possibly my dumbest question ever....

[pinkjimiphoton]

so building lectric-fx flintstone flanger. got the board populated last nite, socketed all the chips, and a couple key caps (like where timing is concerned, etc... forget the values, but on a couple things i had to use "next standard value" parts)
anyways, comes down finally to the regulator.

it calls for a 7815l on the build doc, which appears to be one of them little tiny black bug lookin transistor kinda dealios...
i can't find a data sheet on it. thanks for the improvement on the internet, congress...  it looks to be silkscreened like a normal transistor, like say, a 3904 or something.

but all i could find was an l7815cv, which is the "larger" variant with the built in heat sink.
i THINK the pinout is backwards, but cuz i can't find a proper data sheet, i'm a little confused.

the l7815 as far as i can see would simply be reversed 180 degrees, correct? i don't like to socket VR's, it seems like "wiggling" and vibration end up killing them.

sorry for the dumb question. i'm a simple fuzzmonger, usually, so this is one of the first big steps above my paygrade and man, i'd love to make it right on the first swing.

second part of dumb question.. to get all this crap to fit in a 1590d, i'm gonna have to bend the reg over so its not sticking straight up. my question tho, is if i do this, it will be contacting one of the SIP duaal opamps with the heat sink, or at least close (1/16th of an inch or so).... will the heat from the regulator damage the opamp? if so, am i better off to order the 7815l regulator specc'd?

just curious. thanks in advance as always, and hey YOU happy holidays to ya!!

[Scruffie]

The 78L15 is indeed a transistor (TO92) sized regulator, Tayda etc. (Edit, seems Tayda don't have them but they're quite common) should have them but you can use the 7815 if you want, they should go in the same way, if you look at these datasheets;

http://www.futurlec.com/Linear/7815T.shtml

http://www.futurlec.com/Linear/78L15.shtml

You'll see the 7815 is showing the 'Top' view (the flat is the back) and the 78L15 is shown from the underside so you have to mentally rotate it.

The regulator shouldn't get more than warm.

[pinkjimiphoton]

thanks scruff. it may have been from trying to look stuff up in the middle of the nite again, or my own abject mental capacitive poverty too.

but looking at them, it appears the pinout IS reversed, correct?

from the bottom, the 78l15 is , left to right <staring at the pins> output, ground, input
the 7815l in the TO2XX package from the bottom (with the heat sink faceing down)
is left to right input ground output.

sorry to be so we todd ed. brain farted, gotta vapor lock

[pinkjimiphoton]

since we can now add images <yes!!! right on, aron!!!> here's a crummy phone pic

[digi2t]

Love the tank farm on the lower right corner.

[pinkjimiphoton]

dude, this board is STUFFED... holy cow!!

i bought one of them illuminated magnifiers... its a little weird, i gotta still wear glasses and cross my eyes a bit, but MAN!!
i can SEE again enough to be able to do close work like this. this is the most populated board i think i've ever built!

so 10 bux says it won't work when i fire it up

[amptramp]

You can go from a TO-92 (transistor-sized) regulator to a TO-220 (Three leads in line and a heatsink built in) without generating any more heat because the heat dissipation is mainly determined by the load.  If the TO-92 was adequate, the TO-220 should not warm up by more than a few degrees.

[EBK]

i'm a simple fuzzmonger, usually, so this is one of the first big steps above my paygrade and man, i'd love to make it right on the first swing.

That's ok, Jimi! Being formally trained in Electrical Engineering, I know next to squat about fuzz.  I will happily bask in your wisdom on the topic.   

[Scruffie]

thanks scruff. it may have been from trying to look stuff up in the middle of the nite again, or my own abject mental capacitive poverty too.

but looking at them, it appears the pinout IS reversed, correct?

from the bottom, the 78l15 is , left to right <staring at the pins> output, ground, input
the 7815l in the TO2XX package from the bottom (with the heat sink faceing down)
is left to right input ground output.

sorry to be so we todd ed. brain farted, gotta vapor lock

Okay, now i'm getting confused, but I think i'm right in saying the pin out stays the same... imagine you're holding the transistor (78L15) with the legs sticking up, from left to right, it's Out, Gnd, In and then you turn it over to put it in the board and now it's In, Gnd, Out.

When the 7815 says Top view which I take as the 'raised' side of things, it matches up.

Love the tank farm on the lower right corner.

dude, this board is STUFFED... holy cow!!

i bought one of them illuminated magnifiers... its a little weird, i gotta still wear glasses and cross my eyes a bit, but MAN!!
i can SEE again enough to be able to do close work like this. this is the most populated board i think i've ever built!

so 10 bux says it won't work when i fire it up

I'll take that as a compliment we had a tricky time getting it all in a 1590BB package without going to 1/8W resistors.

Any problems with it firing up, let me know.

I gotta know if you're gonna build up the Dandy Horse next Jimi?

[Scruffie]

You can go from a TO-92 (transistor-sized) regulator to a TO-220 (Three leads in line and a heatsink built in) without generating any more heat because the heat dissipation is mainly determined by the load.  If the TO-92 was adequate, the TO-220 should not warm up by more than a few degrees.

Indeed, a LT1054 will only put out about 50mA max if I recall and I think the current drain for this is about 35mA max, so the heatsync might feel body temperature but that's about it.

[pinkjimiphoton]

guys, i'm late to leave for my thursday nite gig, i'll check this tomorrow...

but comparing pinouts, it appears what i have and what is speccd ion the build doc are 180degrees different. i'll post pics tomorrow. pretty sure i'm right..
i see i'm not the only one confused!!
anyways..
rock on my friends. peace!

[Mark Hammer]

This is precisely why I tend to get hold of multiple PDF datasheets for different 3-pin semiconductors.  It is not at all uncommon to look at the pinout diagram on one datasheet and still not be certain.  Some of them include clear 3-D drawings that label everything so the simplest among us can understand them, while others will leave one asking "Is that supposed to be the front of the transistor, or the back?".

[Scruffie]

This is precisely why I tend to get hold of multiple PDF datasheets for different 3-pin semiconductors.  It is not at all uncommon to look at the pinout diagram on one datasheet and still not be certain.  Some of them include clear 3-D drawings that label everything so the simplest among us can understand them, while others will leave one asking "Is that supposed to be the front of the transistor, or the back?".

It wouldn't be the first time I put something in the wrong way based on the datasheet!

But I have a simple solution, I have both package types and a charge pump, i'll try them out on the breadboard tomorrow and give you a definitive answer but i'm 99% sure i'm right (famous last words).

[Beo]

If you aren't 100% sure, then test it out on a breadboard first. Stack a couple of 9v batteries if you don't have a wall wart or power supply >15v. I don't think you would blow it wired backwards, but better to do so on the breadboard than soldered on that pcb. I have that pcb too, but only partially stuffed so far.

[Scruffie]

This is precisely why I tend to get hold of multiple PDF datasheets for different 3-pin semiconductors.  It is not at all uncommon to look at the pinout diagram on one datasheet and still not be certain.  Some of them include clear 3-D drawings that label everything so the simplest among us can understand them, while others will leave one asking "Is that supposed to be the front of the transistor, or the back?".

It wouldn't be the first time I put something in the wrong way based on the datasheet!

But I have a simple solution, I have both package types and a charge pump, i'll try them out on the breadboard tomorrow and give you a definitive answer but i'm 99% sure i'm right (famous last words).

Tested it and I was right, the flat side of the package is the same for both parts regarding pin out.

[pinkjimiphoton]

yeah i believe ya scruffie...  if its the ones tayda sells, that's AWESOME.

but i found a couple discrepancies... check this out


weird, it won't load the other one... if at first, yada yada... sorry, post image is uploading then hanging. its the TO-92 pic in this one

http://www.futurlec.com/Linear/78L15.shtml



the bloody pinouts are opposite, unless i'm mistaken. i'll have to mess with the BB to be sure. usually i'd plug it in... 50/50 chance of being right but this thing was a lot of work and i don't wanna kill it already... gotta play with it a little to let the magick smoke out

ok, looked on the tayda site for a data sheet for THIS PARTICULAR variant...  page 3, TO -220 package
http://www.taydaelectronics.com/datasheets/A-181.pdf

the pins are absolutely reversed from the one specc'd in the build sheet in the TO 92 package



makes me widdle head hurt



the silkscreen below shows the TO92 .... but the one i got i am fairly certain will have to be reversed.




bugger!!! sometimes the stupidest stuff turns into a real head scratcher!! thanks for the help guys!! and the comedic inserts too

[Scruffie]

You are mistaken, I can see where you're going wrong and I don't blame you because it does confuse things but the TO-92 is from the 'Bottom view' So it is upside down in the datasheet picture and if you turn it the 'right way up' it matches the TO-220, both the Tayda & Futurlec TO-220 package are the same pin outs.

The flat side is the same in all cases.

[anotherjim]

To answer.
The TO92 pinout is reversed compared to the TO220... If you're looking at the printed side and legs downward. TO92 input on right. TO220 input on the left.
However, you can put a TO92 to a heatsink (by means of a shaped clip that clamps from the curved side), in which instance the printed side goes flat on the heatsink - that arrangement puts the pinout the same way around as the TO220 would be. That at least is how I figure the reason for the TO92 pinout apparently going the other way around.

[Scruffie]

Yes, if we go by the printed side, they are reversed, I was saying 'the flat side' because they both have a distinct flat side to them and you can see it on the silk screen, flat face = same in both cases.

[R O Tiree]

From OnSemi, Texas Instruments and STMicroElectronics datasheets (they all give the same answers as the ones you found at futurlec and tayda):

TO-92 package (the one that looks like a little black transistor) - flat face towards you, pins downwards and reading left-to-right, they are V_Out, Gnd, V_In.

TO-220 package (the bigger one with the heatsink) - heatsink away from you, pins downwards and reading left-to-right, they are V_In, Gnd, V_Out.

So, I'm with Scruffie and anotherjim - the In/Out pins are reversed between the 2 types.