Showing posts with label pump. Show all posts
Showing posts with label pump. Show all posts

Wednesday, August 20, 2014

5v Powered Charge Pump Battery Charger

The schema below will trickle charge a four cell pack of AA or AAA NiMH batteries.  The schema draws current from the +5v available a USB connection and pumps about 70ma of current into the battery. This should be enough current to fully charge a pack of 2500ma-hour cells in about 36 hours.  The schema uses a single 74HC14 hex Schmitt trigger inverter in conjunction with a voltage doubler charge pump schema.

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