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Motivation: I am discouraged at the
increasing number of continuous draw
DC-powered devices that are designed to
consume alkaline batteries, far from a
renewable natural resource. Clocks are a
perfect example. I received a
clock as a gift last year, it consumes 4 D-
alkaline batteries every 6 months. It
came with no AC adaptor, nor offers a DC
power input jack.
Sure, I could download specs for an AC/
DC adaptor and soldier one together
myself, but perhaps I know very little
about electronics; or just would rather
deal with rectifiers, transformers, filters,
and building a switching circuit.
My solution (and I was surprised my
search-engine-foo located no such
animal) is a retrofit kit for battery
devices. The kit includes:
1) an AC-to-DC brick and AC power
with selectable voltage output - These
widely known to exist. It will accept
automotive-style mini-atc blade fuses to
help prevent disaster, and several low-
amperage fuses will be provided in the
2) collection of battery "blanks" for use
devices that take multiple batteries -
Essentially, this is a piece of steel in the
shape of a battery that will short + to -.
know something that achieves this goal
was baked in some toy car I remember
from childhood, alas I could not find a
link. Perhaps it is lost technology.
4) battery "feeders" for each standard cell
size (AA, AAA, C, D, 9V), and DC power
cable - Similar to a blank, it is just a
of HDPE in the shape of a battery. Only
instead of shorting + and -, it provides
3.5mm jacks to connect the DC power
cable to the brick. This fake battery is
center of the idea.
5) a user manual - RTFM! It will explain
the difference between parallel and
how to calculate the voltage required by
your device, and why not to use blanks if
the batteries in your device are wired
Use case: The user, Carla, is a quality
assurance representative for a company
that sells custard-filled hullaballoons.
has an alarm clock that takes two AA
batteries in series. After removing the
biodegradable packaging from her new
"ACsault and Battery", she inserts one
"blank" and one "feeder" into the battery
slots of the clock. She then connects the
DC power cable from the feeder to the
brick and sets it to 3.0 volts output.
plugging the brick into the wall, Carla's
alarm clock will be drawing electrical
power from a much more efficient
She can choose to leave the battery door
off the clock or mod it to accept the new
Wikipedia : Power supply
This typically involves converting 120 or 240 volt AC supplied by a utility company (see electricity generation) to a well-regulated lower voltage DC for electronic devices. [ed, Dec 21 2006]
Wikipedia: Battery Eliminator
What this class of device is usually called. [jutta, Aug 07 2007]
Amazon: AA battery eliminator, $32.99
Plugs into 110 or 220V. Not as flexible as this idea, though. [jutta, Aug 07 2007]
AA, 9V Cell battery eliminators
As mentioned by one of their customers in e-mail - thanks! They have a 110V option; just ask for it. [jutta, Aug 07 2007]
||This would lead to that every little electrical device occupying a power outlet, leaving nowhere to plug in the vacuum cleaner. Personally, I would use rechargeable batteries.
||Maybe use only feeders and no blanks - then it doesn't matter if they're fitted in series or parallel. Whether this would lead to a profusion of low-powered devices occupying plugs is up to the user (and the marketing department); I have only a few items that would need this. [+]
||// Yeah, ed, what angel said. Buy Rechargeables. //
||My first paragraph mentions this is targeted at constant-drain devices that rely on alkaline batteries. Put a NiMH battery in a clock, and it will be running slow within days. I believe rechargables are best used in switched devices.
||Rechargable batteries usually have less power, and lose the charge quickly. I bought a bunch of them, in different flavors, for a while, and never use them anymore.
||There are flat power cables around, so it may be possible to work this idea without breaking battery-compartment covers.
||If you want to avoid breaking battery compartment covers, another option would be an inductive coupling.
||This idea is great. It seems though, as mentioned, you'd have more wall-wart adapters. I myself have used such a device (to power capsela, wires and wooden dowels). It seems that the idea is not new.
||I worried this would be just another lame pun idea, but now I see that the lame pun is the frosting on a moist mouthwatering cake of an idea.
||Oi, you're making me hungry.
||Is it possible that the transformer could be packaged in a AA sized feeder cell (which could be nested inside larger covers) so as to remove the wall-wart?
||Underwriters Laboratories would likely reject a design where the user plays with 110v AC supply leads. Moreover, crispy customers would not be happy customers.
||I was envisioning the power lead into the feeders being male. Female makes more sense from a safety perspective. Perhaps my design needs more detail on how that connection should be made.
||To keep this idea halfbaked (instead of mostly-baked), and to solve the wall-wart problem, I propose the following design modification:
||The transformer and fuse circuitry shall be located within the battery compartment of the target device instead of an inline or socket-mounted brick. Ventilation provisions shall be made (read: holes shall be drilled) in the target device to prevent overheating.
||[ed] I know the toy car with the battery blank you speak of. It was a slot car. Battery powered all plastic slot car.
||And your idea is good for a product, for lazy (electrically ignorant) people that havent herd of alligator clips. Alligator clips trumps everything in this idea, sorry. Just get a switchable transformer (radioshack) and a set of alligator clip jumpers and your in busniess.
||A grandfather clock really should be driven by a pendulum.
||If it was driven by a pendulum, it would not run for very long.