3.4 Sound alarm circuit3.4.1 Introd

3.4 Sound alarm circuit3.4.1 Introduction of circuit elementsThe triode SS8050 is a common ordinary triode. It is a low voltage, high current, small signal NPN silicon triode made of silicon.3.4.2 Working principleAs shown in Figure 3-7 below: The treble alarm circuit uses 12V treble as the alarm device and SS8050 high-power audion as the driving circuit. When SPK is at high level, the audion conducts and transmits signals to the treble alarm so that the treble alarm sounds and alarms. The reverse is up to. In this system, through software setting, the alarm truly simulates the process of raising the sound frequency evenly, restoring it and raising it again. To create a sound effect with a smooth increase in frequency between 976 hz and 194 Hz. The sound of the alarm is very realistic.Rule 3.4.3 roleThis circuit receives the level signal transmitted by the single chip microcomputer and drives the high-pitch alarm to make the loudspeaker sound so as to achieve the alarm effect. Its circuit schematic diagram design is shown in Figure 3-6