The USB-C power supply concept isn’t novel, with prior examples like the XIAO Powerbread and Axiometa BrodBoost-C. With USB PD adapters and power banks becoming cheaper, newer options like PocketPD and BenchVolt PD have surfaced, though each has limitations; PocketPD features only a single channel, while BenchVolt PD isn’t very portable.
Introducing Ampisu, a compact, pocket-friendly, isolated three-output lab power supply, merging the features of full-sized power supplies for low-power embedded tasks, field debugging, and automated testing.
Ampisu specs include:
– MCU: Raspberry Pi RP2040, dual-core Cortex-M0+ @ 125 MHz with 264KB SRAM
– Storage: Non-volatile memory for configurations
– Power Input: 5V via USB Type-A or C, auto-adapting to host power (up to 3A on USB-C)
– Power Output:
– 3x isolated outputs (transformer-isolated flyback converters)
– Adjustable Outputs 1 and 2: 0 V – 7.5 V @ up to 500 mA each
– Auxiliary channel: 3.3 V @ up to 100 mA
– Combination modes: Parallel up to 1 A, Series up to 15 V or ±7.5 V
– Performance:
– Resolution: 10 mV / 1 mA
– Ripple: ~8.44 mV RMS / ~39.5 mV peak-to-peak
– Load regulation: 1%
– Dual-channel DACs and ADCs for current/voltage measurement
– Low-noise outputs via linear post-regulation
– Protections: Analog current limiting, ESD, reverse current, overcurrent, overvoltage
– Misc: 3x RGB status LEDs, high-resistance grounding path
– Dimensions: 62 x 62 x 20 mm
– Weight: ~100 – 110 grams
– Enclosure: CNC-machined aluminum
Ampisu differs from power profilers as it offers isolation, avoiding ground loops and enabling split-rail supplies. Configured via WebUSB GUI, SCPI commands, and Python API, it integrates with PCs, Raspberry Pi, and automated tests without requiring drivers. It supports USB control with serial log interface, CSV-based automation, and retains configurations for standalone use. It’s open-source, with project files to be released post-campaign.
Ampisu is crowdfunding on Crowd Supply for $179, with free US shipping and $12 worldwide shipping, expected by August 31, 2026.
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