AC and DC power

[Shape D.]

Anyone know how you would go about powering something off a wall outlet and a battery?

I'm looking to build a plug and play unit with the jakks units and want to make it use battery power or  use a plug to use ac power. would I just connect both? or do I have to do something more technical for it. I'm guessing the batteries wouldnt use power if theres ac goin into the unit. but I'm not really shure.

[SirPeale]

Get a 6v adapter.  Measure it with a multimeter first, before connecting it!  I've had a lot of adaptors, and a lot will say 7V and actually be putting out a lot more.

I cut the end off mine and soldered it to the battery leads, but I know there are other solutions.

[Shape D.]

but if I have it plugged into a wall and I have batteries in the unit will the batteries lose power while its running?

[RayB]

uhhh that could be dangerous if there's power running to the same leads as the batteries.

[Tailgunner]

They (whoever "they" are) make phono jacks that would work. The jack is designed with three solder tabs, one being negative (ground) with the other two being positive. One of the solder tabs connects through a set of contacts inside the plug that are normally closed, inserting the plug from the AC adapter opens them.

Your battery will connect through those internal contacts, when you plug in the AC adapter you break the normally closed connection effectively removing the battery from the circuit.

Clear as mud?

[LordDamo]

Is the unit your building going to be like a bartop style thing? I.E. the tv and Jakk's units in the same unit? or is this more of a portible unit that you can take anywhere and plug into a tv?

Really, you dont need the batteries in one of these things. Its better to wire a transformer up to it. It will save you money (no need to buy batteries all the time) as well as the environment (not buying batteries, so you wont be throwing them away).

[Druin]

Yes it's very wrong to have batteries and some other voltage source connected in parallel - just think about all those warnings about not putting normal batteries in a battery charger and that should suffice.

So to give a unit 2 options of power source, as mentioned the power sources have to be somehow switched between, whether it's a plug with switching capabilities or just an added toggle switch that routes one source at a time to the unit.

As for measuring a higher voltage on a transformer than is written on the label, that is an unregulated power supply and it will read higher when it's unloaded, but when you use it to power something, it should drop down to more around the expected level. Try putting the meter on it when it's plugged into whatever it was designed for.  Unregulated supplies are used either when the target device has a voltage regulator to stabilize it, or when the exact voltage doesn't matter.

[Shape D.]

Is the unit your building going to be like a bartop style thing? I.E. the tv and Jakk's units in the same unit? or is this more of a portible unit that you can take anywhere and plug into a tv?

Really, you dont need the batteries in one of these things. Its better to wire a transformer up to it. It will save you money (no need to buy batteries all the time) as well as the environment (not buying batteries, so you wont be throwing them away).

I'm planning on building a portable unit with a removable lid to keep the joysticks from being damaged, and a handle to make it easier to carry around. I haven't figured it all out yet. I just figured If I could run it off batteries when I need to the option for it would be nice.

[Jabba]

Ummmm, wouldn't a UPS suffice? It would last for maybe an hour before the bateery dies, but wouldn't a MAME cabinet running off a battery be the same (i.e., would drain the battery quickly?)