Converting battery powered children's toys into USB powered ones

Is it possible to convert conventional battery powered children's toys to usb-powered ones? I am trying to find if I can convert my kids' small electronic piano power source that currently draws power from 3 AA batteries to a one that will draw power from a USB port.
Please advice.

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lemonie8 years ago
Find a USB lead, cut the end off, peel the outer insulation and you want Red (+5V) and Black (0V). For the small piano I reckon it would take 5V without any modification - but you'd probably want to fit a power-plug & jack, like a mono-audio arrangement.
Still you might find a plug-in (to the wall socket) 4.5V supply, and you may find the thing has a power socket for suck a thing anyway?

sreerao (author)  lemonie8 years ago
Thanks L,
Unfortunately, this toy doesn't have a power socket :(. If I can get this working, I can implement similar mods to other toys, that are battery hoggers.
lemonie sreerao8 years ago
You can pick these things up fairly cheap, look for:
DC Barrel Power Jack/Connector, these often come with switch built in which you can use to disconnect the battery when you plug in the power supply, so you don't have to give up the battery function.


Jayefuu8 years ago
You've got the voltage requirements there, 3xAA batteries in series is 4.5V , USB is 5V. It will depend upon what current the keyboard draws, does it say on the back? The max USB can supply is 500mA.
sreerao (author)  Jayefuu8 years ago
Thanks so much for the prompt response. This particular keyboard does not provide any specifications. My first instinct was to connect it to a DC 5V power adapter but the keyboard does not have a DC input jack. When I went to a local Fry's store, they didn't carry it (or perhaps I was not able to explain them correctly what I wanted).
On searching the Instructables, I was curious if I could use USB instead, and hence my question posted over here.
Is there a way to identify the current rating for the keyboard?
Any suggestions is highly appreciated.