Artificial batteries

[CP5670]

I'm looking for "fake" batteries that are powered off a wall outlet. These should basically be battery-shaped objects that will fit into various things that run on batteries, but are connected to an external transformer with a variable resistor to control the input voltage. Have any of you seen anything like this that is commercially available?

This page shows the kind of thing I'm looking for, near the bottom. I don't really have the experience or time to build such a setup myself, but would find this sort of thing very handy. I would like to use these to run some Lego motors and other electric parts. I find that I have to stop using normal alkaline batteries when they're drained only about a quarter of the way, since the voltage drop slows down the motors too much. I have numerous Lego battery boxes around, but I tend not to use them much due to this voltage drop issue, and I only have two "official" Lego wall-powered sources that can run the motors directly.

 

[alfa147x]

Oh i would be glad to find a set of these too!

 

[corkyg]

Such A/C adapters that fit into a battery compartment have been around for several years for Canon DSLR cameras. I have one, and it is used for things like flashing the cameras BIOS where a battery failure would be catastrophic.

A/C Battery

I believe you are looking for one that would have a standard AA battery form factor. That would be useful.

 

[RandomFool]

I would love to get something like this.

 

[CP5670]

Originally posted by: corkyg
Such A/C adapters that fit into a battery compartment have been around for several years for Canon DSLR cameras. I have one, and it is used for things like flashing the cameras BIOS where a battery failure would be catastrophic.

A/C Battery

I believe you are looking for one that would have a standard AA battery form factor. That would be useful.

Yes, this looks like the right sort of thing, but the wrong shape. I basically need to the batteries to be shaped like AAs, although a C size variant might be useful as well.

 

[zig3695]

uh, so if i started a company and made fake batteries that run off a/c you all would buy them? thats all i have to do to make a million dollars? i can make those, anyone can...

 

[mikeyes]

I would buy some.

 

[corkyg]

Canon calls the device a "DC Coupler." The model DR-400 is current, and has been around for several years. (I have 2 of them)

This article may help you design a generic version based on the AA battery form factor.

Coupler

Note that it does not plug into the A/C mains, but connects to Canon's battery charger.

 

[RandomFool]

Originally posted by: zig3695
uh, so if i started a company and made fake batteries that run off a/c you all would buy them? thats all i have to do to make a million dollars? i can make those, anyone can...

Yeah pretty much, as long as you guarantee they won't blow up my stuff.

 

[potato28]

Originally posted by: RandomFool

Originally posted by: zig3695
uh, so if i started a company and made fake batteries that run off a/c you all would buy them? thats all i have to do to make a million dollars? i can make those, anyone can...

Yeah pretty much, as long as you guarantee they won't blow up my stuff.

Make sure not to buy the batteries from Sony.

 

[CP5670]

uh, so if i started a company and made fake batteries that run off a/c you all would buy them? thats all i have to do to make a million dollars? i can make those, anyone can...

If they're professionally made and fairly durable, then yes, certainly.

Apart from that, I guess I'm going to have to learn how to build this myself. I see a few AC adapters on the Radio Shack site that have an output voltage switch built in, and the concept is very simple otherwise.

What I'm thinking of doing is to attach wires to the leads in the battery compartments of various devices, and running a male connector for the AC jack out of each such device. I have no experience with soldering, so I would need to get some practice with that. Maybe I could just tape them on, although that may not hold up very well. It would be better if I could solder the wires onto the ends of existing dead batteries and use them to hold the wires in place, but I don't know if that would risk blowing up the battery or something.

 

[zig3695]

Originally posted by: CP5670

What I'm thinking of doing is to attach wires to the leads in the battery compartments of various devices, and running a male connector for the AC jack out of each such device. I have no experience with soldering, so I would need to get some practice with that.

thats exactly what i do. well, i get those 9v battery clips from radio shack, and solder that to the device. that way its easier to snap an ac pack on it or just leave it off and use regular batteries anytime you want.

the soldering is very easy. just put a little flux on your wire and spring before you heat it up. flux makes all the difference. i did this for an fm transmitter of mine and the adapter has yet to fall off through years of abuse, soldering makes a very strong connection.

these here- http://www.radioshack.com/prod...lead&parentPage=search
just dont forget and snap a 9v battery to it when the device only wants 5v or something though!

 

[CP5670]

Thanks for the tips. One question though, what is flux and how do you use it?

I basically have a cheap radio shack iron and a tube of rosin core solder that came with it. It was part of one of those computer toolkits but looks identical to this.

The things I want to power all accept anything in the 9-12V range, although it may be useful to set the voltage lower in some situations (to limit the motor speeds).