Abstract: A multistationed integrated life safety system in which each station will be situated at a diffferent location and have complete capabilities in terms of local fire protection, fire detection, control and/or monitoring and controlling the security of an area. Each station communicates with four adjacent stations so that when an event occurs at one station, that station is programmed to cause that information or that new status to be transmitted to each of the four adjacent stations. Thus, each station will be interconnected or networked to four other stations to provide multiple location control and annunciation so that each station may act independently.

Abstract: An electronic circuit for simulating the sound of a percussive bell struck at a predetermined repetition rate. A realistic electronically generated sound is produced by appropriately modulating two or more audio frequencies with a decaying exponential control signal and thereafter mixing the modulated frequencies. The system comprises a repetition rate generator; a modulation envelope generator; a high and low frequency oscillator; a modulator; and a mixer together with a loud speaker. The repetition rate generator determines the ringing frequency of the simulated bell sound. The modulation envelope generator generates two decaying control signals with differing time constants with the time constant of the low frequency generator usually being greater than the time constant of the high frequency generator. Filter networks may be used to eliminate some of the harmonics. Potentiometers may be provided to vary the magnitude of the low and high frequency components at the input to the mixer.

Abstract: Circuit means for synthesizing the sound of a mechanical bell by combining the three most significant frequencies of the bell to be synthesized and modulating these with a decaying exponential control signal which is derived from a clock signal having a pulse repetition rate equal to the stroke repetition rate of the bell being synthesized. The combined and modulated signal is amplified and coupled to suitable audio distribution means. Modulation of the exponential signal can provide a tremolo effect.