Power supply as a load

Introduction

A power supply is a device that creates current and voltage, and its function is to convert electrical energy into the forms of energy that we need, such as mechanical energy, acoustic energy, thermal energy and so on. In modern industry, communications, computers, aircraft and other fields, power supplies are widely used as one of the infrastructures of production and life. However, the performance of power supplies can vary greatly under different load conditions. This article will focus on the power supply when the load is the power supply itself.

What is a load

In an electric circuit, a load is the resistance, capacitance, inductance, electronic components, appliances, equipment, etc., connected to the output of a power supply. The current and voltage output from a power supply is dissipated by the load, and changes in the load parameters affect the performance characteristics of the power supply.

Power supply when the load is the power supply itself

When the power supply is used as a load, the load current is 0 and the output voltage is equal to the rated voltage. In this case, the power supply's ability to adjust with load is very strong, and the stability of the output voltage and the load adjustment ability are very good. For a linear regulated power supply, when the load is the power supply itself, it has high voltage regulation accuracy and linearity because there is no change in load current to affect the output voltage.

Current limiting protection of power supply

When the power supply encounters a short circuit in the power supply circuit or an overload load, the power supply output current will increase dramatically. At this time, if the power supply does not have current-limiting protection measures, it is easy to cause the power supply or power supply circuit components fire, damage, and even serious threat to the use of the environment and personnel.

Generally speaking, linear regulated power supply using current-limiting diodes and overload protection circuit; switching regulated power supply using current-limiting circuits, overload protection circuit and thermal protection circuit. The current limiting diode is a diode with a conduction voltage drop of about 0.6V, which can stably limit the current and is a widely used protection circuit component. When the output is short-circuited, the current-limiting diode conducts so that the output current is restrained, protecting the power supply and other loads from damage.

Power supply output waveform stability

Whether it is a linear regulated power supply or switching regulated power supply, when the load is the power supply itself, the output voltage and current are very stable, the waveform amplitude and frequency will not change. This is because when the load is zero, the internal voltage regulator circuit of the power supply is not affected in any way, the stability of the output voltage is very high, and the amplitude and frequency are constant.

Temperature Abnormality Protection for Power Supplies

Under special circumstances, such as high ambient temperature, fan failure, etc., the power supply will overheat, resulting in large fluctuations in the output voltage and current, or even fuse, automatic shutdown, and so on. In order to improve the safety and reliability of the power supply, modern power supplies usually use overheating protection measures, such as high temperature automatic shutdown, dynamic adjustment of the size of the air inlet and other ways to prevent overheating of the power supply.

Summary

Power supply is an important equipment for industrial production and family life, and its performance and stability have an important impact on the quality and efficiency of production and life. When the load is the power supply itself, the stability of the power supply is high, and the output voltage, current waveform amplitude and frequency are very stable, which makes the energy output from the power supply safe and reliable to be used, and provides a good energy security for various applications.