Họ tên : Lê Văn Hải Đỗ Mạnh Cường Phạm Hồng Phái Trần Văn Tuất Nguyễn Văn Đại Vũ Anh Cường Lacture 5: Alarm system 1: Vocabulary Alarm : báo động Foil: ( kim loại) Passive infra-red detector: máy dò tia hồng ngoại thụ động Presure: áp lực Switch: cơng tắc Detection: khám phá, tìm Device: phương sách, thiết bị, dụng cụ Bias: hiệu dịch Purpose: mục đích Prevent: chặn, ngăn ngừa Transducer: máy biến Saturtion: bão hòa Buzz: còi Relay: rơ-le Current: dòng Form: hình thái Decreases: giảm Base: nguồn Rise: tăng lên De-energize: cắt điện Rapid: nhanh chóng Task 2: Study diagram at the top of the following page Try these answer the question 1: What does this diagram show a circuit of? Alarm system 2: How many detection devices does it show? Name them There are eight detection Pressure mat, bell, door switch, power, window foil, sense circuit, passive infra-red detector, key- operated switch control box 3: What warning device it show? Antitrespassing 4: Why is control box switch operated with a key? Break switch and safe with children 5.How does the system work? Senser: The processor center will accept signal of sensor admit The first is Door contact This sensor searchs your door open or close Part is magnet on the door and part is magnetism switch When close the door, magnet on the door will attract magnetism switch and mode close is activate Mode open will attract because when you open the door, magnet and magnetism aren’t power Signal open/ close will send the processor center.Motion sensor: When one people move then motion sensor will to feel.Glass break detector: Use on the window, when who is try break glass window then attract alarm.Vibration sensor: Use on the wall or floor, when the wall or floor is impulse then attract alarm 6: What problem is there this circuit? Task 3: Detection devices thiết bị bảo vệ Magnetic switches: These are used on windows and doors A magnet mounted on the moving part of the window or door trips a switch mounted on the frame when the window or door is opened (Thiết bị chuyển mạch từ: thiết bị sử dụng cửa sổ cửa vào Một nam châm gắn phần chuyển động cửa sổ cửa vào tác động vào công tắc gắn khung cửa cửa sổ cửa vào bị mở ra.) Break detectors: These are fitted on the inside surface of glass in windows and doors Some use a thin metal foil which is glued around the edge of the glass: if the glass is broken the foil breaks too Others are vibration sensors, and respond to the shock of the glass being broken (Thiết bị phát vỡ: thiết bị gắn khớp bên bề mặt thủy tinh cửa sổ cửa vào Một số sử dụng kim loại mỏng dán xungquanh cạnh kính: kính vỡ bị phá vỡ kim loại bị đứt Số khác cảm biến rung động, chúng cảm nhận tiếng kính vỡ.) Pressure mats: These are fitted under the carpet-at the bottom of the stairs, for example The pressure of someone stepping on them causes two thin metal plates inside to come in contact, setting off the alarm Because they’re constantly being walked on, pressure mats can get ‘tired’ quite quickly and should be regularly tested and replaced if necessary (Thảm cảm nhận áp lực: Chúng gắn phía thảm, ví dụ chân cầu thang Áp lực dẫm vào chúng làm cho hai kim loại mỏng bên tiếp xúc nhau, bật hệ thống báo động Bởi chúng liên tục bị dẫm lên, thảm áp lực bị ‘nhờn’ nhanh chóng cần thường xuyên kiểm tra thay cần thiết.) Motion sensors: These may use passive infra-red, ultrasonic or microwave energy to detect movement within their range (Cảm biến chuyển động: sử dụng tia hồng ngoại, lượng siêu âm vi sóng gắn cố định để phát chuyển động phạm vi chúng.) Task 5: Match each action its consequence Active A burglar disconnect the supply The glass is broken A door is opened A window is opened Consequence The alarm stops after a set time The foil break too A magnet on the door trip a switch on the frame A magnet on the moving part Device Break detector You are not there to reset the system A burglar tries to force the alarm open Someone step on them trips a switch The alarm continues to operate on battires Sensor trigger the alarm Two thin metal plates come in contact Pressure mat Task 6: Complete these sentences with a suitable action or consequence If pressure mats are constanly walked on, two thin metal plates come in contact so alarm system on If you fit an exit delay, alarm system will sense you If your system doesn’t have an automatic cut- off, alarm system isn’t safe If a burglar walks in front of a motion sensor, motion sensor will detection thing action and ring a bell Vibration sensor will respond if something( someone) attact it Tamper sensor will trigger the alarm if someone tries to force the alarm open A magnet on the moving part trips a switch if someone attract the switch door The alarm stops after a set time if the alarm disconnect with a supply Task 8: 1: integrated circuit 2: circuit control 3: alternating 4: primary 5: zener diode 6: remote 7: reed 8: surface 9: vibration 10: reverse 11: mains Task 9: Use information from the text below to complete the table/ answer the question Complete this table Sensing device Used to detect LDR Light Microphone Sound Thermistor Heat What effect does light have on a LDR? Light falls on the LDR What is purpose of RV1 in Fig.2 on page 5.3? When light falls on the LDR, its resistance decreases The sensitivity of the input can be adjust using RV1 Use words from the text to complete the following table: Term Opposite Cut-off saturation Fixed resistor Increases Decreases Energize De- energize Slow Fast Forward Bias Task 10: Explanations provide answers to Why? And How? Question Try to answers these question about the diagram below What does the diagram show? Why are the reeds sealed in the glass envelope? Why does the envelop contain nitrogen? How does it operate? The diagram shows a reed switch It consists of two reeds made of ferromagnetic material They are easily magnetized and demagnetized The reeds are sealed in a glass envelope to protect them The envelope contains notrogen, which helps to prevent corrosion of the contacts When a magnet is brought close to the reeds, they are magnetized, attract each other, and close When the magnet is removed, the reeds open ...Form: hình thái Decreases: giảm Base: nguồn Rise: tăng lên De-energize: cắt điện Rapid: nhanh chóng Task 2: Study diagram at the top of the following page Try these answer