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For electric parameters measurement and facilitation, through the study of control and theory of power parameter measurement, design a kind of take alarm device can measure the voltage and current at the same time power three electricity parameters of simple measuring instrument, the measurement system uses single-chip microcomputer as the main control unit, using ADC0832 as voltage acquisition chip, through multiple harmonic oscillation circuit resistance is converted into frequency, again by resistance transformation to calculate the current, finally calculated by single chip microcomputer power displayed on the LCD screen. Alarm circuit by relay all the way and the light-emitting diode (led), as well as of the horn, when an ADC chip, the detection of voltage, current, or power more than setting the maximum threshold, can make the I/O mouth into a low level, Triode and relay conduct, led and horn line pressure drop resulting alarm, through simulation and experiment validate the correctness and feasibility of the design.

In this study, we make a study of a new two-level configure gas technology. This technology can expend the configure gas device's dilution ratio and combined with inner set baffled spiral cast to achieve a full-sacle configure gas of SF6 and air. Further to make the SF6 leaking alarm testing device to be not only a multi-function portable device but also have the advantages like compact structure, light weight, large dilution ratio, high accuracy, degree of automation and so on. And this device can solve the situation of SF 6 leaking alarm device can't calibrate conveniently in indoor workplace, such as electric power system GIS obviously.

Introduced one ultrasonic ranging alarm device based on SN8P2501B microcomputer, it mainly included ultrasonic emission circuit, receiving circuit, keyboard, alarm circuit and the software. Compared with the traditional ranging methods, the system used 555 time-base circuit to produce ultrasonic, and designed a temperature compensation circuit to eliminate effect of sound velocity produced by the environment temperature. The practical application results show that the ranging system is stable , reliable and highly accurate, so the technology and methods adopted in the system are highly practical and worthy of being used abroad.

With the development of social economy and the progress of science and technology, the dangers of fire for human is obvious. Therefore, carries on the effective prevention and control, reduce the loss brought by the fire to the smallest degree is the key of the current research on fire prevention and control technology, develop all kinds of fire alarm device for this people, common are based on the cable network and wireless network Fire alarm system, but these alarm system construction cost is higher, difficult to maintain, poor reliability, are not suitable for use in the bad environment, so a single based on cable or wireless fire alarm system can not be widely used. This paper will design a set of independent type fire alarm system based on electric power carrier. This system adopts the power carrier communication technology, electric power carrier as a unique communication mode in the power system, with the existing power line as a carrier to transmit the fire alarm signal, the biggest characteristic is don't need

Aiming at the problems that the traditional temperature and humidity recording manual operation is low efficiency, put forward a design scheme of temperature and humidity automatic alarm recorder. real-time monitor temperature and humidity sensors using single chip microcomputer technology, after the data is collected and processed, the results is displayed on the LCD screen, at the same time, transmit the data to PC for display through the RS485 serial communication, also The design has the function of data record and historical data inquiry, the host computer remote control and so on, when temperature and humidity exceeds user-set upper and lower limits, the device will automatically alarm. Introduction Temperature and humidity measurement is an important part of the modern detection technology, in order to ensure the quality of the products, saving energy and safety production and plays a key role. Therefore, to ensure fast and accurately measuring technology and device for temperature and humidity generally by various countries attention. With the development of communications technology and computer technology, temperature and humidity measurement technology in Japan, Netherlands, United States, Israel and other developed countries has been rapid developed. Now foreign temperature and humidity measurement technology is moving towards the development of high-tech direction, Network technology, remote sensing technology has been gradually integrated with the production activities. In recent years, China has also increased the research efforts in the temperature and humidity measurement technology, Despite advances in technology, more humane, but there is not remote control the working status of the equipment. This design in the original technical level, has made the further improvement: 1, environmental parameters data processing with higher accuracy requirements, ensure the goods in storage environment, increase the economic efficiency of enterprises; 2, using low power components, the power consumption will be greatly reduced, reducing the power consumption cost; 3, the adjustment of environment monitoring technology, not only can observed the data in the main equipment on the site, but also observation the data in any PC equipped with corresponding PC machine, The parameters of the main equipment, set command to complete the monitoring and control of the combined, largely reduce manpower participation process. Overall System Design The system is mainly composed of three parts, data acquisition device, control center, host computer .( the overall design diagram of the system see Fig. 1). 2016 6th International Conference on Applied Science, Engineering and Technology (ICASET 2016) © 2016. The authors Published by Atlantis Press 0082 Fig.1 the overall design of the system Controlled by MCU, the data acquisition terminal using temperature and humidity sensor AM2321 to temperature and humidity data real-time acquisition and the collected data were processed and displayed on the LCD screen, also through the RS485 serial communication would be processed by the data to PC display, when the temperature and humidity exceeds the setting upper and lower limit, the alarm device will be activated. Hardware Design The circuit design of data acquisition terminal Fig.2 The system block diagram in figure 2 data acquisition Mainly use the high precision temperature sensor, capacitive humidity sensing element, A/D converter, signal amplifier and a high performance embedded microcontroller integrated consisting of AM2321 temperature and humidity sensor to achieve the data collection. Through the amplifier to collect the data signal stronger than normal, and the conversion of the collected data through the A/D converter in a timely manner, so that the output digital signal is more anti-interference . Data acquisition in the system block diagram as shown in Fig. 2, the smallest system consists of DC/DC voltage stabilizer, reset circuit, MSP430, crystals circuit structure, etc. Data display and alarm circuit design The MSP430 as control center processor, using 2.8 inch alientek TFTLCD liquid crystal module as the display unit, the control center alarm and prompt the user through the buzzer, the NPN triode 8050 as alarm circuit switch, when beep is a 3.3V high level,after the voltage division, the base Power supply module

Through the analysis of TN-C and TN-S connection mode, this paper expounds the advantages and disadvantages of TN, the voltage distribution of the load is introduced through an example, and further introduces the necessity of developing neutral wire over current alarm device in the distribution network, and it discusses the composition, working principle and using method of the neutral wire over current alarm device. Through the application in the field, it is proved that the use this device for distribution network can prevent the neutral line outage and have the advantages of early warning. The development can improve corporate image, and has a wide range of promotion value and application prospects.

AT89S52 microcontroller was the center controler for wireless temperature measurement and alarm system, through temperature measurement circuit and remote wireless alarm circuit, realized the temperature detection and off-limit alarm of the ambient temperature. The system was composed of temperature acquisition circuit, display circuit and alarm circuit. Temperature sensor was DS18B20, real-time temperature displayed via LED displayer. Users can customize the alarm lower limit and superior limit. when the ambient temperature exceeds the alarm limit, the microcontroller will start the sound and light alarm, and remote wireless alarm. Temperature measurement range from -40 °C to +85 °C, measurement accuracy is 0.5 °C, wireless alarm distance is up to 100 meters. This system is of high precision, wide temperature measurement, and timely alarm.

The design of the crane anti-collision alarming system based on electric field measurement is introduced in this paper. The crane anti-collision alarming system consists of many electric field acquisition devices and an alarm device. The electric field acquisition devices are responsible for collecting the electric field value of each point. The alarming device can receive all the signals sent by the various electric field acquisition devices wirelessly, and then the different alarming information is given by judging the safe electric field value to ensure the safety of the working cranes in the occasion of the high-voltage transmission wire.

The rate at which technology is improving has never been equaled at any other time. As such, there is an increase in reliance on this continually improving technology. We often rely on some product of technology for activities, from the alarm device that prompts us to wake up in the morning to the mobile devices and their various applications that accompany us throughout the day. As these products become more convenient and accessible, greater numbers of people tend to use them more frequently.

A microcontroller based on alarm device is developed for detecting a combine working station preventing crop conveying pipeline blocked by excessive feed-in quantity so as to avoid driving belt or driving wheel being damaged. An Atmel 89C2051 single chip microcontroller is employed as the core of the device to make the system simple in structure and small in size. Using Hall effect tachometric transducers detecting the magnetic induction pulses induced by magnetic steel pieces attached on belt wheel, the wheel rotate speed is detected. Moreover, with some filtering measures and logical judgements, pseudo pulses are filtered out. According to the measured speed, the belt wheel spin tendency is estimated, at the same time, audible and visual alarm signal are also emitted to warn operator to reduce the operating speed so that wheel blocking and belt spin are avoided, thus crop loss is reduced. The system achieves a low cost, high reliable equipment for detecting combine working station automatically with acousto-optic alarm.

This paper presents the design and evaluation of an oxygen low-pressure alarm for use in conjunction with medical oxygen cylinders. Patients, who are dependent on oxygen supply through portable, high pressure oxygen cylinders, rely on staff vigilance to ensure that the volume of oxygen in the cylinder does not drop below a critical level, thereby compromising their safety. To minimise such risks, a low cost, mechanically driven, easy to interface, low pressure alarm was developed to generate an audible warning intended to alert patients and their carers of depleting oxygen pressure levels. The device is designed to interface with portable medical oxygen cylinders and their pressure regulators. It implements a spring-loaded diaphragm mechanism, which opens a vent when the pressure level in the cylinder drops below a pre-set level of 15 bars (1.5 MPa). The gas then passes through a nozzle incorporating an orifice, thus generating an audible whistling sound. The proposed device is compact and cost effective in terms of manufacture and power consumption. (4 pages)

According to the phenomenon that high-voltage places may endanger personal safety, we have designed high-voltage approaching alarm equipment powered by solar energy, taking the high-performance low-power chip ATmega64 as the control core. This paper mainly introduces the system's battery charge and discharge circuit, voice alarm circuit, GSM communication circuit, the main CPU circuit and power supply circuit, etc. The high-voltage alarm device has the characteristic of high reliability, simple operation, low power consumption and high charging efficiency.

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are advancing the emerging technology of electromagnetic proximity detection, which provides a promising means of protecting workers around any machinery that presents striking, pinning or entanglement hazards. This technology is particularly applicable to mobile underground mining equipment such as remote-control continuous mining machines, which offer perhaps the most difficult safety challenges in the mining industry. Other industries have effectively implemented proximity detection technology, with successful test cases at surface and underground mines. However, applying this technology to remote-control continuous mining machines presents uniquely difficult challenges. These machines typically weigh close to 100,000 pounds and have heavy, articulated parts. Due to visibility and space limitations, machine operators often work in very close proximity to the machine despite the clear hazards that this proximity creates. To protect miners without preventing them from doing their jobs or causing nuisance alarms, intelligent electromagnetic proximity detection technology is now being developed at the NIOSH research facility in Pittsburgh. At the heart of this technology are a number of electromagnetic field generators mounted on a mining machine and magnetic flux density sensors built into a Personal Alarm Device (PAD) worn by the operator. In this paper, the authors present a novel algorithm created to calculate an accurate position based on PAD readings from multiple field generators coupled with a previously developed model of the generated magnetic field. The use of this algorithm allows for the calculation of an accurate PAD location relative to the mining machine. A prototype of this intelligent proximity detection system has been successfully implemented and demonstrated on a Joy 14CM continuous mining machine at the NIOSH research facility in Pittsburgh. This technology has the potential to significantly affect the mining industry by greatly advancing the current state-of-the-art in proximity detection technology, leading to increased operator safety and preventing serious injuries and fatalities.

Temperature underground coal mine is an important index, especially for mining workers underground. To monitor the temperature effectively, a temperature measurement and control system is necessary to design. Temperature value is displayed on LED screen on line. When temperature value reaches the maximum, conditioning device connected with the opening end of the relay controlled by the MCU will start up. Temperature signal and control information is all transmitted by wireless signal transmission module nRF905. The system program consists of transducer control and display of the temperature value. The control program of transducer is compiled according to its communication protocol. Program of wireless data transmission should be debugged between the data transmission modules. Alarm device is designed to provides effective information to workers when the temperature value is unusual. Thus monitoring of the temperature underground coal mine can be real and effective.

This paper describes the design and development of a small, portable alarm device that can be used by first responders to an emergency event to warn of the presence of low levels of a toxic nerve gas. The device consists of a rigid reusable portion and a consumable packet that is sensitive to the presence of acetylcholinesterase inhibitors such as the nerve gases Sarin or Soman. The sensitivity level of the alarm is set to be at initial physiological response at the meiosis level, orders of magnitude below lethal concentrations. The AChE enzyme used is specific for nerve-type toxins. A color development reaction is used to demonstrate continued activity of the enzyme over its twelve-hour operational cycle.

With the increase of the living standards of city dwellers, home decoration has been more and more popular these years. Different kinds of material have come into people's home, which brings about beauties to the house as well as some bad effect. Because of differences in manufacturing techniques and quality, much of the material will emit poisonous gases more or less. Even if you have selected the qualified product, the toal amount of gases in you houses may not be guaranteed because of the simple reason that more than one kind of material are applied. Living in the complex environment for a long time will eventually have a bad effect on one's health. In addition the fear of the harm to be done will exert great impact psychologically. In another aspect, the coal-gas in the house-hood for cooking is also explosive and poisonous. In conclusion, the research on the indoor hazardous gases measurement and alarm device is of much economic and practical importance. The device is portable and versatile. We use rechargeable battery as the power supply. The device can detect the density of gases at the ppb level for the emission of the material and the measured value can be shown on the display. As for coal gas it can detect the percentage of LEL and make sound of alarm. We use two kinds of gas-sensors in the device, with catalytic combustion principal for coal gas detection and the PID method for the gas emissions of the decoration material. UV will destroy harmful material (such as: ammonia, dimethylamine, methyl-sulfhydrate, benzene etc.) into positive or negative ions. The sensor detects the electric charges of ionized gases and converts them into electric current signals. It is then amplified and changed into digits by amplifier and A/D. The digit signal is processed by micro-controller system of the device.

The invention concerns an alarm device including an acoustic pressure sensor ( 10 ) delivering an analog signal to first amplifying means ( 12 ) and to second amplifying means ( 14 ), a first comparator ( 34 ) whereof the + input is connected to the output of the second amplifying means and whereof the output delivers a warning signal to alarm means ( 26, 28 ) when there is a break-in or an attempt at breaking in, and self-adjusting means consisting of a microprocessor ( 26 ) programmed to deliver a digital signal at the −input of said first comparator whereof the pulses have a variable width which increases in accordance with the duration and the importance of said atmospheric disturbance so as to automatically increase the alarm device triggering threshold and hence reduce its sensitivity when the acoustic sensor detects an atmospheric disturbance such as wind.

Summary A ventilator alarm device is described with some unique features. It has a very low current consumption. This allows prolonged operation from small batteries which may be recharged from the ambient light in the room. The device is automatically activated and de-activated by the pressure wave from the ventilator. No external switches or other controls are necessary. The very small size means that the device can be directly attached to a ventilator ‘in line’ with the ventilator circuit. There are no tubing connexions between the ventilator and the alarm device and no separate shelf-space is required.

An ultrasonic alarm device has a detector for detecting a reflected ultrasonic wave in a watching area to obtain a Doppler signal due to motion of a person, a Schmitt circuit for converting the detection output into a pulse output and a waveform shaping circuit for shaping the pulse output into a pulse train having a certain pulse width. The output of the waveform shaping circuit is fed in parallel to two band-pass digital filters, one for the Doppler signal and the other for noise signals. Each of the filters comprises two monostable multivibrators connected in parallel and an AND gate having three inputs of which one is connected through an inverter to the output of one monostable multivibrator, a second is connected to the output of the second monostable multivibrator and the third to the input of the monostable multivibrators. The output of the Doppler signal filter is fed through a first integrator to a level decision circuit while the output of the noise signal circuit is fed through a second integrator to the first integrator. The level decision circuit is connected through a third integrator to an output circuit which produces an alarm signal when the signal level is above a predetermined value. Through this circuitry, the Doppler signal due to motion of a person is distinguished from external disturbances such as those due to wind, a telephone bell, an electric click or movement of a small animal, bird or insect.