For Double Action Doors
Electronic drop bolts are mortice electric locks that work differently from Electromagnetic Locks and overcome the two disadvantages of using Electromagnetic Locks.
Electronic drop bolts can operate in either fail-safe or fail-secure modes. Under the fail-safe mode, it will leave the door unlocked in the event of a power failure whereas, under the fail-secure mode, it can keep the door locked when there is no power whereas the EM Lock will leave the door unlocked once there is no power.
Electronic drop bolts allow the door to swing in or out whereas, with EM Locks, the door can only swing one way The upper part of the bolt comprises the solenoid that drives the bolt and the lower portion comprise a door sensor with a guide hole. For a wooden door, the upper portion is installed into the door frame while a hole is bored into the top edge of the door to hold the bottom half.
When the door is closed, both upper and lower portion door sensors are aligned and the drop bolt is released into the guide hole, securing the door. When a valid card is flashed at the reader, the card access controller will send a command to pull or retract the bolt, releasing the door.