Modern Keypad lock
Coded Door Lock: Mechanical and Electronic : Modern Keypad Lock
Quote from Article entitled Coded Door Lock: Mechanical and Electronic:
The device of a magnetic coded lock is powered by electromagnetic pulses transmitted remotely to the control panel. However, a magnetic lock has its disadvantage. When you disconnect the power source a lock either is blocked or disabled. Therefore, it is important that a magnetic coded lock on a door has its own uninterruptible power supply, or the possibility for manual unlocking.
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