NiCd - NiMH Charger

<div dir="ltr" style="text-align: left;" trbidi="on"> <div style="text-align: justify;"> The charger is build around a LM317 adjustable regulator.</div> <div style="text-align: justify;"> The charge starts when a battery is connected between pins JP1-JP4 or JP2-JP4 or JP3-JP4.</div> <div style="text-align: justify;"> <br /></div> <div style="text-align: justify;"> For example, if a battery is connected to JP1-JP4 pins then the current that flows cause a voltage drop to R1, then D1 causes a voltage drop of 0,7 volts and Τ1 conducts. Then through transistor's emitter flows a current that comes from Adjustment pin of LM317.<br /> <br /></div> <div style="text-align: justify;"> </div> <div style="text-align: justify;"> Diode D4 prevents current to flow from battery back to the charging circuit. Resistors R1, R2 and R3 adjusts the charging current and it's value is given from : Rx = (1,25 + 0,1) / I , where x = 1,2,3.</div> <div style="text-align: justify;"> <br /></div> <div style="text-align: justify;"> I is 1/10 of the battery's charging capacity. For example if battery has a rated capacity of 1700mA then Ι = 170.</div> <div style="text-align: justify;"> <br /></div> <div style="text-align: justify;"> The input voltage must be at least 3 times the battery's voltage. For example an input voltage of 25V can charge a 8, 4V (9V) battery.</div> <div style="text-align: justify;"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzPXjEalQoiCuCTA-x9OxcBaiWQDlSyPADHD_CPx4wmxamvdwC_5ycwy98m4o1nSMzL2F23MnL7suCJAMwncPYcsiE2oDVlvo2DN0Wdr-pyUzupTJ9KoNAAiHGyDM3OHVm9zNEJRWsT_UB/s1600/Charger.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img alt="NiCd - NiMH Charger Circuit" border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzPXjEalQoiCuCTA-x9OxcBaiWQDlSyPADHD_CPx4wmxamvdwC_5ycwy98m4o1nSMzL2F23MnL7suCJAMwncPYcsiE2oDVlvo2DN0Wdr-pyUzupTJ9KoNAAiHGyDM3OHVm9zNEJRWsT_UB/s1600/Charger.png" title="NiCd - NiMH Charger" width="400" /></a></div> </div>

NiCd - NiMH Charger

The charger is build around a LM317 adjustable regulator. The charge starts when a battery is connected between pins JP1-JP4 or JP2-JP4 ...

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