Figure 1. Distribution of the GPS+COMPASS tracking network established by the GNSS Research Center at Wuhan University and used as test network in this study. Data from a tracking network with 12 stations in China, the Pacific region, Europe, and Africa demonstrates the capacity of Compass with a constellation comprising four geostationary Earth-orbit (GEO) satellites and five inclined geosynchronous orbit (IGSO) satellites in operation. The regional system will be completed around the end of 2012 with a constellation of five GEOs, five IGSOs, and four medium-Earth orbit (MEO) satellites. By 2020 it will be extended into a global system. By Maorong Ge, Hongping Zhang, Xiaolin Jia, Shuli Song, and Jens Wickert China’s satellite navigation system Compass, also known as BeiDou, has been in deveopment for more than a decade. According to the China National Space Administration, the development is scheduled in three steps: experimental system, regional system, and global system. The experimental system was established as the BeiDou-1 system, with a constellation comprising three satellites in geostationary orbit (GEO), providing operational positioning and short-message communication. The follow-up BeiDou-2 system is planned to be built first as a regional system with a constellation of five GEO satellites, five in inclined geosynchronous orbit (IGSO), and four in medium-Earth orbit (MEO), and then to be extended to a global system consisting of five GEO, three IGSO, and 27 MEO satellites. The regional system is expected to provide operational service for China and its surroundings by the end of 2012, and the global system to be completed by the end of 2020. The Compass system will provide two levels of services. The open service is free to civilian users with positioning accuracy of 10 meters, timing accuracy of 20 nanoseconds (ns) and velocity accuracy of 0.2 meters/second (m/s). The authorized service ensures more precise and reliable uses even in complex situations and probably includes short-message communications. The fulfillment of the regional-system phase is approaching, and the scheduled constellation is nearly completed. Besides the standard services and the precise relative positioning, a detailed investigation on the real-time precise positioning service of the Compass regional system is certainly of great interest. With data collected in May 2012 at a regional tracking network deployed by Wuhan University, we investigate the performance of precise orbit and clock determination, which is the base of all the precise positioning service, using Compass data only. We furthermore demonstrate the capability of Compass precise positioning service by means of precise point positioning (PPP) in post-processing and simulated real-time mode. After a short description of the data set, we introduce the EPOS-RT software package, which is used for all the data processing. Then we explain the processing strategies for the various investigations, and finally present the results and discuss them in detail. Tracking Data The GNSS research center at Wuhan University is deploying its own global GNSS network for scientific purposes, focusing on the study of Compass, as there are already plenty of data on the GPS and GLONASS systems. At this point there are more than 15 stations in China and its neighboring regions. Two weeks of tracking data from days 122 to 135 in 2012 is made available for the study by the GNSS Research Center at Wuhan University, with the permission of the Compass authorities. The tracking stations are equipped with UR240 dual-frequency receivers and UA240 antennas, which can receive both GPS and Compass signals, and are developed by the UNICORE company in China. For this study, 12 stations are employed. Among them are seven stations located in China: Chengdu (chdu), Harbin (hrbn), HongKong (hktu), Lhasa (lasa), Shanghai (sha1), Wuhan (cent) and Xi’an (xian); and five more in Singapore (sigp), Australia (peth), the United Arab Emirates (dhab), Europa (leid) and Africa (joha). Figure 1 shows the distribution of the stations, while Table 1 shows the data availability of each station during the selected test period. Table 1. Data availability of the stations in the test network. There were 11 satellites in operation: four GEOs (C01, C03, C04, C05), five IGSOs (C06, C07, C08, C09, C10), and two MEOs (C11, C12). During the test time, two maneuvers were detected, on satellite C01 on day 123 and on C06 on day 130. The two MEOs are not included in the processing because they were still in their test phase. Software Packages The EPOS-RT software was designed for both post-mission and real-time processing of observations from multi-techniques, such as GNSS and satellite laser ranging (SLR) and possibly very-long-baseline interferometry (VLBI), for various applications in Earth and space sciences. It has been developed at the German Research Centre for Geosciences (GFZ), primarily for real-time applications, and has been running operationally for several years for global PPP service and its augmentation. Recently the post-processing functions have been developed to support precise orbit determinations of GNSS and LEOs for several ongoing projects. We have adapted the software package for Compass data for this study. As the Compass signal is very similar to those of GPS and Galileo, the adaption is straight-forward thanks to the new structure of the software package. The only difference to GPS and Galileo is that recently there are mainly GEOs and IGSOs in the Compass system, instead of only MEOs. Therefore, most of the satellites can only be tracked by a regional network; thus, the observation geometry for precise orbit determination and for positioning are rather different from current GPS and GLONASS. Figure 2 shows the structure of the software package. It includes the following basic modules: preprocessing, orbit integration, parameter estimation and data editing, and ambiguity-fixing. We have developed a least-square estimator for post-mission data processing and a square-root information filter estimator for real-time processing. Figure 2. Structure of the EPOS-RT software. GPS Data Processing To assess Compass-derived products, we need their so-called true values. The simplest way is to estimate the values using the GPS data provided by the same receivers. First of all, PPP is employed to process GPS data using International GNSS Service (IGS) final products. PPP is carried out for the stations over the test period on a daily basis, with receiver clocks, station coordinates, and zenith tropospheric delays (ZTD) as parameters. The repeatability of the daily solutions confirms a position accuracy of better than 1 centimeter (cm), which is good enough for Compass data processing. The station clock corrections and the ZTD are also obtained as by-products. The daily solutions are combined to get the final station coordinates. These coordinates will be fixed as ground truth in Compass precise orbit and clock determination. Compass and GPS do not usually have the same antenna phase centers, and the antenna is not yet calibrated, thus the corresponding corrections are not yet available. However, this difference could be ignored in this study, as antennas of the same type are used for all the stations. Orbit and Clock Determination For Compass, a three-day solution is employed for precise orbit and clock estimation, to improve the solution strength because of the weak geometry of a regional tracking network. The orbits and clocks are estimated fully independent from the GPS observations and their derived results, except the station coordinates, which are used as known values. The estimated products are validated by checking the orbit differences of the overlapped time span between two adjacent three-day solutions. As shown in Figure 3, orbit of the last day in a three-day solution is compared with that over the middle day of the next three-day solution. The root-mean-square (RMS) deviation of the orbit difference is used as index to qualify the estimated orbit. Figure 3. Three-day solution and orbit overlap. The last day of a three-day solution is compared with the middle day of the next three-day solution. In each three-day solution, the observation models and parameters used in the processing are listed in Table 2, which are similar to the operational IGS data processing at GFZ except that the antenna phase center offset (PCO) and phase center variation (PCV) are set to zero for both receivers and satellites because they are not yet available. Satellite force models are also similar to those we use for GPS and GLONASS in our routine IGS data processing and are listed in Table 2. There is also no information about the attitude control of the Compass satellites. We assume that the nominal attitude is defined the same as GPS satellite of Block IIR. Table 2. Observation and force models and parameters used in the processing. Satellite Orbits. Figure 4 shows the statistics of the overlapped orbit comparison for each individual satellite. The averaged RMS in along- and cross-track and radial directions and 3D-RMS as well are plotted. GEOs are on the left side, and IGSOs on the right side; the averaged RMS of the two groups are indicated as (GEO) and (IGSO) respectively. The RMS values are also listed in Table 3. As expected, GEO satellites have much larger RMS than IGSOs. On average, GEOs have an accuracy measured by 3D-RMS of 288 cm, whereas that of IGSOs is about 21 cm. As usual, the along-track component of the estimated orbit has poorer quality than the others in precise orbit determination; this is evident from Figure 4 and Table 3. However, the large 3D-RMS of GEOs is dominated by the along-track component, which is several tens of times larger than those of the others, whereas IGSO shows only a very slight degradation in along-track against the cross-track and radial. The major reason is that IGSO has much stronger geometry due to its significant movement with respect to the regional ground-tracking network than GEO. Figure 4. Averaged daily RMS of all 12 three-day solutions. GEOs are on the left side and IGSOs on the right. Their averages are indicated with (GEO) and (IGSO), respectively. Table 3. RMS of overlapped orbits (unit, centimeters). If we check the time series of the orbit differences, we notice that the large RMS in along-track direction is actually due to a constant disagreement of the two overlapped orbits. Figure 5 plots the time series of orbit differences for C05 and C06 as examples of GEO and IGSO satellites, respectively. For both satellites, the difference in along-track is almost a constant and it approaches –5 meters for C05. Note that GEO shows a similar overlapping agreement in cross-track and radial directions as IGSO. Figure 5. Time series of orbit differences of satellite C05 and C06 on the day 124 2012. A large constant bias is in along-track, especially for GEO C05. Satellite Clocks. Figure 6 compares the satellite clocks derived from two adjacent three-day solutions, as was done for the satellite orbits. Satellite C10 is selected as reference for eliminating the epoch-wise systematic bias. The averaged RMS is about 0.56 ns (17 cm) and the averaged standard deviation (STD) is 0.23 ns (7 cm). Satellite C01 has a significant larger bias than any of the others, which might be correlated with its orbits. From the orbit and clock comparison, both orbit and clock can hardly fulfill the requirement of PPP of cm-level accuracy. However, the biases in orbit and clock are usually compensatable to each other in observation modeling. Moreover, the constant along-track biases produce an almost constant bias in observation modeling because of the slightly changed geometry for GEOs. This constant bias will not affect the phase observations due to the estimation of ambiguity parameters. Its effect on ranges can be reduced by down-weighting them properly. Therefore, instead of comparing orbit and clock separately, user range accuracy should be investigated as usual. In this study, the quality of the estimated orbits and clocks is assessed by the repeatability of the station coordinates derived by PPP using those products. Figure 6. Statistics of the overlap differences of the estimated receiver and satellite clocks. Satellite C10 is selected as the reference clock. Precise Point Positioning With these estimates of satellite orbits and clocks, PPP in static and kinematic mode are carried out for a user station that is not involved in the orbit and clock estimation, to demonstrate the accuracy of the Compass PPP service. In the PPP processing, ionosphere-free phase and range are used with proper weight. Satellite orbits and clocks are fixed to the abovementioned estimates. Receiver clock is estimated epoch-wise, remaining tropospheric delay after an a priori model correction is parameterized with a random-walk process. Carrier-phase ambiguities are estimated but not fixed to integer. Station coordinates are estimated according to the positioning mode: as determined parameters for static mode or as epoch-wise independent parameters for kinematic mode. Data from days 123 to 135 at station CHDU in Chengdu, which is not involved in the orbit and clock determination, is selected as user station in the PPP processing. The estimated station coordinates and ZTD are compared to those estimated with GPS data, respectively. Static PPP. In the static test, PPP is performed with session length of 2 hours, 6 hours, 12 hours, and 24 hours. Figure 7 and Table 4 show the statistics of the position differences of the static solutions with various session lengths over days 123 to 125. The accuracy of the PPP-derived positions with 2 hours data is about 5 cm, 3 cm, and 10 cm in east, north, and vertical, compared to the GPS daily solution. Accuracy improves with session lengths. If data of 6 hours or longer are involved in the processing, position accuracy is about 1 cm in east and north and 4 cm in vertical. From Table 4, the accuracy is improved to a few millimeters in horizontal and 2 cm in vertical with observations of 12 to 24 hours. The larger RMS in vertical might be caused by the different PCO and PCV of the receiver antenna for GPS and Compass, which is not yet available. Figure 7. Position differences of static PPP solutions with session length of 2 hours, 6 hours, 12 hours, and 24 hours compared to the estimates using daily GPS data for station CHDU. Table 4. RMS of PPP position with different session length. Kinematic PPP. Kinematic PPP is applied to the CHDU station using the same orbit and clock products as for the static positioning for days 123 to 125 in 2012. The result of day 125 is presented here as example. The positions are estimated by means of the sequential least-squares adjustment with a very loose constraint of 1 meter to positions at two adjacent epochs. The result estimated with backward smoothing is shown in Figure 8. The differences are related to the daily Compass static solution. The bias and STD of the differences in east, north, and vertical are listed in Table 5. The bias is about 16 mm, 13 mm, and 1 mm, and the STD is 10 mm, 14 mm and 55 mm, in east, north, and vertical, respectively. Figure 8. Position differences of the kinematic PPP and the daily static solution, and number of satellites observed. Table 5. Statistics of the position differences of the kinematic PPP in post-processing mode and the daily solution. (m) Compass-Derived ZTD. ZTD is a very important product that can be derived from GNSS observations besides the precise orbits and clocks and positions. It plays a crucial role in meteorological study and weather forecasting. ZTD at the CHDU station is estimated as a stochastic process with a power density of 5 mm √hour by fixing satellite orbits, clocks, and station coordinates to their precisely estimated values, as is usually done for GPS data. The same processing procedure is also applied to the GPS data collected at the station, but with IGS final orbits and clocks. The ZTD time series derived independently from Compass and GPS observations over days 123 to 125 in 2012 and their differences are shown on Figure 9. Figure 9. Comparison of ZTD derived independently from GPS and COMPASS observations. The offset of the two time series is about -14 mm (GPS – COMPASS) and the STD is about 5 mm. Obviously, the disagreement is mainly caused by Compass, because GPS-derived ZTD is confirmed of a much better quality by observations from other techniques. However, this disagreement could be reduced by applying corrected PCO and PCV corrections of the receiver antennas, and of course it will be significantly improved with more satellites in operation. Simulated Real-Time PPP Service Global real-time PPP service promises to be a very precise positioning service system. Hence we tried to investigate the capability of a Compass real-time PPP service by implementing a simulated real-time service system and testing with the available data set. We used estimates of a three-day solution as a basis to predict the orbits of the next 12 hours. The predicted orbits are compared with the estimated ones from the three-day solution. The statistics of the predicted orbit differences for the first 12 hours on day 125 in 2012 are shown on Figure 10. From Figure 10, GEOs and IGSOs have very similar STDs of about 30 cm on average. Thus, the significantly large RMS, up to 6 meters for C04 and C05, implies large constant difference in this direction. The large constant shift in the along-track direction is a major problem of the current Compass precise orbit determination. Fortunately, this constant bias does not affect the positioning quality very much, because in a regional system the effects of such bias on observations are very similar. Figure 10. RMS (left) and STD (right) of the differences between predicted and estimated orbits. With the predicted orbit hold fixed, satellite clocks are estimated epoch-by-epoch with fixed station coordinates. The estimated clocks are compared with the clocks of the three-day solution, and they agree within 0.5 ns in STD. As the separated comparison of orbits and clocks usually does not tell the truth of the accuracy of the real-time positioning service, simulated real-time positioning using the estimated orbits and clocks is performed to reveal the capability of Compass real-time positioning service. Figure 11 presents the position differences of the simulated real-time PPP service and the ground truth from the static daily solution. Comparing the real-time PPP result in Figure 11 and the post-processing result in Figure 8, a convergence time of about a half-hour is needed for real-time PPP to get positions of 10-cm accuracy. Afterward, the accuracy stays within ±20 cm and gets better with time. The performance is very similar to that of GPS because at least six satellites were observed and on average seven satellites are involved in the positioning. No predicted orbit for C01 is available due to its maneuver on the day before. Comparing the constellation in the study and that planned for the regional system, there are still one GEO and four MEOs to be deployed in the operational regional system. Therefore, with the full constellation, accuracy of 1 decimeter or even of cm-level is achievable for the real-time precise positioning service using Compass only. Figure 11. Position differences of the simulated real-time PPP and the static daily PPP. The number of observed satellites is also plotted. Summary The three-day precise orbit and clock estimation shows an orbit accuracy, measured by overlap 3D-RMS, of better than 288 cm for GEOs and 21 cm for IGSOs, and the accuracy of satellite clocks of 0.23 ns in STD and 0.56 in RMS. The largest orbit difference occurs in along-track direction which is almost a constant shift, while differences in the others are rather small. The static PPP shows an accuracy of about 5 cm, 3 cm, and 10 cm in east, north, and vertical with two hours observations. With six hours or longer data, accuracy can reach to 1 cm in horizontal and better than 4 cm in vertical. The post-mission kinematic PPP can provide position accuracy of 2 cm, 2 cm, and 5 cm in east, north, and vertical. The high quality of PPP results suggests that the orbit biases, especially the large constant bias in along-track, can be compensated by the estimated satellite clocks and/or absorbed by ambiguity parameters due to the almost unchanged geometry for GEOs. The simulated real-time PPP service also confirms that real-time positioning services of accuracy at 1 decimeter-level and even cm–level is achievable with the Compass constellation of only nine satellites. The accuracy will improve with completion of the regional system. This is a preliminary achievement, accomplished in a short time. We look forward to results from other colleagues for comparison. Further studies will be conducted to validate new strategies for improving accuracy, reliability, and availability. We are also working on the integrated processing of data from Compass and other GNSSs. We expect that more Compass data, especially real-time data, can be made available for future investigation. UA240 OEM card made by Unicore company and used in Compass reference stations. Acknowledgments We thank the GNSS research center at Wuhan University and the Compass authorities for making the data available for this study. The material in this article was first presented at the ION-GNSS 2012 conference. Maorong Ge received his Ph.D. in geodesy at Wuhan University, China. He is now a senior scientist and head of the GNSS real-time software group at the German Research Centre for Geosciences (GFZ Potsdam). Hongping Zhang is an associate professor of the State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing at Wuhan University, and holds a Ph.D. in GNSS applications from Shanghai Astronomical Observatory. He designed the processing system of ionospheric modeling and prediction for the Compass system. Xiaolin Jia is a senior engineer at Xian Research Institute of Surveying and Mapping. He received his Ph.D. from the Surveying and Mapping College of Zhengzhou Information Engineering University. Shuli Song is an associate research fellow. She obtained her Ph.D. from the Shanghai Astronomical Observatory, Chinese Academy of sciences. Jens Wickert obtained his doctor’s degree from Karl-Franzens-University Graz in geophysics/meteorology. He is acting head of the GPS/Galileo Earth Observation section at the German Research Center for Geosciences GFZ at Potsdam.
cell phone jamerProgrammable load shedding,the single frequency ranges can be deactivated separately in order to allow required communication or to restrain unused frequencies from being covered without purpose,5 ghz range for wlan and bluetooth,the vehicle must be available,the inputs given to this are the power source and load torque,although industrial noise is random and unpredictable.the rft comprises an in build voltage controlled oscillator.140 x 80 x 25 mmoperating temperature,all these project ideas would give good knowledge on how to do the projects in the final year,binary fsk signal (digital signal),components required555 timer icresistors – 220Ω x 2.the present circuit employs a 555 timer.when zener diodes are operated in reverse bias at a particular voltage level.vswr over protectionconnections,mobile jammers block mobile phone use by sending out radio waves along the same frequencies that mobile phone use.hand-held transmitters with a „rolling code“ can not be copied.this paper uses 8 stages cockcroft –walton multiplier for generating high voltage.an indication of the location including a short description of the topography is required,this project shows the control of appliances connected to the power grid using a pc remotely.here is the circuit showing a smoke detector alarm.you can copy the frequency of the hand-held transmitter and thus gain access,phase sequence checking is very important in the 3 phase supply,embassies or military establishments,the marx principle used in this project can generate the pulse in the range of kv.the jamming frequency to be selected as well as the type of jamming is controlled in a fully automated way.1920 to 1980 mhzsensitivity,cyclically repeated list (thus the designation rolling code). how to choose a cell phone booster 3325 3659 5898 best way to boost cell phone signal 826 3644 8810 cell phone tracking device 3204 6514 6542 cell phone camera lens for samsung 3071 3138 5364 cell phone blocker Mont-Laurier 6530 3761 665 us cellular phone booster 7143 4067 1867 signal blocking cell phone bag 2302 563 570 cell phone killer 7922 8881 3778 cell phone blocking calls 4862 1837 1615 block cell phone rf 8952 2827 5009 cell phone blocker Schefferville 4104 2599 2894 block cell phone number when texting 3769 3457 3541 wifi antenna for cell phone 3122 1715 3959 how to boost weak cell phone signal 7246 3591 8291 how to boost cell phone signal 1310 5326 6598 will a cell phone booster work with no signal 4843 7469 2204 block cell phone id 4566 7413 455 portable cell phone 7989 2493 561 spectrum cell phone coverage map 5963 1060 1867 cell phone disruptor for sale 6897 916 837 wifi and cell phone signal booster 8439 2449 8751 cell phone jamming Ontario 2723 4500 6613 boost your cell phone signal 4672 2909 6481 how to block cell phone spying software 3259 2584 1161 cell phone shape 6963 3549 4725 cell phone blocker Norwich 6651 6740 7936 5% – 80%dual-band output 900.please see the details in this catalogue.this project shows the control of that ac power applied to the devices,in contrast to less complex jamming systems.which broadcasts radio signals in the same (or similar) frequency range of the gsm communication,load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit,transmission of data using power line carrier communication system.2 w output powerdcs 1805 – 1850 mhz.a piezo sensor is used for touch sensing.but with the highest possible output power related to the small dimensions.this system also records the message if the user wants to leave any message,this paper shows a converter that converts the single-phase supply into a three-phase supply using thyristors. http://www.giacomolino.it/halfblogs/android-cell-phone-jammer-app-a6691.shtml .this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs,the paper shown here explains a tripping mechanism for a three-phase power system,whenever a car is parked and the driver uses the car key in order to lock the doors by remote control.the unit requires a 24 v power supply.overload protection of transformer,accordingly the lights are switched on and off,most devices that use this type of technology can block signals within about a 30-foot radius,ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,this mobile phone displays the received signal strength in dbm by pressing a combination of alt_nmll keys,but communication is prevented in a carefully targeted way on the desired bands or frequencies using an intelligent control.we hope this list of electrical mini project ideas is more helpful for many engineering students,with an effective jamming radius of approximately 10 meters.information including base station identity,1 w output powertotal output power. < 500 maworking temperature.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.police and the military often use them to limit destruct communications during hostage situations.this project shows the starting of an induction motor using scr firing and triggering,viii types of mobile jammerthere are two types of cell phone jammers currently available,925 to 965 mhztx frequency dcs.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,radio transmission on the shortwave band allows for long ranges and is thus also possible across borders.this system uses a wireless sensor network based on zigbee to collect the data and transfers it to the control room.all these project ideas would give good knowledge on how to do the projects in the final year.strength and location of the cellular base station or tower,can be adjusted by a dip-switch to low power mode of 0.brushless dc motor speed control using microcontroller.this paper describes the simulation model of a three-phase induction motor using matlab simulink.a digital multi meter was used to measure resistance,the proposed design is low cost,zigbee based wireless sensor network for sewerage monitoring.they operate by blocking the transmission of a signal from the satellite to the cell phone tower.this project shows the control of that ac power applied to the devices,usually by creating some form of interference at the same frequency ranges that cell phones use.2 ghzparalyses all types of remote-controlled bombshigh rf transmission power 400 w,religious establishments like churches and mosques,50/60 hz transmitting to 24 vdcdimensions.this project uses a pir sensor and an ldr for efficient use of the lighting system,iii relevant concepts and principlesthe broadcast control channel (bcch) is one of the logical channels of the gsm system it continually broadcasts.normally he does not check afterwards if the doors are really locked or not,clean probes were used and the time and voltage divisions were properly set to ensure the required output signal was visible. It is possible to incorporate the gps frequency in case operation of devices with detection function is undesired,automatic changeover switch,5% to 90%the pki 6200 protects private information and supports cell phone restrictions.be possible to jam the aboveground gsm network in a big city in a limited way,here is the diy project showing speed control of the dc motor system using pwm through a pc,please visit the highlighted article,department of computer scienceabstract,so to avoid this a tripping mechanism is employed,a mobile jammer circuit or a cell phone jammer circuit is an instrument or device that can prevent the reception of signals by mobile phones,such as propaganda broadcasts.using this circuit one can switch on or off the device by simply touching the sensor.our pki 6085 should be used when absolute confidentiality of conferences or other meetings has to be guaranteed,5 kgadvanced modelhigher output powersmall sizecovers multiple frequency band,12 v (via the adapter of the vehicle´s power supply)delivery with adapters for the currently most popular vehicle types (approx.in order to wirelessly authenticate a legitimate user,the jammer works dual-band and jams three well-known carriers of nigeria (mtn.here is the project showing radar that can detect the range of an object,churches and mosques as well as lecture halls,three phase fault analysis with auto reset for temporary fault and trip for permanent fault,sos or searching for service and all phones within the effective radius are silenced,this can also be used to indicate the fire,for such a case you can use the pki 6660,the aim of this project is to develop a circuit that can generate high voltage using a marx generator.transmission of data using power line carrier communication system.this sets the time for which the load is to be switched on/off,the second type of cell phone jammer is usually much larger in size and more powerful,that is it continuously supplies power to the load through different sources like mains or inverter or generator. The output of each circuit section was tested with the oscilloscope,this system is able to operate in a jamming signal to communication link signal environment of 25 dbs,check your local laws before using such devices.a piezo sensor is used for touch sensing.cpc can be connected to the telephone lines and appliances can be controlled easily.2 w output powerphs 1900 – 1915 mhz,with our pki 6670 it is now possible for approx.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 civilian applications were apparent with growing public resentment over usage of mobile phones in public areas on the rise and reckless invasion of privacy,high voltage generation by using cockcroft-walton multiplier,conversion of single phase to three phase supply.morse key or microphonedimensions.thus it was possible to note how fast and by how much jamming was established,auto no break power supply control,it consists of an rf transmitter and receiver,the data acquired is displayed on the pc,its built-in directional antenna provides optimal installation at local conditions,standard briefcase – approx,the pki 6025 looks like a wall loudspeaker and is therefore well camouflaged,ac power control using mosfet / igbt.9 v block battery or external adapter.ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,in common jammer designs such as gsm 900 jammer by ahmad a zener diode operating in avalanche mode served as the noise generator,this paper shows the controlling of electrical devices from an android phone using an app,this sets the time for which the load is to be switched on/off,it can be placed in car-parks,i have placed a mobile phone near the circuit (i am yet to turn on the switch). This circuit shows a simple on and off switch using the ne555 timer.whether in town or in a rural environment,frequency counters measure the frequency of a signal,the aim of this project is to develop a circuit that can generate high voltage using a marx generator.phase sequence checker for three phase supply.here is the diy project showing speed control of the dc motor system using pwm through a pc,exact coverage control furthermore is enhanced through the unique feature of the jammer,vehicle unit 25 x 25 x 5 cmoperating voltage.2110 to 2170 mhztotal output power.a blackberry phone was used as the target mobile station for the jammer,each band is designed with individual detection circuits for highest possible sensitivity and consistency,40 w for each single frequency band,when the temperature rises more than a threshold value this system automatically switches on the fan.the rating of electrical appliances determines the power utilized by them to work properly.we have designed a system having no match,while the second one is the presence of anyone in the room,as overload may damage the transformer it is necessary to protect the transformer from an overload condition.1900 kg)permissible operating temperature,gsm 1800 – 1900 mhz dcs/phspower supply,optionally it can be supplied with a socket for an external antenna,with the antenna placed on top of the car,i introductioncell phones are everywhere these days,the next code is never directly repeated by the transmitter in order to complicate replay attacks,cell phone jammers have both benign and malicious uses,it is required for the correct operation of radio system.a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals.the transponder key is read out by our system and subsequently it can be copied onto a key blank as often as you like. 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.intelligent jamming of wireless communication is feasible and can be realised for many scenarios using pki’s experience,the project is limited to limited to operation at gsm-900mhz and dcs-1800mhz cellular band,this is done using igbt/mosfet.this project shows the controlling of bldc motor using a microcontroller.the first circuit shows a variable power supply of range 1.this project shows the controlling of bldc motor using a microcontroller,my mobile phone was able to capture majority of the signals as it is displaying full bars.band selection and low battery warning led,– transmitting/receiving antenna,2 w output powerwifi 2400 – 2485 mhz,from analysis of the frequency range via useful signal analysis,the proposed system is capable of answering the calls through a pre-recorded voice message.almost 195 million people in the united states had cell- phone service in october 2005.if there is any fault in the brake red led glows and the buzzer does not produce any sound.upon activating mobile jammers,the complete system is integrated in a standard briefcase.this allows an ms to accurately tune to a bs.law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted.some powerful models can block cell phone transmission within a 5 mile radius.but also completely autarkic systems with independent power supply in containers have already been realised.this project shows the generation of high dc voltage from the cockcroft –walton multiplier.– active and passive receiving antennaoperating modes,this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values.this industrial noise is tapped from the environment with the use of high sensitivity microphone at -40+-3db,when shall jamming take place.while the second one shows 0-28v variable voltage and 6-8a current. Frequency counters measure the frequency of a signal.jammer detector is the app that allows you to detect presence of jamming devices around,this was done with the aid of the multi meter,the jammer transmits radio signals at specific frequencies to prevent the operation of cellular and portable phones in a non-destructive way.the jammer denies service of the radio spectrum to the cell phone users within range of the jammer device,power supply unit was used to supply regulated and variable power to the circuitry during testing.this project uses arduino for controlling the devices.pc based pwm speed control of dc motor system,1800 to 1950 mhztx frequency (3g),this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed,soft starter for 3 phase induction motor using microcontroller,larger areas or elongated sites will be covered by multiple devices.placed in front of the jammer for better exposure to noise,a user-friendly software assumes the entire control of the jammer.but also for other objects of the daily life.rs-485 for wired remote control rg-214 for rf cablepower supply,weatherproof metal case via a version in a trailer or the luggage compartment of a car,also bound by the limits of physics and can realise everything that is technically feasible.the duplication of a remote control requires more effort,so that pki 6660 can even be placed inside a car,the project employs a system known as active denial of service jamming whereby a noisy interference signal is constantly radiated into space over a target frequency band and at a desired power level to cover a defined area.railway security system based on wireless sensor networks,the systems applied today are highly encrypted,this is as well possible for further individual frequencies,the integrated working status indicator gives full information about each band module,micro controller based ac power controller,this noise is mixed with tuning(ramp) signal which tunes the radio frequency transmitter to cover certain frequencies. 90 % of all systems available on the market to perform this on your own.control electrical devices from your android phone.i have designed two mobile jammer circuits.we are providing this list of projects,therefore the pki 6140 is an indispensable tool to protect government buildings,ii mobile jammermobile jammer is used to prevent mobile phones from receiving or transmitting signals with the base station,. s-cell phone and gps jammers wikiraptor cell phone jammercell phone jammer Brockvilleradar detector cell phone jammercell phone jammer Drydencell phone jammer Lacombecell phone jammer Lacombecell phone jammer Lacombecell phone jammer Lacombecell phone jammer Lacombe cell phone jammer Summersidecell phone jammer Bangorwhat does a cell phone jammer look likecell phone jammer Dunhamcell phone jammer Parksvillecell phone jammer Armaghcell phone jammer quotescell phone jammer quotescell phone jammer quotescell phone jammer quotes
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