Skip to main content

Li Ion Battery Charger Circuit Diagram


The LP2951 regulator is manufactured by National Semiconductors. The choice of values is from an application note Battery Charging, written by Chester Simpson. Diode D1 can be any diode from the 1N00x series, whichever is conveniently available. It functions as a blocking diode, to prevent a back flow of current from the battery into the LP2951 when the input voltage is disconnected. Charging current is about 100+mA, which is the internally-limited maximum current of the LP2951. For those wondering, this is compatible with just about any single-cell li-ion battery since li-ion can generally accept a charging current of up to about 1c (i.e. charging current in mA equivalent to their capacity in mAh, so a 1100mAh li-ion cell can be charged at up to 1100mA and so on).

Li-Ion Battery Charger Circuit Diagram



Li-Ion Battery Charger Circuit Diagram A lower charging current just brings about a correspondingly longer charge time. IMHO 100mA is quite low, low enough that the circuit can be used for an overnight charger for many typical single-cell li-ion batteries. The resistors are deliberately kept at large orders of magnitude (tens/hundred Kohm and Mohm range) to keep the off-state current as low as possible, at about 2?A. Resistor tolerances should be kept at 1% for output voltage accuracy. The 50k pot allows for an output voltage range between 4.08V to 4.26V - thus allowing calibration as well as a choice between a charging voltage of 4.1V or 4.2V depending on the cell to be charged. The capacitors are for stability, especially C2 which prevents the output from ringing/oscillating.

Parts List

IC1 = LP2951, voltage regulator
D1 = 1N4002, General purpose diode
R1 = 2M, 1%, metal-film
R2 = 806K, 1%, metal-film
P1 = 50K, potentiometer
C1 = 0.1uF, polyester
C2 = 2.2uF/16V, electrolytic
C3 = 330pF, ceramic

Comments

Popular posts from this blog

Power Amplifier with voltage regulator 4 × 50 Watt TDA8588

Power Amplifier with voltage regulator 4 × 50 Watt TDA8588    The TDA8588 is a multiple voltage regulator combined with four independent audio power amplifiers configured in bridge tied load with diagnostic capability. The output voltages of all regulators except regulators 2 and 3 can be controlled via the I2C-bus. However, regulator 3 can be set to 0 V via the I2C-bus. The output voltage of regulator 2 (microcontroller supply) and the maximum output voltage of regulator 3 (mechanical digital and microcontroller supplies) can both be either 5 V or 3.3 V depending on the type number. The maximum output voltages of both regulators are fixed to avoid any risk of damaging the microcontroller that may occur during a disturbance of the I 2C-bus. The amplifier diagnostic functions give information about output offset, load, or short-circuit. Diagnostic functions are controlled via the I2C-bus. The TDA8588 is protected against short-circuit, over-temperature, open ground and open VP connectio

PIC16F887 877 programming in C Tutorial 5 LCD Interfacing

LCD Interfacing: In this tutorial i will show you how to interface 16x2 LCD with micro-controller. 16x2 means there are two rows and each row contain maximum 16 characters.  For more detail refer to the LCD datasheet, which you are using. Basic Connection: Applies 5v to pin 2 and gnd to pins 1 & 5. Use variable resistor at pin 3 to set contrast. Pins 7 to 14 are the data pins,, used to send/rec data. Pin 6 is of enable; every time when you write to lcd you should have to give high to low, to this pin. pin 4 is register select pin use to give commands like clear, home etc.   In this tutorial i will interface lcd in 4-bit instead of 8-bit, so we only required four data pins. Code: Lets write a code that will display the motor status and its direction; it will be fun!!!! Requirements: Design a motor controller circuit using l298 and display its status on lcd. LCD is connected to portb and motor controller circuit is at portd. Required two switches to change motor direction; if both ar

12V to 30V DC to DC Converter circuit Diagram

 12V to +/- 30V DC to DC Converter circuit Diagram This is a DC to DC converter for car power amplifier. 12V input generates +30V and -30V output for preamp or power amplifiers. Circuit uses SG3525 IC, Mosfets and switching power supply.