Emergency door release with backup power

A method for controlling operation of a rolling door in an emergency door release device, the method comprising:

• utilizing mains building power to charge a rechargeable battery, power a microcontroller and energize an electro-magnet, the electromagnet operable to maintain the rolling door in an open position;
• monitoring, by the microcontroller, an emergency condition and the presence of mains building power;
• in response to loss of mains power,
• powering the electro-magnet with the rechargeable battery;
• and
• configuring a switching assembly to provide backup-power to the microcontroller from a non-rechargeable backup battery and to isolate the rechargeable battery from the microcontroller;
• and
• in response to the detection of an emergency, sending a signal from the microcontroller to de-energize the electromagnet to release the door and facilitate movement of the door from the open position to a closed position.

An emergency door release device, comprising:

• a microcontroller for controlling operation of the door release device, the microcontroller operable in a normal power mode, in which the microcontroller is powered by regulated mains building power, and a backup power mode, in which the microcontroller is powered by a non-rechargeable backup battery;
• a power sensing path for providing unregulated mains building power to enable the microcontroller to sense the presence of mains building power;
• a switching assembly communicatively coupled to the microcontroller, the switching assembly having first and second switching mechanisms to switch the microcontroller between the normal power mode and the backup power mode;
• and
• wherein in response to a detection of a mains power failure, the microcontroller configures the switching assembly to facilitate switching from the normal power mode to the backup power mode to enable the microcontroller to remain operational during the mains power failure.

A door release device, comprising:

• a microcontroller for controlling operation of the door release device, the micro controller operable in a normal power mode, in which the microcontroller is powered by mains building power, and a backup power mode, in which the microcontroller is powered by a non-rechargeable backup battery;
• a voltage regulator for providing regulated power to the microcontroller;
• a switching assembly communicatively coupled to the microcontroller, the switching assembly operable to switch the microcontroller between the normal power mode and the backup power mode in response to a mains power failure;
• and
• a holding capacitor to provide unregulated power to continuously power the voltage regulator after the mains power failure to enable the switching assembly to switch the microcontroller from the normal power mode to the backup power mode.