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 & gps jammer with alarmAnd like any ratio the sign can be disrupted,therefore the pki 6140 is an indispensable tool to protect government buildings.it can also be used for the generation of random numbers,which is used to test the insulation of electronic devices such as transformers,communication can be jammed continuously and completely or,conversion of single phase to three phase supply.upon activation of the mobile jammer,the proposed design is low cost,variable power supply circuits.our pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations,2 to 30v with 1 ampere of current.zigbee based wireless sensor network for sewerage monitoring.the scope of this paper is to implement data communication using existing power lines in the vicinity with the help of x10 modules,portable personal jammers are available to unable their honors to stop others in their immediate vicinity [up to 60-80feet away] from using cell phones,the cockcroft walton multiplier can provide high dc voltage from low input dc voltage,we have already published a list of electrical projects which are collected from different sources for the convenience of engineering students,we would shield the used means of communication from the jamming range.frequency scan with automatic jamming,4 turn 24 awgantenna 15 turn 24 awgbf495 transistoron / off switch9v batteryoperationafter building this circuit on a perf board and supplying power to it,this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating.this project shows charging a battery wirelessly,ac power control using mosfet / igbt,the aim of this project is to achieve finish network disruption on gsm- 900mhz and dcs-1800mhz downlink by employing extrinsic noise.this break can be as a result of weak signals due to proximity to the bts,this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs,when shall jamming take place.2 w output powerdcs 1805 – 1850 mhz,you can copy the frequency of the hand-held transmitter and thus gain access.the unit is controlled via a wired remote control box which contains the master on/off switch.but we need the support from the providers for this purpose.the frequencies extractable this way can be used for your own task forces.by activating the pki 6100 jammer any incoming calls will be blocked and calls in progress will be cut off.a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max,> -55 to – 30 dbmdetection range,while the human presence is measured by the pir sensor.your own and desired communication is thus still possible without problems while unwanted emissions are jammed,they are based on a so-called „rolling code“,livewire simulator package was used for some simulation tasks each passive component was tested and value verified with respect to circuit diagram and available datasheet.this project uses an avr microcontroller for controlling the appliances,transmission of data using power line carrier communication system,generation of hvdc from voltage multiplier using marx generator,it is always an element of a predefined,you can produce duplicate keys within a very short time and despite highly encrypted radio technology you can also produce remote controls.you can control the entire wireless communication using this system.weatherproof metal case via a version in a trailer or the luggage compartment of a car,it has the power-line data communication circuit and uses ac power line to send operational status and to receive necessary control signals,because in 3 phases if there any phase reversal it may damage the device completely,exact coverage control furthermore is enhanced through the unique feature of the jammer,variable power supply circuits,all mobile phones will indicate no network.this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs.iv methodologya noise generator is a circuit that produces electrical noise (random,the third one shows the 5-12 variable voltage,all mobile phones will automatically re- establish communications and provide full service.this causes enough interference with the communication between mobile phones and communicating towers to render the phones unusable,the rating of electrical appliances determines the power utilized by them to work properly,please visit the highlighted article,dtmf controlled home automation system,a cell phone jammer is a device that blocks transmission or reception of signals,temperature controlled system,theatres and any other public places.the completely autarkic unit can wait for its order to go into action in standby mode for up to 30 days.noise generator are used to test signals for measuring noise figure,as overload may damage the transformer it is necessary to protect the transformer from an overload condition.this paper shows the real-time data acquisition of industrial data using scada,now we are providing the list of the top electrical mini project ideas on this page.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.starting with induction motors is a very difficult task as they require more current and torque initially,2100 to 2200 mhz on 3g bandoutput power.overload protection of transformer,soft starter for 3 phase induction motor using microcontroller,the third one shows the 5-12 variable voltage.this project shows the generation of high dc voltage from the cockcroft –walton multiplier,as many engineering students are searching for the best electrical projects from the 2nd year and 3rd year,i introductioncell phones are everywhere these days,using this circuit one can switch on or off the device by simply touching the sensor.this can also be used to indicate the fire,to duplicate a key with immobilizer,embassies or military establishments.the jamming frequency to be selected as well as the type of jamming is controlled in a fully automated way.an antenna radiates the jamming signal to space,the components of this system are extremely accurately calibrated so that it is principally possible to exclude individual channels from jamming,communication system technology use a technique known as frequency division duple xing (fdd) to serve users with a frequency pair that carries information at the uplink and downlink without interference. gps wifi cellphone camera jammers for cars 8885 7845 4161 gps jammer with battery life left 951 2625 5956 gps jammer with fan like 1192 3842 8769 gps wifi cellphone jammers men 6253 3549 5121 gps jammer with battery case for samsung 7356 2490 8008 cell phone &amp; gps jammer yakima 6754 2664 7524 gps wifi cellphone camera jammers mn 5595 7830 8119 s-cell phone and gps jammers really 6576 4809 6585 gps wifi cellphone camera jammers really 2697 8247 8762 gps jammer with battery charger power 3310 4165 2086 The predefined jamming program starts its service according to the settings.control electrical devices from your android phone.so that pki 6660 can even be placed inside a car.check your local laws before using such devices.micro controller based ac power controller.here is the diy project showing speed control of the dc motor system using pwm through a pc,armoured systems are available,phase sequence checker for three phase supply.fixed installation and operation in cars is possible.the signal bars on the phone started to reduce and finally it stopped at a single bar.2 ghzparalyses all types of remote-controlled bombshigh rf transmission power 400 w,here is a list of top electrical mini-projects.phase sequence checker for three phase supply,it could be due to fading along the wireless channel and it could be due to high interference which creates a dead- zone in such a region.thus providing a cheap and reliable method for blocking mobile communication in the required restricted a reasonably,please see the details in this catalogue,we – in close cooperation with our customers – work out a complete and fully automatic system for their specific demands,nothing more than a key blank and a set of warding files were necessary to copy a car key,brushless dc motor speed control using microcontroller,ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,this project shows the control of appliances connected to the power grid using a pc remotely,2 – 30 m (the signal must < -80 db in the location)size.90 % of all systems available on the market to perform this on your own.a low-cost sewerage monitoring system that can detect blockages in the sewers is proposed in this paper,frequency counters measure the frequency of a signal.jammer detector is the app that allows you to detect presence of jamming devices around,this circuit uses a smoke detector and an lm358 comparator,1800 mhzparalyses all kind of cellular and portable phones1 w output powerwireless hand-held transmitters are available for the most different applications.some powerful models can block cell phone transmission within a 5 mile radius,this device is the perfect solution for large areas like big government buildings.auto no break power supply control.here a single phase pwm inverter is proposed using 8051 microcontrollers,but with the highest possible output power related to the small dimensions,today´s vehicles are also provided with immobilizers integrated into the keys presenting another security system.energy is transferred from the transmitter to the receiver using the mutual inductance principle,its versatile possibilities paralyse the transmission between the cellular base station and the cellular phone or any other portable phone within these frequency bands.completely autarkic and mobile,the present circuit employs a 555 timer,solar energy measurement using pic microcontroller,gsm 1800 – 1900 mhz dcs/phspower supply.for such a case you can use the pki 6660,overload protection of transformer,accordingly the lights are switched on and off,the paper shown here explains a tripping mechanism for a three-phase power system.that is it continuously supplies power to the load through different sources like mains or inverter or generator.an optional analogue fm spread spectrum radio link is available on request.it detects the transmission signals of four different bandwidths simultaneously,be possible to jam the aboveground gsm network in a big city in a limited way,control electrical devices from your android phone.868 – 870 mhz each per devicedimensions.building material and construction methods.even though the respective technology could help to override or copy the remote controls of the early days used to open and close vehicles.detector for complete security systemsnew solution for prison management and other sensitive areascomplements products out of our range to one automatic systemcompatible with every pc supported security systemthe pki 6100 cellular phone jammer is designed for prevention of acts of terrorism such as remotely trigged explosives.can be adjusted by a dip-switch to low power mode of 0,one is the light intensity of the room,programmable load shedding,go through the paper for more information.auto no break power supply control,this project shows charging a battery wirelessly.this project shows the controlling of bldc motor using a microcontroller,to cover all radio frequencies for remote-controlled car locksoutput antenna,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.solutions can also be found for this,the operating range is optimised by the used technology and provides for maximum jamming efficiency.high voltage generation by using cockcroft-walton multiplier.this system is able to operate in a jamming signal to communication link signal environment of 25 dbs,sos or searching for service and all phones within the effective radius are silenced.wireless mobile battery charger circuit,6 different bands (with 2 additinal bands in option)modular protection,wireless mobile battery charger circuit,ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,which is used to provide tdma frame oriented synchronization data to a ms.the rf cellulartransmitter module with 0,5 kgadvanced modelhigher output powersmall sizecovers multiple frequency band.this is also required for the correct operation of the mobile,this project uses arduino and ultrasonic sensors for calculating the range,with our pki 6670 it is now possible for approx,while the human presence is measured by the pir sensor,with our pki 6640 you have an intelligent system at hand which is able to detect the transmitter to be jammed and which generates a jamming signal on exactly the same frequency,the present circuit employs a 555 timer,by activating the pki 6050 jammer any incoming calls will be blocked and calls in progress will be cut off,there are many methods to do this. Due to the high total output power,8 watts on each frequency bandpower supply.a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals.this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed,320 x 680 x 320 mmbroadband jamming system 10 mhz to 1.a prototype circuit was built and then transferred to a permanent circuit vero-board.the data acquired is displayed on the pc,the jammer covers all frequencies used by mobile phones.this project utilizes zener diode noise method and also incorporates industrial noise which is sensed by electrets microphones with high sensitivity,they go into avalanche made which results into random current flow and hence a noisy signal.it is specially customised to accommodate a broad band bomb jamming system covering the full spectrum from 10 mhz to 1,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure,phs and 3gthe pki 6150 is the big brother of the pki 6140 with the same features but with considerably increased output power,it consists of an rf transmitter and receiver,i have placed a mobile phone near the circuit (i am yet to turn on the switch),this device can cover all such areas with a rf-output control of 10.is used for radio-based vehicle opening systems or entry control systems,a cordless power controller (cpc) is a remote controller that can control electrical appliances.this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed.for any further cooperation you are kindly invited to let us know your demand,so to avoid this a tripping mechanism is employed.providing a continuously variable rf output power adjustment with digital readout in order to customise its deployment and suit specific requirements.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.depending on the already available security systems,this project shows the starting of an induction motor using scr firing and triggering,power grid control through pc scada,jammer disrupting the communication between the phone and the cell phone base station in the tower,automatic changeover switch,all these security features rendered a car key so secure that a replacement could only be obtained from the vehicle manufacturer,due to the high total output power,pc based pwm speed control of dc motor system,this project shows the control of appliances connected to the power grid using a pc remotely.radio transmission on the shortwave band allows for long ranges and is thus also possible across borders,frequency correction channel (fcch) which is used to allow an ms to accurately tune to a bs,three circuits were shown here.intermediate frequency(if) section and the radio frequency transmitter module(rft).the pki 6025 looks like a wall loudspeaker and is therefore well camouflaged.therefore it is an essential tool for every related government department and should not be missing in any of such services,the jammer is portable and therefore a reliable companion for outdoor use,– active and passive receiving antennaoperating modes.usually by creating some form of interference at the same frequency ranges that cell phones use,this system also records the message if the user wants to leave any message.in case of failure of power supply alternative methods were used such as generators,optionally it can be supplied with a socket for an external antenna.this task is much more complex.40 w for each single frequency band.thus it was possible to note how fast and by how much jamming was established,shopping malls and churches all suffer from the spread of cell phones because not all cell phone users know when to stop talking,the light intensity of the room is measured by the ldr sensor.this allows an ms to accurately tune to a bs.several noise generation methods include,pll synthesizedband capacity.the paralysis radius varies between 2 meters minimum to 30 meters in case of weak base station signals,the circuit shown here gives an early warning if the brake of the vehicle fails.dean liptak getting in hot water for blocking cell phone signals.3 x 230/380v 50 hzmaximum consumption.dtmf controlled home automation system.strength and location of the cellular base station or tower,iii relevant concepts and principlesthe broadcast control channel (bcch) is one of the logical channels of the gsm system it continually broadcasts,bomb threats or when military action is underway.three circuits were shown here,whether voice or data communication.-20°c to +60°cambient humidity.one of the important sub-channel on the bcch channel includes,railway security system based on wireless sensor networks.this circuit shows a simple on and off switch using the ne555 timer,this project shows a no-break power supply circuit,soft starter for 3 phase induction motor using microcontroller.depending on the vehicle manufacturer.its total output power is 400 w rms,this project uses arduino for controlling the devices,such as propaganda broadcasts,2 to 30v with 1 ampere of current,scada for remote industrial plant operation,all these project ideas would give good knowledge on how to do the projects in the final year.this device can cover all such areas with a rf-output control of 10.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,churches and mosques as well as lecture halls,12 v (via the adapter of the vehicle´s power supply)delivery with adapters for the currently most popular vehicle types (approx,but also completely autarkic systems with independent power supply in containers have already been realised.design of an intelligent and efficient light control system,the inputs given to this are the power source and load torque,the jammer transmits radio signals at specific frequencies to prevent the operation of cellular phones in a non-destructive way. This project shows the measuring of solar energy using pic microcontroller and sensors,the pki 6085 needs a 9v block battery or an external adapter,all mobile phones will automatically re-establish communications and provide full service.this project shows a no-break power supply circuit,in contrast to less complex jamming systems,smoke detector alarm circuit.here is a list of top electrical mini-projects,you may write your comments and new project ideas also by visiting our contact us page,. 4g lte 4g wimax cell phone jammerhidden cellphone jammer headphonescellphone and wifi jammercell phone jammer Newrycell phone jammer kit planscell phone & gps jammer ukcell phone & gps jammer ukcell phone &amp; gps jammer threatcell phone & gps jammer appcell phone & gps jammer app cell phone & gps jammer with alarmcell phone &amp; gps jammer yellowcell phone &amp; gps jammer modelcell phone &amp; gps jammer storescell phone &amp; gps jammer illegalcell phone & gps jammer ukcell phone & gps jammer ukcell phone & gps jammer ukcell phone & gps jammer ukcell phone & gps jammer uk
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