AC and 9v pedals, how do you keep from shorting the ground path?

[Sir H C]

How do you keep a battery plug from shorting to the case or other bits when the AC adaptor is used.  Do you assume that it is up to the user, or what?  I am thinking about shorting either to the inside case (if unpainted) or the PCB or other wires.

[widdly]

I never worry about it, but perhaps you could glue a second battery clip into the case so you can clip it onto that when not in use.

[mojo_hand]

I use a battery clip which is mounted into a little plastic holder for the battery, so it can't short against anything.

If you wanted, though, and could afford to lose a fraction of a volt, you could put a diode into the + side of the battery lead.  That would protect you from shorts, accidental polarity reversals, and inadvertent recharging of non-rechargeable batteries, all at the same time. (I'm assuming that - is tied to ground.)

[dxm1]

If you use the common three lug switched DC jack, the positive battery wire is removed from the power circuit when a DC plug is inserted. There is nothing to 'short'.

[Skreddy]

There's no danger with regard to the battery clip shorting to ground (the insertion of a plug into the adapter jack disconnects the battery's + terminal), but there's the very small danger of the battery clip floating around inside and perhaps shorting against a switch lug or something that carries a signal.  So I actually advise my customers to wrap their battery clip with tape if they plan on running on AC with the battery removed.  Maybe not necessary or the most effective solution, but does seem to solve the potential for a problem.

[R.G.]

There is a plastic imitation of the top of a battery that we use in our pedals when they're shipped.

Good question - it's entirely possible that a battery will never be put into a pedal these days.

[darron]

you can also buy battery clips which have the terminals sunken inside a plastic ring, called safety clips:




not foolproof though. i've been thinking about this also. maybe use that, and also cable tie the battery clip lines shortly to the switch or something in a safe position so that it couldn;t accidentally hit a component on the pcb.

[Sir H C]

Since I had a bunch of shrink tubing that worked around, that is what I used.  I guess my thought was that the ground path could short to ground and hose things, or short somewhere else if the battery clip moves dramatically causing the pedal to "fail". 

One reason to go the boss route and paint the pedal and have the battery in its own spot.

[Processaurus]

Make a simple little plastic divider with a slot for the battery clip wires, to make a little battery compartment, that the clip couldn't get to your circuit and short on stuff.  Kind of like the weird little battery holders in the back of DOD pedals.

to hold it in place, fold a tab over with a 1/2" hole in it, and use the stompswitch to anchor it?