Human being sensor

• Main Author: Fong, Poh Cheh
• Format: Academic Exercise
• Language: English
• Published: 2008
• Online Access: https://eprints.ums.edu.my/id/eprint/19410/1/Human%20being%20sensor.pdf; https://eprints.ums.edu.my/id/eprint/19410/

A human being sensor is used to dctect the eddy current which induced by a human being that goes near to this sensor. In this research, the human being sensor is used to trigger a buzzer. The buzzer in this sensor will play sound to scare away the human being that approach to this sensor. The human being sensor can be used to trigger other electronics circuit for different usage. The human being sensor in this research is more likely to be an alarm system that detects the human being who wants to enter or break in our house or forbidden places. This sensor detects the magnetic field in a human being by the electromagnetic field in the coil. The magnetic field in human body is generated by chemical reaction within cells and ionic currents of the nervous system. So, when a human being is approaching to the sensor range of the coil, the sensor wiII be triggered: The sensor will deactivated when the human being goes away from it. Some experiments have been conducted to test the sensitivity of this sensor. The coil is built in circular shape and wind in 50 turns with three different diameters which is IOcm, I5cm and 20cm respectively. The first experiment has been conducted to measure the maximum front and side detection distance for three different coil's diameter. The Second experiment has been conducted to measure the maximum detection distance for three of the coil with different coil's diameter in the condition where the door knob is in the centre of the coil. The third experiment has been conducted to test the sensitivity of this sensor with five different value of variable resistor which are 5 ill, 15 ill, 25 ill, 75 kG and 110 kn. The final experiment has been conducted to test the starting voltage for three different coil's diametcr in two conditions. The first condition is the coil with door knob in the centre and second condition is the coil without the door knob. The coil with 10 cm diameter is suitable to place on the door knob and require the lowest starting voltage to generate this sensor as compare to the coil with 20 cm diameter. So, the best result or performance for this sensor act as an alarm system is using the 10 cm coil's diameter with this coil place on the door knob behind the door. The maximum front and side detection distance for this sensor using the 10 cm coil's diameter are (30.00 ± 0.05) em and (27.17 ± 0.05) em respectively with the 150 kn variable resistor and the starting voltage is (8.3 ± 0.1) v.