Flyback Transformer Designer

Last updated: 2026-06-05

Flyback Transformer Designer is an offline flyback transformer design application tailored for power engineers: starting from electrical specifications and design constraints, it automatically completes core selection, turn ratio and wire gauge optimization, loss and temperature rise estimation, and generates archivable PDF / JSON reports. All calculations run locally on your device; design data is never uploaded to the developer's servers.

Available for iPhone, iPad, and Mac via the App Store (Apple silicon Macs run the iOS-compatible version, as shown in the App Store). The annual subscription product includes an Apple 14-day free trial; start the Apple trial or subscribe to use the full workflow and export features.

Product Advantages

Purpose-built for flyback transformers: Supports DCM / BCM / QR / CCM modes, up to 3 secondary outputs, covering common flyback topologies and multi-output power supplies.
Joint iterative selection: Core × turn ratio × wire gauge (including Litz wire) scanned in one pass, compare multiple solutions, eliminate tedious manual recalculation.
Built-in component databases: Integrated core, bobbin, and material data (E / ETD / PQ / RM / EFD, etc.), filterable by manufacturer.
Air gap and inductance alignment: Air gap analytically calculated from Lm and Np with fringing effect correction; Lm, B_peak, and temperature rise verified simultaneously.
Extensible databases: "My Database" maintains custom materials, cores, and bobbins on your device, merged with built-in libraries for selection.
Privacy and offline-first: Core design functionality works offline; no third-party ads; independent app from "Inductor Designer Expert" with no shared accounts or data.

Key Features

Rectified DC input, multi-output specifications, and cross-regulation advisory.
AP method core pre-selection, iGSE / Steinmetz core loss, Dowell harmonic correction for copper loss.
Window allocation, insulated wire gauge, and thermal class constraints.
Interface: Simplified Chinese / English.

Workflow (Three Steps)

Specifications & Constraints — Enter input voltage, multi-output requirements, switching frequency, operating mode, and constraints (Bmax, Jmax, Ku, etc.).
Core & Winding Design — Review candidate solutions; select final design by loss, temperature rise, flux density, and window utilization.
Summary & Report — Verify parameter tables and warnings, export PDF or JSON files.

Trial & Subscription

Apple 14-day free trial: The annual subscription product includes an App Store introductory free trial; while the trial transaction is active, all three workflow steps and export functionality are available.
Annual subscription: Product ID com.deepthinker2026.flybacktransformerdesigner.yearly, auto-renews; trial eligibility, billing, and refunds are managed by Apple.
If you have not started the Apple trial and do not have an active subscription, access to steps 2 and 3 is blocked, as is report export.
Activate or restore purchase: in the app, open Settings → Subscription, or follow the Paywall prompts.

Frequently Asked Questions

How do I enable the subscription? Open "Settings" → "Subscription", then complete annual subscription or restore previous purchase.
Can I use it offline? Transformer design operations work offline; subscription verification and App Store operations require network connectivity.
Is my data uploaded? No. See the Privacy Policy.

Contact Us

GitHub Issues (bug reports and feature requests).
Email: Deepthinker2026@outlook.com