Standard battery charge
This is especially designed for the soundtrack of voltage limit 700 750mAh, 3.6V and 4.2V lithium battery high PP2182D charger.HP solution, HP 338794-001 Battery, HP battery PP2182L, the load order is divided into three phases : pre-load, the perception of constant phase current and voltage phase constant. When only a little power and therefore can produce a very low output voltage, there must be pre-indictment stage. In this case, you must use low load current to protect the battery. However, if the rechargeable battery can produce a higher voltage (> 3 V), you can skip the pre-load. Of course it is the most common situation. Most power is in the constant voltage and constant current charging phase flows from the battery charger. The battery charge current rating of the battery of the decision. For fast charging, for example, noted the 700mAh battery can be recharged 350 to 400mA current. In the case of lithium batteries, MCU must be to maintain the normal battery voltage is also control the charging current of the battery is fully charged when the process was halted. Temperature monitoring can be used to ensure the application of step load safely, because the battery is full, any extra energy is converted into heat. Although the MCU to function as its control over the increasing temperature, but the current market, most come with a lithium battery overload protection, temperature control despite the need for so seldom used. Dell Inspiron 1100 Dell Inspiron 1150 Battery
Buck Converter
To design a charger with conical end features, the most effective and cheapest way is to use a buck converter switching regulator. HP 338794-001 Battery, Buck converter inductor to store energy. Figure 1a and 1b were the switch is off position of the buck converter schematic work.
PWM control signal load switch. When the switch is closed (Figure 1a), the current offering, because the voltage of the charger (charger wine) and flow through the circuit, the charging time of capacitor inductance. When the switch is open (as shown in 1b), the inductor tries to maintain the flow of current induced voltage, but can not charge immediately. Then, current flows through the Schottky diode and a capacitor. This process is cyclical. When the PWM duty cycle shortened by reducing the change "through" time, the average reduction of stress. By contrast, when the PWM duty cycle will be extended to increase the switch to "off", the tension increases on average. Therefore, by controlling the PWM cycle to the MCU adjusts the charging voltage (or current) can achieve the desired output value. In discussing the design details before the need to discuss first with the inductance and capacity of the two main points: Dell Inspiron 1440 Battery Dell Inspiron Mini 10 Battery
1. inductor size is easy to see, to determine the size of the inductor buck converter is to achieve a proper voltage and incorporate load. inductor size and cost are also relevant. volume coil can be used to calculate the formula 1: Formula 1, PP2182D HP HP battery 338794-001 battery, HP battery PP2182L where: Vi: INPUT to change the voltage of the charger; Vsat: pass "through" the loss of voltage, output voltage Vo:; T: PWM period; dutycycle: PWM cycle, Io: Output current (ie, current load). Formula 1 shows the PWM switching frequency higher (ie, HP PP2182D the battery, the greater the change in the period T), the required inductance, reducing the cost of the device.
2. Capacity should be noted that the ability of this circuit is used to reduce the spread of the total current, so the best, dominoes and the capacitance is inversely proportional. Dell XPS M140 battery Dell XPS M1730 Battery
