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A project log for 1 Square inch 4-quadrant floating power supply

A 4-quadrant power supply built on a 1sqin PCB, +/-12V, 100mA, and floatable for multiple paralleling/series. 4layer, $10 OSHPark PCB.

Martin HeldMartin Held 09/30/2018 at 01:000 Comments

The circuit board is functional.  I can set the DAC output, and get an output from +12.8V to -13.6-ish volts.  I need to get some basic software working, but serial communications from the ATSAMD21 out via the isolated port is working, and basic ADC functions are in place, just need to calibrate and do a little math to do measurements right.  My initial code was stuck at 8Mhz, figured that one out today so it's now at 48MHz I think.

Next steps:

Disable output ; apply bench power supply and measure ADC value over voltage range using NIST-calibrated DMM/Power Supply, to see what correction factors I need for the ADC

Bypass output system and do the same for the current sense ADC; Make sure current/voltage ADC values are getting into memory appropriately and scaled right.

Define local variables and function to set voltage and current limits.

Write final control loop

Characterize the response waveform to transient load application.

Draw presentation slides

Make a video for final submission

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