My Circuit

Using the BQ24002 from Texas Instruments it  is possible to build a simple and small charger  module for single lithium-ion (Li-ion) cells. The device is available in a SSOP20 package  and so does not require heroic assembly and  soldering skills. Individual cells are becoming available from  the main catalogue suppliers, but a much  cheaper option is to rescue cells from defunct  notebook  batteries.  In  most  cases  only  a  couple of cells are faulty and the others can still look forward to a long and useful life.  A single cell is ideal for any equipment that  needs a 3.3 V power supply, and will generally give a good operating life. The charger  circuit requires a 5 V input, which can readily  be obtained from a USB port or from any 5 V  power supply.   Circuit diagram: Single Lithium Cell Charger Circuit diagram   The  charge  process  begins  with  a  trickle  charge current. When the cell terminal volt-age is sufficiently high the charger switches  to a higher constant ...

This is simple but low cost universal battery Charger for NiCD - NiMH batteries. This circuit is Ideal for car use. It has ability to transform a mains adapter in to a charger . This one can be used to charge cellular phone, toys, portables, video batteries, MP3 players, ... and has selectable charge current. An LED is located in circuit to indicate charging. Can be built on a general purpose PCB or a veroboard. I hope you really like it. Low Cost Universal Charger Circuit Diagram:  Parts: R1 = 120R-0...5W R2 = See Diagram C1 = 220uF-35V D1 = 1N4007 D2 = 3mm. LED Q1 = BD135 J1 = DC Input Socket Specifications:     Ideal for in car use.     LED charge indication.     Selectable charge current.     Charges Ni Cd or NiMH batteries.     Transforms a mains adapter into a charger.     Charge cellular phone, toys, portables, video batteries … Features:     LED function indication. ...

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 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 typ...

Normally, chargers available in the market do not have any sort of control except for a ro-tary switch that can select different tap-pings on a rheostat, to vary the charging current. This type of control is not adequate because of the irregular fluctuations in the mains supply, rendering the control ineffective.  A simple circuit intended for automatic charging of lead-acid batteries is presented here. It is flexible enough to be used for large capacity inverter batteries. Only the rating of transformer and power transistor needs to be increased. Circuit diagram : Automatic Battery Charger Circuit Diagram   The circuit has been basically designed for a car battery (about 40 Ah rating), which could be used for lighting two 40W tube lights. The circuit includes Schmitt trigger relay driver,float charger,and battery voltage monitor sections.  The Schmitt trigger is incorporated to avoid relay chattering. It is designed for a window of about 1V. During charging, when the ...

id America recently released LX, its latest dual USB car charger with leather grip. If you’re looking for a decent USB charger for your car, the LX may be able to catch your eyes. The LX is a practical USB car charger designed to offer a handy way to charge your mobile device in your car .  As we can see from the images, the USB charger features a stylish combination of leather grip and matte casing in order to compliment the interior of your car, and the USB charger comes with two USB port so you can use it to charge up to two mobile devices at the same time, including a 2.1A output for tablets and other high-power devices. Apart from that, built-in fuse protects your mobile devices against power surges. The LX dual USB car charger is available in two colors, each one is priced at $24.95 USD. If you’re interested, jump to id America official site for more details. [Via]

There is a wide variety of NiCd (nickel-cadmium) battery chargers on the market, but there are not many that can work from an in car 12 V cigar lighter. Such a charger would, for instance, be of interest to campers and caravanners who do not have a 230 V a.c. mains supply available. To satisfy the needs of these users, a charger could be designed for operation from the cigar lighter, but it is, of course, of far greater interest if it could also work from the domestic mains supply. Furthermore, it would also be very useful if a number of cells, say, 1 to 4, of different format could be charged simultaneously. Lastly, another benefit would be if the charger would automatically switch off once the battery or cells have been charged fully. The charger described in this article does all that: it accommodates batteries or cells Type R6 and R14. Switching off after a period of 2 h 30 m, 5 h, or 10 h is arranged by 3-way switch S1. The 2 h 30 m period is for charging Type R6 batteries (1/2 ch...

Solar Cell Array Charger with Regulator circuit can be used to charge batteries from a solar cell array. The circuit consists of an oscillator, a DC-DC step-up or ‘boost’ converter and a regulator that pro-vides regulation of the output voltage.The oscillator is built around a hex Schmitt trigger inverter IC, the 40106B, one resistor, R1, inserted between the input and the output of one of the gates in the 40106 to supply charge to C3. Depending on the values of resistor R1 and capacitor C3 you’re using in the circuit, the oscillator will operate at different frequencies, but a frequency below 100 kHz is recommended.  By consequence, the oscillator frequency should not exceed the maximum ripple frequency of capacitor C2 connected on the output. C2 should be an electrolytic capacitor with a DC working voltage larger than the desired output voltage. Besides, it should have a low ESR (equivalent series resistance).  Solar Cell Array Charger with Regulator Circuit Diagram : IC1...

Using this charger, you can safely charge up to two pieces of Ni-Cd cells or Ni-MH cells. The circuit is compact, inexpensive and easy-to-use.The 230V AC mains is down-converted to 12V AC (at 500 mA) by step-down transformer X1, converted into pulsating DC voltage by diodes D1 and D2, and fed to the battery charger terminals via current-limiting resistor R1 and silicon-controlled rectifier SCR1. SCR1 is at the heart of the charger. Normally, it conducts due to the gate biasing voltage available through resistor R2 and diode D3, and the battery is in charging mode, which is indicated by LED1. Resistor R2 limits the charging current to a safe value. Charging current of this circuit is about 250 mA.  Simple Multicell Charger Circuit Diagram When the battery reaches full charge, SCR2 conducts to pull down the gate of SCR1. This state is indicated by LED2. Now remove the cells from the charger. Normally, Ni-Cd cell with a rating of 500 mAH will take around 2.5 hours to reach full charge...

This circuit came about as the result of an  urgent need for a NiMH battery charger. No  suitable dedicated IC being immediately to  hand, the author pressed an L200 regulator and a 4.7 kΩ NTC thermistor into service.  Those components were enough to form the  basis of a charger with a cut-of f condition  based on cell temperature rise rather than  relying on the more common negative delta-V detection. L200 Charger Circuit Diagram :   The circuit uses the L200 with the thermistor in the feedback loop. When ‘cold’ the  output volt age of the regulator is about 1.55 V per cell; when ‘warm’, at a cell temperature of about 35 °C to 40 °C, the out-put voltage is about 1.45 V per cell and the  thermistor has a resistance of about 3.3 kΩ.  This temperature sensing is enough to pre-vent the cells from being overcharged. P1  adjusts the charging voltage, and R2 limits  the charge current to 320 mA. The IC is fitted with a small 20 ...

Batteries often serve as the main energy source for portable electronic devices. Although they depend on batteries, portable consumer electronic products, such as GPS devices and multi-media players, often consume energy directly from an ac-dc wall adapter or accessory power adapter (or “Auto Adapter”) when the battery is low or the device is in a stationary mode. Due to their cost effectiveness over their useful life, rechargeable batteries are often used for the power source of the portable electronic device.   Attributes such as “relatively high energy density” and “maintenance free” make Lithium-Ion (Li-Ion) batteries popular in the portable consumer electronic products. Refer to the application note, AN1088, “Selecting the Right Battery System For cost Sensitive Portable Applications While maintaining Excellent Quality” (DS01088) for characteristics of Li-Ion batteries. Some examples of how to properly design with Li-Ion batteries will be discussed in this application note.