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Power Supply Factor

Posted:31 October,2009

If the output is required to be isolated from the input, as is usually the case in mains mac g3 power supplies Replacment Cheap Sales, the inverted AC is used to drive the primary winding of a high-frequency transformer. This converts the voltage up or down to the required output level on its secondary winding. The output transformer in the block diagram serves this purpose.If a DC output is required, the AC output from the transformer is rectified. For output voltages above ten volts or so, ordinary silicon diodes are commonly used. For lower voltages, Schottky diodes are commonly used as the rectifier elements; they have the advantages of faster recovery times than silicon diodes and a lower voltage drop when conducting.

Simpler, non-isolated mac g4 power supplies Discount Cheap Sales contain an inductor instead of a transformer. This type includes boost converters, buck converters, and the so called buck-boost converters. These belong to the simplest class of single input, single output converters which use one inductor and one active switch. The buck converter reduces the input voltage in direct proportion to the ratio of conductive time to the total switching period, called the duty cycle.

A feedback control loop is employed to regulate the output voltage by varying the duty cycle to compensate for variations in input voltage. The output voltage of a boost converter is always greater than the input voltage and the buck-boost output voltage is inverted but can be greater than, equal to, or less than the magnitude of its input voltage. There are many variations and extensions to this class of converters but these three form the basis of almost all isolated and non-isolated DC to DC converters. Switching mac g3 power supplies Fashion Cheap Sales in computers, TVs and VCRs have these opto-couplers to tightly control the output voltage.

A feedback circuit monitors the output voltage and compares it with a reference voltage, which is set manually or electronically to the desired output. If there is an error in the output voltage, the feedback circuit compensates by adjusting the timing with which the mosfets are switched on and off. This part of the power supply is called the switching regulator. The Chopper controller shown in the block diagram serves this purpose. Depending on design/safety requirements, the controller may or may not contain an isolation mechanism to isolate it from the DC output.

Open-loop regulators do not have a feedback circuit. Instead, they rely on feeding a constant voltage to the input of the transformer or inductor, and assume that the output will be correct. Regulated designs compensate for the parasitic capacitance of the transformer or coil. Monopolar designs also compensate for the magnetic hysteresis of the core.The feedback circuit needs power to run before it can generate power, so an additional non-switching mac g4 power supply Discount Cheap for stand-by is added.

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Power Supply Troubleshooting

Posted:31 October,2009

When you troubleshoot a user’s PC, don’t forget to test the mac g3 power supply Replacment Cheap with a multimeter. Learn some easy-to-follow techniques to help you rule out the possibility that the power supply has gone bad.It may seem unlikely, but over a quarter of all PC problems are in some way related to trouble with the power supply. It’s tempting to think that if something is wrong with the power supply, the PC simply won’t power up at all, making the culprit easy to identify. But this isn’t always the case. Power-supply problems can also cause lockups, unexpected reboots, and intermittent boot problems. To help you ensure that you’ve covered all of the bases, I’ll explain how to test the PC’s power supply using a multimeter on your power connections and motherboard.

Almost every PC mac g4 power supply Discount Replica Fashion in use today is either an AT or an ATX power supply. The main difference between the two is the number of connectors attached to the wires. But regardless of which type of power supply you’re working with, there are some basic components that apply to all power supplies. The first is the power connection, which is where the power supply connects to the electrical outlet. Next is the motherboard power, which is delivered via a set of cables running from the power supply.

Because of the many brands of multimeters that are available, I can’t provide you with specific instructions on how to use your particular brand. So before you begin, make sure you have a thorough understanding of how to use your multimeter. Using it incorrectly could result in your receiving a strong electric shock, or it could destroy your multimeter.Mac g3 power supplies Onsales Discount also have a fan (which you can troubleshoot easily by just looking at it to see if it’s working).

The power supply’s purpose is to convert the 115-volt alternating current supplied by an electrical outlet into direct current that the PC can use. Typically, the power supply converts the AC into a 12-volt, 5-volt, or 3.3-volt direct current. The 12-volt direct current is used to power devices with motors, such as hard drives and CD-ROM drives. The 5-volt and 3.3-volt outputs are used to power various electronics on the system board.

If you’re using an AT power supply, you’ll have two connectors, called P8 and P9, that connect the power supply to the system board. Detach the P8 and P9 connectors from the system board but make sure to note their positioning. Although both connectors are keyed to prevent you from putting them on backwards, it is possible to accidentally reverse the two connectors. Reversing the connectors will almost certainly destroy the motherboard and will likely destroy the mac g4 power supply Fashion Oem Onsale,too. When replacing the P8 and P9 connectors back on the motherboard, remember that the two black ground wires should be next to each other.

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Power Supply Definitions

Posted:31 October,2009

Mac g3 power supplies Replacment Cheap Sales themselves require several definitions (these are discussed later in this article), but the requirements of the amplifier that is to be connected need to be understood before we start. This makes a very big difference to the way the supply performs.Poor earthing practices, such as connecting components to the nearest available ground reference can also create problems, and these can introduce hum, or more usually a “buzz” into the signal circuits. This applies equally to Class-AB and Class-A amplifiers, but is usually more apparent with Class-A since the maximum current is drawn on a continuous basis. It is not only the amplifier which creates current pulses, but the filter capacitor combination as well.

The mac g4 power supply Onsale Fashion Replica rectifier diodes usually conduct for only a short time during each AC cycle – this may be as little as 3 or 4 degrees at idle, but both the angle of conduction and the amplitude of the current pulse will increase as more power is drawn from the supply.Any amp that draws a quiescent current through the output devices is by definition, Class-AB. The main problem is the revolting waveshape of the current on each supply lead, typically half-wave pulses, in sympathy with the program content.

These waveforms – this is current, not voltage – have sharply defined transitions, and as such will generate a magnetic field which varies with the current. Since a sharp transition equates to high order harmonics, care must be taken to ensure that voltages are not induced into the input stages of the amp from the supply lines. Because of the low inductance of the wiring of an amp, these problems are going to create distortion components which will tend to be worse at higher frequencies. These amps draw a large current on a continuous basis, and place a completely different loading on the mac g3 power supply Discount Genuine Fashion.

The current pulses are gone from the supply leads, but the rectifier and filter now must handle the maximum current on a continuous basis. The continuous load creates a new set of constraints on the design of a power supply, and the use of a Class-A amp implies that the builder already wants the very lowest noise. Although the noise of the power supply DC output will normally be low because of extensive filtering, regulation or a capacitance multiplier, the switching noise of the diodes in the rectifier can become more than a nuisance if proper care is not taken.

There are others, but they are not commonly used in low voltage amplifiers. The dual full wave is probably the most common of all, and some further analysis of this rectifier shall be covered next. I have chosen to ignore half wave rectifiers,but decided to add voltage doublers. These are normally only useful for low power applications where their operation is not critical. This is especially true of preamp mac g4 power supplies Onsales Cheap, which will almost always be followed by a regulator.

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Power Supply Requirements

Posted:31 October,2009

Mac g3 power supplies Onsales Replacment are needed for every type of amplifier (or any other electronic equipment for that matter) we will ever use. I do not intend to deal with “esoteric” designs with interesting names, but the simple, linear power supply that is still the mainstay of audio.Somewhat surprisingly perhaps, the fundamental requirements of the final design are not greatly influenced by the different loading presented by the two amp types described above. The continuous rating of a Class-A amp means that you must design the supply for a continuous (rather than transient) current, but since we are discussing properly designed, quality power supplies, the final result will often be quite similar.

With only these three criteria, it is possible to design a suitable mac g4 power supply Fashion Cheap Sale for almost any amplifier. I shall not be describing high current regulators or capacitance multipliers in this article – only the basic elements of the supply itself. These other devices are complete designs in themselves, and rely on the rectifier/ filter combination to provide them with DC of suitable voltage and current.

The first component of the power supply is the transformer. Using magnetic coupling between windings, the transformer is used to isolate the amplifier (and the users) from the mains voltage, and to reduce the voltage to something the amplifier can tolerate. The primary winding will be rated at 240, 220 or 120V AC depending on where you live, and the secondary will be a more user friendly (or less user hostile) voltage to suit the amplifier. Having searched the Web for reference material (and found very little!), this would appear to be the definitive article on the design of a ’simple’ linear mac g3 power supply Replica Cheap Onsale for a power amplifier.

The DC output is approximately equal to the secondary voltage multiplied by 1.414, but as we shall see, this is a rather simplistic calculation, and does not take the many variables into consideration. At light loading, this rule can be applied without fear, and it will be accurate enough for most applications. When an appreciable current is drawn, this simple approach falls flat on its face.

These occur in all situations, and the mains voltage at any point in time will usually be somewhat different from the nominal voltage quoted by the supplier. Any variation of 10% or less can be considered “normal”, and greater variations are not at all uncommon. In nearly all cases, an amplifier is rated at a certain power output into a specified load impedance, and at the nominal mains voltage. For those who live close to a sub-station or pole transformer, expect the voltage (and power output) to be higher than quoted – the rest of us can expect a lower mains voltage and less power, especially during peak electricity usage times using mac g4 power supplies Replica Onsales.

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Power Supply Testing

Posted:31 October,2009

Mac g3 power supplies Discount Replacment are a huge industry, with so many manufacturers, models, and specifications, it can become quite an intimidating task for the average consumer to choose wisely. All too often we see retail boxes with huge stickers stating the overall rated power, but exact specifications are often omitted or obfuscated. In our primer article about power supplies, we covered the basics of how a modern power supply works and many related common questions. This article is to explain how we will be testing & reporting power supplies here at extreme Overclocking, and hopefully allow the consumer to make better purchasing decisions.

Every PC consumes different amounts of power, which is why there are different sizes of mac g4 power supplies Replica Fashion Discount available. There are devices available like the Seasonic Power Angel, or the Kill-A-Watt meter, which give reasonably accurate figures for the amount of AC power a device consumes (and can even calculate out PF automatically). If you had one of these devices, you could make a rough estimate of DC wattage requirements by guestimating your PSU is about 75% efficient. However, a more accurate method to measure the DC wattage would be to use a voltmeter & ammeter to measure each rail.

An extreme overclocking forum member has been kind enough to create & maintain a nice online PSU calculator program, called the eXtreme PSU Calculator. Note: The wattage ratings that the eXtreme PSU Calculator uses are considered “absolute maximum” figures, so the total wattage calculated should have a reasonable amount of excess capacity compared to the actual hardware.Determining overall power requirements is only one part of the equation, choosing a quality mac g3 power supply Cheap Onsale to meet these needs is the real challenge.

While the ATX12V & EPS12V 24pin (2×12) main power connectors are pin compatible, the main ATX ges connector is different. For all practical purposes you can consider the ATX ges standard dead, there were only a couple motherboards that ever supported it. For all practical purposes any mainstream consumer level power supply will conform to the ATX12V standard, either v2.x or the older v1.3 standard.EPS12V specifications are a lot more beefier than ATX12V specs. However, some of these extra 12V rails are wired to connectors that will not fit a regular ATX motherboards. Skim through the PDF documents for more information about this.

Some portable power supplies can also sometimes be charged before you leave home and can carry that charge, even away from mains supply power points. This is particularly useful if you decide to go hiking in a remote area and discover that your mobile has run out of power when you need it in an emergency. With a portable mac g4 power supply Discount Cheap Sale, you can recharge your phone there and then.

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Portable Power Supply

Posted:31 October,2009

Some portable mac g3 power supplies Onsales Replica Cheap can also sometimes be charged before you leave home and can carry that charge, even away from mains supply power points. This is particularly useful if you decide to go hiking in a remote area and discover that your mobile has run out of power when you need it in an emergency. Unlike many users of laptops, I do not have to take computer to meetings. I only need to carry it to a new site, set it up at a fixed location, and work there for a month or two. Given this pattern of usage, I feel using a desktop will be more productive. (Of course, I will still bring the ultra-light Dell Latitude with me, just in case.) There is no need for gaming, but graphics-intensive applications are used from time to time.

With a portable mac g4 power supply Discount Replacment Sale, you can recharge your phone there and then.Since I don’t need to lug it around, a machine that can fit into a wheeled carry-on suitcase would be good enough for me. I do not want a tiny machine, which usually means fewer expansion slots and mediocre performance- I want it to be as powerful as possible, as long as it can stay within the size limit.

Most airlines limit the carry-on luggage size to 9″ x 14″ x 22″, but that is for the outer shell of the suitcase. Taking into account all the padding, round corners, handles, and inner steel frames etc, I would say the maximum size for the machine would be:A relatively new design.The type of motherboard used is the FlexATX, but most mini-PCs come as barebones units — motherboard, power supply and chassis in one assembled unit. They’re light, portable, extremely quiet, and in many instances they are just as powerful as a standard desktop system. The drawbacks are the limited upgrade potential, and limitations imposed by a small mac g3 power supply Fashion Oem Discount(high-powered video cards can have a lot of trouble in mini-PCs).

Today’s computer chip manufacturers have succeeded in a remarkable sleight of hand: convincing the buying public that the measure of a computer’s quality is dependent upon a glamorous chip. Yet savvy users understand that the real driving force behind a stable, powerful computer is a rugged power supply. Unfortunately, the low profile of the prosaic power supply has let many users choose a computer with an inadequate or low quality power supply, only to suffer a myriad of problems.

Fortunately, you don’t need to be an electrical engineer to troubleshoot power supply problems or to replace a failing power supply. In this article, we’ll help you make sense of all the components in a power supply and how they function. After explaining the ins and outs of power supplies, we’ll also show you how to choose a replacement mac g4 power supply Fashion Cheap Onsale and install it in your computer.

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Common ATX Power Supply

Posted:31 October,2009

Basically ATX is the same architecture as Baby-AT except it’s turned 90 degrees, has a more advanced mac g3 power supply Replacment Discount Cheap connector, mounts the CPU away from the expansion slots to accommodate longer PCI cards, and has side-mounted I/O connectors hardwired onto the board. Basically this design was implemented to make computers cost less by having more integrated peripherals and to cut down on build times and electro-magnetic interference (EMI) by eliminating a lot of the internal cabling. The official ATX specification is 12″x9.6″, but manufacturers have the option of making the board smaller while still retaining the ATX standard. For that reason you’ll find that many ATX boards are not exactly 12×9.6.

ATX also refers to the mac g4 power supply Replica Cheap Sale and chassis requirements that an ATX motherboard needs. An ATX power supply must deliver a certain amount of power at the correct frequency, and it must have the proper connectors. Modern Pentium4-approved ATX power supplies have a four-pin 12V connector that provides extra power for the voltage regulator. This is required on all Pentium4 boards and recommended for some of the newer AMD-based motherboards that have the extra 12V socket. A derivative of the full-size ATX motherboard standard.

Mini-ATX motherboards are not all that common, although there are still new motherboards out there that conform to this size standard. It is functionally no different than the ATX standard except for its slightly smaller size; Mini-ATX motherboards generally have very few onboard peripherals and can have a somewhat cramped board design which makes them difficult to install. Asus motherboards generally have a standard Molex (drive) power socket on the motherboard that allows you to give power to the voltage regulator using a regular drive power cable even if you don’t have a mac g3 power supply Replica Discount Sale that has one of the newer-style 12V connectors.

There is no standard for towers, so what one manufacturer calls a mid-tower, another may call a super tower. They can have any number of drive bays  and generally come with a power supply already installed. It’s become quite popular to put an acrylic window in the side of tower cases, but this practice can cause problems with the design of the system that force it into non-compliance with FCC regulations. If you see a pre-modded case that does not come with a power supply in it, chances are it is not FCC compliant and you should probably stay away from it. Tower cases can be made of a variety of materials, but steel and aluminum are the most popular. Steel is obviously a lot more durable, but also heavier. Aluminum is flimsy and easily bent and it cannot be easily painted, but it is extremely light and better at conducting heat conductor than steel with using mac g4 power supplies Onsales Discount.

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Power Supply Fundamentals

Posted:31 October,2009

Often one of the biggest noise makers in a PC, the mac g3 Power Supply Replacment Cheap Unit delivers regulated DC voltages to various components. Computer PSUs are switching mode types, which provide relatively high efficiency at low cost. They utilize forced air cooling, usually an 80mm fan, and sometimes incorporate a second fan. The fan is the primary source of noise in a PSU. Coils in a PSU can buzz and hum, especially when pushed under high loads, but usually fan noise masks coil noise. Typically, the fan is rated for higher than the maximum airflow needed to keep the PSU cool. It’s cheap engineering insurance for the manufacturer and also fulfills the case cooling role of the PSU fan.

Mac g4 power supplies Discount Replica Sale fulfill a pretty simple role in today’s computers, providing clean, uninterrupted power to the computer’s components. On the surface, this seems a mundane task, but the truth is a bit more complicated. Your computer can’t simply use the electricity that comes out of your wall outlet. Standard household electricity is AC (alternating current), and your computer uses DC (direct current) to power its internal devices. In addition, most household current is 110 volts, much too powerful for today’s sensitive electronic componen

In the ATX case specification, cool air is drawn into a typical case from vents in the front panel. The incoming air helps cool components as it moves through the case, becoming warm in the process. It is evacuated through the PSU and out the rear by the PSU fan. So the loud, fast fans do help to keep a case cooler. Manually varying a high airflow PSU fan can cause CPU temperature to be affected as much as 5-6 degrees C. Now, they are up over 130W. The airflow arrangement of exhausting hot case air out through the PSU no longer makes as much sense as it did in the past. The PSU has to handle both its own self-generated heat, which is naturally higher than before, as well as the heat generated by the other components with mac g3 power supply Discount Replica Sale.

Fast-spinning fans make a lot of noise, especially when confined in a small space with nearby airflow obstructions. It is not unusual for the noise of a PSU to be 12-15 dB higher than the rated noise of its fan in free air. The noise is further exacerbated by the way a PSU is mounted in a typical tower case: the typical 4~5 pound weight “hangs” off the top of the back panel on 4 screws. In this mounting configuration, excitation of case panel resonances by direct transfer of PSU fan vibrations is almost unavoidable. The end result is more noise, especially as a droning type of hum in the lower frequencies.

The quietest PSUs on our list feature either no fan at all or a fan that spins at low speed under most conditions. Keep in mind that components will tend to run a bit hotter than usual as a result of reduced airflow by mac g4 power supplies Onsale Replacment.

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Power Supply Dissipation

Posted:31 October,2009

Perhaps the toughest challenge that designers of portable mac g3 power supplies Replica Discount face is powering modern high-performance CPUs. Recently, CPU supply currents have doubled every two years. In fact, today’s portable core supplies can require up to 60A or more, at between 0.9V and 1.75V. But while current requirements have increased steadily, the space available for power supplies has not—a fact that has stretched thermal designs to the limit, and beyond. Supplies with such high current are typically broken into two or more phases, with each phase handling between 15A and 30A. This approach eases component selection. A 60A supply, for example, essentially becomes two 30A supplies. But because this approach does not create additional board space, it hardly eases the thermal design challenge.

Mosfets are the most difficult components to specify for high-current mac g4 power supplies Replica Cheap Sale. This is especially true for notebook computers, an environment where heatsinks, fans, heatpipes, and other means of disposing heat are typically reserved for the CPU itself. Thus, the power supply often contends with cramped space, still air, and heat from nearby components. Moreover, nothing is available to aid power dissipation except a minimal amount of PC-board copper underneath the supply. For all but the lightest loads, the drain-to-source voltage of the synchronous rectifier’s Mosfet is clamped by the catch diode during turn-on and turn-off. 

During this process, the junction temperature of each Mosfet is assumed, and both the Mosfets’ power dissipation and allowable ambient temperature are calculated. The process ends when the allowable ambient temperature is at, or slightly above the maximum temperature expected within the enclosure that houses the mac g3 power supply Fashion Oem Discount and the circuitry which it powers.

In a sense, assuming a Mosfet junction temperature and then calculating an associated ambient temperature entails working backwards. After all, the ambient temperature determines the Mosfet’s junction temperature—not the reverse. However, the calculations required when starting with an assumed junction temperature are easier to accomplish than when starting with an assumed ambient temperature and working from there.

Mosfet selection begins by choosing devices that can handle the required current, given an adequate thermal dissipation path. Selection ends with quantifying the needed thermal dissipation and ensuring the dissipation path. This article provides step-by-step instructions for calculating the power dissipation of these Mosfets and determining the temperature at which they operate. It then illustrates these concepts by stepping through the design of one 30A phase of a multiphase, synchronous-rectified, step-down CPU core mac g4 power supply Discount Cheap Sale.

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Power Supply Review

Posted:31 October,2009

Put the pedal to the metal, feel the rush, the power and unrivalled performance of the high wattage mac g3 power supply Replica Onsale you know you want. Allieviate any guilt you may have, knowing the Antec’s TruePower Quattro is 80 Plus certified. Designed specifically for the most demanding computer specifications, this power supply features four 12V output circuits ensuring unbeatable system stability. Combined with ±3% load regulation to protect your computers components, gold plated connectors for superior conductivity, modular and sleeved cable connectors and 80 Plus certified, TruePower Quattro delivers when the race is on. Don’t be last across the finish line. Unquestionably stable power through high efficient technology for tomorrows ultimate PC.”This time around, I will be putting it through its paces, following the OCC testing methodology and giving it a little more to think about.

The Antec Truepower Quattro 1000W mac g4 power supply Discount Cheap Sale comes in a mainly matte white box with black end panels, with color only used sparingly for photographs and logos. The lid clearly shows the 1000W rating of the power supply, which is used as a window through which a photograph of the power supply can be seen. Dual graphics ready, 80 Plus and Quiet Computing logos, along with a short sentence telling us the power supply is a high performance modular power supply, complete the picture. The base of the box carries a list of main features with the 80 Plus Certified logo and a brief explanation of what 80 Plus is all about, in English, French and German. Color photographs of the available connectors along with quantities run along the bottom of the base.

The front panel contains an Antec logo, power supply dimensions in imperial and metric, and a small color photograph of the power supply. The back panel gives some of the technical detail, including specification table, warehouse and storage instructions, and the AQ5 warranty logo.Lift the lid and the user manual is the first thing you see along with mac g3 power supply Cheap Replica Sale protective foam envelope, captive cables with power cord on one side and all the modular cables contained in a plastic bag on the other side. Remove the top foam protective lid and the Antec Truepower Quattro 1000W is revealed with its white racing stripes and racing number, keeping with the racing car theme mentioned in the introduction.

Congratulations to Antec for being one of the few manufacturers to send me the UK version with the correct power cord. The packaging is fairly simple and not too flashy. It scored an OCC Gold award the first time around, so let’s see how it performs and what award, if any, it merits when supplying its full power rating of 1000W.Perhaps Antec feels it doesn’t need to be, letting the mac g4 power supply Fashion Replica Sale do all the talking – we will see. The accessories set is basic, but adequate – a few cable ties, however, would have been a welcome addition.

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