⚡ Flyback Converter Calculator
Estimate the ideal duty cycle and switch voltage stress for a flyback converter design from your input voltage, output voltage and turns ratio.
What a flyback converter does
A flyback converter is a switching power supply topology that stores energy in a transformer while the switch is on, then releases it to the output while the switch is off. It is widely used for low to medium power isolated supplies.
The formula used
For an ideal continuous-conduction-mode flyback, the steady-state relationship is Vout = Vin × D/(1−D) × n, where n is the secondary-to-primary turns ratio (Ns/Np). Solving for duty cycle gives D = Vout / (Vout + n × Vin). The switch also sees the input voltage plus the output voltage reflected back through the turns ratio, which sets its minimum required voltage rating.
This calculator ignores leakage inductance, snubber losses and voltage spikes, all of which raise real-world switch stress above this ideal estimate. It is meant for general electronics planning and education, not as a substitute for full converter design and simulation.