Question
Design a digital combination lock is a security system that requires users to input a specific sequence of numbers (the combination) to unlock a door
Design a digital combination lock is a security system that requires users to input a specific sequence of numbers (the combination) to unlock a door or access a secure area.
Components required:
Keypad: A 4x3 matrix keypad to input the combination.
_Logic Gates ICs: You can use standard CMOS logic gate ICs like 74HC00 (Quad 2-input NAND gate), 74HC02 (Quad 2-input NOR gate), and 74HC08 (Quad 2-input AND gate).
_Flip-Flops IC: For this project, you'll need a JK flip-flop IC, such as 74HC73 (Dual JK flip-flop).
_LEDs: Two LEDs, a RED LED, and a GREEN LED, to indicate the lock status (locked/unlocked).
_Resistors and Capacitors: Required to set up the proper biasing and timing for the flip-flop.
_Power Supply: +5V power supply to power the circuit.
Circuit Operation
_The 4x3 matrix keypad allows the user to input a 4-digit combination.
_The keypad output is connected to the inputs of the 74HC00 NAND gates, which are used to perform logical operations on the keypad input.
_The output of the 74HC00 NAND gates is connected to the JK inputs (J, K) of the 74HC73 JK flip-flop.
_The flip-flop stores the previously entered digits and compares them with the correct combination.
_The correct combination is hardcoded into the NAND gates using appropriate connections. For example, if the correct combination is 1234, the NAND gates will be wired to output 0 only when the input is 1234.
_If the user enters the correct combination, the flip-flop's output will change, activating the RED LED to indicate that the lock is unlocked.
_If the user enters an incorrect combination, the flip-flop's output will remain unchanged, and the GREEN LED will be lit, indicating that the lock is still locked.
Generate the Truth Table
Generate the truth table for the Digital Combination Lock circuit using logic gates. Use the correct combination that you have chosen. Where:
_Inputs_:_A_,_B_,_C_,_D (_Row pins of the key_pad_)
_Outputs: Y1, Y2, Y3, Y4 (Outputs of the NAND gates representing the logic for the correct combination)
Q is the output of the JK flip-flop
In the truth table, the inputs A, B, C, and D represent the user input from the keypad. The outputs Y1, Y2, Y3, and Y4 represent the logic gates' outputs for the correct combination (____). The output Q represents the state of the JK flip-flop, indicating whether the correct combination has been entered or not.
Note that the output Q will be '1' only when the correct combination is entered. Otherwise, the output Q will remain '0', indicating that the lock remains locked.
Generate the truth table and create the logic circuits diagram using the above components required (need details and correct design).
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