DIGITALLY controlled double POWER supply

[Kerry] set out to develop a digitally controlled double supply for his bench. He’s already built a supply based on the LM338 linear regulator, however the goal this time around was to develop it without a linear regulator IC, as well as add digital manage over both the present as well as voltage.

In part one of the build, [Kerry] describes the analog style of the device. He had an additional heatsink kicking around, which can dissipate sufficient warm from this linear supply to let it run at 10 A. A NE5532 opamp is utilized to track a recommendation voltage, which can be supplied by a DAC. The present is determined by a LT6105 shunt sense amplifier, then compared to a recommendation supplied by one more DAC.

Part two focuses on the digital components. To interface with the analog circuitry, two MCP4821 DACs are used. These are controlled over SPI by an ATmega328P.

Fortunately, [Kerry] likewise has his own DC tons project to test the supply with.