When people talk to each other in person, they use human language and body language to communicate information. But what if they cannot see/hear each other, how could they represent and send messages?
Before human learnt how to use electricity, our ancestors used rope knots, picture on rocks/total back to keep messages. After human created writing languages, characters were employed to represent information.
In the modern world, electrical voltage is used to represent a wide range of information, including audio, video, and data. It is a reliable, versatile, scalable, and cost-effective way to transmit information. we could define a term-signal, conveying information about the behavior or attributes of some phenomenon.
There are a number of other ways to represent signals, such as light, sound, and mechanical motion. However, electrical voltage has a number of advantages over these other methods.
- Reliability: Electrical voltage is a physical quantity that can be easily measured and transmitted over long distances. It is also relatively immune to noise and interference.
- Versatility: Voltage can be used to represent a wide range of information, including audio, video, and data.
- Scalability: Voltage can be easily amplified or attenuated to represent different levels of information.
- Cost-effectiveness: The cost of electrical components that generate and detect voltage is relatively low.
In addition to the advantages listed above, electrical voltage also has a number of other advantages over other methods of signal representation. For example, electrical voltage can be easily processed by electrical devices, such as computers and smartphones. This makes it possible to store, transmit, and manipulate information in a variety of ways. Please see the following pictures, how I used Matlab to proceed human voice signal in real time.
Human voice signal real-time analysis in time domain and frequency domain
In the last 70 years, humans have been making progress in information technology, which include hardware and software. Here are main events for circuits part development:
- The invention of the transistor in 1947: The transistor was a major breakthrough in the development of electrical devices. It allowed for the miniaturization of electrical circuits, which made it possible to create more powerful and versatile electrical devices.
- The development of the integrated circuit in 1958: The integrated circuit was another major breakthrough in the development of electrical devices. It allowed for the integration of multiple transistors onto a single chip, which further miniaturized electrical circuits and made them even more powerful and versatile.
- The development of the internet in the 1980s: The internet has revolutionized the way we communicate and share information. It has made it possible to transmit electrical signals over long distances almost instantaneously.
- Audio: Electrical voltage is used to represent audio information in a variety of devices, such as radios, speakers, and headphones. In a radio, for example, the electrical voltage from an antenna is amplified and then used to drive a speaker. The speaker then converts the electrical voltage into sound waves that can be heard by the listener.
- Video: Electrical voltage is also used to represent video information. In a television, for example, the electrical voltage from a camera is amplified and then used to drive a display. The display then converts the electrical voltage into images that can be seen by the viewer.
- Data: Electrical voltage is also used to represent data. In a computer, for example, the electrical voltage from a keyboard is used to enter data into the computer. The computer then stores the data in its memory and processes it as needed.
