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What size of wire used in smoke alarm system?
Different types of smoke alarms require different sizes of wire. Conductors connecting a mains-powered alarm to electricity might be sufficient for 20 amps (i.e., 12 AWG), while signaling wires could be 20 AWG, more or less, depending upon the current of the latching load and the round-trip distance from the panel to the alarm sensor.
What does ldr sensor work in fire alarm?
An LDR (Light Dependent Resistor) sensor in a fire alarm detects changes in light levels, typically caused by the presence of smoke or flames. When a fire occurs, it can produce a significant amount of light, which the LDR senses by decreasing its resistance and triggering an alarm. This allows the fire alarm system to respond quickly to potential fire situations by alerting occupants and emergency services. However, LDR sensors are often used in combination with other types of sensors, such as smoke or heat detectors, for more reliable fire detection.
What way can a sensor be used in a car?
A sensor can be used on a car for a number of things car alarm, video sensor, traffic sensor Type your answer here...
What is a function of a transistor in a fire alarm circuit?
A special sensor or transducer called a thermistor is used to detect an increase in the temperature of the surrounding air whenever smoke is produced by a fire. A different type of sensor is used to detect an increase in the size and density of particles in the surrounding air after it has been contaminated by smoke from a fire. Either sensor gives an output in the form of an increase in voltage whenever it detects an increased temperature and/or smoke particles. That increase in voltage is fed to the base of a transistor. When the voltage to its base increases, the current from the transistor's emitter to collector (or from its collector to emitter) increases and that increase in current operates the alarm. In other words, in a fire alarm circuit, the transistor acts as a switch which turns on the alarm whenever a sensor or transducer detects the presence of a fire, else it remains off.
What all is found in a fire alarm circuit?
There are many possible types of sensors and circuits for fire alarms. If you mean alarm SENSOR circuit, there are often two types to a smoke sensor: a power circuit and a sensor trip circuit. The power circuit supplies power to the sensor for its internal electronics and the sensor trip circuit is a separate pair of wires to the dry contacts that open or close to signal an unusual smoke or heat condition. Various supervisory means are used to determine whether the sensor is properly connected and operating (i.e., no open circuit or short circuit), such as an "end-of-line" (EOL) resistor, or a modulated, query-response or polling signal. At the alarm-panel end, each circuit would have its own connection for a zoned system: one pair for the power and the other pair for the trip circuit. Other types of circuits include heat detectors, manual pull stations, sprinkler flow switches, supervisory tamper switches, and other types of inputs. Output circuits could include lights, sirens, bells, door-closing signals, HVAC control signals (on or off), elevator return commands, remote signalling to monitoring centers, etc. Many residential fire alarm circuits now include one or more wires to connect the otherwise independent smoke alarms so that any one of them will trigger all the others, for better sound penetration of the alarm annunciation.
What is the tranducer used in a smoke detector?
A photoelectric sensor or an ionization chamber is typically used as the transducer in a smoke detector. These components convert the presence of smoke particles in the air into an electrical signal that triggers the alarm.
Your smoke alarm goes off without fire occuring?
If the smoke alarm goes off because of steam or smoke from cooking, the alarm should be moved to a better location or a different type of sensor used. It is very dangerous to have too many false alarms because people tend to ignore them, until the one time it really is a fire, and then it may be too late. If a smoke detector makes an intermittent "chirp", not a loud and continuous alarm, it may be signalling that it is time to replace the battery. Smoke detectors should be replaced every ten years, even if they still seem to be working, since they are only designed for a limited useful lifetime.
What form of electromagnetic waves are used in smoke detectors?
There are two types of smoke detectors:Alpha particle - these do not use electromagnetic wavesPhotoelectric - these use a beam of either visible lightor near infrared electromagnetic waves
How is radioactivity used in smoke detectors?
There are two types of smoke detectors:Photoelectric Smoke detectorsIonizing Smoke DetectorsIonization smoke detectors are more commonly used. The smoke detector uses an ionization chamber and a source of ionizing radiation to detect smoke.Alpha particles are emitted from from the chamber, which ionize the air, so that the air conducts electricity and a small current flows.If smoke enters the alarm, it absorbs the alpha particles causing the current to reduce, and the alarm sounds.Generally, smoke detectors use a weak source made of Americium-241 (241Am95).Note: Alpha particles are the nuclei of a Helium Atom (4He2).
What is the Use of potentiometer in burglar alarm?
A potentiometer can be used in a burglar alarm system to adjust the sensitivity of the sensor. By adjusting the potentiometer, the user can calibrate the sensor to detect the desired level of movement or intrusion, making the alarm system more effective in detecting unauthorized activity.
How long has americium been used in smoke detectors?
Americium has been used in smoke detectors since the 1950s. Its radioactive properties make it ideal for ionizing smoke particles in the detector, allowing it to quickly detect smoke and trigger the alarm.
How are alpha particles used in smoke alarms?
Alpha radiation is emitted from the amercium button in a smoke detector. When smoke goes into the smoke detector it blocks the stream of alpha particles emitted from the americium. That triggers an alarm.
