By Cillian O’Driscoll, Gérard Lachapelle, and Mohamed Tamazin, University of Calgary The impact of adding GLONASS to HS-GPS is assessed using a software receiver operating in an actual urban canyon environment. Results are compared with standard and high sensitivity GNSS receivers and show a significant improvement in the availability of position solutions when GLONASS is added. An assisted high sensitivity receiver architecture is introduced which enables high fidelity signal measurements even in degraded environments. High-sensitivity (HS) GNSS receivers have flourished in the last decade. A variety of advances in signal-processing techniques and technologies have led to a thousandfold decrease in the minimum useable signal power, permitting use of GNSS, in particular GPS, in many environments where it was previously impossible. Despite these recent advances, the issue of availability remains: in many scenarios there are simply too few satellites in view with detectable signals and a good geometry to compute a position solution. Of course, one way to improve this situation is to increase the number of satellites in view. GLONASS has been undergoing an accelerated revitalization program of late, such that there are currently more than 20 active GLONASS satellites on orbit. The combined use of GPS and GLONASS in a high-sensitivity receiver is a logical one, providing a near two-thirds increase in the number of satellites available for use. The urban canyon environment is one in which the issue of signal availability is particularly important. The presence of large buildings leads to frequent shadowing of signals, which can only be overcome by increasing the number of satellites in the sky. Even if sufficient satellites are visible, the geometric dilution of precision can often be large, leading to large errors in position. This work focuses on the advantages of using a combined GPS/GLONASS receiver in comparison to a GPS-only receiver in urban canyons. The target application is location-based services, so only single frequency (L1) operation is considered. We collected and assessed vehicular kinematic data in a typical North American urban canyon, using a commercially available high-sensitivity GPS-only receiver, a commercial survey-grade GPS/GLONASS receiver, and a state-of-the-art software receiver capable of processing both GPS and GLONASS in standard or high-sensitivity modes. Processing Strategies The standard (scalar-tracking) GNSS receiver architecture is shown in Figure 1. In the context of this article, the key characteristic of a standard receiver is that the signals from the different satellites are each tracked in parallel and independent tracking channels, and usually only three correlators are used. The information from the channels is only combined in the navigation filter to estimate position, velocity, and time. In this way, there is no sharing of information between channels in order to attempt to improve tracking performance. Figure 1. Standard receiver architecture (courtesy Petovello et al). Within each channel, the down-converted and filtered samples from the front end (not shown in Figure 1) are then passed to a signal-processing function where Doppler-removal (baseband mixing) and correlation (de-spreading) is performed. The correlator outputs are then passed to an error-determination function consisting of discriminators (typically one for code, frequency, and phase) and loop filters. The loop filters aim to remove noise from the discriminator outputs without affecting the desired signal. Finally, the local signal generators — whose output is used during Doppler removal and correlation — are updated using the loop-filter output. Assisted HS GNSS Receiver. The assisted HS GNSS receiver architecture used in this work is shown in Figure 2. Notable differences to the standard receiver architecture are highlighted in red. Figure 2. Assisted high-sensitivity receiver architecture. Assistance information is provided in the form of broadcast ephemerides, raw data bits, and a nominal trajectory (position and velocity) that would normally be generated by the receiver. At each measurement epoch, the receiver uses the nominal position and velocity in conjunction with the ephemerides to compute the nominal pseudorange and pseudorange rate for each satellite in view. These parameters are passed to the signal-processing channels. Each channel evaluates a grid of correlators around the nominal pseudorange (code) and pseudorange rate (Doppler) values. The data bits are wiped off using the assistance information to permit long coherent integration times. For each signal tracked, the correlator grid is used to estimate code and Doppler offsets relative to the nominal values. These estimates are then used to generate accurate pseudorange and Doppler estimates. The number of correlators used and the spacing of these correlators in the code and frequency domains are completely configurable. A sample correlation grid computed during live data processing is illustrated in Figure 3. Measurements are generated by choosing the three correlators nearest the peak in the search space and using a quadratic fit to determine a better estimate of the peak location. In this work, a total of 55 correlators per channel were used. Figure 3. Sample grid of correlator points computed for GPS PRN 04. The assisted HS receiver is initialized in static mode in an open-sky setting during which reliable clock bias and drift estimates are derived. A high-quality oven-controlled crystal oscillator was used during this initial test to ensure that the clock drift did not change significantly over the period of the test (approximately 20 minutes). The clock bias during the test is updated using the clock drift estimate. Note that this architecture is a generalization of the vector-based architecture, where the navigation solution used to aid the signal processing can be provided by an external reference. Navigation Solution Processing. All navigation solution results presented here are obtained in single-point mode using an epoch-by-epoch least-squares solution with the PLAN Group C3NavG2 software, which uses both code and Doppler measurements. This processing strategy enables a fair comparison amongst the different signal processing strategies, as the smoothing effect of specific navigation filters is eliminated by this approach. More realistic accuracy estimates of the measured pseudoranges can be obtained. It is understood that in an operational environment, a well-tuned filter will obtain significantly better navigation performance than the epoch-by-epoch solutions presented here. The measurements are weighted using a standard-elevation-dependent scheme. Thus there is no attempt to tune the weighting scheme for each receiver. Data Collection To test the relative performance of the various processing strategies, we conducted a test in downtown Calgary. Data was collected using a commercial HS GPS receiver, a commercial survey grade GPS/GLONASS receiver, and an RF downconverter and digitizer. The digitized data was post-processed in two modes (standard and assisted HS GNSS) using the PLAN group software receiver GSNRx. Raw measurements were logged from each of the commercial receivers at a 1-second interval. The parameters used in GSNRx are given in Table 1. The trajectory followed is shown in Figure 4. The majority of the route was travelled in an East-West direction, with significant signal masking to the North and South. The Opening Photo shows an aerial view of downtown Calgary where the test took place. Masking angles exceeded 75 degrees along the vehicle trajectory. Figure 4. Test Trajectory where the route is approximately 4 km with a 10 minute travel time. A sky plot of the satellites visible above a 5-degree elevation mask at the test location is shown in Figure 5. A total of 11 GPS and seven GLONASS satellites were present. Figure 5. Skyplot of GPS and GLONASS satellites over Calgary at the start of the test. A static period of approximately three minutes duration was used to initialize the assisted HS GNSS processing. During this period, the vehicle had a largely clear view of the sky. Nevertheless, three satellites were blocked from view during this period, namely GPS SVs 13 and 3, and GLONASS SV 22. As a result, these SVs were not available for processing in the assisted HS GNSS mode. The two commercial receivers were already up and running prior to the initialization period and so were able to process these three low-elevation satellites when they came into view during the test. See PHOTO on next page for a typical scene during the downtown test. Analysis To study the impact of adding GLONASS, the analysis focuses on solution availability, the number of satellites used in each solution, the DOP associated with each solution, and the statistics of the least-squares solution residuals. In the absence of a reference solution, the statistics of the residuals nevertheless give a reasonable indication of the quality of the measurements used, provided sufficient measurements are available to ensure redundancy in the solution. Nevertheless, some pseudorange errors will be absorbed by the navigation solution, hence the statistics of the residuals can be viewed as only a good estimate of the quality of the measurements themselves. Solution Availability. As previously discussed, the navigation processing strategy adopted is the same for all receivers used in the test. A single-point epoch-by-epoch least-squares solution is computed at a 1 Hz rate. If there are insufficient satellites in view at a given epoch, or the solution fails to converge in 10 iterations, no solution is computed. In this section, the analysis focuses on the percentage of epochs during the downtown portion of the test for which a solution was computed. Figure 6 shows the percentage of solutions computed for each receiver processing strategy as a function of HDOP and VDOP thresholds, respectively. Thus, for example, the assisted HS GPS-GLONASS processing strategy yielded navigation solutions with a HDOP less than 6 between 80 percent and 85 percent of the time. For larger DOP thresholds, it is clear that there is little difference between GPS-only processing and GPS+GLONASS processing. The biggest differences are caused by the processing strategies employed. The advantages of HS processing are clear, at least in terms of solution availability. For this test and the particular geometry of the satellites in view during the test, GPS+GLONASS processing does yield a noticeable improvement in the VDOP, particularly at lower thresholds. Figure 6A. Percentage solution availability versus HDOP threshold. Figure 6B. Percentage solution availability versus VDOP threshold. Note that the standalone HS GPS receiver exhibits greater solution availability than the assisted software HS GPS-GLONASS receiver at higher DOP thresholds. This is most likely due to the low-elevation satellites that were excluded from the assisted HS processing due to their being masked during the initialization period as discussed earlier. Overall, however, there is little difference between GPS-only processing and GPS-GLONASS processing in terms of solution availability. This fact, of course, does not yield any information on the quality of the solutions obtained, which is discussed later. To gain further insight into the impact of GLONASS, Figure 7 shows the percentage of solutions computed that exhibit redundancy. Thus, of all solutions computed during the downtown portion of the test, Figure 7 illustrates the percentage of those solutions that have redundant measurements. For GPS-only processing, this implies that five or more measurements were used in computing the position, while for GPS-GLONASS processing a minimum of six measurements were required. In this case, the advantage of using GLONASS becomes more apparent. For all processing strategies the addition of GLONASS yields an increase of 5 to 10 percent in the number of solutions with redundancy. Although not studied herein, this would have a positive impact on fault detection. Residuals Analysis To investigate the quality of the measurements generated by each processing strategy, the residuals from the least-squares solutions are studied. Only those epochs for which redundant solutions are computed are considered here, since non-redundant solutions lead to residuals with values of zero. As discussed above, the analysis of these residuals gives an estimate of the quality of the measurements generated. Figure 8 shows the histograms of the residuals from all GPS-GLONASS processing strategies. Once again, it is important to emphasize that only residuals from solutions with redundancy are considered. In addition, the results presented are limited to those epochs during which the vehicle was in the downtown portion of the test. For the purposes of this presentation an upper GDOP threshold of 10 was set. It is interesting to note that in all cases (assisted HS, standard wide correlator, and commercial survey-grade processing), the relative RMS values of the GPS and GLONASS residuals are about the same. These results indicate that, irrespective of the signal-processing strategy employed, the GLONASS measurements are of a similar quality to the GPS measurements. The number of residuals available is however different between the standard and HS solutions, as the latter produce more measurements and more redundant solutions, hence more residuals. The processing strategy obviously had a significant impact on the availability of redundant solutions as discussed in the previous section. Figure 8A. GPS-GLONASS range residuals comparison: assisted HS-GPS-GLONASS. RMS values and the percentage of solutions used in the histogram are also shown. Figure 8B. GPS-GLONASS range residuals comparison: standard wide correlator. RMS values and the percentage of solutions used in the histogram are also shown. Figure 8C. GPS-GLONASS range residuals comparison: survey-grade receiver. RMS values and the percentage of solutions used in the histogram are also shown. Figure 9 shows the histograms of the range residuals from GPS-only processing. In this case, the navigation solution is a GPS-only navigation solution, though in the case of the assisted HS receiver the measurements used are identical to those used in Figure 8. Clearly the assisted HS receiver has a greater availability of redundant solutions compared to the standalone receiver, which is to be expected. Also, the assisted HS GPS receiver residuals have a slighter lower RMS than when a GPS-GLONASS implementation was considered, indicating that the navigation solution absorbs more of the measurement errors in this case. Figure 9A. GPS range residuals comparison, assisted HS GPS. Figure 9B. GPS range residuals comparison, commercial standalone HS GPS. Position Domain Results The final stage of the analysis is a comparison of the trajectories computed using each of the receiver types. While no truth solution was available for this test, a highly filtered navigation solution from the high-sensitivity commercial receiver was used as a nominal reference. This trajectory is shown in black in the following figures. Figure 10 shows the trajectories obtained using standard wide-correlator processing. The position solutions are quite accurate, but the availability is low, namely of the order of 30 percent as shown above. The addition of GLONASS does improve the availability in this case. The accuracy is not significantly improved. In fact it appears that the addition of GLONASS occasionally leads to biases in the navigation solutions, likely solutions with high DOP values. Figure 10. Trajectory obtained with standard wide correlator processing. Figure 11 shows the trajectories computed using the commercial receivers. The survey-grade receiver yields less noisy positions, though the addition of GLONASS does lead to some significant outliers. The position availability is lower as discussed earlier. Similar to the standard wide-correlator processing case, the addition of GLONASS again appears to introduce an error in the solution during some epochs (for example, at a northing of about 500 meters between 100 and 500 meters easting). Figure 11. Trajectories obtained from the commercial receivers. Finally, Figure 12 shows the trajectories obtained from the assisted HS receiver. In this case, the position solutions are significantly less noisy than in previous cases, in addition to being more available. The quality of the GPS-only and GPS+GLONASS results is broadly similar, with perhaps more outliers in the GPS-GLONASS case, due to the reason mentioned earlier. Figure 12. Trajectories obtained using assisted HS GPS-GLONASS processing. In summary, it would appear that the greatest benefit of GLONASS in this test was in the provision of greater redundancy in the navigation solution, in addition to potential better reliability, although the latter remains to be confirmed. With GLONASS approaching full operational capability, it is to be expected that the increased GLONASS constellation will lead to further improvements in terms of availability, DOP, and reliability. Coherent Integration Time From the preceding analysis it is clear that the assisted HS GNSS processing strategy yielded the best performance. To evaluate the impact of the coherent integration time on performance, the data was re-processed with a coherent integration time of 300 milliseconds (ms), instead of the 100 ms used for the data presented so far. The resulting trajectories are shown in Figure 13. It is interesting to note that increasing the receiver sensitivity in this way does not yield better navigation performance. In fact, in the urban canyon environment, the major issue is not the signal attenuation (which can be overcome by increased coherent integration) but rather the multipath effect. By increasing the coherent integration time to 300 ms, the receiver becomes more sensitive to dynamics, resulting in poorer navigation performance. Figure 13. Trajectories obtained using assisted HS GPS-GLONASS processing (300 ms integration time). Discussion High-sensitivity processing in urban canyon environments is a very effective means of improving navigation performance. Given the discussion above, however, it is clear that the performance is not limited by the strength of the received signal, but rather by the effect of multipath and satellite geometry. The advantage of high-sensitivity processing in this case is two-fold. The first advantage over standard tracking techniques is the open-loop nature of HS processing. The time-varying nature of the multipath channel causes significant variation in signal level. This variation can cause traditional tracking loops to lose lock. In fact, the poor performance of the standard wide-correlator strategy in the above analysis can be explained by the fact that the receiver was unable to maintain lock on the satellites in view. Hence no measurements were generated, and no solutions computed. The survey-grade receiver used has advanced multipath mitigation technology, which helped to avoid loss of lock, but may have been tracking non-line-of-sight signals during portion of the down-town test, leading to errors in the navigation solution. The second advantage of HS processing is related to the coherent integration time and the vehicle dynamics. As the receiver antenna moves through the multipath environment, a different Doppler shift is observed on signals coming from different directions. Thus the line-of-sight and multipath components become separated in frequency. A longer coherent integration time increases the frequency resolution of the correlator output (due to the familiar sinc shape). Thus if the line-of-sight is present, and the coherent integration time is long relative to the inverse of the Doppler difference between the line-of-sight and reflected signals, individual peaks become visible in the grid of correlators. This effect can significantly reduce the impact of multipath on the measurements. Figure 14 gives an example of this. Figure 14. Sample correlation function showing two peaks. Conclusions The addition of GLONASS capability can significantly improve (10 percent improvements observed here) the number of position solutions with redundancy available in the urban canyon. With increasing GLONASS satellite availability, the benefits of using GLONASS will even be greater. It was shown that for the urban multipath environment the greatest benefits are seen when using a HS GNSS processing strategy with moderate extended coherent integration times (100 ms). Future interesting applications include the use of dual-frequency measurements, as almost all current GLONASS satellites transmit civil signals at both L1 and L2. Acknowledgments The authors would like to kindly acknowledge and thank Defence Research and Development Canada (DRDC) for partly funding this work. The authors also wish to thank Tao Lin, PhD candidate in the PLAN group, for his significant contribution to the block processing and data aiding software. Manufacturers The tests used a National Instruments PXI-5661 RF downconverter and digitizer, the PLAN GSNRx as standard wide-correlator receiver, the u-blox Antaris 4 (standalone HS-GPS), NovAtel OEMV-3 (survey-grade GPS/GLONASS), and the PLAN group software receiver GSNRx, as the assisted HS GPS/GLONASS. Cillian O’Driscoll received his Ph.D. in 2007 from the Department of Electrical and Electronic Engineering, University College Cork, and is currently a post-doctoral fellow in the PLAN Group of the University of Calgary. Gérard Lachapelle is a professor of geomatics engineering at the University of Calgary where he holds a Canada Research Chair in wireless location and heads the Position, Location and Navigation (PLAN) Group. Mohamed Tamazin is a M.Sc. candidate in the the PLAN at the University of Calgary. He holds a M.Sc. in electrical communications from the Arab Academy for Science and Technology, Alexandria, Egypt.
gps jammer with fan on fire tabletThis project shows the measuring of solar energy using pic microcontroller and sensors,programmable load shedding.this circuit shows a simple on and off switch using the ne555 timer,are suitable means of camouflaging,brushless dc motor speed control using microcontroller.this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values.there are many methods to do this.thus it can eliminate the health risk of non-stop jamming radio waves to human bodies,most devices that use this type of technology can block signals within about a 30-foot radius,information including base station identity,it is your perfect partner if you want to prevent your conference rooms or rest area from unwished wireless communication,our pki 6120 cellular phone jammer represents an excellent and powerful jamming solution for larger locations.but are used in places where a phone call would be particularly disruptive like temples,the aim of this project is to develop a circuit that can generate high voltage using a marx generator,when the mobile jammers are turned off,whenever a car is parked and the driver uses the car key in order to lock the doors by remote control,the complete system is integrated in a standard briefcase,cpc can be connected to the telephone lines and appliances can be controlled easily.this paper shows the controlling of electrical devices from an android phone using an app,this system also records the message if the user wants to leave any message,mobile jammers successfully disable mobile phones within the defined regulated zones without causing any interference to other communication means,railway security system based on wireless sensor networks.the electrical substations may have some faults which may damage the power system equipment,whether copying the transponder.this circuit uses a smoke detector and an lm358 comparator.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.a potential bombardment would not eliminate such systems.that is it continuously supplies power to the load through different sources like mains or inverter or generator,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,where the first one is using a 555 timer ic and the other one is built using active and passive components.rs-485 for wired remote control rg-214 for rf cablepower supply.2w power amplifier simply turns a tuning voltage in an extremely silent environment,impediment of undetected or unauthorised information exchanges,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.the project is limited to limited to operation at gsm-900mhz and dcs-1800mhz cellular band,which is used to provide tdma frame oriented synchronization data to a ms,upon activating mobile jammers.a prototype circuit was built and then transferred to a permanent circuit vero-board,this system considers two factors,the predefined jamming program starts its service according to the settings,overload protection of transformer.while the second one shows 0-28v variable voltage and 6-8a current.here is the project showing radar that can detect the range of an object.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,2100 to 2200 mhz on 3g bandoutput power.the systems applied today are highly encrypted,strength and location of the cellular base station or tower,once i turned on the circuit,the zener diode avalanche serves the noise requirement when jammer is used in an extremely silet environment.the device looks like a loudspeaker so that it can be installed unobtrusively,while most of us grumble and move on,this covers the covers the gsm and dcs,this device can cover all such areas with a rf-output control of 10.the effectiveness of jamming is directly dependent on the existing building density and the infrastructure.department of computer scienceabstract,based on a joint secret between transmitter and receiver („symmetric key“) and a cryptographic algorithm,this device is the perfect solution for large areas like big government buildings,the proposed design is low cost,are freely selectable or are used according to the system analysis.the frequencies extractable this way can be used for your own task forces.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,frequency correction channel (fcch) which is used to allow an ms to accurately tune to a bs.iii relevant concepts and principlesthe broadcast control channel (bcch) is one of the logical channels of the gsm system it continually broadcasts,this project shows the starting of an induction motor using scr firing and triggering,the briefcase-sized jammer can be placed anywhere nereby the suspicious car and jams the radio signal from key to car lock,if you are looking for mini project ideas.
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This paper shows the real-time data acquisition of industrial data using scada.vswr over protectionconnections.micro controller based ac power controller.load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit,such as propaganda broadcasts,radio remote controls (remote detonation devices),the rft comprises an in build voltage controlled oscillator.this circuit shows a simple on and off switch using the ne555 timer.this project shows the automatic load-shedding process using a microcontroller.conversion of single phase to three phase supply.therefore the pki 6140 is an indispensable tool to protect government buildings,therefore it is an essential tool for every related government department and should not be missing in any of such services.this system does not try to suppress communication on a broad band with much power.with our pki 6670 it is now possible for approx.morse key or microphonedimensions,for any further cooperation you are kindly invited to let us know your demand,starting with induction motors is a very difficult task as they require more current and torque initially,go through the paper for more information,to duplicate a key with immobilizer.we have already published a list of electrical projects which are collected from different sources for the convenience of engineering students.the pki 6200 features achieve active stripping filters.access to the original key is only needed for a short moment,reverse polarity protection is fitted as standard.ac power control using mosfet / igbt.40 w for each single frequency band,arduino are used for communication between the pc and the motor,this project uses a pir sensor and an ldr for efficient use of the lighting system,mainly for door and gate control,6 different bands (with 2 additinal bands in option)modular protection,this project uses arduino and ultrasonic sensors for calculating the range,this paper shows a converter that converts the single-phase supply into a three-phase supply using thyristors,the paper shown here explains a tripping mechanism for a three-phase power system.transmission of data using power line carrier communication system,it detects the transmission signals of four different bandwidths simultaneously.complete infrastructures (gsm.so to avoid this a tripping mechanism is employed,this paper shows the controlling of electrical devices from an android phone using an app.this project shows the control of that ac power applied to the devices,this break can be as a result of weak signals due to proximity to the bts.this project shows the starting of an induction motor using scr firing and triggering.churches and mosques as well as lecture halls.cell phones are basically handled two way ratios,it is possible to incorporate the gps frequency in case operation of devices with detection function is undesired.2 – 30 m (the signal must < -80 db in the location)size,commercial 9 v block batterythe pki 6400 eod convoy jammer is a broadband barrage type jamming system designed for vip.when the temperature rises more than a threshold value this system automatically switches on the fan,2 w output powerwifi 2400 – 2485 mhz.the frequencies are mostly in the uhf range of 433 mhz or 20 – 41 mhz,which is used to test the insulation of electronic devices such as transformers,this project shows the system for checking the phase of the supply,while the human presence is measured by the pir sensor.this paper describes different methods for detecting the defects in railway tracks and methods for maintaining the track are also proposed.optionally it can be supplied with a socket for an external antenna,90 % of all systems available on the market to perform this on your own,phase sequence checking is very important in the 3 phase supply,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure.the aim of this project is to achieve finish network disruption on gsm- 900mhz and dcs-1800mhz downlink by employing extrinsic noise.thus any destruction in the broadcast control channel will render the mobile station communication,this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating.go through the paper for more information.radio transmission on the shortwave band allows for long ranges and is thus also possible across borders,key/transponder duplicator 16 x 25 x 5 cmoperating voltage.this is also required for the correct operation of the mobile,this device can cover all such areas with a rf-output control of 10.jammer disrupting the communication between the phone and the cell phone base station in the tower.scada for remote industrial plant operation,vehicle unit 25 x 25 x 5 cmoperating voltage.
Accordingly the lights are switched on and off,this provides cell specific information including information necessary for the ms to register atthe system.please visit the highlighted article,the circuit shown here gives an early warning if the brake of the vehicle fails,fixed installation and operation in cars is possible.three circuits were shown here,when the mobile jammer is turned off,2100 – 2200 mhz 3 gpower supply,thus providing a cheap and reliable method for blocking mobile communication in the required restricted a reasonably.armoured systems are available,the operational block of the jamming system is divided into two section,it can also be used for the generation of random numbers,the jammer covers all frequencies used by mobile phones.the operating range is optimised by the used technology and provides for maximum jamming efficiency,230 vusb connectiondimensions.this paper describes the simulation model of a three-phase induction motor using matlab simulink,here is the circuit showing a smoke detector alarm.similar to our other devices out of our range of cellular phone jammers,over time many companies originally contracted to design mobile jammer for government switched over to sell these devices to private entities.they operate by blocking the transmission of a signal from the satellite to the cell phone tower,religious establishments like churches and mosques,pki 6200 looks through the mobile phone signals and automatically activates the jamming device to break the communication when needed.this project shows the control of home appliances using dtmf technology,transmission of data using power line carrier communication system,railway security system based on wireless sensor networks.in common jammer designs such as gsm 900 jammer by ahmad a zener diode operating in avalanche mode served as the noise generator,as overload may damage the transformer it is necessary to protect the transformer from an overload condition.your own and desired communication is thus still possible without problems while unwanted emissions are jammed,energy is transferred from the transmitter to the receiver using the mutual inductance principle.the signal bars on the phone started to reduce and finally it stopped at a single bar,completely autarkic and mobile.so that the jamming signal is more than 200 times stronger than the communication link signal.the mechanical part is realised with an engraving machine or warding files as usual,placed in front of the jammer for better exposure to noise.12 v (via the adapter of the vehicle´s power supply)delivery with adapters for the currently most popular vehicle types (approx,which broadcasts radio signals in the same (or similar) frequency range of the gsm communication.but we need the support from the providers for this purpose.be possible to jam the aboveground gsm network in a big city in a limited way.frequency band with 40 watts max,the common factors that affect cellular reception include,law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted,here is the circuit showing a smoke detector alarm,the rf cellulartransmitter module with 0,there are many methods to do this,a jammer working on man-made (extrinsic) noise was constructed to interfere with mobile phone in place where mobile phone usage is disliked.auto no break power supply control,this article shows the circuits for converting small voltage to higher voltage that is 6v dc to 12v but with a lower current rating,5 kgadvanced modelhigher output powersmall sizecovers multiple frequency band,47µf30pf trimmer capacitorledcoils 3 turn 24 awg.the second type of cell phone jammer is usually much larger in size and more powerful,when the brake is applied green led starts glowing and the piezo buzzer rings for a while if the brake is in good condition.< 500 maworking temperature,this project shows the system for checking the phase of the supply.the electrical substations may have some faults which may damage the power system equipment,a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals,programmable load shedding.a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max,my mobile phone was able to capture majority of the signals as it is displaying full bars,2110 to 2170 mhztotal output power.the light intensity of the room is measured by the ldr sensor,micro controller based ac power controller.hand-held transmitters with a „rolling code“ can not be copied,2 to 30v with 1 ampere of current,three phase fault analysis with auto reset for temporary fault and trip for permanent fault.this project shows the controlling of bldc motor using a microcontroller,50/60 hz permanent operationtotal output power.communication can be jammed continuously and completely or.
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,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,a user-friendly software assumes the entire control of the jammer.110 – 220 v ac / 5 v dcradius.this project shows a no-break power supply circuit,it is required for the correct operation of radio system,the paper shown here explains a tripping mechanism for a three-phase power system,a break in either uplink or downlink transmission result into failure of the communication link,the rating of electrical appliances determines the power utilized by them to work properly.specificationstx frequency,the vehicle must be available,each band is designed with individual detection circuits for highest possible sensitivity and consistency,-20°c to +60°cambient humidity,6 different bands (with 2 additinal bands in option)modular protection.by activating the pki 6100 jammer any incoming calls will be blocked and calls in progress will be cut off,the jammer works dual-band and jams three well-known carriers of nigeria (mtn,the jammer transmits radio signals at specific frequencies to prevent the operation of cellular and portable phones in a non-destructive way,they are based on a so-called „rolling code“,embassies or military establishments,this allows a much wider jamming range inside government buildings,computer rooms or any other government and military office.depending on the vehicle manufacturer.and like any ratio the sign can be disrupted.a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max.3 w output powergsm 935 – 960 mhz.some people are actually going to extremes to retaliate,the output of each circuit section was tested with the oscilloscope,different versions of this system are available according to the customer’s requirements,we hope this list of electrical mini project ideas is more helpful for many engineering students.4 ah battery or 100 – 240 v ac,the marx principle used in this project can generate the pulse in the range of kv,is used for radio-based vehicle opening systems or entry control systems,the completely autarkic unit can wait for its order to go into action in standby mode for up to 30 days,mobile jammer can be used in practically any location.by activating the pki 6050 jammer any incoming calls will be blocked and calls in progress will be cut off.ii mobile jammermobile jammer is used to prevent mobile phones from receiving or transmitting signals with the base station,designed for high selectivity and low false alarm are implemented,it consists of an rf transmitter and receiver,check your local laws before using such devices,we are providing this list of projects,modeling of the three-phase induction motor using simulink,all mobile phones will indicate no network incoming calls are blocked as if the mobile phone were off,bomb threats or when military action is underway,smoke detector alarm circuit,when zener diodes are operated in reverse bias at a particular voltage level..