IETE

The circuit measures the level of CO2 in the classroom environment. As the level touches a certain amount of CO2 the sensor gives an indication that it has reached a hazardous level and the windows should be opened. For this, a chaotic circuit is being used to increase the sensitivity of the sensor, so that even the slightest increase in the level of CO2 can be detected.

Biometric time and attendance systems use the fingerprints of students to verify who is actually clocking in and clocking out of class each day. The system scans the finger of the student, coordinates are determined and then the system maps the endpoints and intersections of the fingerprint. Biometric systems are easy to use, easy to install and track data regarding students for management to analyse.

Simulation of a non-inverting bidirectional converter for controlling the power flow between the battery and 350-volt dc-link by operating it in four modes including buck and boost operations based on the state of charge of battery and requirement of the load.Hardware design of a dc-dc converter for charging battery pack of 30 lithium-ion cells of 96 volts from a 350 volts dc link.