What role does capacitance play in electrical appliances

1.Capacitors are mainly used in AC circuits and pulse circuits, and capacitors generally play the role of blocking DC in DC circuits.

2.Capacitors neither produce nor consume energy and are energy storage components.

3.Capacitors are important devices to improve power factor in power systems; In electronic circuits, it is the main component that obtains the functions of oscillation, filtering, phase shift, bypass, coupling, etc.

4.Because the loads used in industry are mainly inductive loads of electric motors, capacitive loads must be combined to balance the grid.

5.On the grounding wire, why do some have to pass the capacitor and then connect to the ground?

Answer: In the DC circuit, it is anti-interference, and the interference pulse is grounded through the capacitor (in this case, it is used to block the potential relationship in the circuit); There are also such capacitors grounded in AC circuits, which generally have a small capacity, and are also anti-interference and potential isolation.

6.What's the deal with capacitor supplementing the power factor?

Answer: Because the voltage on the capacitor first needs to have a charging process, with the charging process, the voltage on the capacitor gradually increases, so that there will be a current first, and then the process of establishing the voltage, usually we call the current ahead voltage 90 degrees (when there is no resistance and inductive elements in the capacitor current circuit, it is called a pure capacitor circuit). Motors, transformers and other coil inductance circuits, due to the current through the inductor can not be abruptly changed, it is just the opposite of the capacitor, it is necessary to establish the voltage at both ends of the coil first, and then there is a current (when there is no resistance and capacitance in the inductor current circuit, it is called a pure inductance circuit), and the current lag voltage of the pure inductor circuit is 90 degrees.

Since power is voltage multiplied by current, when voltage and current are not generated at the same time (e.g., when the voltage on the capacitor is maximum, the current is fully charged, and the current is 0; When there is a voltage on the inductor, the inductor current is also 0), so that the product (power) obtained is also 0! This is reactive power.

Then, the relationship between the voltage and current of the capacitor is exactly the opposite of the relationship between the voltage and the current of the inductor, and the reactive power generated by the inductor is compensated by the capacitor, which is the principle of reactive power compensation.

What is the role of capacitors in the input and output of the transistor?

1. Coupling: The capacitance used in the coupling circuit is called the coupling capacitor, and the capacitance circuit is widely used in the resistor-capacitance coupling amplifier and other capacitive coupling circuits to play the role of blocking the DC flow and AC.

2. Filtering: The capacitor used in the filter circuit is called the filter capacitor, which is used in the power supply filter and various filter circuits, and the filter capacitor removes the signal in a certain frequency band from the total signal.

3. Decoupling: The capacitor used in the decoupling circuit is called the decoupling capacitor, which is used in the DC voltage supply circuit of the multi-stage amplifier, and the decoupling capacitor eliminates the harmful low-frequency cross-connection between each stage of the amplifier.

4. High-frequency vibration cancellation: The capacitor used in the high-frequency vibration cancellation circuit is called the high-frequency vibration cancellation capacitor, in the audio negative feedback amplifier, in order to eliminate the high-frequency self-excitation that may occur in the vibration cancellation, this capacitive circuit is used to eliminate the high-frequency acoustic noise that may occur in the amplifier.

Charge and discharge

1. The process of charging.

The process of making a capacitor live (storing charge and energy) is called charging. If one plate of the capacitor is connected to the positive pole of the power supply, and the other plate is connected to the negative pole of the power supply, the two plates will each carry the same amount of dissimilar charge. After charging, there is an electric field between the two plates of the capacitor, and the electrical energy obtained from the power supply is stored in the capacitor during the charging process.

2. The process of discharge.

The process of decharging a charged capacitor (releasing charge and energy) is called discharge. For example, if you connect the two poles of a capacitor with a wire, the charges on the two poles will neutralize each other, and the capacitor will release charge and energy. After discharge, the electric field between the two plates of the capacitor disappears, and the electrical energy is converted into other forms of energy.

The understanding, function and working principle of the three major capacitors of induction cooker are explained, and the knowledge is long.

Capacitive role: charge and discharge.

The basic function of the capacitor is to charge and discharge, but many circuit phenomena extended from this basic charge and discharge make the capacitor have a variety of different uses, such as: in the electric motor, it is used to generate phase shift; In a photographic flash, it is used to produce high-energy instantaneous discharges and so on. In electronic circuits, capacitors have many uses of different properties, and although there are completely different uses, they all come from charging and discharging.

Introduction: Capacitance, also known as "capacitance", refers to the amount of charge stored at a given potential difference, denoted as c, and the SI unit is farad (f). Generally speaking, the charge will move under force in the electric field, and when there is a medium between the conductors, it hinders the movement of the charge and makes the charge accumulate on the conductor, resulting in the accumulation and storage of charge, and the amount of stored charge is called capacitance.

Because capacitors are one of the electronic components used in electronic devices, they are widely used in DC-blocking, coupling, bypass, filtering, tuning loops, energy conversion, control circuits, etc.

1. In the circuit that requires DC power supply, the AC power supply is rectified and filtered with a capacitor to obtain a smooth DC current. If this capacitor is not used, the fluctuating DC current of the AC power supply after rectification cannot be filtered into a smooth DC current, and the circuit powered by it cannot work normally;

2. In equipment with one-way AC motor, the capacitor is used as the starting capacitor of the motor, and the capacitor is used to make the AC current produce phase shift, so that the stator of the motor produces a rotating magnetic field, so that the motor rotates. If you don't use this capacitor, the motor can't start and can't rotate to work;

3. If the equipment powered by the AC power supply is an inductive load, after being connected to the AC power supply, the inductive load current will produce phase shift, which will generate reactive current in the power supply line and increase the loss of the power supply line, so it is necessary to connect the compensation capacitor at the power input end of the equipment to reduce the reactive power loss.

Capacitors must be used for the above 1 and 2 equipment as mentioned above, and if capacitors are not used in the third case, the work of the equipment will not be affected, but the reactive power loss of the line will be increased, and the power supply line will be adversely affected.

Capacitors do a variety of things, and when put into a coupling circuit, they allow an AC signal to be transmitted to the next circuit. Capacitors also have the function of filtering, which can remove a certain frequency band signal from the total signal. Capacitors can also improve the stability of the circuit by compensating for the effects of other components due to temperature incompatibility, as well as provide a low-impedance path.

2. Filtering: The role of capacitor in filtering is to remove a certain frequency band signal from the total signal, and the larger the capacitor, the smaller the impedance, the higher the frequency will pass.

3. Compensation: The capacitor can also be used to compensate for the temperature by analyzing the influence of other components due to not adapting to the temperature, which can improve the stability of the circuit.

4. Bypass: The capacitor used in the bypass circuit can remove the signal of a certain frequency band, and can also provide some low-impedance paths for some parallel components in the AC circuit.

5. Decoupling: The decoupling capacitor actually takes the output signal as the filter object, playing the role of a "battery", which can meet the change of the current of the driving circuit, and can also avoid the coupling interference between the circuits.

6. Rectifier: The capacitor also has the function of rectification, which can turn on or off the semiconductor switching element at a predetermined time, so as to make the circuit pass more stable.

Capacitors are components that store electricity and electrical energy and are one of the most commonly used electronic components. Its function is mainly through the AC mode, to isolate the circuit DC, at the same time there is a storage charge and the release of the charge of the spine effect, has a good filtering machine, can be through the orange attack smooth way of the pulsating signal output.

Capacitors are used for many purposes, including coupling, filtering, decoupling, high-frequency vibration cancellation, resonance, bypass, neutralization, timing, integration, differentiation, compensation, bootstrapping, frequency division, etc. With the rapid development of electronic information technology, the upgrading speed of digital electronic products is getting faster and faster, which has driven the growth of the capacitor industry.