laptop battery

Single-slope conversion according to a fixed point for charging capacitors, resistors and through the known reference (MCU internal integration by comparison to measure the resistance) to measure the discharge time. System of the unknown resistance to repeat the cycle. Integrated timer can automatically collect discharge time laptop battery, as allowed in the discharge cycle in the process of measuring the closure CPU, automatic acquisition of such power can be saved. Technology to follow the slope of the single-rate principle, can be eliminated with the RC-related charge voltage discharge, charging capacitor and the complex index equation. Measurement of time and discharge resistance proportional to the accuracy of the sensor and reference the same resistance, and can eliminate expensive calibration procedures.

10 K can be a resistance for the external temperature sensor reference resistance and 10 K's thermistor; 20 K for the potential of 6.8 K resistance in series with the potential of set points. Series resistance can be identified with the maximum temperature ibm battery set point (about 95 F) the corresponding minimum resistance. Resistance to set a maximum 26.8 K, corresponding to the minimum temperature set point (about 40 F).

Measuring sequences need to refer to resistance, set point and thermistor potential of the implementation of discharge time measurement. MCU calculated by the set-point potential of the value and thermistor, is a highly efficient form of software routines for the code to minimize the number of cycle and the corresponding effective current ThinkPad R51 battery. Effective measurement sequence takes about 10 ms and the average 50 A current, including the need comparators, timers and CPU functional implementation. Without the need for the system to turn off all the built-in MCU peripherals and components. As every five seconds before the need for a 10 ms measurement series, the effective duty cycle is only 0.2 percent, equivalent to about 1 A system of the average current consumption.

Trigger low-voltage heating / cooling relay the current 10 ms of 100 mA current pulse. According to statistics, the relay may be necessary to trigger 16 times per hour. Therefore, the effective duty cycle for the relay 0.0044 percent, equivalent to about 4.4 A of the current system.

From the battery perspective, we care about is triggered by the need to relay the 100 mA current. The first generation of electronic thermostat initial selection of button-type battery is CR2032 lithium ThinkPad T41 battery. Because less than 1% in each of the inherent ultra-low leakage and extremely flat discharge curve (the two of the extended battery life ideal choice), this battery is rated capacity of 200 mAh. CR2032 impedance of the problem is high, about 20, so it prevents the battery to trigger cooling and heating systems to provide 100 mA current relay. Although the required 100 mA pulse current only lasted 10 ms, but still far beyond the button battery capacity. Designers have considered using large-capacity capacitors (due to cost reasons can only be used electrolytic capacitor), but because of this high capacitance leakage, finally gave up.