A coupler for use with model trains. The coupler includes a body member; a knuckle pivotally mounted on the body member, where the knuckle is in either an open state or a closed state; a locking pin disposed on the body member, where the locking pin is operable for maintaining the knuckle in the closed state when the locking pin is in a first position, and for allowing the knuckle to transition to the open state when the locking pin is in a second position; and an actuator wire coupled to the body member and the locking pin. In operation, the actuator wire contracts in length when an electrical signal is supplied thereto such that the locking pin is transitioned to the second position when said electrical signal is supplied to the actuator wire.