Two new features to MightyWatt R3 and some observations:

• First, it is possible to disable autoranging. This may be useful to get rid of glitches when switching ranges. When a range is switched, a few millisecond long dip can form before the load stabilizes. Disabling autoranging can prevent this. The logic is this: When in CC mode, the current range autoranging can be disabled while the voltmeter autoranges as usual. And vice versa.
• Another feature concerns constant power (CP) and constant resistance (CR). Typically, these software modes are internally constant current but in some cases, it might be better to use constant voltage internally. This is now possible. But I recommend using internal CC mode for normal operation.

The observations:

• 3 A CC mode, the current noise/ripple is 0.75 mA RMS in 20 Hz to 300 kHz band.
• Temperature coefficient for current measured at 10 A, 70 W was about 18 ppm/K.
• Slew rate measured as the time taking to get from 10 % to 90 % is about 19000 A/s when going from 0 to 20 A.