cp1610: introduction to computer components computer power supplies
TRANSCRIPT
Purpose of a Power Supply
Connect PC to wall outlet. Distribute the right amount of power to all
parts. Transformer. Rectifier.
What is a Transformer?
PC power supplies ‘transform’ electrical voltage from the building’s power supply.
Reduces voltage from 120V or 240V down to 12V, 5V, or 3V (as needed by the PC).
Distributes the right voltage to each PC part.
What is a Rectifier?
Wall outlets provide Alternating Current (AC).
Computer needs Direct Current (DC). Power supply converts electricity from AC
to DC.
Power Regulation
Computers need stable, well-regulated power supplies.
Fluctuations or interruptions can:Damage parts;Cause loss of data;Create electromagnetic interference (EMI);
SPS vs. UPS
SPS Stand-by Power
Supply; Acts like a backup
battery in case of power failure;
UPS Uninterruptable Power
Supply; Computer is constantly
powered by the battery;
Also regulates voltage; Reduces EMI;
Electricity Basics
Three fundamental properties:Potential difference across the circuit
(Voltage)Current, or flow of electricity (Ampere or Amp)Resistance on the circuit (Ohm)
Ohm’s Law
Formula to calculate voltage, current, or resistance.
V = I x R
Symbols: V = Voltage I = Current R = Resistance
Calculating with Ohm’s Law
Voltage:V = I x R
Current: I = V / R
Resistance:R = V / I
Symbols: V = Voltage I = Current R = Resistance
Alternating vs. Direct Current
AC cycles back and forth. DC travels in only one direction. AC is more economical on a large scale. Computers require DC to operate.
Short Circuits
Occur when electricity crosses paths or circuits.
Can be dangerous. Can damage equipment. Prevented by using fuses.
Electrical Safety
Before you open the case: Turn off the computer; Unplug the computer;
After you open the case: Use a static strap and rubber mat; Never use magnetized tools; Don’t touch parts with a graphite pencil; Don’t stack parts on top of each other; Don’t touch parts with your hands or fingers!
Working with Monitors;
DON’T! Monitors use very high voltage. Retain a charge, even when turned off. The high voltage can KILL! Let a qualified technician do the work. Do not throw monitors in the garbage.
Overheating
Computers overheat above 180oF. Use fans to cool:
Power supply;CPU; Interior of case;
Never leave your case open. You can also use liquid cooling.
Power Management Conserve electricity Protect environment Save money Can control power to:
Main system; Monitor; Hard drives; Printers; Other components;
Power Management Settings
Doze Time Reduces 80% of power consumption;
Standby Time Reduces 92% of power consumption;
Suspend Time Reduces 99% of power consumption;
Hard Drive Standby Time Shuts down the hard drive;