HOW can I have 9v to 12V(+-) for Ray's Cool LFO Schematic??

[mathflan]

Hi!

I finish to build the Ray's Cool New LFO Schematic.
http://www.musicfromouterspace.com/analogsynth/coolnewlfo.html*
But I'am wondering how can I have 12v power supply.
Can I use a AC adaptater???
If the schematic use AC or DC??
Thanks you of yours answers

[RickL]

You'll need +12vdc and -12vdc. The simplest way is to use a bunch of batteries, 8 x 1.5v batteries for +12v and 8 more, hooked up with the opposite polarity for -12v.

Your other option is to build or buy a +/- 12 volt power supply using one of the schematics available on the net. Or I suppose you could use two 12vdc wall warts, with one hooked up to give -12v.

I think the article assumes you will either build a +/- 12 volt supply or already have one.

[D Wagner]

Hi!

I finish to build the Ray's Cool New LFO Schematic.
http://www.musicfromouterspace.com/analogsynth/coolnewlfo.html*
But I'am wondering how can I have 12v power supply.
Can I use a AC adaptater???
If the schematic use AC or DC??
Thanks you of yours answers

Mathflan,

The schematic requires 12V DC.  Use a 12V AC wallwart and this:

for those who always wonder how to get 2 oppositely polarized voltages out of a non-centre-tapped transformer:



(for larger img., go: http://www.pure-tube-technology.de/DS7.jpg)

I have this on the breadboard right now, and it works beautifully.  

I am not recommending that you do this, but I cracked open a 16VDC wallwart, and removed the rectifying diodes.  I then soldered the leads back to the transformer and sealed up the unit with duct tape.  I marked it on both sides with 16VAC so there are no accidents in the future.  I did this with a 12VDC wallwart, too, but that one had screws holding the case together.

Derek

[mojotron]

Hi!

I finish to build the Ray's Cool New LFO Schematic.
http://www.musicfromouterspace.com/analogsynth/coolnewlfo.html*
But I'am wondering how can I have 12v power supply.
Can I use a AC adaptater???
If the schematic use AC or DC??
Thanks you of yours answers

You might want to use charge pumps to take you form 9v to whatever voltage you needed. The GGG page at:

http://www.generalguitargadgets.com/index.php?option=content&task=view&id=114&Itemid=160
is a good place to find info on charge pumps you can add to a design.

[Nasse]

I have ugly stripboard layout for such dual powersupply as the schem of puretube. I can post it later today or tomorrow if someone is interested. I believe it works ok because did two of them, used a transformer from old mini vacuum cleaner charger, another transformer I bought at flea market.

I have not yet the layout on paper but maybe I could draw it, think I need it myself anyway

[mathflan]

thanks a lot all of you!!

Just an other question:

I built the bipolar voltage converter 9+ 9-
and when I test the ouput voltage when the voltage converter's ciruit is separated to the effet's circuit, I have 18v, but when I solder the + and - on the effect's circuit I have only 1.30v!! (Ve+ - Ve- = 1.30V)

Do you know how it  is possible?

Thanks

[Paul Perry (Frostwave)]

Mathflan, I suppose you have the earth (ground) connected as well?
Excluding that, it might be that there is a short in the effect & too much current is beign sucked, Does the effect work on a pair of 9v batteries?

[Nasse]

My notes from a dual power supply project, I just bought the parts, put them on stripboard (about 18x18 holes) without much brainwork, and it worked. I think there is a fuse or some protecting inside the transformer

Low tech messy drawing done with no brains, unchecked, bad photo (used 7908 and 7808 regulators and 1N4003 diodes)

http://img.photobucket.com/albums/v411/Nasse/unchecked.jpg


Leftover psu, old charger about 12 V AC
http://img.photobucket.com/albums/v411/Nasse/psu3.jpg


Look mother, I designed it so I need no drilling!
http://img.photobucket.com/albums/v411/Nasse/psu2.jpg


Could be cleaned
http://img.photobucket.com/albums/v411/Nasse/psu1.jpg


Last but not least, she is a cat
http://img.photobucket.com/albums/v411/Nasse/kisu.jpg