Pin layout for a voltage regulator

T

the dipshit

Guest
Hello, I am wondering if anyone knows the pin layout for a l7812acv cc077 v6
march 819 and a l7912acv gk243 vw chn 734. The products where purchased via
newark.com from ST electronics. I checked the datasheets and the three that
I have read all provide different pin layouts. I like to be sure that I get
the pins right before I start pulling from the transformer - it's just a
minor issue but the koreans TL431 datasheet is much different than the ones
that are available to US citizens.

Also I cannot access ``datasheets.com'' or any of those sites do to security
problems that my browser will not pass through (I do not use adobe reader or
internet explorer so I can't OLE the document into the web browser (this was
done by choice on my part)).

I will try and draw a picture of the chips. I will use a convention that
seems to be unknown to most IC design companies - I will label the legs.

The drawing assumes that, like a good plumber, you are staring at the front
of the chip whith the writing eye level so that the chip can be read and
identified without having to roll around on the floor like a jackass - (yes,
I know a quarter turn really doesn't get the air pockets out of the glue,
but the directions say it is a good idea and it seems like one being that I
leaked 100 gallons in my hydroponic system because of a slow leak caused by
bad priming.)




----------------
/ \
| _ |
| | | |
| | | |
| - |
|=--------------=|
| l7812ACV |
| - |
\ /
| |
/ \
| |
| |
| 691 (ST?) |
| 0 |
----------------
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3



----------------
/ \
| _ |
| | | |
| | | |
| - |
|=--------------=|
| l7912ACV |
| - |
\ /
| |
/ \
| |
| |
| 691 (ST?) |
| 0 |
----------------
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3



In the above pictures I will be refering the the vertical string of digits
`1' as pin 1. I will be refering to the vertical string of digits `2' as pin
2. I will refer to the vertical string of digits `3' as pin 3. The casing
will not be refered but assumed to be the conductive metal part on the
backside of the chip and in the drawing topside =--= (just in case ground
goes to emitter or some bullshit like such).


Can some kind sole please tell me what pin 1, pin 2, and pin 3 are in terms
of input, output, and ground; or if I should just throw this junky piece of
shit out. I like using voltage regulators to test my transformers voltage
jump because I don't care if I melt a piece of plastic shit and I also use
them to test the current because I know that the keen senses of the
datasheet droids would never lie or just omit information about the amount
of current that a regulator can withstand over unknown time limits at
uncertain temperature conditions. We all know that they all just pull 1.5
amps with a heat sink and output 1.5 amps over an infinite timespan under
-/+ time / heat fluctuations. Like duh, why don't you just buy a new chip
that does what you want when we can't even get the fucking pin labeling
right on the old chip. I can proudly say that some of my transistors have
the letters `e', `b', and `c' etched into their holding containers (if I
could figure the color codes on the back I'd be really happy).

Sorry for the aggrevated tone, I just lost radio signal and am now being
swamped by transformer hum. I would like to investigate what the fuck
happened. I think it might be my using the lm358 improperly - but who knows
when the control is a piece of marketing propaganda and the variable is the
flucuation of the petro-pegged dollar bill.

I would appreciate emails (this is not like a 44 pin plcc or padded device -
it's just fucking annoying). The problem with email is that my ``new'' cable
company does not seem to send me my email. In order to get my 911 service
and email turned on I must return to them their transponder (like what the
fuck is a transponder and how do I have it? (another question for the
audience ...)).

thanx... sorry for the bad language.
 
On Fri, 12 Sep 2008, the dipshit wrote:

Hello, I am wondering if anyone knows the pin layout for a l7812acv cc077 v6
march 819 and a l7912acv gk243 vw chn 734. The products where purchased via
newark.com from ST electronics. I checked the datasheets and the three that
I have read all provide different pin layouts. I like to be sure that I get
the pins right before I start pulling from the transformer - it's just a
minor issue but the koreans TL431 datasheet is much different than the ones
that are available to US citizens.

The 7812 is a positive regulator, the 7912 is a negative voltage
regulator, and the two never had the same pinout.

If you're looking at both and thinking they are different, that's because
they are.

Assuming they are TO-220 packages (and if not, you should be specifying
it since all the peripheral junk around the basic part number is not
consistent from company to company and may not tell us anything):

7812 7912
----- -----
| | | |
| | | |
I G O G I O

I=input
G=ground
O=output
In both cases, the tab connects to the center pin, which means it's ground
on the 7812 and input on the 7912.

This is the standard method of showing the pins, you will be looking at
the regulators and seeing the part number on the plastic; the tab is
further away from you.

Michael
 
On Fri, 12 Sep 2008 02:33:18 -0400, the dipshit <sgonedes@comcast.net>
wrote:

Hello, I am wondering if anyone knows the pin layout for a l7812acv cc077 v6
march 819 and a l7912acv gk243 vw chn 734. The products where purchased via
newark.com from ST electronics. I checked the datasheets and the three that
I have read all provide different pin layouts. I like to be sure that I get
the pins right before I start pulling from the transformer - it's just a
minor issue but the koreans TL431 datasheet is much different than the ones
that are available to US citizens.
From the National Semiconductor website (they invented the 78xx and
79xx voltage regulators):

The 78xx datasheet is available from
http://www.national.com/JS/searchDocument.do?textfield=lm7812&x=0&y=0
and shows your pin 1 as input, 2 as ground, and 3 as output.

The 79xx datasheet is at http://www.national.com/mpf/LM/LM7912.html ,
and shows pin 1 as ground, 2 as input and 3 as output. (yes, the
positive and negative regulators do have different pinouts)

Other manufacturers will follow the same pinouts, so we can buy parts
from anyone without having to change the board layout.

You can find the genuine ST Electronics datasheets at
http://www.st.com

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
On Fri, 12 Sep 2008 02:33:18 -0400, the dipshit <sgonedes@comcast.net>
wrote:

Hello, I am wondering if anyone knows the pin layout for a l7812acv cc077 v6
march 819 and a l7912acv gk243 vw chn 734. The products where purchased via
newark.com from ST electronics. I checked the datasheets and the three that
I have read all provide different pin layouts. I like to be sure that I get
the pins right before I start pulling from the transformer - it's just a
minor issue but the koreans TL431 datasheet is much different than the ones
that are available to US citizens.

Also I cannot access ``datasheets.com'' or any of those sites do to security
problems that my browser will not pass through (I do not use adobe reader or
internet explorer so I can't OLE the document into the web browser (this was
done by choice on my part)).

A further note: I try to avoid sites such as datasheets.com, instead
going directly to the manufacturer's site - almost all IC makers have
their datasheets online, and most distributors will provide links to
those datasheets. (and if you don't trust the maker's datasheet,
whose will you trust?)


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
On Fri, 12 Sep 2008, ian field wrote:

"the dipshit" <sgonedes@comcast.net> wrote in message
news:868wtx3mc1.fsf@smtp.comcast.net...


Hello, I am wondering if anyone knows the pin layout for a l7812acv cc077
v6
march 819 and a l7912acv gk243 vw chn 734. The products where purchased
via
newark.com from ST electronics. I checked the datasheets and the three
that
I have read all provide different pin layouts. I like to be sure that I
get
the pins right before I start pulling from the transformer - it's just a
minor issue but the koreans TL431 datasheet is much different than the
ones
that are available to US citizens.

As others have pointed out the 78xx and 79xx regulators have different
pinout also the TL431 is an adjustable zener not a voltage regulator.

I missed the bit about the TL431. If he thought all three ICs
were equivalent, no wonder he was puzzled about why the pinouts
were different on each datasheet.

Michael
 
"ian field" <gangprobing.alien@ntlworld.com> writes:

< "the dipshit" <sgonedes@comcast.net> wrote in message
< news:868wtx3mc1.fsf@smtp.comcast.net...

< As others have pointed out the 78xx and 79xx regulators have different
< pinout also

[ ... cut ... ]

I finally got frustrated and blew the damn regulator up. I never seen
something fly that far. Luckily I used one of them heat sinks. Damn thing
gets hot as hell. Must have a fuse inside of it - I wish I could look inside
the case (I dunno all the names for cases, it was probably made of plastic).
I just was doing stupid experiments. (I thought that it was a negative
voltage regulator so I could flip the capacitors around - it seemed to work
but that fuse finally gave way.) I was getting nasty spikes and was annoyed.
Thanks all, for the replies - it's nice to talk to people sometimes...

Anywayz...

< the TL431 is an adjustable zener not a voltage regulator.

How can a zener be adjustable aside of external components and such? Coils
would be inductive (?) and probably dangerous unless encased? Is it like a
crystal of sorts? What's in a zener and them blue diodes (the ``fast switching
diodes'')?

I'd look it up but I'm re-compiling x at the moment, funny thing that xrx
is, and bugging me and I absolutely hate dri/opengl/nvidia/intel91xx at the
moment. dunno what's so bad about CRTs... damn funky pixman-1 and mmx.
(anyone know what the hell is mmx while I'm -a- asking?)

thanks, for the relief...
 
"steve" <sgonedes@comcast.net> wrote in message
news:8663oclnl7.fsf@smtp.comcast.net...
"ian field" <gangprobing.alien@ntlworld.com> writes:

"the dipshit" <sgonedes@comcast.net> wrote in message
news:868wtx3mc1.fsf@smtp.comcast.net...

As others have pointed out the 78xx and 79xx regulators have different
pinout also

[ ... cut ... ]

I finally got frustrated and blew the damn regulator up. I never seen
something fly that far. Luckily I used one of them heat sinks. Damn thing
gets hot as hell. Must have a fuse inside of it - I wish I could look
inside
the case (I dunno all the names for cases, it was probably made of
plastic).
I just was doing stupid experiments. (I thought that it was a negative
voltage regulator so I could flip the capacitors around - it seemed to
work
but that fuse finally gave way.) I was getting nasty spikes and was
annoyed.
Thanks all, for the replies - it's nice to talk to people sometimes...

Anywayz...

the TL431 is an adjustable zener not a voltage regulator.

How can a zener be adjustable aside of external components and such?
The TL431 is known by various names - "adjustable zener" and "adjustable
shunt regulator" being just two of them, in actual fact it is a comparator
with a 100mA sink output and a built in 2.5V reference.
 

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