Ch 4 - Power Supply
Today's power supply form factors are
-ATX, -ATX12V v1.x -ATX12V v2.x -LFX12V (low profile) -SFX12V (small form factor) - EPS12V (used with server motherboards and has an extra 8-pin connector) -CFX12V (compact form factor) -TFX12V (thin form factor), -WTX12V (workstation form factor for high-end workstations and select servers) -FlexATX (smaller systems that have no more than three expansion slots).
Are power supplies universal?
-Both Intel and AMD certify specific power supplies that work with their processors. The same is true for video card manufacturers. -A computer manufacturer can also have a proprietary power supply form factor that is not compatible with other vendors or even computer models. -Laptop power supplies are commonly proprietary.
What are drawbacks of SPS (standby power supply).
-It does not provide constant power like the UPS. -An SPS is not as effective as the UPS because an SPS pro- vides no protection against noise or under/over voltages. -The SPS must detect a power-out condition first, and then switch over to the battery to supply power to the computer.
What are some troubleshooting questions can help you determine the location of a power problem?
1.Did the power supply work before? If not, check the 115/230 switch on the power supply and verify that it is on the proper setting. 2.Is the power supply's fan turning? If yes, go to step 5. If not, check the wall outlet for proper AC voltages. If the wall outlet is OK, go to step 3. 3.Is a surge strip used? If so, check to see if the surge strip is powered on, then try a different outlet in the surge strip, or replace the surge strip. 4.Is the computer's power cord OK? Verify that the power cord plugs snugly into the outlet and into the back of the computer. Swap the power cord to verify it is functioning. 5.Are the voltages going to the motherboard at the proper level? Check the voltages to the motherboard. If they are low, something may be overloading the power supply. Disconnect the power cable to one device and re-check the voltages. Replace the power cable to the device. Remove the power cable from another device and re-check the motherboard voltages. Continue doing this until the power cord for each device has been disconnected and the motherboard voltages have been checked. A single device can short out the power supply and cause the system to malfunction. Replace any device that draws down the power supply's output voltage and draws too much current. If none of the devices is the cause of the problem, replace the power supply. If replacing the power supply does not solve the problem, replace the motherboard.
What protects the computers or devices attached to the power strip?
A MOV (metal oxide varistor), which protects the computer or device that plugs into one of the outlets on the surge strip.
What is a UPS (uninterruptible power supply)?
A UPS (uninterruptible power supply), sometimes called online UPS or true UPS, provides power to a computer or device for a limited amount of time when there is a power outage.
What type of power supply does a computer use?
A computer uses a switching power sup- ply. It provides efficient power to all the computer's internal components (and possibly to some external ones, such as USB devices). It also generates minimum heat, comes in small sizes, and is cheaper than linear power supplies. A switching power supply requires a load (something attached to it) in order to operate properly.
What is a dual rail power supply?
A dual rail power supply has two +12V output lines, one of which is used for the CPU. Version 2 of the ATX standard requires that the CPU has a separate and independent power connection.
What happens if you turn on a power supply that isn't attached to anything?
A good power supply has internal circuitry that shuts down the power supply if it is without a load—that is, it is connected to something. However, some cheap power supplies can be destroyed if powered on without a device or the motherboard connected.
Whats difference between good quality power supply and a cheap one?
A high-quality power supply delays sending the power good signal until all of the power supply's voltages have a chance to stabilize. Some cheap power supplies do not delay the power good signal. Other cheap power supplies do not provide the power good circuitry at all, but instead tie five volts to the signal, sending a power good signal even when it is not there.
What is the "power good signal" pin on new 12V ATX V.2 x power supplies used for?
A power good signal (labeled PWR_OK in the figure) goes to the motherboard. When the computer is turned on, part of POST is to allow the power supply to run a test on each of the voltage levels. The voltage levels must be correct before any other devices are tested and allowed to initialize. If the power is OK, a power good signal is sent to the motherboard. If the power good signal is not sent from the power supply, a timer chip on the motherboard resets the CPU. Once a power good signal is sent, the CPU begins executing software from the BIOS.
Whakt is a surge protector?
A surge protector, also known as a surge strip or surge suppressor, is commonly a six-outlet strip with built-in protection against overvoltage.
What is wake on Ring?
Allows a computer to come out of sleep mode when the telephone line has an incoming call. This lets the computer receive phone calls, faxes, and emails when the user is not present.
What does an auto-switching power supply do?
An auto-switching power supply monitors the incoming voltage from the wall outlet and automatically switches itself accordingly. Auto-switching power supplies accept voltages from 100 to 240VAC at 50 to 60Hz. These power supplies are popular in laptops and are great for international travel.
What are the Windows 7 power plans?
Balanced - The most common plan because it provides full power when you need it and saves power when the computer is not in use. Power Saver - Saves power by running the CPU more slowly and reduces screen brightness. High Performance - Select the "Show additional plans" link to see the option. this provides the maximum performance possible.
How do know the exact amount of power you need?
Every device in the computer consumes power and each device could use one or more different voltage levels (+5V, -5V,+12V, -12V, +3.3V). A power supply has a maximum amperage for each voltage level, for example 30 amps at +5 volts and 14 amps at +12V. To determine the maximum power in watts being used, multiply the amps and volts In order to determine the power being consumed, every device must be researched to determine how much current it uses at a specific voltage level. Internet power calculators are available to help with this task.
Drawbacks of MOV?
If a large surge occurs, the MOV will take the hit and be destroyed, which is better than damaging the computer. However, with smaller overvoltages, each small surge weakens the MOV. A weakened MOV might not give the proper protection to the computer if there is a bigger surge. Also, there is no simple check for the MOV's condition. Some MOV shave indicator lamps attached, but these only indicate when the MOV has been destroyed, not when it is weakened
What is the United State regulations on Lithium batteries?
If battery contacts come in contact with metal or other batteries, the battery could short-circuit and cause a fire. ●Lithium batteries are to be kept in original packaging. If original packaging is not available, place electrical tape over the battery terminals or place each battery in an individual bag . ●Spare lithium batteries are not allowed in checked baggage but can be taken in carry-on bags.
What is an A phone line isolator, sometimes called a modem isolator?
It provides protection against phone line surges. No computer connected to a phone line through a modem should be without one. Many surge protectors now come with a modem isolator built into the strip.
Why are 12 volt rails a factor?
Keep in mind that most manufacturers do not have two or more independent 12Vsources; they all derive from the same 12V source but have independent output lines. The most important thing to remember about 12V output is that multi-core processors and video cards use 12V power in addition to devices that have motors (hard drives, CD/DVD drives, for example). Ensure that enough amperage is provided for all installed devices that use 12V power.
What are line conditioners?
Line conditioners, sometimes known as power conditioners, are more expensive than surge protectors, but they protect the computer from over voltages, under voltages, and adverse noise conditions over electrical lines.
What is overvoltage (a surge or spike)?
Overvoltage occurs when the output voltage from the wall outlet (the AC voltage) is over the rated amount. Normally, the output of a wall outlet is 110 to 130 volts AC. When the voltage rises above 130 volts, an overvoltage condition exists. The power supply takes the AC voltage and converts it to DC. An overvoltage condition is harmful to the components because too much DC voltage destroys electronic circuits.
What is SPS (standby power supply)?
SPS (standby power supply). An SPS contains a battery like the UPS, but the battery only provides power to the computer when it loses AC power. As a result, SPS switching time is important. Any time under five milliseconds is fine for most system
What is a surge protector?
Surge protector, also known as a surge strip or surge suppressor, is commonly a six-outlet strip with built-in protection against overvoltage.
What are some features of ATX 12V V.2 x?
The ATX12V version 2 standard has a 24-pin motherboard connector that does away with the need for the extra 6-pin auxiliary connector and can only be inserted one way. It also adds a SATA power connector. Some 24-pin motherboard connectors accept the 20-pin power supply connector.
How does a line conditioner work?
The line conditioner monitors AC electricity. If the voltage is too low, a line conditioner boosts voltage to the proper range. If the voltage level is too high, a line conditioner clamps the voltage down and sends the proper amount to the computer. Figure 4.18 shows a line conditioner.
What does a power supply do?
The power supply converts AC to DC, distributes lower voltage DC power to components throughout the computer, and provides cooling through the use of a fan located inside the power supply.
How does the power supply keep computer cool?
The power supply's fan circulates air throughout the computer. Most computer cases have air vents on one side, both sides, or in the rear of the computer. The ATX-style power supply blows air inside the case instead of out the back. This is known as reverse flow cooling.
What if the power supply doesn't have enough connections for all devices needed?
There are possible adapters. For example, If a device requires a Berg connector and the only one available is a Molex, a Molex-to-Berg connector converter can be purchased. If a SATA device needs a power connection, a Molex-to-SATA converter is available.
What types of power supplies are there?
There are two basic types of power supplies: switching and linear.
What is most common power supply rating (watts)?
Today's computers have power supplies with ratings rang- ing from 250 to 500 watts, although powerful computers, such as network servers, can havepower supplies rated 600 watts or higher.
Which fire extinguishers should you have on hand next to computer equipment?
Use a Type C or a Type A-B-C fire extinguisher to put out the fire. Type C fire extinguishers are made specifically for Type C (electrical) fires. T
What is the different voltage on a motherboard used for?
Voltage to CPU from power supply are +3.3, +5, -5, +12, and -12 volts ●The motherboard and adapters use +3.3 and +5 volts. ●Integrated serial ports use +12 and -12 volt power. ●Hard drives use +5(latest) and +12 volts(most common). ●Graphics card. Drives are now being made that use +5 volt motors. ●Chips use +5 volts and +3.3 volts. ●memory, AGP/PCI/PCIe, adapters, and some laptop fans. use +3.3 volts The negative voltages are seldom used
What is undervoltage (burnout or sag)?
When the voltage falls below 110 volts AC, an undervoltage condition exists. If the voltag o low, a computer power supply cannot provide enough lower to all the components. Underthese conditions, the power supply draws too much current, causing it to overheat, weakening or damaging the components. An undervoltage condition is known as a brownout or sag.
Where can you access power options on windows 7
With windows 7, the Power Options control panel can be accessed through System and Maintenance/Security (7) and also the Hardware and Sound control panels.
Symptoms of a bad power supply?
● The computer power light is off ●The power supply fan does not turn when the computer is powered on ●The computer sounds a continuous beep (this could also be a bad motherboard or a stuck key on the keyboard) ●When the computer powers on, it does not beep at all (this could also be a bad motherboard) ●When the computer powers on, it sounds repeating short beeps (this could also be a bad motherboard) ●During POST, a 02 X or parity POST error code appears (where X is any number); one of the POST checks is a power good signal from the power supply; a 021, 022, . . . error message indicates that the power supply did not pass the POST test ●The computer reboots without warning ●The power supply fan is noisy ●The power supply is too hot to touch ●The monitor has power light, but nothing appears on the monitor and no PC power light illuminates
When a computer comes out of sleep mode and not all devices respond, and you have to reset computer what may be the causes?
●A screen saver conflicts with ACPI ●All adapters/devices are not ACPI compliant ●An adapter/device has an outdated driver ●The system BIOS or an installed adapter BIOS needs to be updated
What is Wake on LAN feature?
●Allows a network administrator to control the power to a workstation remotely and directs the computer to come out of sleep mode. ●Software applications can also use the Wake on LAN feature to perform updates, upgrades, and maintenance tasks. ●The feature can also be used to bring up computers immediately before the business day starts. ●Wake on LAN can be used with Web or network cameras to start recording when motion is detected or to bring a network printer up so that it can be used when needed.
What is the purpose of a power supply?
●Convert AC to DC ●Provide DC voltage to the motherboard, adapters, and peripheral devices ●Provide cooling and facilitate air flow through the case
What are ways to prevent overheating of laptops?
●Keep air vents unblocked and avoid placing laptop on lap when using it ●Check what the temperature settings for fans to turn on in the BIOS ●Check for any fan/temperature gauges through manufacturers website or documentation. ●Place laptop on something that elevates off desk or purchase a mat that has fans
What came before Li-ion (lithium-ion) batteries
●NiCad (nickel Cadmium) ●NiMH (nickel-metal hydride) replaced NiCad
When traveling with laptop:
●Remove cards, cds, or attached devices and put them in container. ●Make sure all drive doors are securely latched ●Make sure device is powered off or in Hibernation mode, not in sleep, suspend, or standbye. ●Make sure it is padded case.
What are the different sleep/global states?
●S0 - (Global system state G0-WORKING) The computer is fully functional. Software, such as the AutoSave function Working used with Microsoft products, can be optimized for performance or lowercbattery usage. ●S1 - CPU is still powered, and unused devices are power ed down. RAM is still being refreshed. Hard disks are not running. ●S2 (G1 Sleeping)- Requires less power than the G0 state and has multiple sleeping states.(S1)CPU is still powered, and unused devices are powered down. RAM is still being refreshed. Hard disks are not running. ●S3 (G1 Sleeping) - CPU is not powered. RAM is still being refreshed. System is restored G1 Sleeping instantly upon user intervention ●S4 - Lowest-power sleep mode and takes the longest to come up. Info in RAM is saved to hard disk. Some manufacturers call this the hibernate state. ●S5 (G2) - Also called soft off. Power consumption is almost zero. Requires the operating system to reboot. No information is saved anywhere ●G3 (Mechanical OFF) - Also called off, or mechanical off. This is the only state where the computer can be disassembled. You must power on the computer to use it again.
What are Li-ion polymer batteries used in laptops?
●They are similar to Li-ion batteries, except they are packed in pouched cells. ●Last longer if kept cool ( can be kept in refrigerator with 40% charge to prolong life) This design allows for smaller batteries and a more efficient use of space, which is important in the portable computer and mobile device industries.
What are benefits of ACPI (Advanced Configuration and Power Interface)
●Users can control how the power switch operates. ●Users can set when exactly power to hard drive and monitor is lowered. ●Case, cpu, and cpu fans can be monitored ●Power supply can be adjusted for power requirements ●CPU can be throttled (reduced speed and usage)
What are some up and coming/alternative batteries for laptop and mobile devices?
●Zinc-Air (AER Energy Resources inc. has several patents) which uses oxygen to generate electricity. ●Fuel cells
