Download 3 PC power supplies - Mid-East Career and Technology Centers

2013
3-27
http://computer.howstuffworks.com/power-supply.htm
Name: _____________________________________
1. The power supply converts the ______________ current line from your home to the _______________
current needed by the personal computer.
2. Power supplies, often referred to as "_______________ power supplies", use switcher technology to convert
the AC input to lower DC voltages.
3. The typical voltages supplied by a power supply are:
1.
2.
3.
4.
5.
6.
7.
8.
9.
What voltage is used to run digital circuits? ________________
What voltage is used to run motors in disk drives and fans? ___________________
The main specification of a power supply is in ________________.
Old computer power on and off button had _____________________ volts running to it.
New computer power on and off button have _____________________ volts running to it.
Prior to 1980 or so, power supplies tended to be heavy and bulky. They used large, heavy transformers and
huge ______________ (some as large as soda cans) to convert line voltage at 120 volts and 60 hertz into
_______ volts and _______ volts DC.
10. Insert a picture of a power supply label………. Refer to image on
http://computer.howstuffworks.com/power-supply1.htm
11. Recently, the industry has settled on using _________-based power supplies
12. Fan manufacturers often use the same connectors as the power cables for ____________ drives, allowing a
fan to easily obtain the 12 volts it needs.
13. APM is an acronym for _____________________ __________________ _______________
14. Where do you disable APM?
15. Fill in the cell below with the wattage that each device uses.
PC Item
Watts
Accelerated Graphics Port (AGP) card
20 to 30
W
Peripheral Component Interconnect (PCI) card
small computer system interface (SCSI) PCI card
floppy disk drive
network interface card
50X CD-ROM drive
RAM
5200 RPM Integrated Drive Electronics (IDE) hard disk
2013
3-27
drive
7200 RPM IDE hard disk drive
Motherboard (without CPU or RAM)
550 MHz Pentium III
733 MHz Pentium III
300 MHz Celeron
600 MHz Athlon
16. Define FORM FACTOR.
17. True / False
18. True / False
The PC power supply is probably the most failure-prone item in a personal computer.
19. True / False
A typical failure of a PC power supply is often noticed as a burning smell just before the
Typically, a stalled cooling fan is a predictor of a power supply failure due to subsequent
overheated components.
computer shuts down
20. True / False
Another problem could be the failure of the vital cooling fan, which allows components in
the power supply to overheat.
21. True / False
22. True / False
Failure symptoms include random rebooting or failure in Windows for no apparent reason.
23. True / False
New designs offer fan control so that the fan only runs the speed needed, depending on
Recent motherboard and chipset improvements permit the user to monitor the revolutions
per minute (RPM) of the power supply fan via BIOS and a Windows application supplied by the motherboard
manufacturer
cooling needs.
24. True / False
Recent designs in Web servers include power supplies that offer a spare supply that can
be exchanged while the other power supply is in use.
25.
26.
27.
28.
29.
True / False
All power supplies are measured of sold by the wattage rating.
True / False
The cover of a computer must be removed in order to change a power supply.
True / False
All desktop computers have internal switching power supplies.
True / False
Some power supplies have a switch for input voltage of 240volts.
True False
Power supplies have different molded connectors that fit into special molded devices on
the systemboard, device drives, and fans.
30. True / False
Laptops have internal switching power supplies.