Basics of chassis and power

1. Briefly describe the classification of the computer chassis.

Chassis according to different classification standards have different classification, first, according to the shape of the chassis can be divided into horizontal and vertical chassis two kinds.

According to the size of the chassis can be divided into ultra-thin, half high, 3/4 high, all 4 types of higher.

According to the chassis structure can be divided into at, ATX, Micro ATX, NLX, Flex-atx. Among them is more common is at, ATX, Micro ATX Three kinds.

　　2. Briefly describe the classification of computer power supplies.

The computer power supply mainly includes at power and ATX power.

At power supply power generally 150w~220w, a total of four output (soil 5V, earth 12V), another to the motherboard to provide a P.G. Signal. The output line is two six-core sockets and several four-pin plugs, and two six-core sockets provide power to the motherboard. The at power supply is powered off by disconnecting the AC grid. The at power supply is used from 286 to 586 computers before the ATX power supply is present.

ATX Power supply and at power supply, its overall size has not changed, mainly increased +3.3v and +5v two auxiliary output and an open electromechanical flat signal, the output line to a 20 core wire to the motherboard power supply. ATX Power supply mainly has two versions, one is ATX1.01 version, the other is ATX2.01 version.

The most important difference is that the ATX power supply itself was shut down without a complete power outage, but a relatively weak current was maintained. It also uses this current to add a power management function.

　3. Briefly describe the main performance indicators related to computer power supply, and briefly explain the meaning of each indicator.

(1) Output voltage stability, the voltage is too low computer can not work, the voltage is too high will burn the machine.

(2) Output voltage ripple, power output ideal situation is a clean DC, the smaller the Exchange component, the Ripple Assembly on the chip caused adverse effects.

(3) Power good signal, power good signal for short p.g. or P.ok signal. P.G. Signal is very important, even if the power of the various DC output is normal, if there is no P.G. Signal, Motherboard still can't work.

(4) Power, power supply power is not greater the better, the key is the overall performance and quality of power, for ordinary users, 300W power supply can meet the requirements.

In addition, the input power of the point source phase number, rated input voltage, voltage range, frequency, input current. The rated voltage of input power varies with different countries or regions, and our country is 220V. Switching power supply voltage range is relatively wide, generally for 180v~260v. AC input power is 50Hz or 60Hz, and it is 47hz~63hz when the frequency variation range affects the characteristics of the switching power supply.

　What are the main differences between 4.ATX power and at power?

(1) power supply of the motherboard power cord is different, at the structure of the two 6-core separation power plug in the ATX structure by a 20-core dual-column plug, and with reverse plug protection, can effectively prevent the wrong plug or plug the power wiring and burned the motherboard.

(2) The ATX Power output voltage Group also provides a +3.3v voltage output to the AT-plus 12V and 5V of the at power supply, which directly supplies part of the 3.3V equipment;

(3) ATX Power to the overall power control than at the power supply is also different, ATX Power will automatically cut off the power of the motherboard, while shutting down the majority of its own circuit work, waiting for the host's power button again issued the start of the signal, unlike at the at the time of the switch machine will be pressed to press the

(4) The wind direction of the ATX power supply internal fan varies according to different versions. All the AT-structure power supply built-in fans take a method of pumping hot air out of the inside of the power supply.