Q: Use a DC power jack with AC

[burningman]

This is probably an obvious one but is it advisable to use a DC jack with an AC supply? Obviously circuitry would have to include rectifier/filtering/regulation, but aside from that would the jack itself or my circuit suffer from using a jack that has been rated as accepting volts DC as opposed to AC?
Thanks.

[R.G.]

There is one screamingly important issue. Many DC jacks have a metal barrel which contacts the outer sleeve of the plug to the enclosure which the jack is mounted in. This will cause you major grief. A DC jack that is isolated from the chassis is fine if you watch what you're doing with the wires coming out.

Another thing is the problem of laying a trap for yourself. If you have the same size jack and expect to get DC in some of them and AC in others you will absolutely, 100% surely put the wrong plug in one day. Or someone who doesn't know what you've wired up will do it for you. Be sure that this is a non-fatal incident to your circuits or don't lay the trap for yourself.

[MoltenVoltage]

The typical rectangular DC and AC jacks look identical but the center pin is wider on the AC ones so you can't plug a standard DC connector in.

I would highly recommend sticking with that protocol.

I also agree that you need to think about other users of the pedal that could hurt themselves down the road, so NO, don't use a DC jack for AC.

[newperson]

looking for an example of an ac connector within mouser but everything i see states dc.  can you show some part numbers to see an example of the difference of an isolated connector?

[Jered]

  One example is the power cord going into your PC.

[Ice-9]

Just a note on a saftey issue ......

When you say AC i am assuming you mean AC in the form of, for example 12v AC adapter and not AC direct from the wall. For obvious reasons  AC mains from the wall can NOT be done this way  and could result in death.


Just thought it was worth mentioning.

[burningman]

When I mentioned AC I meant 9VAC adapter, not line level.

Can anyone spot any board-mount AC jacks on Mouser? Thanks.

[slacker]

I've never seen specific AC jacks, and both the AC wallwarts I've got have identical connectors to DC ones. I just use normal round plastic DC jacks, I suppose if you want to make sure you don't plug the wrong thing in just use a different sized one.

[burningman]

I planned on using an isolated DC jack that would only connect to ground/enclosure on the other side of the rectifier, the output.

I am basically powering a PIC some optos and LEDs, regulating with an LM7805.

Here's another question. Can anyone spot a safety or performance issue if someone did by chance mistakingly plug a 9VDC adapter into a rectified/regulated circuit?
Thanks.

[MoltenVoltage]

It's the size of the center pin that differentiates the AC jacks.  The AC pin is 2.5 mm and DC is 2.1 mm.

[R.G.]

It's the size of the center pin that differentiates the AC jacks.  The AC pin is 2.5 mm and DC is 2.1 mm.

That's possibly what was intended, but I've seen both used as both. There are several sizes of the center-pin-and-barrel plug, and they get used for different purposes.
Astec, for instance, produces DC power supplies with the 2.5mm output plug (http://mouser.com/catalog/catalogUSD/638/2035.pdf)  and Triad produces AC-output adapters with the 2.1mm plug (http://mouser.com/catalog/catalogUSD/638/2047.pdf). Since the manufacturers don't observe any kind of standard on this, I have simply marked it as "not a standard" inside my head and count on checking to be sure each time.

[Paul Marossy]

It's the size of the center pin that differentiates the AC jacks.  The AC pin is 2.5 mm and DC is 2.1 mm.

Not in my experience. For example, the "original" ADA Flanger used a DC wall wart power supply - the DC jack on it has a 2.5mm pin.

You know, this is one of those things where I ask myself why on earth do they have to have so many different sizes of DC jacks? It seems like two sizes would be sufficient if you ask me...