How can the output of a switching power supply be used in parallel?
Switching power supply is a widely used power supply in various electronic devices, including DC switching power supply and AC switching power supply. Switching power supply can provide stable, reliable, and efficient voltage and current output, making it the preferred power supply for many electronic devices. However, in some cases, a single switch power output cannot meet the demand, and multiple switch power outputs need to be used in parallel. In this article, we will provide a detailed introduction to how to use switching power supply outputs in parallel.
1. Principle of parallel connection
Parallel connection of multiple switching power supply outputs enables them to be combined into a larger output power. The principle of parallel connection of power supplies is simple: connect all positive poles of the power supply and connect all negative poles of the power supply. This can coordinate all power sources and jointly output larger currents and voltages. Multiple power sources connected in parallel, each of which outputs the same voltage and current. If the number of parallel output power sources is greater, the output power is also greater.
2. Applicable occasions for parallel power supply
Multiple switch power outputs connected in parallel can be applied to various electronic devices, such as high-power LED lighting, high-speed motor drives, frequency converters, and so on. In these applications, the output voltage or current of a single switching power supply cannot meet the demand. Parallel connection of multiple switching power supplies can increase output power and meet the needs of high-power, high-voltage, and high current applications.
3. Precautions for parallel power supply
The parallel connection of power supplies must follow certain standards, otherwise it may lead to unstable power output, shortened power life, equipment damage, and other issues. Here are a few things to note:
(1) The power supply model must be consistent
Multiple switch power supplies in parallel must use the same model of switch power supply to ensure that their output voltage and current are the same. If different models of power supplies are connected in parallel, the output power and stability of the power supply may be affected.
(2) The length of cables connected in parallel should be consistent
For multiple switch power supplies connected in parallel, their output voltage and current must be within the same voltage and current range. Different lengths of connecting wires can increase impedance changes and voltage drops, which can lead to unstable output of the power supply. Therefore, the cable length must be the same, and the wire diameter should also be the same to ensure the stability of the power output voltage and current.
(3) The output terminals of the switching power supply must be connected to the load separately
Multiple switch power supplies connected in parallel must be connected to different loads to fully utilize output power. If the output terminals of multiple power supplies share a load, the failure of one of the power supplies will cause the output current of the shared load to be too high, thereby damaging the load.
(4) The output current requirements of parallel power sources are equal
When multiple switching power supplies are connected in parallel, their output current must be equal to avoid the occurrence of excessive output current from a single power supply. If the output current of multiple power supplies is different, the power supply with smaller current may experience overload during operation, which can affect the normal operation of the power supply.
(5) When the power output is connected in parallel, the cable interface must be connected for protection
When multiple switch power supplies are output in parallel, the connecting cables between the power supplies must be protected. Because under high power, high voltage, and high current, the connector may become loose, resulting in arc light. At the same time, the joint of the power output parallel connection must also be regularly inspected and maintained to prevent problems such as poor contact of the joint and aging of the insulation material.
