. Sorry,
but I don't think lecturing the entire electronics industry on the
proper use of the "hyphen", "dash", and "minus" signs.

The best you can do is that if the symbol is preceded by a space, and
succeeded by a number, it's a minus sign as in -12volts. However, if
proceeded by a character, as in a part number, it's a hyphen. However,
that doesn't help when the laser markings word wrap the part number,
or someone arbitrarily adds a space to improve the appearance.

Note that the hyphen and dash are different:
<http://en.wikipedia.org/wiki/Dash>
<http://en.wikipedia.org/wiki/Hyphen>
<http://en.wikipedia.org/wiki/Minus#Minus_sign>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
Jeff Liebermann <jeffl@cruzio.com> wrote in message
news:dcodr557dgv0ueki1aob7idt0esai9jl3k@4ax.com...
On Fri, 2 Apr 2010 16:26:31 +0100, "N_Cook" <diverse@tcp.co.uk> wrote:

not printed as LM2940CT /12 say.
Any other awkward ones like that, hopefully to lodge in memory, or just a
NS
thing.
Not being familiar with that range the 9 in the type number triggers a
mental connection with 79 series negative regs

Because sometime, back in the days when electricity was being
discovered, decided to recycle the "hyphen" as a "minus" sign, under
the assumption that a "hyphen" would never be used in electronics, and
a "minus" would never be used in typography. The "hyphen" always
appends or prepends a letter, while the "minus" always prepends a
number. That actually worked quite well, until the invention of
electronic part numbers, causing problems as you have noticed. Sorry,
but I don't think lecturing the entire electronics industry on the
proper use of the "hyphen", "dash", and "minus" signs.

The best you can do is that if the symbol is preceded by a space, and
succeeded by a number, it's a minus sign as in -12volts. However, if
proceeded by a character, as in a part number, it's a hyphen. However,
that doesn't help when the laser markings word wrap the part number,
or someone arbitrarily adds a space to improve the appearance.

Note that the hyphen and dash are different:
http://en.wikipedia.org/wiki/Dash
http://en.wikipedia.org/wiki/Hyphen
http://en.wikipedia.org/wiki/Minus#Minus_sign

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Click to expand...

I later found a supplier listing of V regs by , indexed by maker name. Only
NS out of 6 makers adopted, still adopts, the use of the minus sign in some
positive device type numbers. The one that confused me is the wrap around
situation , but I still don't see why they could not have used underscore_
or slash/
 
In article <hp6vbc$dur$1@news.eternal-september.org>,
N_Cook <diverse@tcp.co.uk> wrote:
Jeff Liebermann <jeffl@cruzio.com> wrote in message
news:dcodr557dgv0ueki1aob7idt0esai9jl3k@4ax.com...
On Fri, 2 Apr 2010 16:26:31 +0100, "N_Cook" <diverse@tcp.co.uk> wrote:

not printed as LM2940CT /12 say.
Any other awkward ones like that, hopefully to lodge in memory, or just a
NS
thing.
Not being familiar with that range the 9 in the type number triggers a
mental connection with 79 series negative regs

Because sometime, back in the days when electricity was being
discovered, decided to recycle the "hyphen" as a "minus" sign, under
the assumption that a "hyphen" would never be used in electronics, and
a "minus" would never be used in typography. The "hyphen" always
appends or prepends a letter, while the "minus" always prepends a
number. That actually worked quite well, until the invention of
electronic part numbers, causing problems as you have noticed. Sorry,
but I don't think lecturing the entire electronics industry on the
proper use of the "hyphen", "dash", and "minus" signs.

The best you can do is that if the symbol is preceded by a space, and
succeeded by a number, it's a minus sign as in -12volts. However, if
proceeded by a character, as in a part number, it's a hyphen. However,
that doesn't help when the laser markings word wrap the part number,
or someone arbitrarily adds a space to improve the appearance.

Note that the hyphen and dash are different:
http://en.wikipedia.org/wiki/Dash
http://en.wikipedia.org/wiki/Hyphen
http://en.wikipedia.org/wiki/Minus#Minus_sign

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


I later found a supplier listing of V regs by , indexed by maker name. Only
NS out of 6 makers adopted, still adopts, the use of the minus sign in some
positive device type numbers. The one that confused me is the wrap around
situation , but I still don't see why they could not have used underscore_
or slash/
Click to expand...
Tradition. That's how they numbered both of their LM320 (negative)
and LM340 (positive) parts.

The 78xx and 79xx numbers were Fairchild, orginally.

Mark Zenier mzenier@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)
 
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