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<title>Power supplies for battery chargers</title>
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<p><b>Power supplies for battery chargers</b><br>
When using an unregulated DC wall transformer (power adapter) to power a battery charger, keep in mind that the output voltage can be much
higher than the rated voltage shown on the label when the current is low. Make sure you don't exceed
the maximum input voltage of the device being powered. If you're not using a regulated power supply, you may need to add a voltage regulator
to the circuit:</p>
<img src="/reference/charger_reg.gif" width="500" height="250">
<p><b>Voltage regulator circuit</b>. IC number 78XX. The last two digits represent
output voltage. Example, a 7815 is a 15V regulator.</p>
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<p><img src="/reference/fut_charger.gif" width="478" height="313"></p>
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