I need a load for testing and fancy a programmable load. My first idea was to use a resistor array and a relay operated switch board as illustrated below.
Next as I looked into more intelligent techniques I also realize how easy it is to make one using a DAC and power transistors. The concept is illustrated below.
I borrowed this illustration from the net, so we can use a MCU with DAC+ADC for the job and add a HMI, transistor array and heat-sinks – should be very doable.