Variable power supplies with the ability to dual feed are very expensive (300€+) but this can be made for under 100€. The project uses a switched power supply for 230 V to 12 V conversion. I choose one that is rated for max 75 W. 12 V is the most energi efficient for the buck and boost converters LTC3780. We need 2 buck and boost converters, 1 for each output. The casing will be 3D printed.
Voltage and ampere limit will be adjusted with screws on potentiometers, replacing the ones on the LTC3780s. Volt and ampere will be measured with digital displays and might be connected to arduino that can show first when adjusting what max amperage is and then what the current draw actually is.