Simple power adapter thumbs its nose at proprietary connectors

[Mike Worth] wanted to use his camera for some time-lapse photography. Since it’s used to take many pictures over a long period of time, he doesn’t want to deal with batteries running low. But there’s no standard power jack on the side; instead the official charger consists of an adapter that is inserted in place of the batteries. Rather than break the bank with the special cable, [Mike] made his own battery compartment A/C adapter.

You can see that it is made up of two parts. The first is a standard wall wart that outputs the correct voltage and has an acceptable current rating. The other part is the adapter cable that connects to the camera on one end, and has a barrel jack on the other. [Mike] rolled some paperboard around a pencil until it matched the diameter of a AA battery. Once of the cylinders has a thumb tack for the negative lead, and the other uses a screw and washer for the positive side. He soldered some wire to these and he’s in business.

He must be snapping photos frequently enough to avoid the auto-shutoff feature. That or he’s disabled it with the use of some custom firmware.

Comments

  1. mikejworth says:

    Hi, this is Mike Worth. Just to clear up a couple of things; the stock wall wart actually gives 5V rather than the desired 3V, there are a couple of diodes included to drop this voltage down a bit and I am using CHDK to do the timing of the photos.

  2. Steve says:

    That is pretty much what I did with my cordless drill. I took a dead battery and put a cord on it! Now when I got a big project, I lug around an Optima Yellow Top car battery for my corded-cordless drill.

    • ojh says:

      fantastic… buy a cordless drill and put a cord on it. Now who would have thought about that one … ?
      :-) LOL

      • saimhe says:

        I did the same. Needed a cordless drill and bought a 12V (1.2 Ah NiCd) one because that voltage is suspiciously common. The battery died in less than two years despite of little usage, and a new one costs almost as much as a new drill. Of course I mercilessly converted the battery casing to a simple adapter with a few meters of 7ga wire and croc clips. There is also an idea about automatically cutting the power when the voltage drops too much, but that can wait.

        “Cordless” has one and only meaning for me, and it’s “independent from the wall socket”. I keep a couple of old car batteries that still contain more than 20 Ah each. For short work it’s also possible to use the battery that’s still in the car.

        Of course when I’ll have spare money, I will buy a stock battery :)

    • draeath says:

      For bonus points you should wrap yellow/black hazard tape around the battery ;)

  3. Natalie says:

    Cool beans Mike!
    A variant of this idea might be to build the AC to DC SMPS in the space taken up by the batteries vs the wall wort. I think it would be quite an interesting and challenging(!!) project based on the size and isolation constraints.

  4. Craig says:

    I have been wanting to do this with our baby swing for a while now. That thing eats D cells like candy.

    Any ideas for suitable conductuve ends for a D-Cell?

    I was thinking I might bypass the battery compartment altogether, but this looks like a cleaner way to not have to cut any wires inside the unit.

    • draeath says:

      Receipt paper rolls might do the job if you can find the right height. Just pull paper until the diameter is right.

      Failing that, if you know someone with a lathe just slap a 2×4 in there and carve it down to size.

    • Eric says:

      Google “battery upsizers”. They’re plastic shells in sizes from AA to D meant to “upsize” a smaller battery to replace a larger one. They should work fine in this application.

      Here are some examples:

    • Cynyr says:

      Baby swings and those hot-wheels car accelerators seem to do it here. The hot wheels ones need 1-1.5 amp at 3V to work. 3.3v is too fast and the cars fly off the track. I was thinking of rigging up some mosfets and a simple 555 PWM circuit with a pot to take my 5V wall wort down to 3v. It would also allow adjusting the speed a little. I should look at just dropping the voltage with a diode as well, but that is less fun.

  5. Reggie says:

    Natalie, whilst its a reasonable idea to want to try and hide circuitry in obvious places, I would probably not put the smps in the cavity taken up by the battery. If it goes horribly wrong in there for whatever reason, then you’ve got a dead camera. There is also the question of extra heat generated by the smps, this could affect image quality or be a fire hazard.

    This mod is common amongst astronomers using DSLRs, as the batteries are proprietary shapes, we usually get a clone battery and remove it’s insides, attach wires and then deal with the power away from the from camera itself, usually dealing with the camera and batteries thermistor protection and attaching a suitable voltage regulator and a 12v battery (mines got a couple of 2400mah 12v packs that I use and if i really need it I’ve got a 7ah battery too!).

    • Natalie says:

      fuses, protection diodes inside a protective case… and then running high pot and destructive testing to verify… at minimum.
      Heat? for a 2W supply at 90% efficiency, Pd less than 200mW
      again it is a non-trivial design and I was more writing just to think out loud to a “option”.

      Agree the wall wort is best for the quick solution for the masses.

    • NewCommentor1283 says:

      i might be wrong but i think i remember reading somewhere that people cool their ccd’s to achieve a better quality picture … noise floor gets lowered (or is it raised?)

  6. MrX says:

    Be sure that the wall adapter can put up over the maximum current load the batteries would otherwise allow. I would also put a fairly big backup capacitor with a limiting resistor in parallel with the supply to deal with load spikes.

  7. hawkbat05 says:

    There was a company, probably 20 years ago, that made these kinds of adapters. You got some battery shaped plastic tubes with conductors on the ends and one of them had a cable that connected with the transformer.

  8. Cricri says:

    Neat, and I can see how this useful bit solved a headache that drove the guy mad. Should have done it on one of my pocket PC, but never got around to do it.

  9. Jarel says:

    Don’t they already make these?

    I used to work at a retail store, and we had a big box of dummy batteries in the back room. If we needed to put a camera on display, we just randomly took a camera from our inventory busted the box open and displayed that one. There were no special “display only” models. All the cameras we sold had this little flap near the battery cover that covered a gap just wide enough to allow a 14 or 16 gauge wire to come out from the battery compartment.

    I can imagine there have to be people selling these things on eBay. I just wish I knew the proper name for the adapters.

    • Jarel says:

      Oh yeah, and for the cameras with the thinner and smaller NiMH battery packs, they made those custom for each model we carried.

      They’ve got to be floating out there somewhere.

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