| 摘要 |
A fire detector is provided to prevent an alarm from being outputted by malfunction if disturbance is temporally generated in a power source of the fire detector by voltage of 24V or external surge, static electricity, and electronic waves by using a bias resistor and a transistor. A fire detector has a sensing unit for detecting the rise of temperature or smoke concentration, and transmits a signal of the sensing unit to an alarm device. Bias resistors(R43,R44) and a transistor are inserted into at least one spot of an electronic circuit. A TNR surge-up server(C41) is inserted into the electronic circuit. If excessive voltage is inputted by surge voltage and static electricity, power is disturbed and the emission of infrared rays is temporally stopped by discharging a condenser(C48), in order to prevent malfunction. |
