Patent attributes
A door opener capable of controlling the door closing speed includes a driving device and a generator mode operating module electrically connected to the driving device. The driving device includes a motor which can be supplied with power to pivot a door from an open position to a closed position. The driving device detects the position of the door by a switch. When pivotal movement of the door is achieved without supplying power to the door, the pivotal movement sets the generator mode operating module to a generator mode or a non-generator mode. In the generator mode, the motor is impeded by the electromagnetic resistance, such that the pivoting speed of the door is reduced. In the non-generator mode, the motor is not impeded by the electromagnetic resistance, such that the pivoting speed of the door is increased.