Warning light system for use with a smoke detector

In a warning device responsive to emergency condition signals and having an input sensing circuit having an input and an output and an output circuit including a switching device and having an input and an output, the improvement comprising:

• means for filtering out false signals and for ensuring the actuation of said warning device upon receiving bona fide emergency condition signals,
• said filtering means including
• an operational amplifier having an input coupled to the output of the input sensing circuit and an output,
• a bandpass filter having an output and an input coupled to the output of said operational amplifier for passing signals having a frequency within a predetermined range,
• a detector circuit having an output and an input coupled to the output of said bandpass filter for converting the passed signals into a direct current, and
• a low pass filter coupled to the output of said detector circuit and to the input of said output circuit for passing to the output circuit only those signals which are of sufficient magnitude and which are present for a long enough duration to allow them to pass through the low pass filter to the output of said switching device to activate the switching device.

In a warning system for alerting a rescuer in the vicinity of a building of an emergency condition in the building and for indicating which one of several openings to the building the rescuer should enter first, the improvement comprising:

• a physically separate and distinct alarm device positioned in close proximity to an emergency sensing and signalling detector, said alarm device including
• sensing means for sensing an emergency condition signal generated by said emergency condition sensing and signalling detector;
• an amplifier coupled to an output of said sensing means for amplifying said emergency condition signal after said signal is sensed by said sensing means;
• a timer circuit and a light source, for generating an intermittent light beam signal;
• a bandpass filter for passing signals having a frequency within a predetermined frequency range of the amplified emergency condition signal;
• a detector circuit for rectifying the passed emergency condition signal and including a low pass filter for passing signals having a predetermined amplitude level coupled in series between the output of said sensing means and an input of said timer circuit;
• said sensing means, said bandpass filter, said detector circuit and said low pass filter being coupled in series;
• and,
• mounting means for mounting said alarm device proximate to one of the building openings in position to emit said intermittent light beam signal so said intermittent light beam signal can be seen from outside the building.