How does the power supply provide voltage? How to provide 5V power

How can this question be asked? Is it because of the exam, or did it pop up out of nowhere? If the voltage difference can be supplied, it can be called a power supply.

Generators can turn mechanical energy.

Converted into electrical energy, dry batteries can convert chemical energy into electrical energy.

power supply (Figure 1).

The generator and the battery itself are not charged, its two poles have positive and negative charges, and the voltage is generated by the positive and negative charges (the current is formed by the directional movement of the charge under the action of voltage), the charge conductor is already there, and the current needs to be added to generate the voltage. Dry batteries, etc., are called power supplies. through transformers and rectifiers.

Put the alternating current. It becomes direct current.

The device is called a rectifier power supply.

This is an encyclopedic explanation, which sounds very professional, but I think it can be understood in this way, there are two major categories of power supplies, one is the physical power supply, and the principle of generation is according to Faraday's law of electromagnetic induction.

The closed conductor moves in a magnetic field, that is, cuts the magnetic field (we call it a magnetic induction line, in fact, for better understanding, there is actually no wire), and in the conductor the electrons will move directionally, forming an electric current, and there is a potential difference.

It's just a power supply.

There is also a type of chemical power, which is the chemical reaction of two substances.

In the process of reaction, there is the exchange of electrons or the exchange of ions to form a stable compound, at this time there is the transfer of electrons, if they are drawn out, an electric current can be formed, there will be a potential difference, which can be called a chemical power source.

In short, the essence of power supply is the same, and other forms of devices that can be converted into power are called power supplies.

Don't know what kind of power supply you're referring to?

A 5V power supply can be generated in a variety of ways, depending on what input power supply is used to convert it. If it is converted by 220V mains, the scheme of step-down, rectification, filtering, and linear regulator 7905 voltage regulation (as shown in the figure below) is adopted.

If the negative voltage (e.g., -8V) with a higher absolute voltage value is used to convert the -5V power supply, the 7905 can be used directly.

If the conversion is made from a positive voltage to -5V, it can be achieved with an inverting switching regulated power supply, such as CS5171 (as shown in the figure below).

The so-called power supply voltage, that is, electromotive force, is generated by the part of the power supply itself that can do work on the charge (for example, the dry battery is the chemical energy produced by the chemical reaction of zinc to do work), the charge obtains electrical energy when the charge is work, and at the same time a voltage is formed between the two poles of the power supply, and the value of the power supply to do work per 1c charge is the electromotive force, which is often called the power supply voltage.

The power supply voltage is generally unchanged, and the terminal voltage is determined according to the internal resistance of the power supply.

The power supply voltage is actually the road-end voltage, I don't know if you are asking about the question of electromotive force and road-end voltage, because the two concepts will be easily mixed in the second year of high school.

The electromotive force is the voltage of the pure power supply just mentioned (just understood as such, not a concept).

The internal resistance must be connected in series with the external circuit, and the voltage applied to the external circuit is the road-end voltage, or the power supply voltage.

As for the closed circuit current, it is determined by the internal resistance r, the external resistance r and the electromotive force e, i.e., i.e. i = e (r + r), and then the circuit end voltage is obtained by u = ir (ohm's law for closed circuits).

First, the role is different.

1. Input voltage: the voltage provided by the car to the on-board power supply, which indicates the requirements of the on-board power supply for the voltage provided by the car.

2. Power supply voltage: a measure of the unit charge in the electrostatic field.

The physical quantity of the energy difference due to the difference in electric potential.

Second, the characteristics are different.

1. Input voltage: The input voltage is a very important indicator of the on-board power supply, because the voltage provided by the car is usually not adjustable, so it largely determines whether the on-board power supply is suitable for a car.

2. Power supply voltage: its magnitude is equal to the unit positive charge.

Due to the force of the electric field.

The work done by the action to move from point A to point B, the direction of the voltage is specified as the direction from the high potential to the low potential.

3. The representation symbols are different.

1. Input voltage: usually represented by the symbol VI.

2. Power supply voltage: usually represented by the symbol V.

Encyclopedia - Input voltage.

Encyclopedia - Voltage.

The power supply voltage is generally DC, and the input voltage, that is, the signal, generally exists in the form of AC.

The power supply voltage is the voltage provided by the power supply, which can also be understood as the voltage on the VCC pins of the chip.

The input voltage refers to the amplitude of a signal, including the digital signal, the high and low levels are several V, and also the amplitude of the analog signal.

Generally, the chip requires that the input voltage is not higher than the power supply voltage, that is, as an input signal, the amplitude cannot be higher than the voltage on the VCC pin.

Of course, there may be different understandings in different contexts, for example, for transformers, the input voltage is the primary side voltage, and for the power supply, the input voltage is the voltage entering the power supply, ......

Summary. My dear, I will answer your questions for you, I hope it can help you! The voltage is the potential difference (or potential difference).

The potential (potential) of the positive pole of the power supply is higher than that of the negative pole, and the potential value of the positive electrode of the power supply minus the potential value of the negative electrode is the potential difference (i.e., voltage) of the power supply. When the connection is made through the connecting wire, an electric current is generated, and the current flows from the high potential pole to the low potential pole. It's the same as when water flows down.

For example, if there is a backwater pool on the mountain, there is also a backwater pool at the bottom of the mountain, and if you connect it with a pipe, the water from the waterhole on the mountain will flow to the waterhole below.

My dear, I will answer your questions for you, I hope it can help you! The voltage is the potential difference (or potential difference). The potential (potential) of the positive pole of the power supply is higher than that of the negative pole, and the potential value of the positive electrode of the power supply minus the potential value of the negative electrode is the potential difference (i.e., voltage) of the power supply.

When the connection is made through the connecting wire, an electric current is generated, and the current flows from the high potential pole to the low potential pole. It's the same as when water flows down. For example:

There is a backwater pool on the mountain, and there is also a backwater pool at the bottom of the mountain, and if you connect it with a pipe, the water from the mountain pool will flow to the bottom of the mountain.

Dear, I can't read the ** you sent, please communicate with text again!

The power supply is divided into voltage source and current source. The power supply that controls the output voltage is called a voltage source, such as a general battery, and a foot current source that controls the current. It is the power supply that you know the output voltage when you look at the power supply, which is the voltage source.

There are two types of power subdivisions: constant and controlled.

Voltage Source Classification:

1. Independent power supply.

It means that the voltage (current) output of the power supply is determined only by the nature of the independent power supply itself, and has nothing to do with the voltage (current) of the rest of the circuit. It is divided into voltage source and current source, and the voltage source and current source are divided into ideal and actual voltage (current) sources respectively.

2. Voltage source.

1) Ideal voltage source: The two-terminal component with a constant output voltage is called the ideal voltage source. Its output voltage is independent of the external circuit, and the inner hall has zero resistance.

2) Actual voltage source: A two-terminal element whose output voltage changes with the change of current flowing through it.

3. Current source.

1) Ideal current source: A two-terminal component with a constant output current is called an ideal current source. Its output current is independent of the external circuit, and the internal resistance is infinite.

2) Actual current source: A two-terminal component whose output voltage changes with the voltage at both ends.

4。Conversion between power sources.

An actual power supply, in terms of its external characteristics, can be seen as either a voltage source or a current source. The principle is proved as follows: there is a voltage source and a current source that are connected to the external electric imitation dissipation resistance r with the same large coarse resistance value. <>