This is a simple circuit that activates an alarm when there is a knock on the door or there are any vibrations due to movement of heavy goods or furniture. The circuit uses readily available components. Circuit and working The circuit is built around quad-opamp LM IC1 , which is configured in amplifier mode. It uses the piezoelectric element of a piezo buzzer as the input sensor, two transistors BC T1 through T2 , a piezo buzzer and some other components for the alarm circuit. The reference voltage at pin 3 of IC1 is set by trimming potmeter VR1. The piezoelectric element plate is fixed at the centre of the door using cello tape.

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Security systems are designed for detecting the intrusion and unauthorized entry into the residential houses, commercial buildings, industries, and military surroundings. In our day-to-day life, security systems for home is a major concern to protect from burglary, property, and self defense from intruders. Generally, security systems for home can be designed using different technologies.

Alarm security systems for home, alarm security system integrated with closed-circuit television surveillance, and so on. Different types of security systems for home can be designed using different types of sensors such as motion sensors, sound sensors, vibration sensors, and so on.

Basically, security systems for home are designed using maximum number of sensors for the detection of intruders. Door knock vibration alarm home security system project is designed using an electrical transducer. The electrical transducer that converts vibration or pressure energy into electrical energy is called as piezoelectric transducer or piezoelectric sensor. The major parts of the home security system project with vibration alarm are piezoelectric sensor, transistors, diodes, IC timer, buzzer or speaker or alarm, and other basic electrical and electronics components.

The security systems for home using door knock vibration alarm circuit is connected as shown in the figure. The piezoelectric sensor is connected to the door using an adhesive. The sensor and the security system project circuit are connected using a wire.

The major components used in the home security system project circuit are vibration sensor, timer IC , transistors BC, BC, and BC, diode 1N, LED, and other basic electrical and electronics components such as resistors and capacitors. To understand the working of the circuit, we must know about the components used for designing security systems for home using door knock vibration alarm.

Piezoelectric sensor is basically called as piezoelectric transducer as it generates an electrical signal based on the measured input quantities such as vibration, flex, touch, knock, shock. If the door is knocked, the vibrations caused due to the knock produces mechanical energy. This mechanical energy is fed to the piezoelectric vibration sensor.

This piezoelectric vibration sensor converts the mechanical energy into an electrical signal, which is further used in the circuit diagram of security systems for home, for activating the security alarm system or vibration alarm.

The base terminal is used to activate the transistor, collector terminal is used as positive lead, emitter terminal as negative lead. In this circuit, the transistors Q1-BC, Q2-BC, Q3-BC58 are connected as common emitter amplifiers and are used for amplifying the signal generated by the vibration sensor.

IC timer is an integrated circuit used as a timer, multivibrator, pulse generator, oscillator, and so on. Here, in this circuit IC timer is connected in astable operation mode in which its operation is controlled using resistors and capacitors.

Thus, in the security systems for home project circuit, whenever Q6 transistor turns on, IC timer is activated and thus an an alarm tone is generated in the speaker. Fundamentally, the signal from the piezoelectric sensor is amplified and processed by the circuit elements such as transistors wired to form common-emitter amplifiers and other components. The mechanical energy produced due to the vibrations caused by door knock is converted into electrical energy.

The diode D1 is used for rectification of this signal and amplified using transistors Q4-Q6. Then, the output signal from collector pin of Q6 transistor is fed to the reset pin pin 4 of the IC timer. The timer used in this circuit is wired as an astable multivibrator. If transistor Q6 turns on, then its collector goes high, activating IC1, thus an alarm tone is produced in the speaker.

This alarm can be turned off after a few seconds here 10s of ceasing the knocks. The time taken by 22 mircoFarad capacitor to discharge that is connected to the emitter of Q4 transistor is equal to the time after which alarm automatically turns off. In general, the suitable value of this resistor is in the range of ohms to ohms.

Do you know other security systems for home, which are practically being used in real time? Then post your ideas regarding the advanced security systems for home and improve the knowledge of other readers.

He has 8 years of experience in Customer Support, Operations and Administration. There are voice activated recorders, little cameras, and even GPS devices out there. You can use a free of charge telephone tracker app but they are really effortless to detect and do not do close to as very much as this app does.

The one drawback to this though, is that often people who text each other a lot develop their own shorthand that only the two of them understand. Your email address will not be published. Security Systems for Home Basically, security systems for home are designed using maximum number of sensors for the detection of intruders.

Home Security System Project Circuit The security systems for home using door knock vibration alarm circuit is connected as shown in the figure. Piezo Vibration Sensor. Transistor and Diode. Post Views: 2, Comments I enjoy the efforts you have put in this, regards for all the great posts. Leave a Reply Cancel reply Your email address will not be published.


Vibration Sensor Arduino Alarm

This circuit Fig. It uses readily-available, low-cost components and can also be used to safeguard motor vehicles. The piezoelectric plate is used as the sensor. It is the same as used in ordinary piezobuzzers and is easily available in the market. The piezoelectric plate can convert any mechanical vibration into electrical variation. The plate can be fixed on a door, cash box, cupboard, etc using adhesive.


knock alarm using piezoelectric material;

The piezoelectric crystal converts physical parameters such as pressure, strain or force to a corresponding electrical charge. If any vibration occurs, proportional rate of electrical potential induces across the piezo terminals. The analog read pin compares the induced voltage with a reference value. If the voltage induced is greater than the reference threshold value the Alarm will ON. The alarm remains ON for 10 seconds after the triggering.


Security Systems For Home Using Door Knock Vibration Alarm

Abstract In this modern world everyone wants something new, something different, so instead of using a switch to ring the door bell just an alarm is produced by knocking the door which people feel more luxurious. The circuit of automatic alarm on knocking uses a thin piezoelectric plate, senses the vibration generated on knocking a surface such as a door or a table to activate the alarm and can also be used to safeguard motor vehicles. The piezoelectric plate is used as the sensor. It consist IC Timer to which speaker is connected at the output. Piezoelectric material is used at the input in order to convert any mechanical vibration into electrical variation, it avoids false triggering.

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