Flyback Transformer Designer

Last updated: 2026-09-12

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). A 3-day full-feature trial starts on first launch and does not auto-charge when it ends. After the trial, a one-time App Store purchase unlocks the full workflow and export. This is not a subscription and does not auto-renew. Existing annual subscriptions remain valid until they expire.

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 & Purchase

3-day trial: Starts the first time you open the app. It is not an App Store introductory offer. You are not charged when it ends.
One-time purchase: Product ID com.deepthinker2026.flybacktransformerdesigner.lifetime. Not a subscription; does not auto-renew. Price is shown in the app from the App Store.
If the trial has ended and you have not purchased (and have no remaining yearly subscription), access to steps 2 and 3 is blocked, as is report export.
Buy or restore: in the app, open Settings → Pro, or follow the paywall. Use Restore Purchase with the same Apple ID.

Frequently Asked Questions

How do I unlock the full app? Open "Settings" → "Pro", then complete the one-time purchase or restore a previous purchase.
Can I use it offline? Transformer design operations work offline; App Store purchase and restore 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