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Circuits designed by David Johnson, P.E.
Last Updated on:
Friday, March 12, 2010 12:08 PM
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Battery Eliminator -- April
5, 2009
If you use a 1.5v or a 3v battery powered MP3 player for long periods of time, you may get
tired of constantly changing batteries. Some older players do not work will NiMH
rechargeable batteries so changing out batteries can get expensive. The circuit
below can be wired into the player, to replace of one or two AAA or AAA batteries. I
designed the circuit using a very common LM317 adjustable voltage regulator.
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| The circuit uses any
off-the-shelf +5v to +6v power adapter. These are often used for USB powered devices and
can be purchased from a variety of sources. I included an illustration showing how
to make a simulated AA or AAA cell, using a wood dowel and metal electrodes from an old
battery. You solder wires onto the electrodes then glue them onto the ends of the
wood dowel, cut to the right length. The dowels can then be snapped into the
player’s battery holder with the two wires routed to the eliminator circuit. |
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Click on Drawing Below
to view PDF version of Schematic |
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Master Schematic
Category List - David A. Johnson, P.E.
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