公开(公告)号：US3872470A

公开(公告)日：1975-03-18

申请号：US35214573

申请日：1973-04-18

Applicant: AIRCO INC

Inventor： HOERZ RICHARD D ,  PROPP DONALD J

IPC: B06B1/02 ,  G08B3/10 ,  G10K9/122 ,  G08B19/00

CPC classification number: G10K9/122 ,  B06B2201/55 ,  G08B3/10

Abstract: A ceramic crystal transducer is connected to a direct current supply in series with a pair of transistors. A pair of independent multivibrator oscillators are connected, each controlling one of the transistors. Each oscillator establishes a rectangular wave and is provided with a continuously adjustable resistor for controlling the output frequency of the corresponding oscillator. The one oscillator is constructed to produce a frequency and a voltage to excite the crystal at the order of the natural resonant frequency and to thereby produce an audio output signal. The second multivibrator oscillator selectively controls the second transistor to control the on/off or pulsing rate of the tone related audible signal. The crystal is pulsed at the output rate of the tone oscillator and vibrates at the fundamental frequency of the rectangular wave as well as harmonics to either side of such fundamental frequency to produce a full and pleasant sound. Variation of the repetition rate of the output signal of the tone generator to either side of the natural resonant frequency of the crystal correspondingly varies the pitch and intensity of the emitted sound to distinguish adjacent alarms. The pulse rate oscillator permits further distinction by adjustment of the signal duty cycle.

Abstract translation: 陶瓷晶体换能器与一对晶体管串联连接到直流电源。 一对独立的多谐振荡器连接，每个控制一个晶体管。 每个振荡器建立一个矩形波，并提供一个连续可调电阻，用于控制相应振荡器的输出频率。 一个振荡器被构造成产生频率和电压以按照固有谐振频率的顺序激发晶体，从而产生音频输出信号。 第二多谐振荡器选择性地控制第二晶体管以控制音调相关的可听信号的开/关速率。 晶体以音调振荡器的输出速率脉冲，并以矩形波的基频振荡，并且在这种基频的任一侧谐波，产生完整和愉悦的声音。 音调发生器的输出信号与晶体的固有共振频率的任一侧的重复频率的变化相应地改变发射声音的音调和强度以区分相邻的警报。 脉冲振荡器允许通过调整信号占空比来进一步区分。