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Li ion Battery Charger for Mobile phone by TL431

Li ion Battery Charger for Mobile phone by TL431

After a simple adjustment can be from the original involvement delete thermistor to compensate for the temperature dependence.
The charging voltage after the treatment is no longer dependent on the threshold voltage of T4 and resistance thermistors. Teplotní stabilita je urèena prakticky jen stabilitou IC1. Temperature stability is determined practically only the stability of IC1. Proto byl ze zapojení odstranìn trimr a nabíjecí napìtí je napevno nastaveno rezistory R4 až R6. It was removed from the involvement of trimmers and charging voltage is set firmly resistors R4 to R6. Vynecháte-li (zkratujete) rezistor R5, bude koneèné nabíjecí napìtí zpravidla nepatrnì vìtší než 4,2 V. Zapojením rezistoru R5 lze napìtí upravit na potøebnou velikost. Miss if (short-circuits) resistor R5, the final charging voltage is usually slightly greater than 4.2 V. The integration of resistor R5 may be necessary to adjust the voltage size. Staèí-li vám nabití akumulátoru na 90 až 95 %, doporuèuji nastavit nabíjecí napìtí na 4,1 až 4,15 V. Pøi menším nabíjecím napìtí se velmi významnì zvìtší poèet nabíjecích cyklù a prodlouží doba života akumulátoru. Just when you charge the battery for 90 to 95%, I recommend to set the charging voltage from 4.1 to 4.15 V. The lower charging voltage is very significantly increase the number of charging cycles and extended battery life time.



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Through resistor R1 when current is the sum of the loss of voltage on R1 and D1 threshold voltage greater than voltage needed to open a transistor T5. T5 je otevírán proudem tekoucím rezistorem R7. T5 is a stream opened tekoucím resistor R7. Rezistorem R8 prochází proud, LED svítí a indikuje nabíjení akumulátoru. Current through the resistor R8, and LED light indicates battery charging. Ve fázi nabíjení konstantním napìtím se zmenšuje nabíjecí proud a úbytek napìtí na rezistoru R1 se zmenšuje. In constant voltage charging phase of the charging current and reduces the loss of voltage on the resistor R1 decreases. Zmenší-li se úbytek témìø k nule, neprochází proud rezistoru do báze T5, ale diodou D1. Reduced if the decrease almost to zero, not the current base resistor to T5, but the diode D1. Ke konci nabíjení jas LED pomalu slábne, až pøi plném nabití témìø zhasne. At the end of the charging LED brightness slowly fades, and almost at full charge is turned off. Na místì D1 jsem pùvodnì použil Schottkyho diodu (má oproti bìžné asi polovièní úbytek napìtí), ale LED pak zhasínala již pøi pøechodu z fáze nabíjení konstantním proudem do fáze nabíjení konstantním napìtím, kdy akumulátor ještì není zcela nabit. On the site I originally used D1 Schottky diodes (as opposed to the loss of about half the normal voltage), but then asking them to turn off the LED in the transition phase from charging constant current to constant voltage charging phase when the battery is not yet fully charged.

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