密码控制器（Digital Keypads、Electronic lock），为数字式门禁安全系统的零组件，一般被使用在企业、住家、隐密场所使用，一般市面上最少有10组~150组用户码容量，依照不同的需求选购不同的控制器，一般像比较隐密的场所，如：银行，由于是存放金钱的地方，所以进出人员必须严格管制，内部人员每人都有一组属于自己的密码，密码按对了才可以进入，相对的，如果银行人员离职后，管制密码控制器人员将离职人员的号码删除，预防非法入侵，其设置方式也非常容易简单，在学习密码控制器机器时，可以轻松添加或移除。

An electronic lock (or electric lock) is a locking device which operates by means of electric current. Electric locks are sometimes stand-alone with an electronic control assembly mounted directly to the lock. Electric locks may be connected to an access control system, the advantages of which include: key control, where keys can be added and removed without re-keying the lock cylinder; fine access control, where time and place are factors; and transaction logging, where activity is recorded. Electronic locks can also be remotely monitored and controlled, both to lock and unlock.