9vdc to 48vdc step up converter advice?

[iandy4]

Hey Guys,
I'm making a phantom supply for a pedal that I'm prototyping.  I have a working design based off of the info I got in this thread, http://www.diyaudio.com/forums/power-supplies/187737-would-work-15vac-12vdc-24vdc.html#post2558928.  The phantom power works just fine but it took more components to build the power supply than the pedal itself as people in the thread mentioned might be the case.  I just didn't realize HOW big it would end up being.

I was hoping somebody could point me in the right direction for how to step up the voltage using a booster converter.  I've been doing research and it seems like a boost converter chips (like the MAX668) are the right way to go for their size and efficiency.  Can someone verify that? or suggest a better chip to start with?  The other thing is I see that you have to use external components to set the output voltage.  If it was just resistors I think I could figure it out but I see its more complicated than that. Does anyone know of a schematic floating around that already goes from 9vdc to 48vdc using a boost converter? or does anyone know of a good resource explaining how to find the right values for the external components of a boost chip?  Any help would be greatly appreciated!

[slacker]

Have a look here, http://www.geofex.com/circuits/+9_to_33.htm you can add more stages to get higher voltages, people here have got up to a 100 volts if I remember correctly.

You could also have a look here http://www.electro-music.com/forum/viewtopic.php?t=47666 the schematic linked to has voltage multiplier using an opamp to get phantom power.

[iandy4]

Have a look here, http://www.geofex.com/circuits/+9_to_33.htm you can add more stages to get higher voltages, people here have got up to a 100 volts if I remember correctly.

You could also have a look here http://www.electro-music.com/forum/viewtopic.php?t=47666 the schematic linked to has voltage multiplier using an opamp to get phantom power.

Hey Ian, Thanks! The first link is definitely intriguing.

[frequencycentral]

http://www.diystompboxes.com/smfforum/index.php?topic=74088.msg738236#msg738236

[iccaros]

how high do you want to get, a transformer on ac can go both ways, so a 12V ac plug with a transformer ,

like the
Toroidal Power transformer
Used to power tube pedals.
12 volts AC input produces a B+ of about 240 VDC when under load. or 120 using one half
Use the AC Wall wart below to power this transformer.
Size is 40mm x 40mm x 19mm high.
Note: Use 12 volts AC, not DC to power this tranny.
This tranny has PC style mounting pins but you can also solder wires to the pins for non PC hookups.
See the tube pedal project on the library page for usage tips and hookup diagrams.
See my chassis page for the tube pedal chassis.
Price each = $23.00

http://www.hoffmanamps.com/MyStore/perlshop.cgi?action=template&thispage=Transformers&ORDER_ID=274142820