| 摘要 |
<p>A motion responsive alarm system including a motion sensor (10) having a housing with a rotatable disk (12) therein, a slot (34) in the disk and a ball bearing (32) in the slot and being loosely confined within an annular chamber (30) in the housing surrounding the disk. The disk contains a plurality of orifices (22) which pass between an LED (24) on one side of the disk and a phototransistor (26) on the other. A signal from the phototransistor is sent to a triggering circuit (51, 89, 100, 102) by interrupting light transfer between the LED and the phototransistor. The circuit includes a novel oscillator (60) having a duty cycle of 10 % which drives the LED in the sensor. The device may be coupled to a self-contained breathing apparatus (104, 106, 150, 152, 154-160, 162, 164, 166, 168) and is energized only when the breathing apparatus mask (156) is being worn by the user.</p> |
