Self-adjusting door closer

A door closer comprising:

• a spring;
• a movable element configured to move in response to movement of a door, the movable element loading the spring;
• a valve configured to control movement of hydraulic fluid around the movable element;
• a position sensor to determine a position of the door;
• at least one input switch to enable user selection of at least one door closer parameter for an installed door closer;
• control circuitry including a connection for a motor to control a valve in the door closer, the control circuitry operable to set the valve in response to the user selection of the at least one door closer parameter, and the position of the door, in order to control force exerted by the door closer on the door;
• and
• a device to provide electricity to power the control circuitry.

A method of operating a self-powered, self-adjusting door closer, the method comprising:

• generating electricity to power control circuitry in the door closer, the electricity being generated from movement of a door;
• repeatedly determining an angular position of the door;
• reading at least one input switch to determine a user selection of at least one door closer parameter;
• moving a valve in the door closer to a safe close position when power available to the control circuitry is insufficient for other operation, wherein the safe close position of the valve results in a force specified to close the door safely;
• and
• otherwise setting the valve in response to the user selection of the at least one door closer parameter and the position of the door in order to control the force exerted by the door closer on the door.

Apparatus for controlling a door closer, the apparatus comprising:

• means for providing electricity to power control circuitry in the door closer;
• means for determining an angular position of the door;
• means for determining a user selection of at least one door closer parameter;
• and
• means for setting the valve in response to the user selection of the at least one door closer parameter and the position of the door in order to control the force exerted by the door closer on the door.