A motorized roller shade that detects obstacles in its travel that create excess torque by sensing the current draw from a motor and method by which the motor can calibrate itself to detect excess torque. During the roller shade's travel, it will record the instantaneous torque being generated at various points. For example, it will store the greatest value in the shade motor's non-volatile memory as the normal operating torque.

A drive arrangement for a door device which includes a door member. The drive arrangement includes a door shaft, a driven shaft which is operatively connected to the door shaft, a transmission arrangement which drives the door shaft, and at least one electric motor which is coupled to the transmission arrangement to move the door member of the door device from a closed state to an open state and vice versa. The at least one electric motor has at least one eccentric drive shaft. The transmission arrangement includes an eccentric gear transmission which has at least two orbiting toothed disks, each of which have an internal toothing. The at least two orbiting toothed disks are driven by the at least one eccentric drive shaft of the at least one electric motor, and, via the internal toothing, engage with the driven shaft.

A method that detects obstacles on a roller shade's travel that create excess torque by sensing the current draw from a motor and method by which the motor can calibrate itself to detect excess torque. During the roller shade's travel, it will record the instantaneous torque being generated at various points. For example, it will store the greatest value in the shade motor's non-volatile memory as the normal operating torque.

The system may include a motor releasably connected to a control module and the control module releasably connected to a drive module. The system may further include a joint releasably connecting the control module to the drive module, wherein the joint includes a floating gear. The method may include determining a motor shaft rotation of a motor shaft in a motor, determining a shade tube rotation of a shade tube that moves a window shade over a path, comparing the motor shaft rotation to the shade tube rotation, determining, based on the comparing, that the shade tube rotation is not equal to the motor shaft rotation and determining that an obstacle exists in the path of the window shade. The method may also include determining a change in at least one of current or torque in the motor.

The system may include a motor releasably connected to a control module and the control module releasably connected to a drive module. The system may further include a joint releasably connecting the control module to the drive module, wherein the joint includes a floating gear. The method may include determining a motor shaft rotation of a motor shaft in a motor, determining a shade tube rotation of a shade tube that moves a window shade over a path, comparing the motor shaft rotation to the shade tube rotation, determining, based on the comparing, that the shade tube rotation is not equal to the motor shaft rotation and determining that an obstacle exists in the path of the window shade. The method may also include determining a change in at least one of current or torque in the motor.