High output smoke and heat detector alarm system utilizing a piezoelectric transducer and a voltage doubling means

Abstract

A high output smoke and heat detector alarm system comprises a high output audible alarm means which includes a piezoelectric transducer and a voltage doubling means in combination with an improved smoke and heat detector which includes a low voltage power supply source, an ambient temperature detecting means, at least one ionization sensing chamber, a voltage amplitude comparing means, and a low voltage sensing means.

What is claimed is: .[.1. In a smoke and heat detector comprising a low voltage power supply source, an ambient temperature detecting means electrically coupled to said power supply source, at least one ionization sensing chamber electrically coupled to said power supply source in parallel with said temperature detecting means, and a voltage amplitude comparing means electrically coupled to said ionization sensing chamber and said power supply source, the improvement wherein said voltage amplitude comparing means includes a field effect transistor and a bipolar transistor which in combination comprise a schmitt trigger..]. .[.2. The smoke and heat detector as recited in claim 1 wherein said field effect transistor has its gate electrically coupled to an output of said ionization sensing chamber, its source electrically coupled to one side of said power supply source through a parallel combination of a resistor and a capacitor, and its drain electrically coupled to another side of said power supply source through a resistor..]. .[.3. The smoke and heat detector as recited in claim 2 wherein said bipolar transistor is an NPN transistor having its emitter electrically coupled to said source of said field effect transistor, its base electrically coupled to said drain of said field effect transistor through a variable resistor, and its collector electrically coupled to an output of said smoke and heat detector through a resistor..]. .[.4. The smoke and heat detector as recited in claim 1 further comprising a low voltage sensing means electrically coupled to said power supply source..]. .[.5. The smoke and heat detector as recited in claim 4 wherein said low voltage sensing means 
     
        includes a relaxation oscillator and a zener diode..]. .[.6.  The smoke and heat detector as recited in claim 5 wherein said relaxation 
     
     
        oscillation includes a programmable unijunction transistor..]. 7. A high output smoke .[.and heat.]. detector alarm system comprising, in combination, a smoke .[.and heat.]. detector which includes a low voltage power supply source, .[.an ambient temperature detecting means,.]. and at least one ionization sensing chamber; and a high output audible alarm means responsive to said smoke .[.and heat.]. detector .Iadd.and .Iaddend.which includes a piezoelectric transducer and a voltage .[.double.]. .Iadd.doubling .Iaddend.means whereby a voltage is supplied to said piezoelectric transducer which is double said power supply source 
     
     
        voltage. 8. The alarm system as recited in claim 7 wherein said smoke .[.and heat.]. detector further includes a voltage amplitude comparing means electrically coupled to said ionization sensing chamber and said power supply source and a low voltage sensing means electrically coupled 
     
     
        to said power supply source. 9. The alarm system as recited in claim 8 wherein said low voltage sensing means includes a relaxation oscillator 
     
     
        and a zener diode. 10. The alarm system as recited in claim 9 wherein said 
     
     
        voltage amplitude comparing means is a schmitt trigger. 11. The alarm system as recited in claim 10 wherein said schmitt trigger includes a 
     
     
        field effect transistor and a bipolar transistor. 12. The alarm system as recited in claim 7 wherein said high output audible alarm means further includes a pulsator means electrically coupled to an output of said smoke .[.and heat.]. detector and an oscillator means electrically coupled to 
     
     
        said pulsator means. 13. The alarm system as recited in claim 12 wherein said pulsator means and said oscillator means comprise a Quad two-input 
     
     
        NAND gate integrated circuit. 14. The alarm system as recited in claim 13 further comprising a logic driving means responsive to said smoke .[.and heat.]. detector for driving said Quad two-input NAND gate integrated 
     
     
        circuit. 15. The alarm system as recited in claim 13 wherein said 
     
     
        piezoelectric electric transducer includes three electrodes. 16. The alarm system as recited in claim 15 wherein said voltage doubling means includes at least two bipolar buffer amplifiers one of which is electrically coupled to a first output of said oscillator means and a first electrode of said piezoelectric transducer and another of which is electrically coupled to a second output of said oscillator means and a second electrode 
     
     
        of said piezoelectric transducer. 17. The alarm system as recited in claim 7 further comprising an acoustics enhancement means acoustically coupled 
     
     
        to said piezoelectric transducer. 18. The alarm system as recited in claim 17 wherein said acoustics enhancement means includes an aperture 
     
     
        termination in spaced relation to said piezoelectric transducer. 19. The alarm system as recited in claim 18 wherein said acoustics enhancement means further includes a resonant cavity coupled to said piezoelectric 
     
     
        transducer. 20. The alarm system as recited in claim 19 wherein said acoustics enhancement means further includes a single wavelength baffle acoustically coupled to said resonant cavity.