Considerations for Choosing the Right Power Supply


When selecting a power supply, it’s crucial to map out all the essential details beforehand, and a napkin drawing can serve as a handy tool for this purpose. Imagine the power supply as a black box, with input parameters on the left and output parameters on the right, encompassing all other pertinent factors within.

Let’s delve into each of these specification parameters individually:

  • AC Input Voltage Range (Vin): Determine the required range for your power supply, whether it’s single-phase or three-phase AC. Understanding the AC input voltage range is vital for selecting the appropriate power supply. Most systems operate within a universal AC input voltage range of 85~264 Vac, 47 to 60Hz. Additionally, consider power supplies with interchangeable blade kits for global compatibility, or fixed blade options tailored to specific voltage ranges and application needs, available in desktop or wall-mount configurations.
  • Output Voltage Range (Vout): Identify the necessary output voltage range for your application. Whether it’s for LED lighting or test and measurement purposes, you might require an adjustable output voltage range. Opting for an AC-DC power supply with variable output range capabilities can save both time and resources. Alternatively, fixed output voltages like 48V or 12V may be suitable for other scenarios.
  • Maximum Output Current (Iout): Determine the maximum output power required from the AC-DC power supply, especially in applications where output current fluctuates significantly. Some power supplies offer the option to parallel for increased power output, providing flexibility for varying demands.
  • Output Regulation / Ripple: Consider the output ripple and regulation, particularly for applications with high-output ripple or fluctuating current demands, such as motor drives. Assess if regulated output is necessary and define acceptable tolerance levels for your application. This information is typically outlined in the datasheet’s electrical specifications.
  • Space and Dimensions: Evaluate whether your application can accommodate the power supply’s dimensions, considering the trend towards compact designs. Determine if there’s ample space for paralleling supplies for increased power output, as well as for additional cooling components like fans or conduction plates.
  • Enclosure, Cooling, and Fan: Assess whether your power supply necessitates an enclosed fan, conduction cooling, or an external fan for efficient heat dissipation. Features like over-temperature protection are essential to safeguard against overheating, emphasizing the importance of maintaining optimal operating temperatures.

Power Suplies Enclosures

  • Temperature Grade: Verify if the power supply can withstand extreme temperature conditions, ranging from -40°C to +50°C, ensuring functionality even in harsh environments. Review the electrical specifications in the datasheet for temperature tolerance information.
  • Derating: Account for environmental factors such as altitude and temperature, which can impact the power supply’s performance by causing derating, resulting in power loss.
  • Standards Compliance: Determine if your application requires adherence to specific standards such as 60601, IP20, or IP22. Some power supplies are tested and certified to meet these standards, with common certifications including UL, TUV and EN.

These parameters collectively contribute to selecting the most suitable power supply for your application. The prioritization of these factors depends on your unique requirements and preferences. Should you require further assistance or information, don’t hesitate to reach out to us for expert guidance and knowledge exchange.