Pulse transformer calculator

Design a high-frequency transformer for push-pull, half-bridge and full-bridge converters with turns, currents, wire sizing, core loss, window fill, up to five outputs and output chokes.

Input and topology

Recommended operating flux
≈ 0.193 T
𝐵=𝑉𝑝𝐷2𝑓𝑁𝑝𝐴𝑒
Timing
Switch drop

Core

𝜇𝑒
1,650
𝑙𝑒
103 mm
𝐴𝑒
173 mm2
𝐴𝑤
210 mm2
𝑉𝑒
17.819 cm3

Outputs

1/5 enabled

Output 1
Output 2
Output 3
Output 4
Output 5

Winding

Maximum single copper strand from skin depth
1.06 mm
𝛿Cu≈66√𝑓

Detailed model

Result

𝜂 97.5 %
Load
600 W
Capacity
835.6 W
Losses
15.19 W
Window
25.2 %

Primary

turns: 24
24
Calculated turns24
𝐿𝑝 2.006 mH
𝐼mag 0.397 A
Peak current5.849 A
Bus current2.051 A
Wire5 × 0.5 mm
Current density4.82 Amm2
Dead time1.429 𝜇s

Losses

Core0.706 W
Copper1.541 W
Switches6.947 W
Diodes6 W

How to use this tool

Design a pulse transformer for push-pull, half-bridge, and full-bridge converters. The calculator selects turns under flux and loss constraints, supports up to five secondary windings, and estimates wire sizing, window fill, losses, and output chokes.

Steps

  1. Choose the topology, input-voltage range, switching frequency, maximum flux density, and switch-drop model.
  2. Select a core and material or enter custom Ae, Aw, le, Ve, and μe values.
  3. Add up to five outputs and enter rectifier type, voltage, current, and diode drop; results update automatically.

Useful for

  • Preliminary SMPS transformer design
  • Window-fill and parallel-strand estimation
  • Comparing push-pull, half-bridge, and full-bridge options

Limits and accuracy

  • Advanced mode accepts Steinmetz coefficients, leakage inductance, Rac/Rdc, parasitic capacitance, switching times, Coss, and thermal parameters so these effects can be included in the loss and temperature estimate.
  • Parasitic-effect fields are an engineering model driven by the entered values. Use the parameters of the actual switches, core, winding construction, and prototype measurements for a final design.

Privacy

Parameters and calculations remain in the browser. Custom cores are stored only in local browser storage.

Sources