Control device, pump unit, and refrigerant circulation device

A pump assembly comprising:

• a first connector detachably attached to an external device including a power supply;
• a motor;
• a pump rotor rotatable by power generated by the motor;
• a power supply path electrically connected between the motor and the first connector, through which a DC voltage is supplied from the power supply via the first connector when the first connector is connected to the external device;
• a load switch to switch between connection and disconnection of the power supply path;
• a protection circuit to prevent inrush current to the load switch;
• and
• a control circuit to detect that the first connector is connected to the external device and output a drive signal to switch the load switch from disconnection to connection;
• wherein
• the protection circuit includes at least a capacitor and is configured to switch the load switch from disconnection to connection over a predetermined first time period that is a time period to gradually transition the load switch from off to on based on a charging time of the capacitor by the drive signal;
• and
• the motor is configured to generate power in response to the load switch being connected.