regarding powering multiple parts of a circuit

[almondcity]

As an ongoing work on my XLR looper, I'd like to include a preamp inside which requires +48V power. Let's say the rest of the circuit requires +/- 12V, and I'd also like to include a pedal effect which would take +12V. Is the diagram I've drawn below feasible? Is 48 to 12 V too much of a voltage drop, will there be thermal considerations (the part # I've included seems to be able to handle this)? Should I use a simple voltage divider instead, or a combination of both (divide 48 to a lower number and use the standard LM7812 regulator)?



Here is the proposed regulator: Mouser link

 

[JTEX]

Why not use a DC-DC module instead of a linear regulator followed by charge pump? 48V in, +/-12V out. There are plenty to choose from:

Power Supplies - Board Mount | DC DC Converters | DigiKey Electronics

DC DC Converters are in stock at DigiKey. Order Now! Power Supplies - Board Mount ship same day

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[almondcity]

Why not use a DC-DC module instead of a linear regulator followed by charge pump? 48V in, +/-12V out. There are plenty to choose from:

Power Supplies - Board Mount | DC DC Converters | DigiKey Electronics

DC DC Converters are in stock at DigiKey. Order Now! Power Supplies - Board Mount ship same day

www.digikey.ca

Simply because I didn't know these existed. Thanks!

 

[Stickman393]

What's the power source?

If you're looking at using phantom power from a mixer, that's typically got a cap of 240mW.

If that's the case, you'll have a total of 5mA to play with.

If it's powered independently, no problem.

 

[JTEX]

On further reflection, I'd have to say that I wouldn't want to feed the pedal 48V. That would be a pretty unusual power supply that you definitely don't want to accidentally plug into anything else. Instead, I'd probably go in 9V or 12V and make the -12V (or -9V?) and the 48V from that. Does it really need +-12V? What's wrong with +/-9 in a pedal?

 

[almondcity]

So, I've built a THAT Mic Pre for which I have a 48V power adaptor. I'd like to make a new box that includes this preamp, then takes that signal straight into a balanced line receiver, sends it to a pedal circuit at 9 or 12V, then goes back to a balanced line driver and sends it to an XLR out. The receiver and driver chips I've run on 9V and seem to be fine, although the color palette uses them at +/-16V, I imagine for a slight audio improvement? I figured I would just compromise and use 12V for everything past the mic pre. Forgive my ignorance here.

 

[JTEX]

Oh, ok, if you're already using 48V as the main supply, it makes sense to DC-DC it to +/-12 for other stuff.

 

[almondcity]

I have one more question, does the "Common" pin on a device like this typically mean it connects to Ground?

datasheet

 

[Stickman393]

Looks to me like "common" is meant to be the middle point between v+ and v-.

It can be connected to ground, or it can be left floating. This decision would need to be determined by the circuit.