Design Steps for a Forward Transformer

Publish Time: 2025-07-08     Origin: Site

  1. Determine Primary Turns (Np): Select a core. Given minimum input voltage (Vs), on-time (Ton), and chosen flux density amplitude (ΔB, typically 0.2-0.25T for forward converters), calculate: Np = (Vs * Ton) / (Ae * ΔB) (where Ae = core cross-sectional area).

  2. Determine Secondary Turns (Ns): Based on required output voltage (Vo), diode forward voltage (Vd), and primary voltage reflected to secondary (Vs * Ns/Np), calculate: Ns = (Vo + Vd) * (Np / Vs).

  3. Calculate Primary Current & Wire Size: Sketch primary current waveform (reflected from secondary inductor current during switch-on). Its RMS value is: Iprms = (Ip * Vo/Vs) * sqrt[((KRP²)/3 - KRP + 1) * D]. Select primary wire based on this RMS current and current density.

  4. Calculate Secondary Current & Wire Size: The secondary current waveform is the inductor current during switch-on. Its RMS value is: Isrms = Ip * sqrt[((KRP²)/3 - KRP + 1) * D]. Select secondary wire based on this RMS current and current density.

  5. Design Reset Winding: Add a reset winding (typically opposite polarity to primary) to facilitate core reset via voltage clamping or other methods.

Why Golden Eagle High-Frequency Transformers Gain Customer Recognition:

  1. Lean One-Piece Flow: Eliminates work-in-progress (WIP) pile-up.

  2. Full Automation: Automated processes from winding and assembly to comprehensive testing.

  3. Premium Materials: 100% materials sourced from globally recognized suppliers, ensuring quality from the origin.


Custom Flat Enameled Wire Coils for Automotive Wireless Charging Modules

Custom 3kW–5kW Induction Coils for Commercial Induction Cookers

Custom Irregular Flat Enameled Wire Coils for Compact Power and Automotive Modules

Custom Fine-Wire High-Turn Coils for Compact Sensors and RF Devices

Custom Wireless Charging Coils for Automotive Center Consoles