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Basic knowledge of circuits
1. Basic knowledge of circuits -- circuits
Circuit---refers to a conductive loop composed of metal wires and electrical and electronic components, called a circuit. A circuit through which direct current passes is called a "DC circuit"; a circuit through which alternating current passes is called an "AC circuit".
The composition of the circuit---The circuit consists of four major parts: power supply, load, connecting wire and auxiliary equipment. A device that supplies electrical energy. The function of the power supply is to convert non-electrical energy into electrical energy. Loads Various devices that use electrical energy in a circuit are collectively referred to as loads. The function of the load is to convert electrical energy into other forms of energy. Wire connection wire is used to connect the power supply, load and other auxiliary equipment into a closed loop, which plays the role of transmitting electric energy. Auxiliary equipment is used to control, distribute, protect and measure circuits.
The role of the circuit---to realize the transmission, distribution and conversion of electrical energy; to realize the transmission and processing of signals.
Circuit Model - In circuit analysis, in order to facilitate the analysis and research of actual electrical devices, it is usually necessary to model the actual circuit under certain conditions, that is, to replace the actual device with an approximation of abstract ideal circuit components and their combinations. , thus forming a circuit model corresponding to the actual circuit.
The main physical quantities in the circuit are current, voltage and electromotive force
2. Circuit Basics – Current
Current - refers to the amount of charge passing through a cross section of a conductor per unit time. The magnitude of the current is called the current intensity, which refers to the amount of charge passing through a section of the wire per unit time. The current is divided into two types: direct current and alternating current. The direction of the current does not change with time is called direct current, and the magnitude and direction of the current change with time is called alternating current.
Current unit and conversion - the unit is ampere, referred to as "ampere", symbol "A".
1A= mA= uA= nA= pA
Electric current is a directional physical quantity, and it is not enough to point out the magnitude. When writing circuit equations, the positive and negative values of voltage and current are based on the pre-assumed reference direction on the current diagram. If the calculation result is positive, it means that the true direction of voltage and current is consistent with the reference direction, otherwise it is opposite.
3. Circuit Basics – Voltage, EMF
Voltage - also known as potential difference or potential difference, is a physical quantity that measures the energy difference of a unit charge in an electrostatic field due to different potentials. It should be pointed out that the word "voltage" is generally only used in circuits, while "potential difference" and "potential difference" are generally used in all electrical phenomena.
The unit of voltage - the main unit in the International System of Units is the volt, abbreviated as volt, represented by the symbol V. A volt is equal to 1 joule of work done per 1 coulomb of charge, or 1 V = 1 J/C.
Electromotive force (E) ---- a physical quantity that represents the characteristics of the power supply. The ability of the non-electrostatic force in the power supply to do work on the charge is called the electromotive force, which is numerically equal to the non-electrostatic force. The work done by the internal movement to the high potential terminal a.
The magnitude of the electromotive force is equal to the work done by the non-electrostatic force to move the unit positive charge from the negative pole of the power supply to the positive pole of the power supply through the interior of the power supply.
The basic elements of a circuit are components, and circuit components are idealized physical models of actual devices, which should be strictly defined. All the lumped elements are studied in the circuit, and the number of terminals of circuit elements can be divided into two-terminal, three-terminal, four-terminal elements, etc. The most basic elements in a circuit are resistors, capacitors, and inductors. Below we briefly introduce these basic elements in turn.
4. Circuit Basics - Resistors, Capacitors and Inductors
Resistance ---- English name is Resistance, abbreviated as R, it is a basic property of conductor, and it is related to the size, material and temperature of conductor. The cross-sectional area, material, length of the conductor can change the resistance of the conductor, and sometimes the temperature can also affect its size. The main physical feature of a resistor is to convert electrical energy into thermal energy. It can also be said that it is an energy-consuming element, and the current passes through it to generate internal energy. Resistors usually play the role of voltage divider and current shunt in the circuit. For signals, both AC and DC signals can pass through resistors.
Capacitance—refers to the amount of charge stored at a given potential difference; denoted as C, and the international unit is Farad (F). Capacitor is also the common name for capacitor. Capacitance is a physical quantity that characterizes the ability of a capacitor to hold charge. The amount of electricity required to increase the potential difference between the two plates of a capacitor by 1 volt is called the capacitance of the capacitor.
Inductor ---- is an electromagnetic induction component wound with insulated wire, and it is also one of the commonly used components in electronic circuits. Inductance is a group of coaxial turns in series made of enameled wire, yarn-covered wire or plastic-covered wire wound on insulating skeleton or magnetic core and iron core. The signal is isolated, filtered or formed into a resonant circuit with capacitors, resistors, etc.
Circuit---refers to a conductive loop composed of metal wires and electrical and electronic components, called a circuit. A circuit through which direct current passes is called a "DC circuit"; a circuit through which alternating current passes is called an "AC circuit".
The composition of the circuit---The circuit consists of four major parts: power supply, load, connecting wire and auxiliary equipment. A device that supplies electrical energy. The function of the power supply is to convert non-electrical energy into electrical energy. Loads Various devices that use electrical energy in a circuit are collectively referred to as loads. The function of the load is to convert electrical energy into other forms of energy. Wire connection wire is used to connect the power supply, load and other auxiliary equipment into a closed loop, which plays the role of transmitting electric energy. Auxiliary equipment is used to control, distribute, protect and measure circuits.
The role of the circuit---to realize the transmission, distribution and conversion of electrical energy; to realize the transmission and processing of signals.
Circuit Model - In circuit analysis, in order to facilitate the analysis and research of actual electrical devices, it is usually necessary to model the actual circuit under certain conditions, that is, to replace the actual device with an approximation of abstract ideal circuit components and their combinations. , thus forming a circuit model corresponding to the actual circuit.
The main physical quantities in the circuit are current, voltage and electromotive force
2. Circuit Basics – Current
Current - refers to the amount of charge passing through a cross section of a conductor per unit time. The magnitude of the current is called the current intensity, which refers to the amount of charge passing through a section of the wire per unit time. The current is divided into two types: direct current and alternating current. The direction of the current does not change with time is called direct current, and the magnitude and direction of the current change with time is called alternating current.
Current unit and conversion - the unit is ampere, referred to as "ampere", symbol "A".
1A= mA= uA= nA= pA
Electric current is a directional physical quantity, and it is not enough to point out the magnitude. When writing circuit equations, the positive and negative values of voltage and current are based on the pre-assumed reference direction on the current diagram. If the calculation result is positive, it means that the true direction of voltage and current is consistent with the reference direction, otherwise it is opposite.
3. Circuit Basics – Voltage, EMF
Voltage - also known as potential difference or potential difference, is a physical quantity that measures the energy difference of a unit charge in an electrostatic field due to different potentials. It should be pointed out that the word "voltage" is generally only used in circuits, while "potential difference" and "potential difference" are generally used in all electrical phenomena.
The unit of voltage - the main unit in the International System of Units is the volt, abbreviated as volt, represented by the symbol V. A volt is equal to 1 joule of work done per 1 coulomb of charge, or 1 V = 1 J/C.
Electromotive force (E) ---- a physical quantity that represents the characteristics of the power supply. The ability of the non-electrostatic force in the power supply to do work on the charge is called the electromotive force, which is numerically equal to the non-electrostatic force. The work done by the internal movement to the high potential terminal a.
The magnitude of the electromotive force is equal to the work done by the non-electrostatic force to move the unit positive charge from the negative pole of the power supply to the positive pole of the power supply through the interior of the power supply.
The basic elements of a circuit are components, and circuit components are idealized physical models of actual devices, which should be strictly defined. All the lumped elements are studied in the circuit, and the number of terminals of circuit elements can be divided into two-terminal, three-terminal, four-terminal elements, etc. The most basic elements in a circuit are resistors, capacitors, and inductors. Below we briefly introduce these basic elements in turn.
4. Circuit Basics - Resistors, Capacitors and Inductors
Resistance ---- English name is Resistance, abbreviated as R, it is a basic property of conductor, and it is related to the size, material and temperature of conductor. The cross-sectional area, material, length of the conductor can change the resistance of the conductor, and sometimes the temperature can also affect its size. The main physical feature of a resistor is to convert electrical energy into thermal energy. It can also be said that it is an energy-consuming element, and the current passes through it to generate internal energy. Resistors usually play the role of voltage divider and current shunt in the circuit. For signals, both AC and DC signals can pass through resistors.
Capacitance—refers to the amount of charge stored at a given potential difference; denoted as C, and the international unit is Farad (F). Capacitor is also the common name for capacitor. Capacitance is a physical quantity that characterizes the ability of a capacitor to hold charge. The amount of electricity required to increase the potential difference between the two plates of a capacitor by 1 volt is called the capacitance of the capacitor.
Inductor ---- is an electromagnetic induction component wound with insulated wire, and it is also one of the commonly used components in electronic circuits. Inductance is a group of coaxial turns in series made of enameled wire, yarn-covered wire or plastic-covered wire wound on insulating skeleton or magnetic core and iron core. The signal is isolated, filtered or formed into a resonant circuit with capacitors, resistors, etc.
The basic knowledge of circuits has been finished, dear, have you learned it?
