Pin layout for a voltage regulator

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

  1. 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 f****ng 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 f*ck 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 f****ng 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 f*ck is a transponder and how do I have it? (another question for the audience ...)).

thanx... sorry for the bad language.

Reply to
the dipshit
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From the National Semiconductor website (they invented the 78xx and

79xx voltage regulators):

The 78xx datasheet is available from

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and shows your pin 1 as input, 2 as ground, and 3 as output.

The 79xx datasheet is at

formatting link
, 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

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--
Peter Bennett, VE7CEI   
peterbb4 (at) interchange.ubc.ca   
GPS and NMEA info: http://vancouver-webpages.com/peter 
Vancouver Power Squadron: http://vancouver.powersquadron.ca
Reply to
Peter Bennett

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
Reply to
Peter Bennett

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

Reply to
ian field
< 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...

Reply to
steve

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.

Reply to
ian field

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