ELECTRIC VEHICLE SUPPORT EQUIPMENT HAVING A SMART PLUG WITH A RELAY CONTROL CIRCUIT

摘要

A smart plug (120) for coupling an electric vehicle to a power supply includes a relay (206) including contacts (264), the relay configured to operate in a closed state to enable power to be supplied to the electric vehicle and an open state to prohibit power from being supplied to the electric vehicle. The smart plug also includes a microcontroller (MCU) (200) coupled to the relay, the microcontroller outputting a control signal (148) to operate the relay in the closed state. The smart plug further includes a zero crossing detector (ZCD) (202) coupled to the relay, the ZCD outputting a close signal to the relay when a voltage of the power is substantially zero and outputting an open signal to the relay when a current of the power is substantially zero.