【 Weak current college 】 computer power purchase considerations

The role of the power supply is our 220V AC into computer equipment required DC. Power in the first place after ** AC into DC power, voltage filter and get the computer to be used in compliance with the specifications of DC.
● Our Why use power?
This is because the computer uses DC and our city is 220V AC, so you want to use power rectifier, the alternating current into direct current, and our computer use in General for low-voltage, so also will be converted to DC and then some processing to supply the use of computers.
Power supply internal inductance, capacitance, transistors and other components, the AC will go through the power of the coil and capacitor, filtering out the high-frequency interference, use the second Aurora rectifier into tributaries electric, finally after switching circuit into low-voltage direct current, then by ** wave capacitor current supply to the system only after use.
● Power shortage?
Power of power by the power of the switch and power rectifier diodes, but a lot of buyers is to filter capacitor size to see the power of power, this is not correct, capacitors only represents the filter properties, the greater the capacitance, the output of the current smoother.
I've seen a lot of power, which has the actual power but in around 300W 1000 μ F used dual filter capacitors, 400W power supply capacitors are used around 450 μ F filter capacitor, what is? because some of the power of brand capacitors, although capacity is not large, but very good filter characteristics, you can effectively filter out high frequency clutter, but another reason is that some high power use Active PFC circuit (general power is no PFC or adopts a huge passive PFC circuit coil), such use of filter capacitor capacity is smaller.
● Power supply voltage instability?
When buyers bought power supply voltage in the BIOS to view, find the voltage constant voltage fluctuation, but some are too low, is not a power shortage of power?
This is normal, because the computer itself is a dynamic load, and increased power consumption while you work, so the voltage may vary according to the different State power have fluctuations, there is a power output of the DC is not possible to reach the theory of absolute smooth, but there are a range of ripple
And voltage values are error is normal, unless you talk to ME as a can adjust the output voltage of power supply, however if the voltage of the error in the hardware can accept, that doesn't affect the computer hardware, so we dont care about the power output of bit error, Intel on power is also developing a specification:

+ 5V: + 4.75V to + 5.25V (5%)
+ 12V: + 11.40V to + 12.60V (5%)
3.135V 3.3V: + to + 3.465V (5%)
-5V:-4.50V to-5.50V (10%)
-12V:-10.80V to-13.20V (10%)
5VSB: + 4.75V to + 5.25V (5%)
Buy power considerations more
● CPU voltage and power?
A lot CPU voltage DIYer found low, this is not also illustrates the power shortage? this is regardless of the power supply, CPU voltage is determined by the Board of the power supply module converts the voltage of the power supply to provide the quality of the CPU voltage to a large extent by the CPU power supply circuit. General CPU voltage value error at 5 per cent or less is normal.
● Power supply too hot?
Due to the power needs of rectifier, transformer
So when the internal components work generates heat, if power work long hours in the hot state, then the internal component life will significantly shorten, thermal power is also very important, there is a lot of power already abandoned the traditional single 8CM fan cooling, switch to a better heat dissipation, noise lower 12cm large fan or dual fan cooling, more use of the turbine ventilator, heat pipe or water cooled to resolve the problem of the heating power. Intel's specifications, points out the power of temperature does not exceed 50 ° c is normal, power supply manufacturers in General will follow the specifications for the design and production.