Vendredi 18 septembre 2009 5 18 /09 /Sep /2009 10:11
four attack of your laptop
ARP Attack
ARP attacks Acer Laptop Battery since 2006, it began to spread. Web intrusion protection an ARP attack is disguised as the beginning gateway IP, forwarding messages, to steal a user name and password, will not cause dropped calls. Early ARP attacks will only result in packet loss, or the Ping values increased, and will not cause serious or large-scale dropped dropped.
At this stage, control measures based on ARP ECHO orders, can be solved only for the Laptop Battery purpose of a traditional Daobao ARP attack. On the overall network will not be affected.
But in the ARP ECHO solution was raised, ARP intensified attacks on evolution occurs. The new attack, the use of higher frequency ARP ECHO, pressure over the user's broadcast ARP ECHO. As the issue of broadcast packets too many times, it will slow down the entire LAN, or occupied by the gateway computing power, occurs very slowly or go inside the network card phenomenon. If severe, frequent blink off, or the whole network dropped the Acer TravelMate 240 Battery case.
Intranet IP to deceive
Intranet IP spoofing is widespread in the ARP attack, another attack occurs followed. Disguised attack on the computer the same IP, so that computer generated by the attacks, IP conflicts, can not access. This attack phenomenon, often affects the computer is limited, not large-scale impact.
Intranet IP fraud using two-way binding, it can be effectively addressed. Prepare the acer BTP-60A1 Battery computer first, binding configuration will not be later disguise the impact of the computer. Therefore, the equivalent to a control ARP and IP intranet solution to deceive. If the ARP control using other methods, will have to use another way to deal with.
Intranet Attack
Intranet network computer attacks from the inside to issue a large number of network packets, within the bandwidth occupied. Network management will find a very slow network, Ping routing substitution, I do not know which units affected. Intranet Acer BTP-58A1 Battery attack is usually the user installed the plug-in into the computer issued by the attack. Some of its own internal network attacks will change IP, make network management more difficult to find out who sent the network packet.
We are attacking intranet solutions distinguish from the router, blocking access to the Internet computer network packet sent capacity. Therefore, users will find that if the attacker program testing, immediately dropped the case happened, this is because they are identified as issued by the router attacks on the computer, automatically cut off due. The correct testing method is to use two tests, one issue of attacks on contracted router, another to see if access to the Internet. For the internal network attacks, additional control measures is the use defense switch directly to the computer's physical abnormal-line cut, but have the ability to switch to kill the defense line and Acer TravelMate 220 Battery Inspector embarrassed thin curtain frog cried phenolic structure of good dice?
Extranet Flow Attack
External network attacks from outside attacks, usually occurs in the use of a fixed IP users. Many Internet cafes since the use of a fixed IP, fiber, they will easily become targets of attack outside the network. At the same time because the external network attacks continue to transform the regular IP, is not easy to be denial or tracing. It is to look at the phenomenon of internal network traffic is normal, but the Internet is very slow or are not able to; watch the router WAN traffic, found that the download traffic is jammed, resulting in broadband access is not smooth.
External network traffic attack, can be supplemented by on-line to determine the number, but no easy solution. In some areas may require the ISP to replace IP, but it had several days later, they again attacked. Some users with more than one dynamic IP dial-up ADSL redundancy, dynamic IP on the more difficult to become the target of attacks. Attacks are outside the network traffic offense, may notify the ISP with the law enforcement agencies to trace, but results were not looking great. At present, the external network traffic as it is the most difficult Acer BTP-43D1 Battery to deal with attacks attacks.
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Mercredi 16 septembre 2009 3 16 /09 /Sep /2009 04:17
Overview of Lithium Battery
Li-ion Asus A42-A3 Battery is a class of lithium metal or lithium alloy anode material, the use of non-aqueous electrolyte solution batteries. First appeared in the lithium battery from the great inventor Thomas Edison, using the following reaction:
Li + MnO2 = LiMnO2
The reaction for oxidation-reduction reaction, discharge.
As a result of the chemical properties of lithium metal is very lively, making lithium Asus Laptop Battery metal processing, preservation, use, very high demands on the environment. Therefore, long-term lithium batteries have not been applied.
However, lithium batteries have become the mainstream.
The characteristics of lithium batteries
1, with a higher power-weight ratio, energy volume ratio;
2, high voltage, single-cell lithium battery voltage of 3.6V, approximately equivalent to three nickel-cadmium or nickel-metal hydride rechargeable battery voltage of the series;
3, Hsiao Ke prolonged storage of self-discharge, which is the most prominent advantages of the battery;
4, poor safety performance lithium batteries;
What is the specific energy it? Than energy refers to the unit weight Laptop Battery or unit volume of energy. With specific energy Wh / kg or Wh / L to indicate. Wh is a unit of energy, W is watts, h is the hour; kg is 1000 grams (weight units), L is liters (volume units).
The structure of lithium batteries
Lithium batteries usually have two kinds of shape: cylindrical and long square.
Battery internal spiral winding structure, with a very elaborate and highly permeable material in polyethylene film isolate positive and negative interval formed. Cathode including lithium and cobalt dioxide, lithium-ion composition and the collector current is composed of aluminum thin film collector. Formed by a sheet of carbon anode materials of lithium-ion collector and copper thin film composed of the composition of the current collector. Rechargeable batteries with organic electrolyte solution. PTC is also equipped with safety valves and components, so that the battery in an abnormal state and output short-circuit the battery to protect against damage.
Single-cell lithium battery voltage is 3.6V, the Acer BTP-ARJ1 Battery capacity can not be infinite, therefore, often single-cell lithium batteries and parallel processing, in order to meet the requirements of different occasions.
The application of lithium batteries
As the twentieth century, the development of microelectronics technology, miniaturization of devices has increased, the power put forward a very high demand. Li-ion battery had entered a practical stage of large-scale.
To be applied in the first cardiac pacemaker. As the lithium battery self-discharge rate is very low, flat discharge voltage. Makes the pacemaker implanted in human long-term use is possible.
Lithium batteries are generally higher than the nominal voltage of 3.0 volts, more suitable for Acer BTP-AQJ1 Battery integrated circuit power supply. Manganese dioxide battery, widely used in computers, calculators, cameras, wristwatches.
Now, a large number of lithium batteries used in mobile phones, it can be said to be the largest group of applications.
Study of lithium batteries
In order to develop a performance superior varieties, people of various materials were studied. Thereby creating an unprecedented product. For example, lithium sulfur dioxide batteries and lithium-thionyl chloride batteries is very characteristic. Their is also a positive active material and electrolyte solvent. This structure is only in the non-aqueous electrochemical system, to appear. Therefore, the lithium battery research, but also contributed to Acer BTP-APJ1 Battery the electrochemical theory of non-aqueous system development. In addition to using a variety of non-aqueous solvent, the polymer film was also carried out cell research.
The role of lithium-ion battery
Lithium-ion batteries currently liquid lithium-ion battery (LIB) and polymer lithium-ion battery (PLB) categories. Among them, liquid lithium-ion battery is the Li + intercalation compound as the positive and negative secondary battery. LiCoO2 cathode using lithium compounds or LiMn2O4, negative use of lithium - carbon intercalation compounds. Lithium-ion batteries as a result of the high voltage, small size, light weight, high energy, no memory effect, no pollution, little self-discharge, long cycle life and is ideal for the 21st century energy.
Successfully developed in 1992, Sony lithium-ion batteries. It's practical, so that people's mobile phones, notebook computers and other portable electronic devices greatly reduced weight and size. Greatly extend the usage time. As the lithium-ion Acer Aspire 1300 Battery do not contain chromium, as compared with the nickel-chromium batteries, greatly reducing the environmental pollution.
History of lithium-ion battery
Lithium batteries and lithium-ion batteries in the 20th century developed a new high-energy batteries. This battery Hang  wall osprey bran     Ren nO2, SOCL2, (CFx) n and so on. 70 years into practical use. Because of its high energy, battery voltage high operating temperature range, long storage life, etc., has been widely used in military and civilian small appliances, such as mobile phones, portable computers, camcorders, cameras and so on, in part to replace the traditional Acer LCBTP03003 Battery.
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Mercredi 16 septembre 2009 3 16 /09 /Sep /2009 04:14
Lithium-ion battery development prospects
Lithium-ion Acer TravelMate 4500 Battery for its unique performance advantages in portable appliances such as laptop computers, cameras, mobile communications are universally applied. At present the development of large-capacity lithium-ion batteries in electric vehicle to start a trial, expected to become the 21st century, the power of electric vehicles, one of the main driving force, and a satellite, aerospace and energy storage aspects applied. With the energy shortage and global environmental pressures. Lithium is now widely used in electric vehicle industry, especially iron phosphate lithium battery materials, the appearance, they also promote the development of the lithium battery industry and application.
The basic performance of the battery
(1) the battery open circuit voltage
(2) The battery internal resistance
(3) The battery voltage
(4) The charging voltage
Charging voltage is the secondary Acer Aspire 1410 Battery charging, the external power added to the battery voltage at both ends. The basic method of charging Youheng current charging and constant voltage charging. Generally use the constant current charging, the characteristics of the process of charging the charge current constant. As the charging progresses, the active substance was restored, the electrode reaction area is shrinking, the electrical polarization gradually increased.
(5) Battery Capacity
Battery capacity refers to the amount of electricity from the battery to obtain, often C, said the unit, said common Ah or mAh. The electrical properties of the battery capacity is an important indicator. The battery capacity is usually divided into theoretical capacity, practical capacity and rated capacity.
The capacity of the battery capacity of the decision by the electrodes, if the electrode capacity Acer Laptop Battery varies depending on the capacity of the battery capacity that smaller electrodes, but by no means the sum of positive and negative capacities.
(6), the storage battery performance and life of
One of the main characteristics of chemical power sources is used to release electrical energy can be stored when not in power. The so-called secondary battery for storage performance is to maintain the ability to recharge your batteries.
For the secondary battery, battery performance measure of good or bad, when life is an important parameter. Following a secondary battery charge and discharge, is called a cycle (or have been in this cycle). At a certain charge and discharge system, the battery capacity reaches a certain specified value before the battery can withstand the charge and discharge times known as the secondary battery life cycle. Lithium-ion batteries have excellent storage performance and long cycle life.
The characteristics of lithium-ion Laptop Battery
A. High-energy density
Lithium-ion batteries are the same weight capacity nickel-cadmium or nickel-hydrogen batteries for half of the volume is 40-50% nickel cadmium, nickel hydrogen 20-30%.
B. High-Voltage
A lithium-ion battery voltage of the monomer 3.6V (average), equivalent to three series of nickel-cadmium or nickel metal hydride batteries.
C. pollution
Lithium-ion batteries do not contain, such as cadmium, lead, mercury, like the harmful metals.
D. non-lithium
Lithium-ion batteries contain lithium metal, which is not on the Prohibition of the transport plane carrying lithium batteries on aircraft restrictions.
E. High cycle life
Under normal conditions, the lithium-ion battery charge and discharge cycles of more than 500 times.
F. No memory effect
Memory effect refers to the nickel-cadmium battery charge-discharge cycle, the Acer Aspire 1680 Battery capacity decrease. Lithium-ion batteries do not exist this effect.
G. Fast Charge
Rated voltage of 4.2V using a constant-current constant-voltage charger can make lithium-ion batteries in one to two hours to be fully charged.
Lithium battery protection circuit
By the two FET and special protection Manifold S - 8232 composition, over and over-charge control tubes FET2 discharge control tube FET1 series in the circuit to protect IC from the battery voltage is monitored and controlled, when the battery voltage up to 4.2V When, over-charging protection tube FET1 deadline, stop charging. To prevent malfunction, generally outside the circuit plus a delay capacitor. When the battery in a discharged state, the battery voltage down to 2.55V, the excessive discharge control tube FET1 deadline to stop power to the load. Over-current protection is greater when the load current flows out of date, control FET1 to close to stop the load discharge, the purpose is to protect the battery and FET. Over-current detection is the use of FET on-resistance as a sense resistor to monitor its voltage drop, when the voltage drop exceeds a set value, to stop discharging. In the circuit there is also generally added delay circuit to distinguish between inrush current and short-circuit current. The circuit is fully Acer TravelMate 2300 Battery functional, reliable performance, but are highly specialized and dedicated Manifold difficult to buy, easy amateur imitation.
Because Li + battery overcharge or over-discharge may cause an explosion and cause personal injury, so the use of such batteries, security is a major concern. Therefore, the commercial lithium-ion batteries typically include a protection circuit such as the DS2720 (Figure 7). DS2720 provides a rechargeable Li + batteries all the necessary protection features, such as: to protect the battery during charging to prevent the circuit overcurrent, by limiting the discharge voltage of the battery to extend battery life. The circuit diagram above. .
Simple charging circuit
At present, many businesses to sell without charging a single-board lithium battery. Its superior performance, low cost, can be used for home-made products and the maintenance of substitution lithium battery pack, so well received by the electronic enthusiasts love. Interested readers can refer to Figure 2 produce a charge sheet. The principle is: use a constant voltage to the battery, ensuring that no overcharge. Input DC voltage is higher than the 3-volt rechargeable Acer TravelMate 4000 Battery can be. R1, Q1, W1, TL431 adjustable precision regulator circuits formed, Q2, W2, R2 constitute the adjustable constant current circuit, Q3, R3, R4, R5, LED charging indicator for the circuit. With the rechargeable battery voltage was increased, the charge current will gradually decrease until the battery is full after the voltage drop on R4 will be reduced, so that Q3 ended, LED will be extinguished, in order to ensure the battery can be sufficient, please continue after lights out Charge 1-2 hours. When used please Q2, Q3 fitted with a suitable heat sink. Advantage of this circuit are: production of simple, easy to purchase components, charging safety, display and intuitive, and will not damage the battery. By changing the W1 series can be multiple-rechargeable lithium battery and change the W2 can be carried out large-scale charge current regulation. The disadvantage is that: no over-discharge control circuit.
Application of single-cell lithium battery for example
1, substitution of products for battery maintenance, many batteries: such as notebook computers that used by the maintenance found that damage to the battery pack when the battery is only an isolated problem. Can be the appropriate choice of a single lithium battery replacement.
2, producing bright mini flashlight I had used a single 3.6V1.6AH lithium Acer TravelMate 290 Battery with an ultra-bright white LED made of a micro-torch, easy to use, compact appearance. And because the battery capacity, the average nightly use of half an hour, has been more than two months remain before needing to recharge.
3, instead of 3V power supply
As a single lithium battery voltage of 3.6V. Therefore, only a lithium battery can be replaced by two regular batteries, to the radio, Walkman, cameras and other small household electrical appliances power supply, not only light weight, but also a long time of continuous use.
Lithium battery saved
After the lithium batteries need to save enough electricity. In more than six months can be stored at 20 ℃, showing that lithium batteries suitable for preservation at low temperatures. It has been suggested that rechargeable battery placed in the refrigerator interior preservation, is indeed a good idea.
There is the phenomenon of self-discharge of lithium batteries for a long time to save battery depletion will lead to the destruction of the internal structure of the battery, reducing battery life. Therefore, long-term preservation of the lithium Acer BATCL50L Battery should be every 3 to 6 months make up power once, that is charged to voltage of 3.8 ~ 3.9V (Li-ion battery voltage of 3.85V the best save so) is appropriate.
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