We carry a lot of vital things on our train and bus journeys, and we’re always afraid that someone will lift our Luggage Security Alarm. So, in order to safeguard our luggage, we usually lock it using traditional methods such as a chain and lock. Despite the locks, we are still concerned that someone will slit the chain and steal our valuables. To help you conquer your fears, here is a simple circuit based on the NAND gate. When someone tries to lift your luggage in this circuit, it will emit a warning alarm, which will be very useful throughout your bus or train ride, even at night, as it can also produce auditory visual indication tied to the relay.
Another application of this circuit is that you can employ these into your house so to avoid the attempt of robbery in your house with the help of this alarm circuit. When anyone tries to open the door of your house, loop break down and sound from the alarm produce.
Luggage Security Alarm Circuit Diagram:
- IC1(CD4011) – 1
- R1(1K) – 1
- R2(4.7K) – 1
- C1(.1uF) – 1
- Relay – 1
- T1(BC547) – 1
- D1(1N4007) – 1
Luggage Security Alarm Circuit Description:
The CD4011 is the basic building block of this circuit, along with certain additional components such as resistors, capacitors, transistors, and relays, which are utilised to protect your valuables from thievery with the help of this simple circuit. When someone tries to unlock the lock, it emits a warning beep as the wire loop splits and an alarm is triggered.
To get familiar with the working, you should get aware with the NAND gate truth table which is shown below –
When any of the input states or both the input states go to the low state in the NAND gate, then the output will be high and if both the inputs are at high state, then the output will be low in that case.
The CD4011 CMOS (Complementary Metal Oxide Semiconductor) chip is the most often utilised. It comes in a 14-pin Dual Inline Package (DIP). On the chip, there is a little notch in one of the corners that is known as pin 1. It consists of a group of four NAND Gates that are all independent of one another on a single chip. Each gate is a three-terminal device with two terminals for input and one terminal for output. The IC’s working voltage range is 5V to 16V. Approximately 10mA of current at 12 V is been deliver by the IC which can be trim down with the reduction of the power supply voltage.
When we get, the operation of these circuits is extremely simple; the output is based on the voltage on pin 5. When a power supply is connected to pin 5 of the circuit, the voltage is zero since the loop is not broken. As a result, pin 4 has a high voltage, which is connected with pin 1 and pin 2, which are likewise in a high state. As you can see from the truth table of the NAND gate, if both inputs are high, the output is low, so we get low at pin 3 of gate 1, which is then attached to pins 12 and 13 again, moving them to low, which causes pin 11 to switch at high, switching pins 8 and 9 at high, and low voltage at pin 10 due to this transistor linked to it via a resistor will not boost the base of it and the alarm will not receive by us. This implies that our baggage is secure.
Now suppose that someone attempt to take your baggage then the loop attached to it broken down. At the time loop break down, pin 5 as well as pin 6 shift to high and just opposite work will take place which we will explained above due to which pin 10 reaches to high state and transistor begin its conduction and alarm is receive by us.
And the alert will continue to sound until we engage with the loop again. The battery value will vary between 6 and 15 volts depending on the rating of the relay you’re using in your circuit. If you don’t want to use a relay, you can just fix the buzzer directly. We used a relay in our circuit so if someone wanted to connect the alarm straight to the AC, it would also work without causing any damage. Our circuit also includes a diode because if there are any spikes in the reverse voltage, the diode will be short-circuited at the source, causing no damage.