am i gonna kill myself trying to do this? seriously? power supply advice sought

[pinkjimiphoton]

i wanna build a power supply unit for a mondo pedalboard i plan on populating.

a friend suggested this, so i ordered it from small bear:



it'll give me 8 separate 11vac taps, and one 9vac tap on the secondary.

so i figure i'll wire it up into a breakout box, which will contain the circuit board and house 16 standard 1/8th inch power jacks with 9vdc regulated and filtered(one pair of power jacks per each tap on the transformer secondary) , and one separate 2.1mm jack to feed the 9vac output to power my digitech whammy.

so i basically laid out this:



on veroboard (below) x 8.





can vero handle 2 amps of current (max)?
each of the 9v taps will be 300ma. the 9vac is gonna just feed it's own jack.

is this gonna be dangerous? it's gonna be hard to keep the wires from the transformer separated when soldering to the veroboard, but
i've built tube amps before and think i'm up to it.

advice appreciated!!!!

for all intents, this is RG's spyder power supply, i think, but with a weber transformer specifically wound for this.

does it NEED to be boxed up? or is it better to let air to it , so it can dissipate heat?

i'm planning on mounting the transformer to the underside of the wood part of the pedal board, and having the wires from the secondarys go to a breakout box that'll be mounted topside.

caveats?

advice?

run, pink, run?

[Earthscum]

advice appreciated!!!!

Don't test the output leads by licking them. Other than that, it's much cleaner than I would do. Just figured I'd throw in that bit of safety advice, since I don't think anyone else will bring it up. Very important to remember. 

[pinkjimiphoton]

heh heh....gonna be hard to keep hippy drool off'n 'em....

so i take it it looks ok to you?

anyone else?

better than advice is humorous advice, so any wise a$$ thing anybody got... lol

[pinkjimiphoton]

fwiw, this is basically what it's gonna be powering...some of the boxes are just placeholders for stuff on my current board..

but, you get the general idea...total, complete, sonic overkill, heavy on the fuzzular...

[Earthscum]

Looking at it, the layout looks good as long as the ends of it aren't connected by gremlins. I would go with a largish cap at the output, too, but that's me and I don't honestly know if it's needed.

Have you looked at R.G.'s Spyder? http://www.geofex.com/article_folders/spyder/spyder.htm I'd follow his layout. As well, I would put a .1uF ceramic paralleled to the 10uF in the Spyder, but as far as I know that's my preference, again.

I really gotta get one of these things built for myself. I have more pedals than most of the guitarists I know, just for my bass... 'cause it's fun. Can you put up a pic with it sitting next to something relevant like a Boss or something when when it comes in? I have been wanting to get a bearing on the size for awhile now. The measurements and actually seeing it are 2 different things to me, lol.

[Mark Hammer]

Just keep in mind that the regulators you're using go pfffffftttt if they pull more than 100ma, though the transformer output feeding them can happily provide 300ma.  So you're going to have to be on your best behaviour with respect to how you use those outputs, or you may be up for a lot of repairs.

Alternatively, use the larger size regulators, that can happily handle 1A, and all will go well.

[pinkjimiphoton]

i already have caps/polarity diodes in most of my pedals, so i think the caps should do the trick, hopefully.

here's a couple pics for ya to see how big it is...sorry, crappy phone pix

[pinkjimiphoton]

Just keep in mind that the regulators you're using go pfffffftttt if they pull more than 100ma, though the transformer output feeding them can happily provide 300ma.  So you're going to have to be on your best behaviour with respect to how you use those outputs, or you may be up for a lot of repairs.

Alternatively, use the larger size regulators, that can happily handle 1A, and all will go well.

<pink waves hands> hi mark, newbe here....

can ya buy me a clue please? i don't THINK anything is gonna draw that much, but better bulletproof then improving my desoldering chops.

what would be a good regulator to use? i don't even really know how t....i dunno what i'm doing.

i CAN assemble stuff, but am often clueless as to what the bits and pieces do still.

appreciate the help!!!

this is what i had ordered from smallbear:    
IC 78L09A
+9 Volt 100 ma. regulator TO-92

if i have to buy others, so be it...these will get used, i'm sure, lol...eventually.

[Earthscum]

here's a couple pics for ya to see how big it is...sorry, crappy phone pix

Thanks a ton, no apologies needed... I have a ME-6 (as well as a DS-1) to compare to... I think the multi gives me the best reference.

@Mark: ya may have just kept me from going with 100mA reg's. I just figured it, and you'd want 100Ohm, 1W resistors in line to the regulator, ugh... 1A is definitely the way to go, isn't it?

[pinkjimiphoton]

hey david, in english?

lol

so,,, it needs resistors added AND different regulators?

i gotta redo the bloody layout? <pink faints>

[pinkjimiphoton]

is this what i need?

http://www.circuitspecialists.com/9-volt-negative-regulator-7809.html

[Keppy]

You need the 7809 +9v regulator, not the 7909 -9v regulator. At least, if you need more than 100 mA.

http://www.smallbearelec.com/Detail.bok?no=464

You might also find these at Radio shack, although I think last time I looked they had the 12v and 5v versions, not the 9v.

[pinkjimiphoton]

hi keppy,

this is what i got from tayda (had to...broke!!)

L7809CV L7809 7809 Voltage Regulator IC 9V 1.5A

positive. looks like the goddess looks out for fools and little children...dodged a bullet!!

thanks!

[Mark Hammer]

You need the 7809 +9v regulator, not the 7909 -9v regulator. At least, if you need more than 100 mA.

http://www.smallbearelec.com/Detail.bok?no=464

You might also find these at Radio shack, although I think last time I looked they had the 12v and 5v versions, not the 9v.

That's what I'm talkin' about.

You don't necessarily need to replace ALL the other regulators with the larger ones, but I think 2 outputs with those ought to be sufficient.  Your analog pedals won't draw more than maybe 20ma a pop.  Many digital effects - and I know you love analog but more and more effects are going that way - are going to draw more than 80-100ma.  If you try and draw more than 100ma ,the transformer will say "Sure thing, Jimi, where do you want me to set up?", but the regulator will say "Is it just me or is it getting awful hot in here?".  If you use the larger regulators for a couple of outputs that you designate for higher-current-draw effects, they will be able to handle the full current of that transformer output without overheating.

As we all learn eventually, one of the tricks to electronics is to only use those things for slo-blo fuses that you want to use for fuses.  

[pinkjimiphoton]

lol...speaking of which, how many amps should the fuse on the primary be?

should i fuse the secondaries, too?

please say no...lol...

[PRR]

DO fuse the primary.

Since you are in 230V land, use a DPST _power_ switch.

Transformer rated output is (2 * 9V*2A) plus (8 * 11V*0.3A) or 63 Watts. Input power may be 20% higher, 76 Watts. 76 Watts divided-by 230V is 0.33 Amps from the wall. With cap-input supply(s) you use a Slo-Blow of twice this size: 0.6A or so. 1A may be fine. The fuse is not to protect from small overloads which may stink the transformer, it protects from dead-shorts which could burn wire and start a fire.

[Ronan]

Might be an idea to build and test just one reg first, to confirm you got all the parts in the right way around. Otherwise you could blow 8 regs in one foul swoop. (Or put all the parts in but only hook up one reg to 11V AC for a test).

[R.G.]

Might be an idea to build and test just one reg first, to confirm you got all the parts in the right way around. Otherwise you could blow 8 regs in one foul swoop. (Or put all the parts in but only hook up one reg to 11V AC for a test).

Oh, sure - do it the smart, effective way!

[R.G.]

... and one separate 2.1mm jack to feed the 9vac output to power my digitech whammy.

You do realize that having 9Vac available on the same size connectors puts 100% of your 9Vdc pedals at risk of being fried if you accidentally plug in 9Vac to one of the DC pedals in a moment of confusion, don't you?

I can't recommend strongly enough to make the 9Vac hard to mix up with the 9Vdc. The pedals you save could be your own.

is this gonna be dangerous? it's gonna be hard to keep the wires from the transformer separated when soldering to the veroboard, but
i've built tube amps before and think i'm up to it.
...
does it NEED to be boxed up? or is it better to let air to it , so it can dissipate heat?

i'm planning on mounting the transformer to the underside of the wood part of the pedal board, and having the wires from the secondarys go to a breakout box that'll be mounted topside.

We really want you with us to keep making music. It is critical for your safety that 100% of the AC power part of this and the transformer be boxed up. Ideally, this would be a metal box, grounded to safety ground. It's marginally acceptable for the transformer secondaries to come outside the box, but it's a fried transformer waiting to happen if something cuts into and shorts a couple of wires.

AC power on a pedalboard is like carrying your pet rattlesnake around. It's interesting and fun, but if it ever sneaks out of some opening, it's going to bite you or someone who's standing near by. There should be no possible way the AC power rattlesnake can get out of the grounded metal box.

[digi2t]

DO fuse the primary.

Since you are in 230V land, use a DPST _power_ switch.

Transformer rated output is (2 * 9V*2A) plus (8 * 11V*0.3A) or 63 Watts. Input power may be 20% higher, 76 Watts. 76 Watts divided-by 230V is 0.33 Amps from the wall. With cap-input supply(s) you use a Slo-Blow of twice this size: 0.6A or so. 1A may be fine. The fuse is not to protect from small overloads which may stink the transformer, it protects from dead-shorts which could burn wire and start a fire.

I was just looking at this again, and I'll second Paul's concern. For safety's sake, PLEASE PLEASE PLEASE, FUSE THE PRIMARY. And not will a piece of foil from your cigarette pack either  .