Stupid Transformer Questions

[blearyeyes]

I would like to use this transformer as basis for additional 18v/12v/9v Guitar Pedal power:

R-Core
Dual Primary 115v (0v-115v-SCN) and (0v-115v) with 5 primary wires.
What would SCN stand for?

Secondary #1 is a dual 18v center-tapped (18v-0-18v) with 3 wires
Is there a way to use as two 18v sources or is it only good for split rail / balanced PS?

Secondary #2 (0v-9v) 2 wires
Secondary #3 (0v-9v) 2 wires
Secondary #4 (0v-9v) 2 wires


Any help or references are greatly appreciated!

[Enzo]

A dual primary means two primaries, which can be wired in series or in parallel for 240v or 120v operation. That requires four wires. I'd wager the fifth wire - and the SCN - refer to a screen in the windings.

[The Dude]

SCN is screen and normally should be grounded. It's hard to tell you what to do with the secondary without knowing what exactly you're powering. You can use the two 18V sources separately with separate rectifier circuits.

[Jazz P Bass]

SCN is an International Ground wire designation.

[blearyeyes]

SCN is screen and normally should be grounded. It's hard to tell you what to do with the secondary without knowing what exactly you're powering. You can use the two 18V sources separately with separate rectifier circuits.

I missed you guys!
I have built 12 + guitar pedals since fixing the Marshall Valve State 2000 two years ago? Sheesh!

I just want to rectify and filter multiple outputs from this transformer to power guitar pedals..
9v, 12 volt and 18 vo0lt.

Thank you for your input it is starting to make sense. Any schematics come to mind?

[Dave H]

The 18-0-18V winding with a two diode full wave rectifier will produce about 24V which could be reduced to 18V with a regulator. The 9V windings with a bridge rectifier will produce about 12V which could be used as it is (if the ripple is low enough) or reduced to 9V with a low drop out regulator.

[blearyeyes]

Can the 18v-0v-18v secondary be used as two separate regulated outputs as The Dude said??

[eschertron]

Can the 18v-0v-18v secondary be used as two separate regulated outputs as The Dude said??

if secondaries #2 through #4 (any two, not all three) are not being used for something else, you can find a combination where two windings will stack and give you 18vac.

JM2C but the 18-0-18 aughta be used for a robust full-wave supply, with twice the power of only half the winding. Of course, the supply depends on the load. What current can the windings provide? What do you need to power up? You may be able to find amp draw on the gear you are running, although most stompboxes do not print that info on the pedal itself

[epis]

Can the 18v-0v-18v secondary be used as two separate regulated outputs as The Dude said??

If you meant by separated - isolated ground, you can't without opening transformer (if it's possible) and separate the winding wires from center tap.
Basically you would get two 18V windings.

[The Dude]

If you meant by separated - isolated ground, you can't without opening transformer (if it's possible) and separate the winding wires from center tap.
Basically you would get two 18V windings.

Agreed, if you need isolated grounds. If you are able to have ground common to both supplies, you can certainly have 2 separate supplies. It would make sense to see if power ground and signal ground are isolated in the pedals being powered. If all is common, you won't gain anything, from a grounding standpoint, isolating all supplies.