By now, we are in the age of electronics, digital to be precise, it is undeniable. Yet the old beloved mechanical combination lock is not dead; on the contrary, it is in excellent health!
Despite the fact that in many cases of failure of “old-style” locks the technicians tend to replace them with digital models, which appeared on the market around 1980, thanks also to the fact that the mounting points inside the door are the same, in an equivalent number of cases the replacement takes place with an identical device, often at the explicit request of the customer.
It is an established fact that, in the catalogs of all manufacturers of combination locks, the two systems coexist. Mechanical combination locks are still in production, and no mention is made of the end of this trade. But we must not forget that, while the mechanical lock has evolved and perfected for well over a hundred years, the equivalent electronic model has recently celebrated thirty years of life.
However, it does not make sense to obstinately deny the inexorable advance of electronics, in this as in many other fields. Sooner or later, the mechanical locks will become the material for nostalgic antique collectors.
The characteristics of digital combination locks
Examining in detail the technical characteristics of a Digital Door Lock, we cannot deny the advanced peculiarities from the point of view of anti-tampering security that restrict and perhaps cancel, the possibilities of “bypass” through electronic devices.
The absence of disks and relative notches, coupling pins, levers, and relative cuff from which to obtain useful information for discovering the combination, replaced by a microprocessor that governs a latch interlocked to a solenoid or a stepper motor.
The very limited number of moving parts (keyboard, solenoid, and bolt) restrict the probability of failure, which, statistically, can be attributed to false electrical contacts in the keyboard or in the coupling cables, to defects in the batteries or to the solenoid itself.
The very high number of different combinations that can be set, recorded in a non-volatile memory, which reaches twelve zeros! (10 12 possible combinations).
The total absence of tolerances between the numbers, also adjacent, and the absence of “forbidden numbers” in the third digit of the combination.
The possibility of entering several valid combinations, one for each user, with memorization of each single maneuver and with the recording of the day, month, year, hour, and minute and “name” of the operator.
The ability to recognize access attempts made with an exhaustive or deductive search for the combinations, to which the lock reacts by locking for a predetermined time (penalty time) and recording such approaches in a non-erasable memory location.
Some models of digital door locks India must be “loaded” just before use, alternately turning the knob in both directions. Immediately after entering the combination, the bolt must be retracted within four to six seconds. If a longer time elapses, the lock does not open, and the process must be repeated from the beginning.
The implementation of the functions of the “time lock”, which makes the lock insensitive to any maneuver, if performed outside the allowed time slots and many other features whose limits depend on the program encoded in the core of the microprocessor rather than the mechanical tolerances.