Patent ID: 8742937
Filing Date: 2014-06-03
Classification: G08B

Abstract:
1. An alarm unit comprising: a light emitting section; a battery power supply; a voltage booster circuit that boosts a voltage from the battery power supply to thereby generate a boosted voltage; a control circuit that sets an operating time of the voltage booster circuit; a light emission control section that selectively couples the boosted voltage to the light emitting section based on the operating time of the voltage booster circuit ending, thereby intermittently driving light emission; a light receiving section that outputs a received light signal based on receiving light from the light emitting section, the received light having been diffused by smoke; a conversion circuit that converts the received light signal from the light receiving section into received light data; a fire hazard detection section that detects a fire hazard based on the received light data from the conversion circuit and outputs a fire hazard detection signal based thereon; an alarm section that outputs an alarm based on the fire hazard detection signal from the fire hazard detection section; a reference voltage circuit that generates a reference voltage for the voltage booster circuit and the conversion circuit; a processor circuit that realizes functions of the light emission control section and the fire hazard detection section by executing a program; and a clock circuit that outputs a clock signal for operating the voltage booster circuit, the processor circuit, and the conversion circuit, wherein the processor circuit, the voltage booster circuit, the conversion circuit, the reference voltage circuit, the clock circuit, and the control circuit of the respective circuit sections are provided on a packaged integrated circuit, and wherein the control circuit switches between a state in which a supply of the clock signal to the processor circuit is stopped and the clock signal is supplied to the booster circuit, a state in which the supply of the clock signal to the booster circuit is stopped and the clock signal is supplied to the processor circuit, and a state in which the supply of the clock signal is to the booster circuit and the processor circuit.