A DC power supply is a device that maintains a steady voltage and current in a circuit
The principle of DC power supply: the electric field caused by the positive charge alone cannot maintain a constant current, but with the help of DC power supply, the non-static effect can be used (so that the positive electricity passes through the negative electrode with a lower potential difference through the inside of the switching power supply) Go back to the positive electrode with a higher potential difference to maintain the potential difference between the two electrodes, thereby generating a constant current. The DC power supply is a device that maintains a stable voltage and current in the circuit.
The non-electrostatic force in a DC power supply is biased from the negative pole to the positive pole. When the DC power supply is connected to the external circuit, outside the switching power supply (external circuit), due to the promotion of the electric field force, a current flow from the positive pole to the negative pole is generated. In the switching power supply (internal circuit), the effect of non-electrostatic force makes the current flow from the negative electrode to the positive electrode, and then makes the flow of positive charges form a closed circulation system.
An important characteristic of the power supply itself is the electromotive force of the power supply, which is equivalent to the work done by the non-static force when the positive electricity of the company moves from the negative pole to the positive pole through the power supply.
When the internal resistance of the switching power supply can be ignored, it can be considered that the electromotive force of the switching power supply is similar in value to the potential difference or operating voltage between the two sides of the switching power supply.
In order to obtain a higher AC voltage, DC power supplies are often used in series. At this time, the total electromotive force is the sum of the electromotive forces of each switching power supply, and the total internal resistance is also the sum of the internal resistance of each switching power supply. Because of the enlarged internal resistance, it is usually only used in power circuits that require a smaller current intensity. In order to obtain a large current intensity, DC power supplies with equal electromotive force can be used in series. At this time, the total electromotive force is the electromotive force of the individual switching power supply, and the total internal resistance is the series value of the internal resistance of each switching power supply.
There are many types of DC power sources. In different types of DC power sources, the characteristics of electrostatic forces are different, and the process of energy conversion is also different. In chemical batteries (such as dry batteries, batteries, etc.), the non-static force is the oxidation associated with the melting and accumulation process of positive ions. When the chemical battery is charged and discharged, the mechanical energy is converted into electromagnetic energy and Joule heat in the temperature difference switching power supply. (such as metal temperature difference couples, semiconductor temperature difference couples), the non-static force is the diffusion effect associated with the temperature difference and the concentration difference of the electronic device. When the temperature difference switching power supply provides output power to the external circuit, the energy partly converted to electromagnetic energy. In the DC generator, the non-electrostatic force is the electromagnetic effect. When the DC generator powers the system, the chemical energy is converted into electromagnetic energy and Joule heat. In photovoltaic cells, the non-electrostatic force is the effect of the photovoltaic effect. When photovoltaic cells power the system, light energy is converted into electrical energy and Joule heat.
