A door operator and related method of setting custom limits on movable barrier travel, includes a motor for moving the movable barrier between two travel limit positions, an operator for controlling operation of the motor, and a disconnect system coupled between the motor and the operator. The display device of the present invention comprises a display unit, an open type head-mounted display, an image acquisition unit and a gesture recognition unit. The three legs, when extended, are independently positionable to give the user the flexibility to use the tripod on non-planar surfaces, and to allow some aiming of the camera. This switching resonant stage converts the rectified voltage into a second rectified voltage of a second constant polarity and a second amplitude.