Flyback SMPS Calculator

Welcome to our tutorial on the Flyback Switch Mode Power Supply (SMPS) Calculator. In the field of electrical engineering, SMPS is a widely used power conversion technique that provides efficient and compact power supplies. The Flyback SMPS is a popular topology in applications such as power adapters, LED drivers, and battery chargers. In this tutorial, we will introduce the concept of the Flyback SMPS, discuss interesting facts about its operation, explain the key parameters and formula used for its calculation, and provide a real-life example to demonstrate its application.

Flyback SMPS Calculator
Transformer VT Product (VoltsÃ-μS)
Voltage Primary (Vin) V
Voltage Out (Vout) V
Turns Ratio
Transformer Primary Inductance μH
Transformer Leakage Inductance μH
Diode Voltage Drop (Vd) V
Transistor Voltage Drop(Vtran) V
Flyback SMPS Calculator Results
Ton max = μs
Frequency (F) = KHz
Duty Cycle =
Energy Per Cycle = μJ
Power = W
Current In(Iin) = A
Current Out(Iout) = A
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Interesting Facts about Flyback SMPS

Before we delve into the details of the Flyback SMPS calculator, let's explore some interesting facts about this power conversion technique:

  • Flyback SMPS is a type of isolated power supply, where energy is stored in the transformer during the switch-on period and transferred to the load during the switch-off period.
  • It is characterized by its ability to step up or step down the input voltage using a single transformer, making it suitable for a wide range of applications.
  • Flyback SMPS provides galvanic isolation between the input and output, offering enhanced safety and noise immunity.
  • The Flyback SMPS topology is known for its simplicity, low cost, and high efficiency, making it a preferred choice for many consumer electronic devices.
  • Design considerations for Flyback SMPS include input voltage, output voltage, output power, switching frequency, transformer turns ratio, and component selection.

The Formula for Flyback SMPS Calculation

Several key parameters of a Flyback SMPS can be calculated using the following formulas:

Output Power (Pout) = Output Voltage (Vout) × Output Current (Iout)

Input Power (Pin) = Output Power (Pout) / Efficiency (η)

Transformer Turns Ratio (N) = √(Vout / Vin)

Duty Cycle (D) = Vout / Vin


  • Pout is the output power in watts (W)
  • Vout is the output voltage in volts (V)
  • Iout is the output current in amperes (A)
  • Pin is the input power in watts (W)
  • η is the efficiency of the Flyback SMPS (expressed as a decimal or percentage)
  • Vin is the input voltage in volts (V)
  • N is the transformer turns ratio (dimensionless)
  • D is the duty cycle (dimensionless)

Example: Application of Flyback SMPS Calculation

Let's consider an example to illustrate how the Flyback SMPS calculation is used in real-life applications:

Suppose we are designing a Flyback SMPS for an LED lighting system. The desired specifications for the power supply are:

  • Output voltage (Vout): 12V
  • Output current (Iout): 2A
  • Efficiency (η): 90%
  • Input voltage (Vin): 120V

Using the formulas mentioned earlier, we can calculate the following parameters:

Output Power (Pout) = Vout × Iout = 12V × 2A = 24W

Input Power (Pin) = Pout / η = 24W / 0.9 = 26.67W

Transformer Turns Ratio (N) = √(Vout / Vin) = √(12V / 120V) = 0.1

Duty Cycle (D) = Vout / Vin = 12V / 120V = 0.1

In this example, the calculated parameters indicate that the Flyback SMPS should be designed to handle an output power of 24W, with an input power of approximately 26.67W. The transformer turns ratio is found to be 0.1, and the duty cycle is 0.1 as well.

In real-life applications, the Flyback SMPS calculator is used by engineers and designers in the development of power supplies for various electronic devices. By inputting the desired output voltage, current, and efficiency, the calculator helps determine the necessary input power, transformer turns ratio, and duty cycle to achieve the desired performance.

Designers can then select appropriate components such as the transformer, switches, diodes, and capacitors based on the calculated parameters. They can also perform additional simulations and optimizations to fine-tune the Flyback SMPS design for specific requirements, such as minimizing losses, improving transient response, and meeting safety standards.

The Flyback SMPS calculation is an essential step in the design process to ensure the power supply meets the desired specifications, operates efficiently, and delivers stable and reliable power to the load.

In summary, the Flyback SMPS calculator is a valuable tool for electrical engineers involved in power supply design. By understanding the concept, formulas, and real-life applications of Flyback SMPS calculations, engineers can develop efficient and compact power supplies for a wide range of electronic devices. The Flyback SMPS topology offers advantages such as galvanic isolation, simplicity, and high efficiency, making it a popular choice in many applications. So, next time you power up an electronic device, remember the calculations and design considerations that went into the Flyback SMPS that powers it, providing efficient and reliable performance.

Remember to always consider safety standards, thermal management, and component selection when designing and implementing Flyback SMPS systems. By leveraging the Flyback SMPS calculator and understanding the underlying principles, you can create power supplies that meet the specific requirements of your applications.

By mastering the calculations and design considerations involved in Flyback SMPS, you can contribute to the development of innovative and efficient power solutions that drive technological advancements across various industries. Whether it's powering LED lighting systems, consumer electronics, or industrial applications, the Flyback SMPS plays a crucial role in enabling reliable and high-performance power delivery.

So, embrace the world of Flyback SMPS and harness its potential to transform the way we power our modern devices. With the knowledge gained from this tutorial, you are now equipped to design and optimize Flyback SMPS systems to meet the power demands of the future.