This is the good old AC Dimmer, but with 2 channels.
This simple set for 3D printer base on microcontroller Mega 2560 + RAMPS 1.4 + motor drivers, it is a solution for
RobotDyn MEGA 2560 ETH R3 is an excellent choice for a controlled-over-the-Net device or a multi-functional data collector.
If you're looking to build a network-connected device with Arduino Nano is the best solution for you!
Relay Shield for Arduino Uno, 4 relays