| 摘要 |
A safety system for a building has an earthquake detector circuit for detect ing ground accelerations exceeding a threshold acceleration/frequency curve dividing sa fe and hazardous ground accelerations throughout a predetermined frequency range. T he earthquake detector includes an accelerometer for measuring linear accelerat ion along an axis, and for generating an acceleration signal indicative of a magnitude of the measured acceleration. A filter circuit produces a filtered acceleration signal from the acceleration signal. The gain/frequency characteristic of the filter circuit is a reflect ion of the threshold acceleration/frequency curve, such that ground accelerations falling on the threshold acceleration/frequency curve yield a filtered acceleration signal having a s ubstantially constant value throughout the frequency range. Finally, a threshold circuit compares the filtered acceleration signal to a predetermined threshold voltage, and produ ces an earthquake detected signal indicative of the comparison result. The safety s ystem can also include a gas detector circuit capable of detecting a gas in air, and genera ting a gas detected signal in response to detection of the gas. A high temperature dete ctor circuit can also be provided for detecting a high gas temperature, and generating a fire detected signal in response to detection of the high temperature gas. A main unit including a microprocessor is responsive to the earthquake detected signal, gas detected signal and the fire detected signal, and generates a first control signal in response to an y one or more of the earthquake detected signal, gas detected signal and the fire detected si gnal. A valve controller closes a gas valve to shut off a supply of gas in response to the first control signal.
|
