LiPo battery charger circuit.

praveen September 2, 2015 3 Comments
LiPo battery charger. Li-Po battery or Lithium-Polymer battery is a rechargeable battery based on the Lithium-ion technology enclosed in a flexible pouch. This soft, flexible pouch makes them very light with a compromise in mechanical strength. Li-Po batteries are widely used in applications where weight is a critical factor. The common applications are radio controlled model flight, RC toys, hand held devices etc. The Lithium Polymer battery is evolved from the Lithium Metal Batteries.The main difference is that instead of...
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12V battery level indicator circuit (LED bargraph)

admin December 1, 2011 20 Comments
12V battery level indicator circuit with   LED bar /dot display LM3914. The heart of this circuit is the LM3914 from national semiconductors. The LM3914 can sense voltage levels and can drive a display of 10 LEDs in dot mode or bar mode. The bar mode and dot mode can be externally set and more than one ICs can be cascaded together to gat an extended display. The IC can operate from a wide supply voltage (3V to 25V...
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24V lead acid battery charger circuit

jacky March 12, 2010 149 Comments
Description. This lead acid battery charger circuit is designed in response to a request from Mr.Devdas .C. His requirement was a circuit to charge two 12V/7AH lead acid batteries in series.Anyway he did not mentioned the no of cells per  each 12V battery. The no of cells/battery is also an important parameter and here I designed the circuit assuming  each 12V battery containing 6 cells. When two batteries are connected in series, the voltage will add up and the...
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Automatic changeover circuit

jacky March 4, 2010 12 Comments
Description. The circuit diagram shown here is of a automatic changeover switch using IC LTC4412 from Linear Technologies. This circuit can be used for the automatic switchover of a load between a battery and a wall adapter.LTC4412 controls an external P-channel MOSFET to create a near ideal diode function for power switch over and load sharing. This makes the LT4412 an ideal replacement for power supply ORing diodes. A wide range of MOSFETs can be driven using the IC...
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Battery eliminator circuit

john December 14, 2009 25 Comments
Description. Here is the circuit diagram of a battery eliminator circuit that can be used as a replacement for 9V PP3 batteries. The circuit given here can be used to power any device that operates from a 9V battery. The transformer T1 steps down the mains voltage and bridge D1 performs the job of rectification. Capacitor C1 is a filter. IC LM317T is the regulator here. The value of R1, R2 and R3 are so selected that the output...
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Ni-MH battery charger using LT4060

john September 24, 2009 18 Comments
Description. This is the circuit diagram of a very powerful and efficient Ni-MH battery charger using IC LT4060 from Linear Technologies. In addition to Ni-MH batteries Ni-Cd batteries can be also charged by slightly modifying the circuit.For charging Ni-Cd batteries connect the CHEM pin (pin12) of the IC to +Vcc.Here the circuit is configured to charge 2 cells connected in series. By altering the connections of SEL0 and SEL1 pins, upto 4 batteries in series can be charged using...
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Ni-Cd battery charger circuit

john July 31, 2009 7 Comments
Description. This circuit can be primarily used for charging 12V Ni-Cd battery packs. Any way 6V and 9V battery packs can be also charged by using this circuit a little compromise on power efficiency. The built in automatic current regulator regulates the charging current to somewhat 4 amperes. When the charging current reaches 4A, the voltage across resistor R1 becomes 0.7V and switches the transistor Q1 ON. The transistor Q2 which is now in ON state will shorts the...
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Car battery charger

john April 7, 2010 53 Comments
Description. Given below, is a very simple circuit that can be used for charging car batteries. In this circuit there is facility for monitoring the charging current and voltage. The circuit is based on the IC MC78T12ABT from Freescale.The IC is nothing but a 7812 in TO-3 package with 3A capacity. The transformer T1 steps down the mains voltage and diodes D1&D2 does the job of rectification. Capacitor C1 does the filtering and C2 acts as a decoupling capacitor....
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Battery charging indicator circuit

john May 14, 2009 34 Comments
Description. This simple circuit can be used to monitor whether a battery is charging or not. The voltage comparator IC LM393 is the heart of this circuit. The LED D1 will remain ON whenever there is at least 25 milli ampere current flowing to the battery. This particular circuit is designed for a 12V battery with charging current less than 1A.By slightly modifying the component values, the charging current and voltage can be modified. Circuit diagram with Parts list....
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Flashing battery monitor

john April 17, 2009 2 Comments
Description. Here is a simple circuit in which an LED will continue flashing as long as the voltage of the battery to be monitored is above the set level.The transistors Q1 and Q2 are wired as a complementary astable multivibrator.The circuit can operate from a voltage range from 6V to 12V. The voltage level at which LED has to stop flashing can be set by adjusting the preset R4.When the battery voltage reaches the threshold the flashing frequency decreases...
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