+5V powered charge pump battery charger

Texas Instruments SN74HC14

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

+5V powered charge pump battery charger

Materials on the topic

  1. Datasheet Texas Instruments SN74HC14
  2. Datasheet Fairchild 1N5819

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