What is it?

A 3-phase 50/60Hz output main AC simulator with 9v peak-to-peak output. The system is in a feather form factor and has successfully been tested with Teensy 3.2 and ESP32 feather boards. Should work with other feather boards capable of High-Speed or at least Fast I2C.

It consists of 4 main subsystems.

• 5v boost converter to allow battery based operation.
• Capacitor charge pump based negative voltage rail generator
• High-Speed I2C capable DAC for generating waveforms
• Quad-opamp for Analog gain control using potentiometers and a constant AC current source to simulate current clamps.

Why did you make it?

While developing the 3-phase energy monitor boards using ATM90E36 and V9203 I was stuck with the lack of easily available 3-phase power supply to easily test them with. I had to travel to hackerspace to test them and ended up blowing up the test load. This synthesizer was born out of the need to have ELV 3-phase supply with controllable frequency and amplitude to test energy monitor ASICs.

What makes it special?

This is a simple to use yet feature rich 3-phase synthesizer. It can be used for numerous other purposes including musical synthesis with appropriate power amplification added. The I2C interface to the main DAC allows use of many microprocessors / microcontrollers as hosts since the I2C bus is very common. The is also a unique constant current source built in using an opamp, which can be used to simulate current clamps and other current output type transducers.

NOTE : I have an initial set with some hardware bodges at a purely parts cost to help with next iterations.

All SMD parts come fully assembled. Headers will be supplied separately to allow flexible use with Featherwings. The molex nanofit cable is optional.