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            An automatic mobile speed violation detection and response system for identifying vehicles traveling in excess of a predetermined speed and providing a response to this violation is proposed. The mobile speed violation detection device includes: measurement of target vehicle speed and outputting signal indicative of the measured speed; capturing license plate data on the RF ID tag affixed to the target vehicle when vehicle exceeds the predetermined speed; identifying the location of the speed violating vehicle; tagging the captured RF ID based license plate data with vehicle speed and location data; wireless communication of transmitting speed, license plate data, location data and local speed limit to and from the information system.             This system is designed to monitor and control the speed of vehicles through wireless network. Zigbee is used for wireless communication in th...

This is a simple Over - Under-Voltage Protection Of Electrical Appliances. This circuit protects refrigerators as well as other appliances from over and under-voltage. Operational amplifier IC LM324 (IC2) is used here as a comparator. IC LM324 consists of four operational amplifiers, of which only two operational amplifiers (N1 and N2) are used in the circuit. Over - Under-Voltage Protection Of Electrical Appliances Circuit Diagram The unregulated power supply is connected to the series combination of resistors R1 and R2 and potmeter VR1. The same supply is also connected to a 6.8V zener diode (ZD1) through resistor R3.Preset VR1 is adjusted such that for the normal supply of 180V to 240V, the voltage at the non-inverting terminal (pin 3) of operational amplifier N1 is less than 6.8V. Hence the output of the operational amplifier is zero and transistor T1 remains off. The relay, which is connected to the collector of transistor T1, also remains de energised. As the AC supply to the ele...