Isolated Power Supplies

[Aentons]

I don't want to hijack the other PSU thread, so I figured I'd start another.

I have a pedal power 2 and got curious about how the isolation actually works and looked up a pic of the inside. I was surprised to see just one large transformer. I guess I misunderstood the marketing blurb that it "isolates EVERY output" as.... there is a separate transformer for each output.

After closer inspection of their marketing, I see it says... "Pedal Power 2 PLUS uses a custom designed, ultra-low noise toroidal transformer, with separate balanced windings for every output." Which makes more sense. But, out on the interwebs, I see lots of smaller isolation transformers for audio applications and am just curious about the differences in application.

Is this just how VoodooLabs chose to implement their solution, or would there be a difference if you used a separate transformers for each output rather than of separate windings of a single one?

[Muadzin]

Well, this one does look a lot less basic then that PSU pic you posted in the other thread.

[thesmokingman]

I guess I don't see the difference in having isolated secondary windings  on a single transformer core vs individual cores in this application. what they did seems appropriate to me.

[Aentons]

So in theory, Could you isolate the outputs of a 9v daisy chain (like a One Spot) by putting a smaller(cheaper) 1:1 transformer at each output?

What I'm really getting at is that, I'm curious about how the DC JuiceBox works with the P3 phantom power stuff.

It says:
"Convert any 9-volt DC power source into 12-volts DC, 18-volts DC, and variable voltage"
"Converted Outputs are isolated, regulated, filtered, high-current"
http://milbert.com/dcjbx?dcv=1

It seems to be similar to the Gigrig isolator/high current adapters.
Anybody know how this works?


I have the P3 external kit. The "Regulated power supply" has "Quasi-isolated and filtered outputs" with 9v DC 1700mA down the cable. The splitter just has a lowpass filter to the jack.
http://dcvoltage.net/products/p3_xk

What does Quasi-isolated mean?

[SirEgno]

So in theory, Could you isolate the outputs of a 9v daisy chain (like a One Spot) by putting a smaller(cheaper) 1:1 transformer at each output?

Transformers block DC, so I don't think it's possible.
You could use small 1:1 transformers after another transformer to have isolated outputs, but I think it's cheaper order a custom transformer as the voodoo-lab one.

What does Quasi-isolated mean?

Quasi in Italian means almost. In Latin stay for like/as.
I hope they meant the Latin meaning 

[Ben N]

So in theory, Could you isolate the outputs of a 9v daisy chain (like a One Spot) by putting a smaller(cheaper) 1:1 transformer at each output?

Transformers block DC, so I don't think it's possible.
You could use small 1:1 transformers after another transformer to have isolated outputs, but I think it's cheaper order a custom transformer as the voodoo-lab one.

Correct, you can't use a transformer on DC. As for DIY, Weber sells a multi-secondary pedalboard power supply transformer. For other full-isolation solutions, check the Spyder article at Geofex.