发布时间 : 星期四 文章火灾自动报警外文翻译及外文原文(1)更新完毕开始阅读c9136383941ea76e59fa0460
Figure 2. ds18b20 and the main chip connection diagram.
C. Smoke Monitoring Module
Smoke sensors choose HIS-07 ion smoke detectors when the flow through the inside and outside the ionization chamber ionization electron flow is unbalanced, collector charges current until the ionization balance. In a smoke-free or non-combustion, the collector being subject to the impact ionization current statistical fluctuation, the potential to maintain a balance. Ionization current have impact when the smoke into the ionization chamber, easily into the ionization chamber smoke outside than inside the ionization chamber of the affected, ionization current decline in and collector to re-charge until the new equilibrium potential, this potential change can be used to trigger the alarm circuit. Technical parameters such as Table 1.
TABLE I.HIS-07 ION SMOKE SENSOR THCHNICAL DATA
Table Head Table Column head
5.5±0.3V
Equilibrium potential collector
Collector potential with the smoke Reduced light rate of 1% / ft Reduced light rate of 4% / ft
Capacitor
0.6V 2.2V
6PF
Smoke signals are processed on the chip of choice is the Motorola company’s MC14468, MC14468 for DIP 16-pin package, contain oscillator, timer, latch, alarm control logic circuit, high input impedance comparator etc. When not detected smoke, MC14468 internal oscillator that oscillation cycle 1.67s. Each 1.67s cycle the internal power supply is provided to the work of the entire chip. It’s all kept detect any smoke in addition to LED flashes, battery voltage alarm and smoke alarm. The oscillator oscillation period becomes 40ms when the MC14448 Once detection smoke, this time piezoelectric buzzer driving circuit to start oscillation, start to be able to output to maintain the high 160 ms after the cessation of 80ms.Continued during the detection of smoke cessation of changes, at this time if not detected smoke beeper will not be issued a warning sound.
In figure 3, the MC14468 1 pin joint PD1 pin of SCM when the ion chamber of the ion current as the scene of smoke detection and change, voltage change generation a weak side-spread seized 15, by the MC14468 internal logic processing circuit processing, the smoke is detected by 1 pin-out high microcontroller for processing. 13-pin then slide rheostat is set to facilitate detection sensitivity when the led flashes and the buzzer sounded a piercing sound of an audio alarm when the department has a fire alarm signal-based.
In figure 3, the MC14468 1 pin joint PD1 pin of SCM when the ion chamber of the ion current as the scene of smoke detection and change, voltage change generation a weak side-spread seized 15, by the MC14468 internal logic processing circuit processing, the smoke is detected by 1 pin-out high microcontroller for processing. 13-pin then slide rheostat is set to facilitate detection sensitivity when the led flashes and the buzzer sounded a piercing sound of an audio alarm when the department has a fire alarm signal-based.
Figure 3. Smoke detection circuit
D. Auto-dial alarm module
Dial-up alarm module choices are the EX-1 dial-up module is a DTMF signal receiving, storing, and sending as integration communications circuits. Module built-in microcontroller and dial-up management process can provide users with a variety of signal input and output ports, in security alarm, signal acquisition, automatic control, remote communication and information transmission areas such as flexible application. 5 groups can have cell phone or group of seven local telephone numbers are stored, power-down is not lost; Telephone line status detection, automatic fault signal output ;Telephone / external switching two kinds of dial-up state control; Trigger time, nine times loop dial preset numbers; To work independently, independent dial-up, do not rely on telephone and other external devices.
EX-1 wiring diagram shown in figure 4, The PD4 pin to connect the main chip HTO , the module began to dial alarm when PD4 output high level signal, PD5
connection ON / OFF pin input is high level signal to open the dial-up settings, the input does not work when this pin become low, ERR pin connected to PD6 pin of MCU, PD6 output 1 begun to test whether the telephone line failure, READY pin connect MCU PD7 pin detection and alarm is completed, the alarm is end when PD7 pin is high .
Figure 4. EX-1 wiring diagram
IV. SOFIW AREDESIGN