What Is Digital Password Door Lock ?

The feature of this circuit:-           

1. Using a four numericode number and can change one thousand numbers.
2. The case of other people to know our original code. The code can be changed easily.
3.  It is a simple digital circuit that without a microcontroller. Thus it is no programming, easiest, and cheaper.

The digital password door lock circuit is designed to have the reset system, immediately enter the wrong code. So can prevent pressing a random numeric code. Because in this circuit the switches are set to the ten numbers, be the code switch 4 pcs. and be reset switches 6 pcs.

The advantages of having a system reset. Suppose we set the code number is 3760. If people do not know the code, they will press random from 0 to 9.  It will have one correct number is 3.

But we press randomly in second, that is not 7. Then, the circuit will reset number 3 that last remember go away.

Thus, we will enter a correct code, just the first digit only.  However, if it is without the reset system. Even those who do not know the code, it can press random in a fourth only.

When we hit 0-9 from the first round, we will correctly hit to the No.3.  Then we hit the second round will correctly is one of No.7 as well. When the full four rounds, it will have a four code so the circuit is working.

This difference is quite obvious.We have talked about its advantage and disadvantages for enough.  Then to look at the circuit and how it works really well.