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Circuits designed by David Johnson, P.E.
Last Updated on:
Saturday, December 23, 2017 03:21 PM
List of Dave's Circuit Designs
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Micro Power Circuits |
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Battery Eliminator -- April 5, 2009
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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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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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