Ultra Clean Power Supply Project

[NaBo]

ahoy good sirs.  I'm currently drawing the pcb for the ultra clean power
source project from GGG...
http://www.generalguitargadgets.com/index.php?option=content&task=view&id=77&Itemid=106
I'd like to add a few more jacks to it.  I don't think i want to just wire
them together at the jacks like it says i can (daisy chain)... so can i just
add more pads like this? (i'd have to do it this way cuz i have no more
room on this board near this project... i have a dod 250, tube screamer,
and rodent all layed out on it too... im gonna be busy this year )  how
many more jacks can i safely add, and would i need to use a heat sink if i
have, say, 12 jacks total?  anyway, heres my idea, dont laugh if its stupid
and wrong, i dont know anything about electrical engineering... im just a
musician for crap's sake!!!!!

[Hal]

yea, looks good.  Either way, I would heatsink it....its not too intimidating.  The total current you can pull depends on the transformer...effects can pull anywhere from 5 ma to 50 ma, or more, or less....so....be careful, use a DMM to check currnt ratings, and err on the safe side.  

You also don't need to use all those jacks, you can use the boss style "daisy chains," or make your own daisy chains.  Those jacks can get expensive

BGMicro has a good deal on 2.1mm  plugs right now, as well as wall warts - much cheeper than buying the stuff from smallbear (hate to say it)

I just did a similar project....didn't use a design, though.  Good luck :-D

[niftydog]

i want to just wire them together at the jacks like it says i can (daisy chain)

why not? effectively it's the same thing, but a bit easier if you ask me! Infact, if I were doing something like this, I'd just have one big ass track and pad on the PCB, then a hefty wire from the board to the first jack, the from the first jack to the second, 2nd to the 3rd etc etc.

how many more jacks can i safely add

depends on the total current drawn from all of the jacks when it's plugged in to ALL of your pedals.

The transformer does limit the available current, but if you have a decent size transformer the regulator will actually be your limiting factor. (or potentially even the rectifier.)

The LM317 regulator has thermal shutdown, so if it's overheating it will just shut itself off until it cools down. Then you'll know that you'll need a heatsink!

Good practice to heatsink it anyway.

[NaBo]

well i didnt wanna do the daisy chain thing for two reasons...
1. i wasnt 100% how to do it exactly  :oops:
2. i thought the "ultra cleanness" came from the jacks being isolated or
 something... which i took to mean not connected directly to
 eachother... ... ... i just dont want any hum  :oops:

but anyways...



would i do it like that?  how much thicker would the tracks have to be cuz the board is pretty tiny as it is...

... maybe i'd be better off following the directions exactly and just building two or something.  i have only very very basic knowledge of this stuff so i always just build what schematics and parts layouts tell me to.

[niftydog]

the tracks are already pretty thick, and again, it all depends on the current you intend to draw from the supply, which in turn depends on the number and type of pedals you connect.

To daisy chain is simple, take some wire and connect all of the positive pins together, then connect all of the negative pins together.

i thought the "ultra cleanness" came from the jacks being isolated or something

nope, just in it's design.

i just dont want any hum

ah, well, I hate to break it to you, but you could still get hum... and it won't be any fault of the power supply design... check out the other recent threads about ground loops and power supply design.