摘要 |
Release mechanism and method for fire doors and the like. The door is normally held in an open position by an electrically energized actuator and is released for closing upon deenergization of the actuator. An energizing current is supplied to the actuator from a source to energize the actuator, and a limited amount of energy from the source is stored in an element such as a capacitor. Upon interruption of the current from the source to the actuator, the actuator is energized with the stored energy to prevent the door from closing for a limited period of time after the current is interrupted.
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