Power Flashcards
When comparing electricity to water, what would voltage resemble?
Voltage (Volts) can be compared to water pressure.
When comparing electricity to water, what would Amperage resemble?
The amount of water coming from a tap. Low = Droplets, High = Stream
What are Watts?
The amount of Volts and Amperage required for a component or device to function. V x A = W.
What are Ohms?
Ohms are the resistance given by the wires electricity passes through
What measurement is used to judge how much electricity can be pushed through a wire?
Wires have Amp ratings for this purpose
How do fuses work?
Fuses have amp ratings similar to the wires around them. If electricity beyond the specified amount passes into a fuse’s tiny filament, it will break, denying the electricity access to your device and potentially saving it from a power surge.
True or false: DC power flows constantly in one direction, and AC power alternates back and forth and is good for long distances?
True
What do the Hot, Neutral and Ground wires do on a plug?
Hot wire carries the voltage, Neutral carries no voltage and acts like a water drain by returning the electric to the local source, the ground wire makes it possible for excess electricity to return safely to the ground in a short-circuit situation.
What is the symbol for AC and DC current
DC is a straight line with dotted lines atop it. AC is a Wavy line. See: https://www.electrical-symbols.com/electric-electronic-symbols/electric-current-symbols.htm
Are the AC to DC adapters laptops use interchangeable?
Non
What is another term for a sag in electric power? And a complete loss of power?
A brownout and a blackout
What is a Joule?
A unit of electricity
How many Joules do authorities suggest your surge protection have at minimum?
2000 minimum.
When referring to UPS (Uninterruptible power supplies) what do these terms mean: Online, Standby, Line-interactive.
Online implies the computer is always drawing power from a UPS even if the power isn’t down. Standby only powers the PC when the power is detected to have been lost from a wall socket. Line-interactive is similar to standby, but has special circuitry to handle moderate AC sags and surges without the need to switch to battery power.
What is the standard AC Voltage in the UK
230v
What voltages does Molex cover?
5 and 12v, usually used for fans. Same as Sata (though sata has a 3.3, it doesn’t use it)
What is a rail?
Rails deliver power through 3.3, 5 and 12v lines to connectors. This is the process just after the transformer turns AC > DC and the power is split into different “tunnels”. A PSU can have multiple rails for the same voltages.
What is over current protection
This protects rails from being overworked and shuts them down if they are in danger. Short version: Dampens the effects of harmonics.
What is Active power factor correction
Protects against the waves of electricity that come pouring through your wall socket every time they bounce back and forth every 60 seconds. These can damage your equipment over time.
What are the colours of 3.3v 5v and 12v and ground?
O R Y B
What happens if you use a 120v wallsocket with a 230v PSU
The socket’s fuse may blow from being overworked
What happens if you use a 230v wall socket with a 120v psu
The 230v would ram the PSU that’s responsible for toning down the volts and likely destroy it
True or false: The wall socket will supply the amount of electricity it’s rated for. It’s down to the appliance to lessen the amount of electricity.
True
How many pins is a p1 connector. Old version and new.
Old is 20, new is 20+4
What is the 80plus rating
PSUs work at 80% efficiency when under 20-100% load
What is the name of the psu part that changes ac to dc?
Rectifier
