# Shared Flashcard Set

## Details

A+ Book 2 - Chapter 7
Working with Power
14
Computer Science
Professional
07/10/2013

Term
 Volt
Definition
 a unit of electrical potential difference across a conductor when a current of one ampere dissipates one watt of power.
Term
 Ohm
Definition
 measure of resistance or electrical impedance
Term
 Ampere (amp)
Definition
 unit of electrical current or the measure of electrical flowI = V / RI is current (amps), V is voltage, R is resistance (ohms)
Term
 Watt
Definition
 unit of power equal to one joule per secondP = V * IP is power (watts), V is voltage, I is current (amps)
Term
Definition
 converting voltage from the building-supplied AC voltage to various DC voltages required by components inside the computer.
Term
Definition
 regulation to provide a very small tolerance of error to the devices receiving the power.a +/- 5% voltage differential is allowed for 12VDC, 5VDC, and 3.3VDC
Term
Definition
 power supply should handle some level of abnormally high current to prevent fuses in the power supply from blowing unnecessarily
Term
Definition
 if voltage being supplied by the building drops below normal operating level, it shouldn't cause damage to power supply itself. Causes the power supply to shut off
Term
Definition
 specification that defines how much power the power supply should provide to the computer components during reduced power states, when the comp is asleep or on standby.
Term
Definition
 allows motherboard to control power supply through a soft power switch.
Term
Definition
 either recommends or requires the use of cooling fans depending on the form factor of the power supply
Term
 *Power Supply Tasks:Input supply voltage (120V or 240V)
Definition
 might be static or configured via manual switching or automatic switching. Many laptops have auto while most desktops have manual
Term
 *Power Supply provides Voltage at
Definition
 3.3VDC, 5VDC, and 12VDC
Term
 Getting an A+ (2:7)
Definition
 -The current specification of power supplies is ATX, and the ATX power supply will be found in one form factor or another on most current computers- The main power connector has 20 or 24 pins. Four-pin floppy, and peripheral connectors supply 5V and 12V, and a five-pin SATA connectors supply 3.3V, 5V, and 12V.- Power supplies convert 120VAC or 240VAC power into DC for the comp- Power supplies come in a variety of power sizes, from 160W up to and beyond 1200W.0 AC adapters are used in laptops to convert power from AC to DC, and usually automatically switch between 120V and 240V- Surge suppressors, line conditioners, and UPS deal with various power supply problems, including surges and brownouts.
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