The password based lock for any access control systems is very common now a day. If there is a password lock for any gate/door, then the gate or door only opens when correct password is entered. Mostly in such system numeric keypad is given to enter password. Sequential code lock differs here with normal password lock system. It does not have full numeric keypad with 10 to 12 switches. Instead it has 2 to 3 switches only. The user has to enter correct sequence of numeric digits just like sequential locks available in briefcases. When the numeric digits are arranged in correct sequence it unlocks.