3.5 Power Supply Flashcards
1
Q
Computer Power Supply
A
- most power sources provide AC voltage
- power supply converts AC to DC voltage for computer
2
Q
Amp
A
Rate of electron flow past a point in one second
- volume of electrons flowing
3
Q
Voltage
A
Force that “pushes” electrons
4
Q
Watts
A
Measurement of real power use
- power output rating
- volts * amps = watts
5
Q
Alternating Current (AC)
A
- direction of current constantly alternates
- input from power sources
US/Canada: 110-120 VAC
Europe: 220-240 VAC
6
Q
Direct Current (DC)
A
- current moves in one direction with a constant voltage
7
Q
Power Supply Output
A
- different voltages for different components
+12 V
- PCIe adapters, hard drive, fans, most modern components
+5 V
- some motherboard components
- legacy motherboard
+3.3 V
- modern motherboard
- M.2 slots, RAM slots
+5 VSB
- standby voltage, used in hibernate mode
-12 V
- older components
-5 V
- ISA adapter card, not used in modern computers
8
Q
Power Supply to Motherboard Connection
A
- 20-pin was the original ATX standard
- 24-pin was added for PCIe power(extra 4 pins are separate)
- 24-pin can connect to a 20-pin motherboard
9
Q
Redundant Power Supply
A
- two or more power supplies in each server
- typically both power supplies would be plugged in at the same time, each handling 50% of the load
- if one fails, the other will take over 100% of the load
- hot-swappable: replace faulty power supply without powering down server
10
Q
Modular Power Supply
A
- cables can be added or removed as needed
- no leftover cables = better airflow
- bit more expensive
11
Q
Wattage Rate
A
- maximum amount of power output by power supply
- calculate the watts required for all computer components to determine which power supply you need
- 50% capacity is a good rule of thumb, runs efficiently and leaves room to grow
12
Q
Dual Voltage Input Options
A
- manually switch between 120 V and 230 V
OR - use an auto-switching power supply
