CP1610: Introduction to Computer Components

CP1610:Introduction to Computer Components Computer Power Supplies

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);

Protecting Power Supplies • SPS • Stand-by Power Supply • UPS • Uninterruptable Power Supply

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; SPS vs. UPS

Electricity Basics • Three fundamental properties: • Potential difference across the circuit (Voltage) • Current, or flow of electricity (Ampere or Amp) • Resistance on the circuit (Ohm)

Formula to calculate voltage, current, or resistance. V = I x R Symbols: V = Voltage I = Current R = Resistance Ohm’s Law

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

Electrical Power • Measured in Watts (W) • Multiply Voltage by Current • W = V x I

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;

Energy Star Ratings • Devices that comply with environmental protection standards. • Can apply to: • Computers; • Monitors • Printers; • Fax Machines; • Other Devices;

CP1610: Introduction to Computer Components