【 Weak current college 】 computer power supply specifications 】

1. power
Power is, of course, the primary indicators of the power supply, but also many people who know only one index. Now the Prescott core: Pentium4 PC power consumption has reached 103 ~ 120W, high-end video card outdone, GeForce6800 power consumption than 100W. Therefore, the power rating from the previous 200 ~ 250W to bove, some high-end power even do 550 ~ 600W, is appalling. However for the average is greater than the "old 2.0G level CPU plus low graphics", the complete machine consumes the electricity normally around 100W. The following is a typical host power common table.

Visible condition of the power sui generally are not full-load, there is no small margin. This to guarantee the power supply provides long-term reliable work, but also as a result, many poor quality power supply to the bait, they are afraid to mark big power, but in fact did not reach.

Many people are accustomed to long close computer power supply, power supply always on standby, not only to long-term consumption 10 Watts of power, but also easy to enable standby circuit due to long-term continuous working triggered fault (at this time no fan exhaust, easy to concentrate the heat), are also vulnerable to accidental damage caused by lightning, etc. So we must cultivate close power gate.

2. power factor

The so-called power factor refers to the AC power push load if the capacitive or inductive load, makes the current and voltage waveforms between the phase shift, results driven load of useful power less than in the current wave of system consumes power, their ratio is the power factor. Power factor when Jr. may reach 0.6 following, this means that 40 per cent of the electric energy is lost online way, and this power is not recorded on the General electric meter, international standards, national standards are becoming more and more strictly on electrical power factor restrictions, General requirements 0.8 above.

Power factor is you can get through appropriate compensation correction improves, this is PFC (PowerFac-tol ' Correction) c in computer power supply since its first level of filtering on a rectifier, capacitive load, in circuit conspiracy into appropriate adjustment of the current wave of inductance, so that the total load near purification resistive characteristics. This is the "passive PFC" principle.

Now the national enforcement of CCC, a request for power factor, so most power is used the iron core inductor as passive PFC components. The best choice here remind everyone of famous brand of high-quality products, do not suffer heavy losses on the cheap.

High-end power supplies using Active PFC circuit for power factor correction, you can get better results.

3. efficiency

Efficiency refers to the power supply output and input power ratio, it reflects the switch tubes, transformer, Rectifier filtering circuit components loss lost power fever (of course including electromagnetic radiation and noise emission of energy, but relatively insignificant). It is obvious that if the power efficiency low, the output power is low and fever, easy out fault, fan noise is also very obvious.

4. voltage range

The United States and Japan use standard 110V AC power, and China and Europe is 220V. Traditional methods of adaptation is to use a toggle switch to change the way the rectifier filtering, to accommodate both voltage and new high-end products using wide voltage range of design, can accommodate 90 ~ 240V power supply voltage input, in areas that are deteriorating particularly useful.

5. noise

All ordinary computer power is the use of the thermal fan forced exhaust, the main source of noise is the fans. Many of the power of small fan noise is very annoying, but now many high-quality power supply using Mercurial's 9cm and even 12cm fan and temperature control design, you can take the heat and mute.

Some old-fashioned bad power supply operating frequency only 20 kHz, sometimes even down to audio, produce extremely annoying high frequency noise, ear sensitive people will hear that people, especially children, listening sensitivity is particularly harmful. A typical high-quality power output stage rectifier filtering before the waveform as 3 below.

The numeric value indicates the oscilloscope to 66.811kHz, scan speed in 5 μ s. Such a high frequency loss in favour of cores and miniaturization, but on the power switching valve's parameter requirements are higher. In any case it is definitely far beyond the audible range.

6.EMC properties

EMC-electromagnetic compatibility ElectroMagnetiCCompatibility,. This is and EMI (electromagnetic interference) performance indicators produced by the company, now has a national mandatory standards. Good EMC design not only require the degree of tolerance EMI compliance, but also produce the extent to which EMI to low enough. Computer power tolerance. EMI General no problem, the problem is that it is a serious EMI interference sources, radiation, or feedback on the power grid, are rather serious interference, must take appropriate means to resolve. All manufacturers of different power products larger differences. Excellent product generally consists of two levels above EMI filter circuit. It bidirectional filtering measures makes power internal and power grid "well not guilty of the river", are kept in good condition.