| 摘要 |
<p>PURPOSE:To prevent an accident caused by a short-circuit, etc., in a fire tube during or after burning by providing a timer circuit, supplying a current to the lighting part of the signal fire tube only for a fixed time when operating a lighting switch, and automatically stopping the supply of the current as well after lighting. CONSTITUTION:When a lighting switch BS is turned on in the state of turning a power supply switch S on, a timer circuit 2 is activated and the current flows from a power source PB to the lighting part of a signal fire tube Fl. Then, the fire tube Fl is lighted. After the lapse of the fixed time, the supply of the current is stopped by the circuit 2. Thus, even when the switch BS is not returned to an OFF state after lighting, the current does not continuously flow into the circuit of the fire tube and the accident caused by the short-circuit, etc., in the fire tube can be prevented. Further, by providing a loading confirmation lamp 4 to be turned on by a current value less than the minimum lighting current of the signal fire tube, it can be confirmed whether the signal fire tube is loaded or not.</p> |
