Some way to rig up 12v AC?

[jwin615]

If you're looking to generate AC from a DC supply you're going to need an inverter, which is not a trivial thing to design and build. There unfortunately isn't a simple way to "reverse-rectify" DC back into AC. You would be better off modding the device to take a DC input (or paying $20 or so for an AC power supply).

EDIT: I found the one I bought recently, I purchased a 12VAC pedal from overseas and needed a US plug adapter for it. $15 and didn't need to modify anything internally.

Amazon.com

www.amazon.com

Jameco. They're good PSUs. Also, they have LM308Ns in stock currently at 6.25 per for 10.
IMPORTANT EDIT: DONT BUY THE PDIPS. THEYRE FAKE. NOT CERTAIN ON THE CANS.

 

[Bricksnbeatles]

Speaking of 12VAC, anyone have a preferred connector for AC supplies on pedals? Seems like a mistake waiting to happen having an AC power supply with the same 2.1mn barrel connection as an equivalent DC walk wart— I’m careful, but you never know what other people might do in a split second. Seems just having a panel mount IEC connector and a 120-12v step down transformer mounted inside the pedal would be the most sure fire bet, but that would be pretty bulky.

 

[finebyfine]

Speaking of 12VAC, anyone have a preferred connector for AC supplies on pedals? Seems like a mistake waiting to happen having an AC power supply with the same 2.1mn barrel connection as an equivalent DC walk wart— I’m careful, but you never know what other people might do in a split second. Seems just having a panel mount IEC connector and a 120-12v step down transformer mounted inside the pedal would be the most sure fire bet, but that would be pretty bulky.

This isn’t really an answer but if you can get the voltage you need with a dc->dc power module that’s the move IMO. There’s tons out there and they’re not too expensive. I’ve used some +/-15V ones before for big ass split rails. Even with a different size or colored barrel connector, someone will plug in 9vdc

 

[Bricksnbeatles]

This isn’t really an answer but if you can get the voltage you need with a dc->dc power module that’s the move IMO. There’s tons out there and they’re not too expensive. I’ve used some +/-15V ones before for big ass split rails. Even with a different size or colored barrel connector, someone will plug in 9vdc

Was thinking that, but the projects it’s for spec a 12VAC 800mA supply, and the most I’ve seen from a DC-DC converter is 100mA. For some upcoming DEFX projects— there’s two that are 12VAC 800mA, and two that are 16-18VAC 1A, and doing a 2.1mm barrel seems like a fatal flaw waiting to happen. Thought maybe a 2-pin aviation connector could be good, but I need to check what those are rated for.

 

[finebyfine]

Was thinking that, but the projects it’s for spec a 12VAC 800mA supply, and the most I’ve seen from a DC-DC converter is 100mA. For some upcoming DEFX projects— there’s two that are 12VAC 800mA, and two that are 16-18VAC 1A, and doing a 2.1mm barrel seems like a fatal flaw waiting to happen. Thought maybe a 2-pin aviation connector could be good, but I need to check what those are rated for.

Ooph thats a heavy requirement. Aviation connector is where my mind went as well, we use them in some tattoo power supply stuff where they carry 3A (whether rated for it or not, now that I think of it)

 

[Bricksnbeatles]

Ooph thats a heavy requirement. Aviation connector is where my mind went as well, we use them in some tattoo power supply stuff where they carry 3A (whether rated for it or not, now that I think of it)

Just checked. Most 2 pin aviation connectors are rated for 7A/125V. 4 pin are rated at 5A/125V

Definitely more than capable in that case.

 

[JTEX]

I would suggest tiny XLR from Rean. Good for 5A, and 3 pins, so you can have the center tap there. Not expensive, and very secure connection. But then why even bother with AC? Might as well feed it dual rail DC. I wish it were a standard... +-15VDC maybe. Pin 1 ground, pin 2 +, pin 3 -.

 

[vigilante398]

Was thinking that, but the projects it’s for spec a 12VAC 800mA supply, and the most I’ve seen from a DC-DC converter is 100mA. For some upcoming DEFX projects— there’s two that are 12VAC 800mA, and two that are 16-18VAC 1A, and doing a 2.1mm barrel seems like a fatal flaw waiting to happen. Thought maybe a 2-pin aviation connector could be good, but I need to check what those are rated for.

There are plenty of DC-DC converters that can do more than 800mA, you just have to know where to look (and be willing to delve into SMD).

It is also worth noting that the spec for the supply isn't necessarily what the circuit really requires. I have a 12VAC pedal that calls for a 2A supply despite only needing about 350mA. It would not be difficult to design a DC-DC converter to meet the requirements of the circuit.