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Multiple Circuits to one power source Answered

I am working on finalizing a circuit bent sculpture I've done for my undergrad thesis. I have three circuit bent items, each with it's own battery source within the sculpture. Here is my dilemma: normally I plug in the batteries when I show it to someone, then promptly take them out, but for my gallery show, the sculpture will be turned on for an extended period of time each day, in my absence. What I would like to do is connect all circuits to one battery source or AC power. After that I can add a switch so that the gallery attendant can turn in on/off as needed. I am looking for any tips on how to do this. As of now, one runs on a 4-AA pack, one on a 2-AA pack, and the last on a 9-volt. Adding these together I am getting 18V(?) and I have an old laptop adaptor that has an output of 18.5 volts. I have a video of the piece functioning if anyone is interested. Thanks for your help (in advance).



9 years ago

Running components that aren't simple resistive loads in series from a voltage source that equals the sums of their voltage requirements is a complex problem and best avoided as far as I know. The easiest solution would be to find separate power supplies for all of them- you can get voltage-selectable DC transformers ("wall warts") at any decent electrical shop, borrow from friends (or the department) etc. Alternatively, you could wire two, four or six D cells (large flashlight batteries) together in series and wire that into the battery compartment- the typical D cell holds as much energy as five AA cells, so the thing should run for quite a long time.

As long as it lasts a while I am fine with batteries. Would wiring six D cells pose any threat of frying a circuit? Thanks for confirming what I was thinking. The more I researched, the more complex the problem looked.

It shouldn't- six D cells in series will put out 9V just like a 9V battery, but will last longer and are able to provide a bit more current. They are still only dry cell batteries, though, so there's no danger of electrocuting yourself or anything like that. Certain types of battery start out life at a bit above the rated voltage so they might go as high as 9.6V when straight out of the box, but I'm sure the circuits will allow for this. Using separate voltage-adjustable wall transformers is probably the most elegant solution if you can do it, using D cells might work out cheaper if this is a one-off thing but needs a bit more work to do the wiring.

3 wall transformers + power strip with switch what kind of loads you have there ? you might connect them to 9 V with appropriate resistors depending on what they are