Power Supply Project

[nzCdog]

OK here's the pcb design.  Its verified... board is assembled and tested ok... rest of the PSU in under construction now!   The big gap by the IC is to allow for the heatsink...  Build pics once its all finished

(Edit... I have four of these side by side on one PCB for my PSU)

[nzCdog]

Build pics here

nzCdog's disclaimer: Please if you are not 100% sure of what you are doing... DON'T TRY THIS AT HOME!  Wiring with mains voltages is dangerous, you could be SERIOUSLY HURT or KILLED if you don't do this right.  If someone else gets hurt or killed by your work you could also be SUED or GO TO JAIL!  This information is provided for the interest of highly skilled enthusiasts and qualified electrical workers only. Please be careful if you attempt building your own power supply!

[Uglogirl]

Wow, this is right on time. I have been working on an integrated effects board with a built in looper and power supply's. It will incorporate my
homeade pedals, (serendipity, zombii, egodriver, sunking, zygote, macheen, fat&pretty(optocomp), Matchless hotbox,  & maybe a Craig
Anderton tube fuzz (but it needs +- 9v. power. It also has 3 effects that I've removed from their rack enclosures or floor boxes and put under
the 18" x 24" top plate along with the other pedals: a Chandler tube drive, a Roland CE-300 (the rack version of the CE-1) and an old
SAD4096 delay (until I finish building the much better one that I have the art and major parts for). Everything will be driven by a buffer and I
like Anderton's design because it is a splitter too, so I could say, send a totally clean signal straight to a mixing board. I'll also probably build
in several points where I can take a separate line out and an ABY since I often gig with two amps.
Also along the top behind the main board there is room for the three commercial pedals I don't want to remove from their enclosures but which
I'll incorporate into the looper: a 1980 ADA flanger, an early (white, non-pedal) Fuller Dejavibe, and a 1998 Fulldrive.  They just fit across the
top and will be bolted down firmly.
Everything goes through the looper so the homeade effects are housed in cheap electrical contracters boxes ($1-$2) and don't require stomp
switches, jacks, etc. since those are all part of the looper. The boards are relatively small so I can easily fit 2 or three to a box.
I guess it seems like I have a lot of overdrive pedals but I've been gigging for 25 years and one things I've learned is 1) you can't have too
many overdrive/fistortion/fuzz pedals 2) diferent pedals sound good or bad with different amps/guitars. For instance, the Fulldrive sounds
great with my Deluxe Reverb but not as good with my JCM800 while the Chandler tube driver is just the opposite - just kills through a
Marshall but is just buzz through Fenders.

Right now I am sorting out my power supply problems.  I have a +-15V. supply for the opto-comp, two more boards to supply bipolar power
to anything, like Anderton designs (I have etching art for his splitter/buffer that uses a 5532 instead of the weird 14 pin opamp he used on
everything which can no longer be found). For the remaining +9 boards I think I'd like to use a  design like in this  thread - I'll put 8 of the
boards together and use them with the Weber 8 out Xformer I ordered.  I'll have to double up a few outputs but since they are 300MA. there
won't be a problem,  I built the slant enclosure for the pedals/looper with a 7" wide ledge at the rear to build the power supply's on and it can be
sheilded easily.

My main problem is doing the computer work to make the etching art. I can't even paste eight of them together to make one board in my
drawing program, Gimp!

My name is Kiira BTW and I kinda started learning things backward. I was tired of lugging my 100 Watt heads to the shop to get repairs done
so I got the idea to try and learn how to repair them myself. Gradually (ESP. after the WWW came along  and all these really great people
started teaching me stuff) I learned how to build my own amps from schematics, do mods, build tube studio gear, and even do some designing.
Now I've gotten around to learning how to build my own pedals. I've done the opto-comp (etched the board) and the first 3 boards I got from
Madbean. a zombii, egodriver and poindexter.  I purchased 3 more discontinued boards from one of the members here, a sunking, zygote and
Macheen.  This forum seems to be the best around.

uglogirl

PS - Weber sells a kit with the multi-tapped output Xformer and four rectifier boards for $30 and you can order additional boards - 4 more
would be $20.  Seems like a good deal to me.

[nzCdog]

Hey Kiira, welcome to the forum!  I use GIMP too, its great software

[djaaz]

Maybe a silly question but why use a 317 instead of a basic 7809?

I just don't get it.

[nzCdog]

Hey djaaz... no not a silly question,  this power supply using the LM317T gives the option of any voltage output...  not just 9V like the 7809.  You can adjust the Volts using the trimmer

[djaaz]

I did not see the trimmer on the schematic, sorry! I was looking at the layout and my eyes went just through R2 and just saw a resistor.

I'm looking at building a regulated power supply since i'm having so much troubles with noises in my delay build but i'm kind of puzzled by the simplicity of the schematic i find.

Basic rectifier, two caps & a regulator. Can't see how the wall warts i'm using with much more complicated schematic can't nail it.

The filtering thing i've seen are all based on playing with the caps values. I've seen some article in which an inductor was used but could not figure out how it could make any difference.

Guess i just need to try.

[nzCdog]

Perhaps if your delay is causing a problem, you should check that out first? Check the wiring, maybe add another filter etc?

Mine is a reasonably simple design, but its important to remember that the PCB is only part of the whole power supply.  Lots of factors other than the schematic contribute to the performance of the power supply... eg: mine is mounted in an earthed metal chassis, has RFI filtration in the IEC socket (those inductors), uses an ultra Clean 'R-Core' type transformer, has all outputs isolated, uses good wiring and construction methods... etc etc... even capacitor materials plays a factor in performance would you beleive!  I found geofex interesting, googled hifi power supplies, and even found this datasheet on the LM317T quite good reading...  Good luck

[aballen]

Hey guys I'm working on a power supply myself right now I though I would share.  I'm using the weber transformer listed in the spyder docs.  If you guys have any feedback let me know, I can tweak it.  It should produce.

• 8 9v DC outs up to 300ma
• 1 9 v AC out up to 2A
• All outputs are completely isolated

I have the transformer, I just need a few more 7809s.

Circuit


Layout(already mirrored for etching)


I have to ask, what is the rationale behind putting a 1000 uf cap in each circuit?  It was suggested to me on another forum, and I see it here as well, but the 780* datasheet suggests .33 and .1 uf.  I provided space for a 220, and a 100 max.  I am planning on a 100, and 10... these should be plenty big for ripple protection right?

[irmcdermott]

You don't need to mirror your entire layout for etching, otherwise it will be backwards when you go to lay it out. All you have to mirror is any text or logo you want to have on the bottom of the board.

When you print it out not mirrored and then transfer it to the copper clad, it mirrors (on the bottom of the board), then when you flip it over to start putting your components through the top, it lays out just the way it printed out originally (not mirrored). Does that make sense?

Great layout, by the way!

Ian

[aballen]

Ian thanks for the feedback.  Can you explain the 1000uf caps in some designs?  I don't really have the space, and the 780x data sheet suggest tiny caps 1 if on the supply side and .3uf on the jack side.  I'll put thEm in m design if they are actually needed, but I don't see why they are.

Again I D thinking a 100uf and a 10uf, but even those seem like overkill for ripple protection

[Willybomb]

Well, although the Cioks AC10 is exactly what I need (bunch of 9vdc, and a 16vac) it's way too expensive for me to currently (ha!) justify.

I've got a bug to build a suitable PS for my board but I'm trying to work out what's required for the AC output beyond a suitable transformer (my googlefu must be weak) ...  I imagine I can get a multi-tapped tranny with 16vac or close enough with and a few 9vac outs to rectify to DC.

Would this one of these be ok as a starting point?
http://www.jaycar.com.au/productView.asp?ID=MM2008
http://www.jaycar.com.au/productView.asp?ID=MM2002

As far as the 16vAC output goes, does it need to be filtered, smoothed, or anything like that, or can I just hook it up directly to/from the proper tranny output, and is 15vac going to be close enough for my 16vac blackstar?

There's heaps on the web about building DC supplies, but not so much about the AC-AC side of things...

[destro]

I was wondering the same thing with regards to the 9vac on the weber.

As far as the 16vAC output goes, does it need to be filtered, smoothed, or anything like that, or can I just hook it up directly to/from the proper tranny output, and is 15vac going to be close enough for my 16vac blackstar?

[Willybomb]

Well, I don't know about the weber, but I just pulled apart my spare Blackstar PS (I got the HT-Dual in the UK, and while the UK ps worked fine in Australia with an adapter plug - same voltages - I decided I wanted a native plugged ps, hence the spare) and there's nothing inside the wart except the transformer between the wall and the pedal beyond a 3A fuse in the wall plug.

So, now I have a 240vac -> 16vac 800mA transformer that could be used in a PS project.  It has no secondary outs though so how would I go about getting 16VAC and a couple (or single - I'm happy to daisy chain) of 9VDC outputs off it?  Can't be that hard, surely?

Alternatively, now I know the AC-AC path is straight wall-pedal, so I can probably just use one of the trannies I posted earlier.

[jubal81]

I was looking into super capacitors today. There are charging control chips that probably make it possible to alternate charge a pair of them so you could make a power supply that essentially powers from mains, but runs your pedals off 'batteries'.

Might be crazy or crazy expensive, but it's got me curious.

EDIT:
Just found this video:
http://www.youtube.com/watch?v=shky9wfpfoc