DIGITAL ELECTRONICS - LOGIC CIRCUITS - 1

V. Ryan © 2003

 Most modern electronic devices such as mobile telephones and computers depend on digital electronics. In fact, most electronics about the home and in industry depend on digital electronics to work. Digital electronics normally based on ‘logic circuits’. These circuits depend on pulses of electricity to make the circuit work. For instance, if current is present - this is represented as ‘1’. If current is not present, this is represented as ‘0’. Digital electronics is based on a series of 1s and 0s. A good example of a digital electronic system is a mobile phone. As you speak into the phone, the digital electronic circuits it contains converts your voice into a series of electronic pulses (or 1s and 0s). These are transmitted and the receiving mobile phone then converts the digital pulses back into your voice. Digital circuits are used because they are efficient and work well, also, digital signals are easier to transmit than actual sound (for example a persons voice). The various parts of a computer communicate through the use of electronic pulses (1s and 0s). Consequently digital logic circuits are ideal for the internal electronics. The main part of the computer is the motherboard. This is a complex piece of electronics that processes all the important data. For instance, when word processing, it is very important to display letters and words on the monitor. The motherboard generates the individual letters on the monitor by sending a series of 1s and 0s to the screen. When the computer operator presses the letter ‘H’ on the keyboard, the motherboard converts this into a digital signal composed of 1s and 0s. The ‘H’ in the form of 1s and 0s is displayed on the monitor. When you word-process a paragraph of writing all the letters/words are displayed on the monitor in a similar way. In reality the letters are not composed of 1s and 0s but as black or white pixels. QUESTION: Look closely at a computer monitor. The pixels are very small but you may be able to see them especially if you use a magnifying glass. If you are looking at a colour picture, the pixels will be in different colours, not only black and white. CLICK HERE FOR NEXT LOGIC PAGE CLICK HERE FOR ELECTRONICS INDEX PAGE

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