The 4 Power is a shield for Arduino that can control until 4 DC motors and one extra resistive load of your choice. To user it just connect one power supply of unitl 46V (Max 1A per motor) connecting the terminals Vcc and GND. The board has indication of positive and negative for each motor, that could pull until 1A in maximum voltage of power supply (Vcc), but it could variates by PWM (available in library). The extra resistive load can pull until 30A in 60V. To use the 4 Power, Just install the library below, after installed the program is very simple.