Asas Sistem Berdigit

DIGITAL VS ANALOG...

1. Digital signals are represented by only two possible 

    - 1 (binary 1) or 0 (binary 0)

2. Sometimes call these values “high” and “low” or  “ true” and “false”

   Example: light switch , it can be in just two position – “ on ” or “ off ”.
 

3. More complicated signals can be constructed from 1s and 0s by stringing them end-to-end.

4. Analog electronics can be any value within limits.

   

Why choose digital signal?

All signals problem with noise
   - Noise isn't just something that you can hear - the fuzz that appears on old video recordings also qualifies as noise. In general, noise is any unwanted change to a signal that tends to corrupt it. 

Digital & Analog Quantities

a) Two ways of representing the numerical values of quantities :

  i)  Analog (continuous)

  ii) Digital (discrete)

b) Analog : a quantity represented by voltage, current or meter movement that is proportional to the value that quantity

c) Digital : the quantities are represented not by proportional quantities but by symbols called digits

 

    c.1.1 Digital system:

       combination of devices designed to     
       manipulate logical information or physical       quantities that are represented in digital forms

 Example :  digital computers and calculators, digital audio/video equipments, telephone system.

d) Analog system:

 contains devices manipulate physical quantities that are represented in analog form

 Example : audio amplifiers, magnetic tape recording and playback equipment, and simple light dimmer switch.