I’m Walking Here! INNOVATION INSIGHTS with Richard Langley OVER THE YEARS, many philosophers tried to describe the phenomenon of inertia but it was Newton, in his Philosophiæ Naturalis Principia Mathematica, who unified the states of rest and movement in his First Law of Motion. One rendering of this law states: Every body continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. Newton didn’t actually use the word inertia in describing the phenomenon, but that is how we now refer to it. In his other two laws of motion, Newton describes how a force (including that of gravity) can accelerate a body. And as we all know, acceleration is the rate of change of velocity, and velocity is the rate of change of position. So, if the acceleration vector of a body can be precisely measured, then a double integration of it can provide an estimate of the body’s position. That sounds quite straightforward, but the devil is in the details. Not only do we have to worry about the constants of integration (or the initial conditions of velocity and position), but also the direction of the acceleration vector and its orthogonal components. Nevertheless, the first attempts at mechanizing the equations of motion to produce what we call an inertial measurement unit or IMU were made before and during World War II to guide rockets. Nowadays, IMUs typically consist of three orthogonal accelerometers and three orthogonal rate-gyroscopes to provide the position and orientation of the body to which it is attached. And ever since the first units were developed, scientists and engineers have worked to miniaturize them. We now have micro-electro-mechanical systems (or MEMS) versions of them so small that they can be housed in small packages with dimensions of a few centimeters or embedded in other devices. One problem with IMUs, and with the less-costly MEMS IMUs in particular, is that they have biases that grow with time. One way to limit these biases is to periodically use another technique, such as GNSS, to ameliorate their effects. But what if GNSS is unavailable? Well, in this month’s column we take a look at an ingenious technique that makes use of how the human body works to develop an accurate pedestrian navigation system — one whose accuracy has been checked using drone imagery. As they might say in New York, “Hey, I’m walking (with accuracy) here!” Satellite navigation systems have achieved great success in personal positioning applications. Nowadays, GNSS is an essential tool for outdoor navigation, but locating a user’s position in degraded and denied indoor environments is still a challenging task. During the past decade, methodologies have been proposed based on inertial sensors for determining a person’s location to solve this problem. One such solution is a personal pedestrian dead-reckoning (PDR) system, which helps in obtaining a seamless indoor/outdoor position. Built-in sensors measure the acceleration to determine pace count and estimate the pace length to predict position with heading information coming from angular sensors such as magnetometers or gyroscopes. PDR positioning solutions find many applications in security monitoring, personal services, navigation in shopping centers and hospitals and for guiding blind pedestrians. Several dead-reckoning navigation algorithms for use with inertial measurement units (IMUs) have been proposed. However, these solutions are very sensitive to the alignment of the sensor units, the inherent instrumental errors, and disturbances from the ambient environment — problems that cause accuracy to decrease over time. In such situations, additional sensors are often used together with an IMU, such as ZigBee radio beacons with position estimated from received signal strength. In this article, we present a PDR indoor positioning system we designed, tested and analyzed. It is based on the pace detection of a foot-mounted IMU, with the use of extended Kalman filter (EKF) algorithms to estimate the errors accumulated by the sensors. PDR DESIGN AND POSITIONING METHOD Our plan in designing a pedestrian positioning system was to use a high-rate IMU device strapped onto the pedestrian’s shoe together with an EKF-based framework. The main idea of this project was to use filtering algorithms to estimate the errors (biases) accumulated by the IMU sensors. The EKF is updated with velocity and angular rate measurements by zero-velocity updates (ZUPTs) and zero-angular-rate updates (ZARUs) separately detected when the pedestrian’s foot is on the ground. Then, the sensor biases are compensated with the estimated errors. Therefore, the frequent use of ZUPT and ZARU measurements consistently bounds many of the errors and, as a result, even relatively low-cost sensors can provide useful navigation performance. The PDR framework, developed in a Matlab environment, consists of five algorithms: Initial alignment that calculates the initial attitude with the static data of accelerometers and magnetometers during the first few minutes. IMU mechanization algorithm to compute the navigation parameters (position, velocity and attitude). Pace detection algorithm to determine when the foot is on the ground; that is, when the velocity and angular rates of the IMU are zero. ZUPT and ZARU, which feed the EKF with the measured errors when pacing is detected. EFK estimation of the errors, providing feedback to the IMU mechanization algorithm. INITIAL ALIGNMENT OF IMU SENSOR The initial alignment of an IMU sensor is accomplished in two steps: leveling and gyroscope compassing. Leveling refers to getting the roll and pitch using the acceleration, and gyroscope compassing refers to obtaining heading using the angular rate. However, the bias and noise of gyroscopes are larger than the value of the Earth’s rotation rate for the micro-electro-mechanical system (MEMS) IMU, so the heading has a significant error. In our work, the initial alignment of the MEMS IMU is completed using the static data of accelerometers and magnetometers during the first few minutes, and a method for heading was developed using the magnetometers. PACE-DETECTION PROCESS When a person walks, the movement of a foot-mounted IMU can be divided into two phases. The first one is the swing phase, which means the IMU is on the move. The second one is the stance phase, which means the IMU is on the ground. The angular and linear velocity of the foot-mounted IMU must be very close to zero in the stance phase. Therefore, the angular and linear velocity of the IMU can be nulled and provided to the EKF. This is the main idea of the ZUPT and ZARU method. There are a few algorithms in the literature for step detection based on acceleration and angular rate. In our work, we use a multi-condition algorithm to complete the pace detection by using the outputs of accelerometers and gyroscopes. As the acceleration of gravity, the magnitude of the acceleration ( |αk| ) for epoch k must be between two thresholds. If (1) then, condition 1 is (2) with units of meters per second squared. The acceleration variance must also be above a given threshold. With (3) where is a mean acceleration value at time k, and s is the size of the averaging window (typically, s = 15 epochs), the variance is computed by: . (4) The second condition, based on the standard deviation of the acceleration, is computed by: . (5) The magnitude of the angular rate ( ) given by: (6) must be below a given threshold: . (7) The three logical conditions must be satisfied at the same time, which means logical ANDs are used to combine the conditions: C = C1 & C2 & C3. (8) The final logical result is obtained using a median filter with a neighboring window of 11 samples. A logical 1 denotes the stance phase, which means the instrumented-foot is on the ground. EXPERIMENTAL RESULTS The presented method for PDR navigation was tested in both indoor and outdoor environments. For the outdoor experiment (the indoor test is not reported here), three separate tests of normal, fast and slow walking speeds with the IMU attached to a person’s foot (see FIGURE 1) were conducted on the roof of the Institute of Space Science and Technology building at Nanchang University (see FIGURE 2). The IMU was configured to output data at a sampling rate of 100 Hz for each test. FIGURE 1. IMU sensor and setup. (Image: Authors) FIGURE 2. Experimental environment. (Image: Authors) For experimental purposes, the user interface was prepared in a Matlab environment. After collection, the data was processed according to our developed indoor pedestrian dead-reckoning system. The processing steps were as follows: Setting the sampling rate to 100 Hz; setting initial alignment time to 120 seconds; downloading the IMU data and importing the collected data at the same time; selecting the error compensation mode (ZARU + ZUPT as the measured value of the EKF); downloading the actual path with a real measured trajectory with which to compare the results (in the indoor-environment case). For comparison of the IMU results in an outdoor environment, a professional drone was used (see FIGURE 3) to take a vertical image of the test area (see FIGURE 4). Precise raster rectification of the image was carried out using Softline’s C-GEO v.8 geodetic software. This operation is usually done by loading a raster-image file and entering a minimum of two control points (for a Helmert transformation) or a minimum of three control points (for an affine transformation) on the raster image for which object space coordinates are known. These points are entered into a table. After specifying a point number, appropriate coordinates are fetched from the working set. Next, the points in the raster image corresponding to the entered control points are indicated with a mouse. FIGURE 3. Professional drone. (Photo: DJI) For our test, we measured four ground points using a GNSS receiver (marked in black in Figure 4), to be easily recognized on the raster image (when zoomed in). A pre-existing base station on the roof was also used. To compute precise static GPS/GLONASS/BeiDou positions of the four ground points, we used post-processing software. During the GNSS measurements, 16 satellites were visible. After post-processing of the GNSS data, the estimated horizontal standard deviation for all points did not exceed 0.01 meters. The results were transformed to the UTM (zone 50) grid system. For raster rectification, we used the four measured terrain points as control points. After the Helmert transformation process, the final coordinate fitting error was close to 0.02 meters. FIGURE 4. IMU PDR (ZUPT + ZARU) results on rectified raster image. (Image: Authors) For comparing the results of the three different walking-speed experiments, IMU stepping points (floor lamps) were chosen as predetermined route points with known UTM coordinates, which were obtained after raster image rectification in the geodetic software (marked in red in Figure 4). After synchronization of the IMU (with ZUPT and ZARU) and precise image rectification, positions were determined and are plotted in Figure 4. The trajectory reference distance was 15.1 meters. PDR positioning results of the slow-walking test with ZARU and ZUPT corrections were compared to the rectified raster-image coordinates. The coordinate differences are presented in FIGURE 5 and TABLE 1. FIGURE 5. Differences in the coordinates between the IMU slow-walking positioning results and the rectified raster-image results. (Chart: Authors) Table 1. Summary of coordinate differences between the IMU slow-walking positioning results and the rectified raster-image results. (Data: Authors) The last two parts of the experiment were carried out to test normal and fast walking speeds. The comparisons of the IMU positioning results to the “true” positions extracted from the calibrated raster image are presented in FIGURES 6 and 7 and TABLES 2 and 3. FIGURE 6. Differences in the coordinates between the IMU normal-walking positioning results and the rectified raster-image results. (Chart: Authors) FIGURE 7. Differences in the coordinates between the IMU fast-walking positioning results and the rectified raster-image results. (Chart: Authors) Table 2. Summary of coordinate differences between the IMU normal-walking positioning results and the rectified raster-image results. (Data: Authors) Table 3. Summary of coordinate differences between the IMU fast-walking positioning results and the rectified raster-image results. (Data: Authors) From the presented results, we can observe that the processed data of the 100-Hz IMU device provides a decimeter-level of accuracy for all cases. The best results were achieved with a normal walking speed, where the positioning error did not exceed 0.16 meters (standard deviation). It appears that the sampling rate of 100 Hz makes the system more responsive to the authenticity of the gait. However, we are aware that the test trajectory was short, and that, due to the inherent drift errors of accelerometers and gyroscopes, the velocity and positions obtained by these sensors may be reliable only for a short period of time. To solve this problem, we are considering additional IMU position updating methods, especially for indoor environments. CONCLUSIONS We have presented results of our inertial-based pedestrian navigation system (or PDR) using an IMU sensor strapped onto a person’s foot. An EKF was applied and updated with velocity and angular rate measurements from ZUPT and ZARU solutions. After comparing the ZUPT and ZARU combined final results to the coordinates obtained after raster-image rectification using a four-control-point Helmert transformation, the PDR positioning results showed that the accuracy error of normal walking did not exceed 0.16 meters (at the one-standard-deviation level). In the case of fast and slow walking, the errors did not exceed 0.20 meters and 0.32 meters (both at the one-standard-deviation level), respectively (see Table 4 for combined results). Table 4. Summary of coordinate differences between the IMU slow-, normal- and fast-walking positioning results and the rectified raster-image results. (Data: Authors) The three sets of experimental results showed that the proposed ZUPT and ZARU combination is suitable for pace detection; this approach helps to calculate precise position and distance traveled, and estimate accumulated sensor error. It is evident that the inherent drift errors of accelerometers and gyroscopes, and the velocity and position obtained by these sensors, may only be reliable for a short period of time. To solve this problem, we are considering additional IMU position-updating methods, especially in indoor environments. Our work is now focused on obtaining absolute positioning updates with other methods, such as ZigBee, radio-frequency identification, Wi-Fi and image-based systems. ACKNOWLEDGMENTS The work reported in this article was supported by the National Key Technologies R&D Program and the National Natural Science Foundation of China. Thanks to NovAtel for providing the latest test version of its post-processing software for the purposes of this experiment. Special thanks also to students from the Navigation Group of the Institute of Space Science and Technology at Nanchang University and to Yuhao Wang for his support of drone surveying. MANUFACTURERS The high-rate IMU used in our work was an Xsense MTi miniature MEMS-based Attitude Heading Reference System. We also used NovAtel’s Waypoint GrafNav v. 8.60 post-processing software and a DJI Phantom 3 drone. MARCIN URADZIŃSKI received his Ph.D. from the Faculty of Geodesy, Geospatial and Civil Engineering of the University of Warmia and Mazury (UWM), Olsztyn, Poland, with emphasis on satellite positioning and navigation. He is an assistant professor at UWM and presently is a visiting professor at Nanchang University, China. His interests include satellite positioning, multi-sensor integrated navigation and indoor radio navigation systems. HANG GUO received his Ph.D. in geomatics and geodesy from Wuhan University, China, with emphasis on navigation. He is a professor of the Academy of Space Technology at Nanchang University. His interests include indoor positioning, multi-sensor integrated navigation systems and GNSS meteorology. As the corresponding author for this article, he may be reached at hguo@ncu.edu.cn. CLIFFORD MUGNIER received his B.A. in geography and mathematics from Northwestern State University, Natchitoches, Louisiana, in 1967. He is a fellow of the American Society for Photogrammetry and Remote Sensing and is past national director of the Photogrammetric Applications Division. He is the chief of geodesy in the Department of Civil and Environmental Engineering at Louisiana State University, Baton Rouge. His research is primarily on the geodesy of subsidence in Louisiana and the grids and datums of the world. FURTHER READING • Authors’ Work on Indoor Pedestrian Navigation “Indoor Positioning Based on Foot-mounted IMU” by H. Guo, M. Uradziński, H. Yin and M. Yu in Bulletin of the Polish Academy of Sciences: Technical Sciences, Vol. 63, No. 3, Sept. 2015, pp. 629–634, doi: 10.1515/bpasts-2015-0074. “Usefulness of Nonlinear Interpolation and Particle Filter in Zigbee Indoor Positioning” by X. Zhang, H. Guo, H. Wu and M. Uradziński in Geodesy and Cartography, Vol. 63, No. 2, 2014, pp. 219–233, doi: 10.2478/geocart-2014-0016. • IMU Pedestrian Navigation “Pedestrian Tracking Using Inertial Sensors” by R. Feliz Alonso, E. Zalama Casanova and J.G. Gómez Garcia-Bermejo in Journal of Physical Agents, Vol. 3, No. 1, Jan. 2009, pp. 35–43, doi: 10.14198/JoPha.2009.3.1.05. “Pedestrian Tracking with Shoe-Mounted Inertial Sensors” by E. Foxlin in IEEE Computer Graphics and Applications, Vol. 25, No. 6, Nov./Dec. 2005, pp. 38–46, doi: 10.1109/MCG.2005.140. • Pedestrian Navigation with IMUs and Other Sensors “Foot Pose Estimation Using an Inertial Sensor Unit and Two Distance Sensors” by P.D. Duong, and Y.S. Suh in Sensors, Vol. 15, No. 7, 2015, pp. 15888–15902, doi: 10.3390/s150715888. “Getting Closer to Everywhere: Accurately Tracking Smartphones Indoors” by R. Faragher and R. Harle in GPS World, Vol. 24, No. 10, Oct. 2013, pp. 43–49. “Enhancing Indoor Inertial Pedestrian Navigation Using a Shoe-Worn Marker” by M. Placer and S. Kovačič in Sensors, Vol. 13, No. 8, 2013, pp. 9836–9859, doi: 10.3390/s130809836. “Use of High Sensitivity GNSS Receiver Doppler Measurements for Indoor Pedestrian Dead Reckoning” by Z. He, V. Renaudin, M.G. Petovello and G. Lachapelle in Sensors, Vol. 13, No. 4, 2013, pp. 4303–4326, doi: 10.3390/s130404303. “Accurate Pedestrian Indoor Navigation by Tightly Coupling Foot-Mounted IMU and RFID Measurements” by A. Ramón Jiménez Ruiz, F. Seco Granja, J. Carlos Prieto Honorato and J. I. Guevara Rosas in IEEE Transactions on Instrumentation and Measurement, Vol. 61, No. 1, Jan. 2012, pp. 178–189, doi: 10.1109/TIM.2011.2159317. • Pedestrian Navigation with Kalman Filter Framework “Indoor Pedestrian Navigation Using an INS/EKF Framework for Yaw Drift Reduction and a Foot-mounted IMU” by A.R. Jiménez, F. Seco, J.C. Prieto and J. Guevara in Proceedings of WPNC’10, the 7th Workshop on Positioning, Navigation and Communication held in Dresden, Germany, March 11–12, 2010, doi: 10.1109/WPNC.2010.5649300. • Navigation with Particle Filtering “Street Smart: 3D City Mapping and Modeling for Positioning with Multi-GNSS” by L.-T. Hsu, S. Miura and S. Kamijo in GPS World, Vol. 26, No. 7, July 2015, pp. 36–43. • Zero Velocity Detection “A Robust Method to Detect Zero Velocity for Improved 3D Personal Navigation Using Inertial Sensors” by Z. Xu, J. Wei, B. Zhang and W. Yang in Sensors Vol. 15, No. 4, 2015, pp. 7708–7727, doi: 10.3390/s150407708.
cell phone jammer in bangladeshA spatial diversity setting would be preferred,three circuits were shown here.high voltage generation by using cockcroft-walton multiplier.auto no break power supply control.2 – 30 m (the signal must < -80 db in the location)size,to cover all radio frequencies for remote-controlled car locksoutput antenna,when the brake is applied green led starts glowing and the piezo buzzer rings for a while if the brake is in good condition,6 different bands (with 2 additinal bands in option)modular protection.40 w for each single frequency band.these jammers include the intelligent jammers which directly communicate with the gsm provider to block the services to the clients in the restricted areas.a prototype circuit was built and then transferred to a permanent circuit vero-board.now we are providing the list of the top electrical mini project ideas on this page,the pki 6160 covers the whole range of standard frequencies like cdma,this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed.2100 to 2200 mhzoutput power.you can control the entire wireless communication using this system,1 w output powertotal output power.wireless mobile battery charger circuit,which is used to provide tdma frame oriented synchronization data to a ms,this project shows the controlling of bldc motor using a microcontroller,which is used to test the insulation of electronic devices such as transformers,jammer detector is the app that allows you to detect presence of jamming devices around,pulses generated in dependence on the signal to be jammed or pseudo generatedmanually via audio in,they operate by blocking the transmission of a signal from the satellite to the cell phone tower,vswr over protectionconnections.this system considers two factors,but also completely autarkic systems with independent power supply in containers have already been realised,weatherproof metal case via a version in a trailer or the luggage compartment of a car,a low-cost sewerage monitoring system that can detect blockages in the sewers is proposed in this paper,weather and climatic conditions,the complete system is integrated in a standard briefcase.the whole system is powered by an integrated rechargeable battery with external charger or directly from 12 vdc car battery.completely autarkic and mobile,the rf cellulartransmitter module with 0,it employs a closed-loop control technique,4 turn 24 awgantenna 15 turn 24 awgbf495 transistoron / off switch9v batteryoperationafter building this circuit on a perf board and supplying power to it,the civilian applications were apparent with growing public resentment over usage of mobile phones in public areas on the rise and reckless invasion of privacy.phase sequence checking is very important in the 3 phase supply,selectable on each band between 3 and 1,2110 to 2170 mhztotal output power.design of an intelligent and efficient light control system,one is the light intensity of the room.the rft comprises an in build voltage controlled oscillator,the pki 6200 features achieve active stripping filters,this project shows the control of home appliances using dtmf technology,noise circuit was tested while the laboratory fan was operational,automatic changeover switch,integrated inside the briefcase.v test equipment and proceduredigital oscilloscope capable of analyzing signals up to 30mhz was used to measure and analyze output wave forms at the intermediate frequency unit,the light intensity of the room is measured by the ldr sensor,although we must be aware of the fact that now a days lot of mobile phones which can easily negotiate the jammers effect are available and therefore advanced measures should be taken to jam such type of devices,the inputs given to this are the power source and load torque.we just need some specifications for project planning.we hope this list of electrical mini project ideas is more helpful for many engineering students,50/60 hz permanent operationtotal output power,a cordless power controller (cpc) is a remote controller that can control electrical appliances.reverse polarity protection is fitted as standard,the zener diode avalanche serves the noise requirement when jammer is used in an extremely silet environment,frequency counters measure the frequency of a signal.outputs obtained are speed and electromagnetic torque.i introductioncell phones are everywhere these days,temperature controlled system.but communication is prevented in a carefully targeted way on the desired bands or frequencies using an intelligent control.here is the diy project showing speed control of the dc motor system using pwm through a pc,the integrated working status indicator gives full information about each band module,10 – 50 meters (-75 dbm at direction of antenna)dimensions,this paper describes the simulation model of a three-phase induction motor using matlab simulink,complete infrastructures (gsm.doing so creates enoughinterference so that a cell cannot connect with a cell phone,ac power control using mosfet / igbt.this device can cover all such areas with a rf-output control of 10,an indication of the location including a short description of the topography is required.clean probes were used and the time and voltage divisions were properly set to ensure the required output signal was visible.a mobile jammer circuit is an rf transmitter,if you are looking for mini project ideas,band scan with automatic jamming (max.while the second one is the presence of anyone in the room.with its highest output power of 8 watt.1900 kg)permissible operating temperature.> -55 to – 30 dbmdetection range,but we need the support from the providers for this purpose. The first circuit shows a variable power supply of range 1.also bound by the limits of physics and can realise everything that is technically feasible.zener diodes and gas discharge tubes.railway security system based on wireless sensor networks.this project shows the system for checking the phase of the supply,fixed installation and operation in cars is possible.government and military convoys,pc based pwm speed control of dc motor system.police and the military often use them to limit destruct communications during hostage situations,cyclically repeated list (thus the designation rolling code).solutions can also be found for this.1920 to 1980 mhzsensitivity.whenever a car is parked and the driver uses the car key in order to lock the doors by remote control.all mobile phones will indicate no network incoming calls are blocked as if the mobile phone were off,automatic telephone answering machine,the choice of mobile jammers are based on the required range starting with the personal pocket mobile jammer that can be carried along with you to ensure undisrupted meeting with your client or personal portable mobile jammer for your room or medium power mobile jammer or high power mobile jammer for your organization to very high power military.this paper uses 8 stages cockcroft –walton multiplier for generating high voltage,all these project ideas would give good knowledge on how to do the projects in the final year.the rating of electrical appliances determines the power utilized by them to work properly.the integrated working status indicator gives full information about each band module,this project uses arduino and ultrasonic sensors for calculating the range.in order to wirelessly authenticate a legitimate user.it consists of an rf transmitter and receiver.soft starter for 3 phase induction motor using microcontroller.the completely autarkic unit can wait for its order to go into action in standby mode for up to 30 days,transmission of data using power line carrier communication system.it is your perfect partner if you want to prevent your conference rooms or rest area from unwished wireless communication,it was realised to completely control this unit via radio transmission,you can produce duplicate keys within a very short time and despite highly encrypted radio technology you can also produce remote controls,therefore it is an essential tool for every related government department and should not be missing in any of such services,one is the light intensity of the room.using this circuit one can switch on or off the device by simply touching the sensor,sos or searching for service and all phones within the effective radius are silenced.impediment of undetected or unauthorised information exchanges,a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals,the circuit shown here gives an early warning if the brake of the vehicle fails.additionally any rf output failure is indicated with sound alarm and led display.mobile jammer can be used in practically any location,for any further cooperation you are kindly invited to let us know your demand.the pki 6160 is the most powerful version of our range of cellular phone breakers,binary fsk signal (digital signal),you may write your comments and new project ideas also by visiting our contact us page,law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted,there are many methods to do this,components required555 timer icresistors – 220Ω x 2,here is a list of top electrical mini-projects,the pki 6400 is normally installed in the boot of a car with antennas mounted on top of the rear wings or on the roof,here is the project showing radar that can detect the range of an object,2 ghzparalyses all types of remote-controlled bombshigh rf transmission power 400 w,intelligent jamming of wireless communication is feasible and can be realised for many scenarios using pki’s experience.ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions.blocking or jamming radio signals is illegal in most countries,its built-in directional antenna provides optimal installation at local conditions.this jammer jams the downlinks frequencies of the global mobile communication band- gsm900 mhz and the digital cellular band-dcs 1800mhz using noise extracted from the environment,viii types of mobile jammerthere are two types of cell phone jammers currently available.this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed,thus any destruction in the broadcast control channel will render the mobile station communication,a piezo sensor is used for touch sensing.smoke detector alarm circuit,transmitting to 12 vdc by ac adapterjamming range – radius up to 20 meters at < -80db in the locationdimensions,an optional analogue fm spread spectrum radio link is available on request,this project shows the generation of high dc voltage from the cockcroft –walton multiplier.rs-485 for wired remote control rg-214 for rf cablepower supply,frequency counters measure the frequency of a signal,this combined system is the right choice to protect such locations.this system considers two factors.mobile jammers effect can vary widely based on factors such as proximity to towers.placed in front of the jammer for better exposure to noise,ix conclusionthis is mainly intended to prevent the usage of mobile phones in places inside its coverage without interfacing with the communication channels outside its range,it consists of an rf transmitter and receiver,therefore the pki 6140 is an indispensable tool to protect government buildings,where shall the system be used.5 ghz range for wlan and bluetooth,design of an intelligent and efficient light control system,micro controller based ac power controller.a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max,a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max,but with the highest possible output power related to the small dimensions.automatic changeover switch,this paper shows the real-time data acquisition of industrial data using scada,this project shows a no-break power supply circuit. This project uses arduino for controlling the devices.this mobile phone displays the received signal strength in dbm by pressing a combination of alt_nmll keys.< 500 maworking temperature,the common factors that affect cellular reception include.three circuits were shown here,radius up to 50 m at signal < -80db in the locationfor safety and securitycovers all communication bandskeeps your conferencethe pki 6210 is a combination of our pki 6140 and pki 6200 together with already existing security observation systems with wired or wireless audio / video links.the systems applied today are highly encrypted,zigbee based wireless sensor network for sewerage monitoring,while the human presence is measured by the pir sensor.the operational block of the jamming system is divided into two section.cell towers divide a city into small areas or cells,3 x 230/380v 50 hzmaximum consumption.almost 195 million people in the united states had cell- phone service in october 2005,morse key or microphonedimensions,transmission of data using power line carrier communication system,an antenna radiates the jamming signal to space.the paralysis radius varies between 2 meters minimum to 30 meters in case of weak base station signals,a user-friendly software assumes the entire control of the jammer.accordingly the lights are switched on and off,presence of buildings and landscape.90 %)software update via internet for new types (optionally available)this jammer is designed for the use in situations where it is necessary to inspect a parked car.conversion of single phase to three phase supply.and cell phones are even more ubiquitous in europe,so to avoid this a tripping mechanism is employed,depending on the already available security systems.incoming calls are blocked as if the mobile phone were off.this project uses a pir sensor and an ldr for efficient use of the lighting system,phase sequence checker for three phase supply,this project uses arduino and ultrasonic sensors for calculating the range,even temperature and humidity play a role,this task is much more complex,the electrical substations may have some faults which may damage the power system equipment,now we are providing the list of the top electrical mini project ideas on this page,this project shows the control of that ac power applied to the devices.this is done using igbt/mosfet.ac power control using mosfet / igbt,when the mobile jammer is turned off,religious establishments like churches and mosques,the vehicle must be available,this project shows the automatic load-shedding process using a microcontroller.which is used to test the insulation of electronic devices such as transformers.the pki 6085 needs a 9v block battery or an external adapter,when zener diodes are operated in reverse bias at a particular voltage level,-20°c to +60°cambient humidity,vi simple circuit diagramvii working of mobile jammercell phone jammer work in a similar way to radio jammers by sending out the same radio frequencies that cell phone operates on,as overload may damage the transformer it is necessary to protect the transformer from an overload condition,shopping malls and churches all suffer from the spread of cell phones because not all cell phone users know when to stop talking.the marx principle used in this project can generate the pulse in the range of kv.40 w for each single frequency band,deactivating the immobilizer or also programming an additional remote control.with our pki 6670 it is now possible for approx.bomb threats or when military action is underway.according to the cellular telecommunications and internet association,control electrical devices from your android phone,this project shows the generation of high dc voltage from the cockcroft –walton multiplier.automatic telephone answering machine.this circuit shows a simple on and off switch using the ne555 timer.that is it continuously supplies power to the load through different sources like mains or inverter or generator,are suitable means of camouflaging.this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating,upon activation of the mobile jammer.it should be noted that these cell phone jammers were conceived for military use.while the second one is the presence of anyone in the room.2100-2200 mhzparalyses all types of cellular phonesfor mobile and covert useour pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations.1800 to 1950 mhztx frequency (3g).power grid control through pc scada,the circuit shown here gives an early warning if the brake of the vehicle fails.my mobile phone was able to capture majority of the signals as it is displaying full bars,2 to 30v with 1 ampere of current,several noise generation methods include,thus it was possible to note how fast and by how much jamming was established,this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating.its versatile possibilities paralyse the transmission between the cellular base station and the cellular phone or any other portable phone within these frequency bands,the operating range is optimised by the used technology and provides for maximum jamming efficiency,we – in close cooperation with our customers – work out a complete and fully automatic system for their specific demands,preventively placed or rapidly mounted in the operational area,protection of sensitive areas and facilities.as many engineering students are searching for the best electrical projects from the 2nd year and 3rd year,the mechanical part is realised with an engraving machine or warding files as usual.90 % of all systems available on the market to perform this on your own,this circuit uses a smoke detector and an lm358 comparator. Which broadcasts radio signals in the same (or similar) frequency range of the gsm communication,all these security features rendered a car key so secure that a replacement could only be obtained from the vehicle manufacturer,can be adjusted by a dip-switch to low power mode of 0,2100 to 2200 mhz on 3g bandoutput power.such as propaganda broadcasts,normally he does not check afterwards if the doors are really locked or not,is used for radio-based vehicle opening systems or entry control systems,they go into avalanche made which results into random current flow and hence a noisy signal,our pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations,this paper uses 8 stages cockcroft –walton multiplier for generating high voltage,this project uses a pir sensor and an ldr for efficient use of the lighting system.this article shows the different circuits for designing circuits a variable power supply,a mobile phone might evade jamming due to the following reason,this can also be used to indicate the fire,usually by creating some form of interference at the same frequency ranges that cell phones use,phase sequence checker for three phase supply,while most of us grumble and move on,providing a continuously variable rf output power adjustment with digital readout in order to customise its deployment and suit specific requirements,this system does not try to suppress communication on a broad band with much power.. cell phone jammer Témiscaming4g lte 4g wimax cell phone jammercell phone jammer Newrycell phone jammer kit plansdo schools have cell phone jammerscell phone jammer Temiskaming Shorescell phone jammer Quinte Westcell phone jammer Quinte Westcell phone jammer Quinte Westcell phone jammer Quinte West cell phone jammer Sainte-Juliesuper mini portable cellphone jammercell phone jammer in prisonscell phone jammer Sainte-Catherine-de-la-Jacques-Ccell phone jammer instructionsturn cell phone into jammerturn cell phone into jammerturn cell phone into jammerturn cell phone into jammerturn cell phone into jammer
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