Power Supply

[kurtlives]

With a growing pedal collection I am tired of using batteries and lame noisy power supplies.

Ok...you get the idea I want to build a power supply unit.

Wants...
Regulation
Filtering
9V DC
12V DC (adjustable from 6V or whatever to 12V)

Here's what I am thinking....Use this transformer https://taweber.powweb.com/store/pdlxfmr.gif . It gives me 10 "supplies". 8 for your standard effects and 2 for the effects that really draw the current .

http://www.smallbearelec.com/Detail.bok?no=339&sfs=3a2f8901 I would then use this for the adjustable 12V DC.

What I need help with is how do I wire the adjustable 12V source? Also what regulator and layout and such should I use for the 9V? And what fuse right after the mains should I use?


Thanks...All suggestions and info welcome...

Chris

[davent]

Hi Chris,

AudioXpress recently did an article on a supply to replace multiple wallwarts. I would think the heatsinks are overkill for the current draw of any pedal you would be plugging in.

http://www.audioxpress.com/magsdirx/ax/addenda/media/tipton2926.pdf

I think i saw a similar project at Geofex.

To create the adjustable supply looking at the aX schematic, you need to replace either R3 or R4 with a pot. Solve the equation, shown under the aX schematic, for an R3 value that will give you 6v out. This would be your fixed resistor value. Now solve the equation to find the (R3+R4) value that will give you 12v out. Subtract the value of R3 from the (R3+R4) value to find the resistance of the pot you need.

Flip the equation around to make it easier to solve;  (R3+R4)= [(Vout*240)/1.25]-240

You will no doubt need to parallel resistors to get the resistor values you need for the 6-12v output.

http://www.fairchildsemi.com/ds/LM/LM317.pdf

Take care
dave

[petemoore]

  RG / GEO / Spyder.
  I didn't use any heat sinks.
  ahhh...floating outputs !! Thanks.
 

[ayayay!]

For what it's worth I just ordered a BBE Supa Charger due to the same wants and needs on your checklist.  They're rather cheap new on Ebay.  No Sag function though. 

[kurtlives]

Thanks...I ordered all the stuff for a power supply from Smallbear on Friday though. Cost me $133

Anyone know of a 9V regulator that can handle 2A?

[ejbasses]

IIRC, the LM350 handles 3 amps. I get mine in the TO-220 package.