AC/DC Flyback Power Supply — Prototyping Bench

An intentionally oversized isolated flyback converter built as a development bench for compact AC/DC designs.

Specs: 85–265 V AC input, 5 V output, VIPer06 offline controller (60 kHz fixed frequency, integrated 700 V MOSFET). Transformer is the Würth 750370423.

Topology: VIPer06 powered from an auxiliary winding. Isolated feedback via optocoupler — isolation maintained end-to-end. RC snubber on the primary switch node.

Input stage: fuse and varistor for overvoltage protection, NTC thermistor for inrush limiting, common-mode choke and X2 capacitor for EMI filtering.

Design intent: THT components throughout for easy value swapping during characterization. Modular areas for snubber, compensation network, and secondary filtering. Dedicated test points for oscilloscope spring probes across all critical nodes. Proper creepage spacing — safe to probe under load.