Computer power supplies - how does it work?
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Interference filter, relay and varistor. In order not to cause electromagnetic interference to other devices connected to a 230 V home or office power supply, as well as not to suffer from similar interference from other devices (for example, electric welding), an electromagnetic filter is installed at the input of the power supply unit. It consists of capacitors and chokes. A relay can also be features installed here, completely disconnecting the communication of the internal electronics with the outlet when the PSU is turned off. As well as a varistor to protect against strong power surges and even zipper strikes. But a varistor is effective only if the socket is properly grounded.
Diode rectifier. An EMF filter is always followed by an assembly of several diodes or a ready-made diode bridge. Its task is to turn alternating power into direct power by smoothing the sine wave. The power in the 230 V outlet, recall, is variable with a frequency of 50 Hz. Nearby, the standby power module is soldered, which is always under voltage and brings the computer out of sleep mode. That is why even a switched-off, but not de-energized PSU consumes a little electricity.
be quiet! System Power 9 400W is a representative of the junior series of power supplies of the German brand. Cables, usually, are not removable, but there is a slightly improved semi-modular CM sub-series. It was awarded a bronze certificate of energy efficiency, although thanks to the efficiency of 89% it is closer to the gold models. It can only work in 220-volt power grids, which, however, is not a problem in our region.
It is based on the HEC electronic platform with active reactive power correction and separate stabilization of low-voltage lines. The main line +12 volts is divided into two sublines — to power the processor and the graphics card, respectively. The total power on all lines is even more than the 400 watts claimed by the manufacturer. So the PSU can be safely compared with 500-watt models of other brands.
The APFC module. Instead of an ineffective passive reactive power correction module, a more progressive active PFC is now mainly used. Its task is to minimize the reverse outflow of electricity into the network, to reduce waste. The Active PFC consists of a transformer, transistors and a PWM controller. It was APFC technology that made it possible to increase the efficiency of power supplies to 80-85 percent, which meets the 80 PLUS White and Bronze certificates.
Holding capacitor. A large and often brightly coloured electric capacitor is perhaps the most noticeable component of the PSU at a cursory glance. Its task is to make the power supply stable, leveling voltage drawdowns and even a short-term complete power outage. Flagship BP models, thanks to a large-capacity capacitor or even two at once, have a holding time of up to 20 milliseconds. For example, the reflective lamps in the room may blink, and the computer continues to work flawlessly.
Even Japanese high-temperature capacitors (up to 105 degrees Celsius, manufactured by Nippon, Nichicon, Rubycon, Hitachi) wear out over time and require replacement. And less hardy Taiwanese (Teapo, CapXon, Elite, Ltec, Suscon) and, moreover, Chinese (ChengX, JunFu, AsiaX, up to 85 degrees) they can swell after a couple of years. Especially in case of prolonged overheating of the PSU due to heavy dustiness.
be quiet! Pure Power 11 FM 550W — the Pure Power series has undergone a long-term transformation from non-modular PSUs first to semi-modular, and then fully modular. In the process, the electronic filling has also changed: instead of FSP, CWT with gold efficiency is now used. The capacitors remained Taiwanese low-temperature to 85 degrees Celsius. However, the BP is poorly heated, so you don't have to worry about electrolyte wear.
The be quiet branded fan is responsible for cooling! on a screw-threaded bearing. They are more durable and quieter, thanks to better alignment than the usual bushing, which is used in the junior series of the be quiet PSU! System Power 9. Cables are made in the form of flat pliable noodles, which contributes to their neat laying. There are four graphics card connectors for connecting two pre-flagship GPUs.
Step-down transformer. The largest, and in the case of an 850 + Watt PSU, a very large part. Firstly, the transformer lowers the voltage from 230 to 12 volts. Secondly, it separates the high-voltage and low-voltage parts of the PS circuitry by galvanic isolation. Simply put, so that a strong voltage surge or zipper, even if it does not save the aforementioned relays and varistor, does not harm computer components. Usually, it is the step-down transformer that is the hottest component of the PSU (up to 100 degrees).
Low-voltage DC-DC converter. Usually made on a separate printed circuit board with vertical mounting, a group of transistors, chokes and electrolytic capacitors responsible for converting a 12-volt line to +5 and +3.3 V. Very low-cost, as well as outdated PSUs, can have simplified group stabilization. This promises large deviations in the output voltage, which promises potential broken sectors on hard drives. In addition, the highly efficient DC-DC stabilization allowed to increase the efficiency to the standard of 80 PLUS Gold and above (92+ percent).
be quiet! Straight Power 11 Platinum 650W is a pre—top series of power supplies, which, perhaps, most accurately meets the brand slogan "be quiet!". Up to half of the load on the PSU from the maximum, the fan noise does not exceed 10 dB, which is generally not distinguishable by ear from a distance of half a metre. Only passive and semi-passive PSUs are even noisier, but they are still at risk of overheating of the capacitors due to the complete absence of blowing.
The turntable is represented by the branded be quiet! Silent Wings 3 with a diameter of 135 millimetres and with an ultra-long HDB bearing. The Straight Power 11 BP series is divided into two subseries: gold and platinum, with an efficiency of up to 92 and 94 percent, respectively. The +12V line is divided into four independent sublines for better voltage stabilization: for two processors and two graphics cards, respectively.
Cooling and protection. Fully fanless PSUs are rare — these are either flagship models 80 PLUS Platinum and Titanium (up to 700 watts), or ultra-compact Pico-ATX (up to 200 watts). More often, either active cooling is always used, or semi-passive, starting the fan only after exceeding a certain load (for example, 30 percent of the maximum power). The speed of the turntable is controlled by either a primitive thermal sensor or a smart chip. It also switches off the PSU in case of a short circuit, overheating, overload and excessive voltage surges.
Fans with a diameter of 12 or 13.5 centimeters can be based on the simplest sliding bearing (up to 20 thousand hours of operation), a slightly more durable threaded or rolling bearing (on average 50 thousand hours), or the most wear-resistant hydrodynamic (150+ thousand). It is important not to confuse a hydrodynamic bearing with a hydraulic one. The second term is a marketing ploy, because it can be called any, even the simplest, bearing.
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