Ali Maleki - Faculty of Electrical Engineering Department Semnan University Semnan, Iran
Farshid Tamjid - Electrical Engineering Department Semnan University Semnan, Iran

In all elevators, a circuit that can conduct the elevator to the nearest floor at the earthquake occurrence in order to survive passengers is necessary. In this paper, we havedesigned and implemented such a circuit in two stages. One recognizes the earthquake and the other guides the elevator tothe nearest floor. The degree of earthquake that can destroy something is 7 in Mercally scale. Using Richter formula, it equals to 0.11 g. Therefore we need an accelerometer for acceleration measurment. In this study an accelerometer based on MEMS technology has been used. We determined 0.11 g forthe acceleration threshold. The applied microcontroller in this circuit receives the acceleration by its ADC channels in 3-axis.It performs a pre-processing and then defines the earthquake properties; if magnitude of this property is greater than the defined threshold, occurrence of earthquake will be asserted and an appropriate reaction order exports to the elevator control circuit. In this study, we have attended to small sizeand we have tried to increase battery life by using low power elements. This circuit has been evaluated by Signal Analyzersystem and its accuracy has been assured. For more accuracywe have to use several accelerometers in different places of network. Also we can apply it in trains and other places that need digital stopping at time of occurrence of earthquake.

Earthquake recognizing circuit; Earthquake early warning; Elevator; train