Computers

Power Supply-PSU

The power supply converts volt alternating current from wall outlets to steady low voltage direct current in electronic circuits. Power supplies have capacitors which is a device for collecting and holding charges of electricity, therefore is dangerous to open. 

 Old computers as shown on the image on the right have cathode ray tubes which made it big and heavy. It took a lot of space.

Newer computers as shown on the image above use LCD's which are smaller and lighter. It also take up less space.

Hard drive

 The hard drive was first introduced  in 1956 and permanently stores all the data in your computer even after your computer is turned off. It can get about 100 GB of data. The data is stored in stacks of disks called platters.

Components of a hard drive

Head actuator- The head actuator is controlled by the motor and moves the head arm. Before the actuator was controlled by a stepper motor but now it is controlled by the servo motor.

 Spindle- The spindle hold the platters in place.

 Platters- The platters are made of aluminum, glass and ceramic and magnetic media. They are in the hard drive and store data permanently. Data is stored in tracks, sectors, cylinders. Platters are constantly rotating when computer is turned on.

 Disk Controller- The disk controller is responsible for the hard drive, floppy disk drive, CD-ROM Drive and many others. It also tell the hard drive what to do and how to move the components when data is sent to the hard drive.

Read/Write Head- The read/write head is found in the arm and reads data from the hard drive's platter disk.

 Access arm- read/write arm, head arm, and actuator arm.

Monitor

The monitor is the screen of the computer. It allows us to visually interact with the computer using only the keyboard and the mouse. It also opens programs for the user to see.