Foundations of electronics

Foundations of electronics

1. vacuum tubes-usually electricity requires a conductor such as a wire, to travel from one place to another,that electricity pass through vacuum.

   • cathode rays-Early experiments with vacuum tubes knew something was crossing the gap between electrodes in a vacuum
     • semiconductors-is a material that is neither a good conductor nor a good insulator
       • picture tubes-Altough crookes invented the cathode rays tube to study cathode rays .
       • semiconductor diodes-devices that,like vacuum-tube diodes ,allow currents to pass only in one direction.
         • types of transitor-junction transitor-field effect transitor
           • software-the hardware of a single computer can perform many diferent tasks
     • mechanical calculator-simple counting devices such as abacus can be thought of as the earliest forerunners of the computer
       • ENIAC-electronic numeral integrator and calculator
         • UNIVACI-universal automatic computer
           • hardware-the actual physical components of the computer
             • types of modern computers-general-purpose computer,personal computer

2. transitor}a semiconductor device that can perform the same function as a vacuum tube , such as acting as switch