03-10-2012, 12:18 PM
project report on rain alarm for class 12 cbse
03-10-2012, 12:18 PM
project report on rain alarm for class 12 cbse
31-10-2013, 10:10 PM
i need ppt presentation for rain alaram at enginneering first year level
18-04-2014, 11:14 AM
Rain Alarm
Rain Alarm.docx (Size: 43.2 KB / Downloads: 86) Water is a conductor of electricity. When water is in contact with the probe then there is a flow of current which reaches to the base of Q1. Transistor Q1 is a NPN transistor which conducts. With the conduction of Q1 electron reaches to Q2 which is a PNP transistor .Q2 also conducts and current flows through the speaker. In a speaker there is inductive coil which causes motion in one direction and also produce induce current which is in opposite direction to the flow of current this induce current in the form of pulse flows through a capacitor, resistance and switches off Q1 and relax .this process repeats again and again till probe is in contact with water or we can say there is a oscillation in the circuit thus speaker diaphragm vibrates and gives a tone. Frequency of the circuit depends on the value of Speaker Coil impendence, Capacitor and Resistance Value. |
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