Why is NS +12V regulator marked LM2940CT -12 ?
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 |
Why is NS +12V regulator marked LM2940CT -12 ?
On Apr 2, 8:26*am, "N_Cook" 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 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. |
Why is NS +12V regulator marked LM2940CT -12 ?
On Fri, 2 Apr 2010 16:26:31 +0100, "N_Cook" 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 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Why is NS +12V regulator marked LM2940CT -12 ?
Jeff Liebermann wrote in message
... On Fri, 2 Apr 2010 16:26:31 +0100, "N_Cook" 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 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/ |
Why is NS +12V regulator marked LM2940CT -12 ?
In article ,
N_Cook wrote: Jeff Liebermann wrote in message .. . On Fri, 2 Apr 2010 16:26:31 +0100, "N_Cook" 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 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/ 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 Googleproofaddress(account:mzenier provider:eskimo domain:com) |
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