What Is the Flyback Transformer Primary Inductance & Peak Current Calculator?
Flyback converters store energy in the transformer core air gap during the primary MOSFET ON-time and release it to the secondary output during the OFF-time.
Selecting the correct primary magnetizing inductance Lp ensures complete core energy discharge in Discontinuous Conduction Mode (DCM) without exceeding switch current limits.
This calculator computes primary inductance Lp, peak primary current Ipk, RMS primary current, and input power demand.
How Does the Flyback Transformer Primary Inductance & Peak Current Calculator Work?
The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.
Flyback Transformer Primary Inductance & Peak Current Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Volt-second energy conservation formulation defining primary magnetizing inductance at DCM boundary.
How to Use the Flyback Transformer Primary Inductance & Peak Current Calculator
- Enter your primary measurements in the input fields above.
- Select your preferred units (e.g. metric or imperial) if applicable.
- Review or adjust operational assumptions such as field efficiency.
- Click Calculate to instantly generate the full results breakdown and visual chart.
- Use the Reset button at any time to clear the form and test a new scenario.
Step-by-Step Example Calculation
Universal Mains SMPS (Vin,min = 100V, Pout = 60W, fsw = 100 kHz, Dmax = 0.45)
Input Values:
Understanding Your Result
Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.
Factors That Affect the Result
Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.
When Should You Use This Calculator?
Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.
Assumptions & Limitations
- Flyback transformers actually function as coupled inductors because they store energy in the magnetic air gap rather than transferring power directly.
- A lower primary inductance increases peak switch currents and conduction losses, while excessively high inductance forces Continuous Conduction Mode (CCM).
Frequently Asked Questions
Calculation Accuracy & Reference Note
This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.