Laptop in modern life for everyone's work, life and learning to provide a lot of help, and the power adapter as the lifeblood of notebook computers, is crucial, so we have a certain understanding of it
Power is, of course, the primary indicator of power and the only indicator that many people know. Now the core of Prescott: Pentium 4 computer power has reached 103 ~ 120W, the high-end graphics cards also has more than 6800 power not resigned to playing second fiddle, GeForce 100W. Therefore, the power rating from the previous 200 ~ 250W to more than 300W, and some high-end power even do 550 ~ 600W, it is astounding. However, for general "CPU" and "low" graphics cards larger than 2.0G level, the power consumption of the machine is generally around 100W. The following are typical typical host power meters.
It can be seen that under the general Sui conditions, the power supply will not work at full load, there are not small margin. This is to ensure that the power long-term reliable operation to provide a guarantee, but also so many poor power to deceive, they dare to mark power is quite big, but in fact did not reach.
2. power factor
The so-called power factor refers to AC power drive if the load is capacitive or inductive load, will cause a phase shift between current waveform and voltage waveform, the power load is less than the useful to promote the total power consumption of the current system, the ratio of them is power factor. When the power factor could reach 0.6, which means that more than 40% of the electrical energy loss in the circuit, and the power is not recorded on the general meter, so the national standard of international standards, more and more strictly on the electrical power factor to limit, the general requirements to reach 0.8 above.
Efficiency refers to the ratio of the output power and input power, which reflects the power switch, transformer, rectifier and filter circuit and other components of the loss and heat loss (including the emitted electromagnetic radiation and noise energy, but relatively speaking, not worth mentioning). Obviously, if the power efficiency is low, not only the output power is low, but also the heat is serious, easy to malfunction, fan noise will be obvious.
4. voltage adaptation range
The United States, Japan and other countries use 110V AC power standards, while China and Europe are 220V. The traditional method is to use a toggle switch to change the rectifier filter, to adapt to the two kinds of voltage, while the new high-end products with wide voltage range of design, can accommodate 90 ~ 240V input voltage, in the power supply situation of poor area especially by.
The general computer power supply is fan forced exhaust heat dissipation, the main source of noise is the fan. A lot of power supply small fan noise is very annoying, and now a lot of high quality power using transverse 9cm and even 12cm fan, and the use of temperature control design, can take into account the cooling and mute requirements.
EMC, Elect ro M agnetiCCompatibility, electromagnetic compatibility. This is the characteristic index associated with EMI (electromagnetic interference), and now there are national mandatory standards. Good EMC design requires not only the tolerance of EMI to the standard, but also the degree of EMI production should be low enough.