I have an electromagnetic device designed to hold a fire door open until either the circuit is cut or the building's electrical supply goes out. At which point the door is released and will close.
It is rated as 12 V/80 mA. What does that mean in terms of the length of time that the device will draw the 80 mA?
Should I read such a rating as 12 V/80 mAh or 12 V/.0080 h?
I'm doing some rough calculations as to how long a given battery combination would keep this device energized.