I. Precautions for Parallel Connection of Switching Power Supplies
Parallel power supply connections must adhere to certain specifications; otherwise, problems such as unstable power output, shortened power supply lifespan, and equipment damage may occur. Below are some points to note:
(1) The power supply model must be consistent.
When connecting multiple switching power supplies in parallel, they must be of the same model to ensure that their output voltage and current are identical. Connecting power supplies of different models in parallel may affect their output power and stability.
(2) The lengths of the cables connected in parallel must be consistent.
For multiple switching power supplies connected in parallel, their output voltage and current must be within the same voltage and current range. Connecting wires of varying lengths will increase impedance changes and voltage drops, leading to unstable power supply output. Therefore, the cables must be of the same length, and ideally, the wire diameter should also be the same, to ensure the stability of the power supply's output voltage and current.
(3) The output terminals of the switching power supply must be connected to the loads respectively.
Multiple switching power supplies connected in parallel must be connected to different loads to fully utilize their output power. If the outputs of multiple power supplies share a single load, a failure in one of the power supplies will cause excessive output current across the shared load, potentially damaging the load.
(4) The output current of parallel power supplies must be equal.
When multiple switching power supplies are connected in parallel, their output currents must be equal to prevent a single power supply from having an excessively high output current. If the output currents of the multiple power supplies are different, the power supply with the smaller current may experience overload during operation, thus affecting the normal operation of the power supply.
(5) When power outputs are connected in parallel, the cable interfaces must be protected.
When multiple switching power supply outputs are connected in parallel, the connecting cables between the power supplies must be protected. Under high power, high voltage, and high current conditions, the connectors may loosen, leading to arcing. Furthermore, the joints of the parallel power supply outputs must be regularly inspected and maintained to prevent problems such as poor contact and aging of the insulation material.
II. Design Considerations for Switching Power Supplies
We need to be extra careful when designing switching power supplies to prevent circuit problems. So, what should we pay attention to when designing a switching power supply? I think the following five aspects require special attention.
1. Wiring
Wiring design requirements are extremely stringent in switching power supply design; proper execution is crucial for success. If the designer fails to address the wiring issues properly in the early stages of the design process, significant safety hazards can arise later. Therefore, I strongly advise paying close attention to the actual condition of the wiring when purchasing switching power supplies to prevent irreparable damage.
2. Component layout
Component design also requires careful consideration. When designing, it's crucial to adhere to physical design principles and avoid altering component positions based on personal preferences to prevent short circuits. Furthermore, designers must personally inspect the quality of components before purchasing them.
3. Parameters
In switching power supply design, it's crucial to understand every structural detail, especially memorizing the parameters. This provides essential information for future applications. Detailed parameters also facilitate later testing of the switching power supply, saving considerable time.
4. Inspection
After each switching power supply is designed, it must undergo rigorous inspection before production. Only through inspection can the usability and applicability of the switching power supply be determined, thus influencing its pricing. The inspection begins with the circuitry, examining the actual operating environment of the switching power supply to determine its optimal operating conditions and prevent circuit malfunctions in certain environments. Safety is our primary concern, therefore, we need to carefully inspect the switching power supply.
5. Select the appropriate power
To extend the lifespan of your switching power supply, I recommend choosing a model with 30% of its rated output power. If your system requires a 100W power supply, then I suggest selecting a model with a rated output power greater than 140W, and so on. This will effectively improve the power supply's lifespan.
After reading the above introduction, you should now know the key considerations for designing a switching power supply. Pay special attention to the five aspects mentioned above when designing a switching power supply; otherwise, design problems can significantly impact its future use.
