Switching power supply is a kind of power supply which is widely used in various electronic equipment, including DC switching power supply and AC switching power supply.
What does switching power supply do?
Switching power supplies 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 switching power supply output is not sufficient and multiple switching power supply outputs need to be used in parallel.
In this article, we will describe in detail how to use switching power output in parallel.
What is the principle of using switching power supply output in parallel?
Connect multiple switching power supply outputs in parallel so that they can be combined into greater output power. Principle of parallel connection:
(1) Connect the positive and negative terminals
All the positive terminals of the power supply are connected, and all the negative terminals of the power supply are connected.
(2) Common output
In doing so, all the power supplies can coordinate with each other to collectively output greater current and voltage.
(3) The more power supplies, the greater the power
Multiple power supplies connected in parallel, each output the same voltage and current.
If the number of parallel output power supply is larger, the output power is also larger.
What are the applications of parallel power supply?
Multiple switching power supply outputs connected in parallel can be used in a variety of electronic devices.
The application of parallel power supply:
(1) High-power LED lighting,
(2) High-speed motor drives
(3) Frequency converters
In these applications, the output voltage or current of a single switching power supply cannot meet the demand.
Multiple switching power supplies in parallel can increase the output power to meet the needs of high power, high voltage and high current applications.
What should you pay attention to when using parallel power supply?
The parallel connection of the power supply must comply with certain specifications.
Otherwise, the output power of the power supply is unstable, the service life of the power supply is shortened, and the device is damaged.
Precautions for parallel power supply:
(1) Power supply model must be the same
Multiple switching power supplies in parallel must use the same type of switching power supply to ensure that their output voltage and current are the same.
What happens when different types of power supplies are connected in parallel?
If different types of power supplies are connected in parallel, the output power and stability of the power supply may be affected.
(2) The length of parallel cables must be the same
For multiple switching power supplies connected in parallel, the output voltage and current must be within the same voltage and current range.
What happens when parallel cables are of different lengths?
The different length of the connection line will increase the impedance change and voltage drop, which will cause the output of the power supply to be unstable.
Therefore, the cable length must be the same, and the wire diameter is also best to ensure the stability of the output voltage and current of the power supply.
(3) The output end of the switching power supply must be separately connected to the load
Multiple switching power supplies connected in parallel must be connected separately to different loads to make full use of the output power.
What happens when the outputs of multiple power supplies share a load?
If the outputs of multiple power supplies share a load, the failure of one of the power supplies will cause the output current of the power supplies of the shared load to be too large, thus damaging the load.
(4) The output current of the parallel power supply is required to be equal
When multiple switching power supplies are connected in parallel, their output currents must be equal, so that the output current of a single power supply can be avoided.
If the output currents of multiple power supplies are different, the power supply with smaller current may be overloaded during the working process, thus affecting the normal operation of the power supply.
(5) When the power output is in parallel, the cable interface must be protected
When multiple switching power supply outputs are connected in parallel, the cables connecting the power supplies must be protected.
Because at high power, high voltage and high current, the joint may loosen, resulting in arc light.
At the same time, the junction of the power output parallel connection must also be inspected and maintained regularly to prevent problems such as poor joint contact and aging of insulation materials.
The parallel connection of switching power supply output can greatly increase the output power to meet the needs of high power, high voltage and high current.
When the power supply is output in parallel, attention should be paid to the standard connection to ensure the stability of the power supply output voltage and current. Only in the case of reasonable connection, the parallel output of multiple switching power supplies can maintain lasting operation and provide power support for various electronic devices.