Electricity is indispensable to modern society, and electrical appliances are crucial components supporting its operation. So how does electricity make electrical appliances work?
For ease of understanding, this article won't delve into theoretical concepts and formulas, but rather describe how electricity powers electrical appliances. To answer this question, we first need to clarify a few definitions: electricity, electrical energy, and electrical appliances.
Electricity refers to the physical phenomenon generated by the movement of electrons; electrical energy is the effect of electricity doing work in different forms; an electrical appliance is a device that functionally relies on electrical energy to drive its core components, generally divided into two types: electrical equipment and electronic equipment.
Electrical equipment refers to devices that convert electrical energy into mechanical energy or other forms of energy, such as electric motors, voltage converters, and light bulbs; electronic equipment, in a narrower sense, refers to devices that use electrical energy for data processing, such as CPUs and graphics cards. The electrical appliances we use daily are generally composed of both types of devices, such as refrigerators, televisions, and computers.
An electrical appliance, such as a mobile phone, consists of several electrical systems, such as a power supply system, an interactive system, and a computing system. Different systems together constitute a handheld electronic device-a mobile phone. How does electricity play a role in these systems? First, it's important to clarify that what drives electrical appliances is not electricity itself, but electrical energy. In other words, electricity does work within the electrical system, driving it to produce corresponding effects. Let's imagine electrons as tiny people; their movement generates electricity, and this movement is work done.
During this work done by these tiny people, energy is converted into forms such as heat, light, chemical energy, and kinetic energy, which are perceived by the user, and then we perceive the appliance as starting to operate. How does this process occur? Let's take a closer look, using a mobile phone as an example.
First, the phone's power supply system prioritizes supplying power to the computing system and power control system. When the battery begins to provide power, electrons within the CPU begin to move under force. The CPU's logic circuits perform calculations, determining the subsequent power allocation and feeding this information back to the power control system. Upon receiving this allocation information, the power control system adjusts the logic pathways within the system to distribute power accordingly.
Then, the electricity reaches the display and interaction systems. After being powered on, the display system uses electrothermal theory to emit light and heat, lighting up the screen, which becomes the content we see on the phone. We won't go into the details of why the screen can display different content; this process is the conversion of electrical energy into light energy. The interaction system presents different forms on different devices. Non-touchscreen devices use switches. In the interaction system, the main role of electricity is information transmission.
After some operation, the phone wants to play a song. Electricity is allocated to the sound system. In this system, electrical energy plays two roles: First, transmitting information by changing the current state through the power distribution system to transmit the specific sound content to be played. Second, using electrodynamic theory, driving the speaker to vibrate and produce sound. At this moment, the phone receives a message requesting vibration. The power distribution system allocates electricity to the vibration motor. Under the combined action of electromagnetic and electrodynamic theories, the motor begins to vibrate; this process is the conversion of electrical energy into kinetic energy.
As winter approaches, "good" mobile phone brands will thoughtfully prepare hand warmers for users-hot, warm phones. This is the heat energy that is almost inevitably generated when electrical energy is converted into other forms of energy. Electric heaters and electric blankets are all appliances designed based on electrothermal theory.
After passing through so many systems, does electricity return to its source, the battery? No! This involves the most fundamental question: how do electrons move? Voltage. The electrons moving throughout the system don't start from the battery and return to it! What drives their movement is called potential energy, which is the voltage difference. When a battery is in use, the voltage across its terminals is gradually leveled out, and the potential energy is slowly depleted, resulting in no power. During charging, the external power source converts this potential energy into chemical energy, creating a voltage difference between the battery terminals.
Therefore, essentially, electricity making appliances work is a process of energy conversion. The main principles involved are electromagnetism, electrokinetic energy, electrical contact, electric arc, and electrothermal energy. Through these summarized theorems, the conversion of electrical energy into other forms of energy can be artificially controlled. Every electrical appliance operates on one of these five principles, but each has its own unique characteristics. Therefore, if you want to understand in detail how electrical appliances work, you should learn electrical theory and analyze specific problems in specific ways.
