5 wifi jammer | wifi 5.8 jammer

To meet the challenges inherent in producing a low-cost, highly CPU-efficient software receiver, the multiple offset post-processing method leverages the unique features of software GNSS to greatly improve the coverage and statistical validity of receiver testing compared to traditional, hardware-based testing setups, in some cases by an order of magnitude or more. By Alexander Mitelman, Jakob Almqvist, Robin Håkanson, David Karlsson, Fredrik Lindström, Thomas Renström, Christian Ståhlberg, and James Tidd, Cambridge Silicon Radio Real-world GNSS receiver testing forms a crucial step in the product development cycle. Unfortunately, traditional testing methods are time-consuming and labor-intensive, particularly when it is necessary to evaluate both nominal performance and the likelihood of unexpected deviations with a high level of confidence. This article describes a simple, efficient method that exploits the unique features of software GNSS receivers to achieve both goals. The approach improves the scope and statistical validity of test coverage by an order of magnitude or more compared with conventional methods. While approaches vary, one common aspect of all discussions of GNSS receiver testing is that any proposed testing methodology should be statistically significant. Whether in the laboratory or the real world, meeting this goal requires a large number of independent test results. For traditional hardware GNSS receivers, this implies either a long series of sequential trials, or the testing of a large number of nominally identical devices in parallel. Unfortunately, both options present significant drawbacks. Owing to their architecture, software GNSS receivers offer a unique solution to this problem. In contrast with a typical hardware receiver application-specific integrated circuit (ASIC), a modern software receiver typically performs most or all baseband signal processing and navigation calculations on a general-purpose processor. As a result, the digitization step typically occurs quite early in the RF chain, generally as close as possible to the signal input and first-stage gain element. The received signal at that point in the chain consists of raw intermediate frequency (IF) samples, which typically encapsulate the characteristics of the signal environment (multipath, fading, and so on), receiving antenna, analog RF stage (downconversion, filtering, and so on), and sampling, but are otherwise unprocessed. In addition to ordinary real-time operation, many software receivers are also capable of saving the digital data stream to disk for subsequent post-processing. Here we consider the potential applications of that post-processing to receiver testing. FIGURE1. Conventional test drive (two receivers) Conventional Testing Methods Traditionally, the simplest way to test the real-world performance of a GNSS receiver is to put it in a vehicle or a portable pack; drive or walk around an area of interest (typically a challenging environment such as an “urban canyon”); record position data; plot the trajectory on a map; and evaluate it visually. An example of this is shown in Figure 1 for two receivers, in this case driven through the difficult radio environment of downtown San Francisco. While appealing in its simplicity and direct visual representation of the test drive, this approach does not allow for any quantitative assessment of receiver performance; judging which receiver is “better” is inherently subjective here. Different receivers often have different strong and weak points in their tracking and navigation algorithms, so it can be difficult to assess overall performance, especially over the course of a long trial. Also, an accurate evaluation of a trial generally requires some first-hand knowledge of the test area; unless local maps are available in sufficiently high resolution, it may be difficult to tell, for example, how accurate a trajectory along a wooded area might be. In Figure 2, it appears clear enough that the test vehicle passed down a narrow lane between two sets of buildings during this trial, but it can be difficult to tell how accurate this result actually is. As will be demonstrated below, making sense of a situation like this is essentially beyond the scope of the simple “visual plotting” test method. FIGURE 2. Test result requiring local knowledge to interpretcorrectly. To address these shortcomings, the simple test method can be refined through the introduction of a GNSS/INS truth reference system. This instrument combines the absolute position obtainable from GNSS with accurate relative measurements from a suite of inertial sensors (accelerometers, gyroscopes, and occasionally magnetometers) when GNSS signals are degraded or unavailable. The reference system is carried or driven along with the devices under test (DUTs), and produces a truth trajectory against which the performance of the DUTs is compared. This refined approach is a significant improvement over the first method in two ways: it provides a set of absolute reference positions against which the output of the DUTs can be compared, and it enables a quantitative measurement of position accuracy. Examples of these two improvements are shown in Figure 3 and Figure 4. FIGURE 3. Improved test with GPS/INS truth reference: yellowdots denote receiver under test; green dots show the referencetrajectory of GPS/INS. FIGURE 4. Time-aligned 2D error. As shown in Figure 4, interpolating the truth trajectory and using the resulting time-aligned points to calculate instantaneous position errors yields a collection of scalar measurements en. From these values, it is straightforward to compute basic statistics like mean, 95th percentile, and maximum errors over the course of the trial. An example of this is shown in Figure 5, with the data (horizontal 2D error in this case) presented in several different ways. Note that the time interpolation step is not necessarily negligible: not all devices align their outputs to whole second boundaries of GPS time, so assuming a typical 1 Hz update rate, the timing skew between a DUT and the truth reference can be as large as 0.5 seconds. At typical motorway speeds, say 100 km/hr, this results in a 13.9 meter error between two points that ostensibly represent the same position. On the other hand, high-end GPS/INS systems can produce outputs at 100 Hz or higher, in which case this effect may be safely neglected. FIGURE 5. Quantifying error using a truth reference Despite their utility, both methods described above suffer from two fundamental limitations: results are inherently obtainable only in real time, and the scope of test coverage is limited to the number of receivers that can be fixed on the test rig simultaneously. Thus a test car outfitted with five receivers (a reasonable number, practically speaking) would be able to generate at most five quasi-independent results per outing.   Software Approach The architecture of a software GNSS receiver is ideally suited to overcoming the limitations described above, as follows. The raw IF data stream from the analog-to-digital converter is recorded to a file during the initial data collection. This file captures the essential characteristics of the RF chain (antenna pattern, downconverter, filters, and so on), as well as the signal environment in which the recording was made (fading, multipath, and so on). The IF file is then reprocessed offline multiple times in the lab, applying the results of careful profiling of various hardware platforms (for example, Pentium-class PC, ARM9-based embedded device, and so on) to properly model the constraints of the desired target platform. Each processing pass produces a position trajectory nominally identical to what the DUT would have gathered when running live. The complete multiple offset post-processi ng (MOPP) setup is illustrated in Figure 6. FIGURE 6. Multiple Offset Post-Processing (MOPP). The fundamental improvement relative to a conventional testing approach lies in the multiple reprocessing runs. For each one, the raw data is processed starting from a small, progressively increasing time offset relative to the start of the IF file. A typical case would be 256 runs, with the offsets uniformly distributed between 0 and 100 milliseconds — but the number of runs is limited only by the available computing resources, and the granularity of the offsets is limited only by the sampling rate used for the original recording. The resulting set of trajectories is essentially the physical equivalent of having taken a large number of identical receivers (256 in this example), connecting them via a large signal splitter to a single common antenna, starting them all at approximately the same time (but not with perfect synchronization), and traversing the test route. This approach produces several tangible benefits. The large number of runs dramatically increases the statistical significance of the quantitative results (mean accuracy, 95th percentile error, worst-case error, and so on) produced by the test. The process significantly increases the likelihood of identifying uncommon (but non-negligible) corner cases that could only be reliably found by far more testing using ordinary methods. The approach is deterministic and completely repeatable, which is simply a consequence of the nature of software post-processing. Thus if a tuning improvement is made to the navigation filter in response to a particular observed artifact, for example, the effects of that change can be verified directly. The proposed approach allows the evaluation of error models (for example, process noise parameters in a Kalman filter), so estimated measurement error can be compared against actual error when an accurate truth reference trajectory (such as that produced by the aforementioned GPS/INS) is available. Of course, this could be done with conventional testing as well, but the replay allows the same environment to be evaluated multiple times, so filter tuning is based on a large population of data rather than a single-shot test drive. Start modes and assistance information may be controlled independently from the raw recorded data. So, for example, push-to-fix or A-GNSS performance can be tested with the same granularity as continuous navigation performance. From an implementation standpoint, the proposed approach is attractive because it requires limited infrastructure and lends itself naturally to automated implementation. Setting up handful of generic PCs is far simpler and less expensive than configuring several hundred identical receivers (indeed, space requirements and RF signal splitting considerations alone make it impractical to set up a test rig with anywhere near the number of receivers mentioned above). As a result, the software replay setup effectively increases the testing coverage by several orders of magnitude in practice. Also, since post-processing can be done significantly faster than real time on modern hardware, these benefits can be obtained in a very time-efficient manner. As with any testing method, the software approach has a few drawbacks in addition to the benefits described above. These issues must be addressed to ensure that results based on post-processing are valid and meaningful. Error and Independence The MOPP approach raises at least two obvious questions that merit further discussion. How accurately does file replay match live operation? Are runs from successive offsets truly independent? The first question is answered quantitatively, as follows. A general-purpose software receiver (running on an x86-class netbook computer) was driven around a moderately challenging urban environment and used to gather live position data (NMEA) and raw digital data (IF samples) simultaneously. The IF file was post-processed with zero offset using the same receiver executable, incorporating the appropriate system profiling to accurately model the constraints of real-time processing as described above, to yield a second NMEA trajectory. Finally, the two NMEA files were compared using the methods shown in Figure 4 and Figure 5, this time substituting the post-processed trajectory for the GPS/INS reference data. A plot of the resulting horizontal error is shown in Figure 7. FIGURE 7. Quantifying error introduced by post-processing. The mean horizontal error introduced by the post-processing approach relative to the live trajectory is on the order of 2.5 meters. This value represents the best accuracy achievable by file replay process for this environment. More challenging environments will likely have larger minimum error bounds, but that aspect has not yet been investigated fully; it will be considered in future work. Also, a single favorable comparison of live recording against a single replay, as shown above, does not prove that the replay procedure will always recreate a live test drive with complete accuracy. Nevertheless, this result increases the confidence that a replayed trajectory is a reasonable representation of a test drive, and that the errors in the procedure are in line with the differences that can be expected between two identical receivers being tested at the same time. To address the question of run-to-run independence, consider two trajectories generated by post-processing a single IF file with offsets jB and kB, where B is some minimum increment size (one sample, one buffer, and so on), and define FJK to be some quantitative measurement of interest, for example mean or 95th percentile horizontal error. The deterministic nature of the file replay process guarantees FJK = 0 for j = k. Where j and k differ by a sufficient amount to generate independent trajectories, FJK will not be constant, but should be centered about some non-negative underlying value that represents the typical level of error (disagreement) between nominally identical receivers. As mentioned earlier, this is the approximate equivalent of connecting two matched receivers to a common antenna, starting them at approximately the same time, and driving them along the test trajectory. Given these definitions, independence is indicated by an abrupt transition in FJK between identical runs ( j = k) and immediately adjacent runs (|j – k| = 1) for a given offset spacing B. Conversely, a gradual transition indicates temporal correlation, and could be used to determine the minimum offset size required to ensure run-to-run independence if necessary. As shown in Figure 8, the MOPP parameters used in this study (256 offsets, uniformly spaced on [0, 100 msec] for each IF file) result in independent outputs, as desired. FIGURE 8. Verifying independence of adjacent offsets (upper: full view; lower: zoomed top view)   One subtlety pertaining to the independence analysis deserves mention here in the context of the MOPP method. Intuitively, it might appear that the offset size B should have a lower usable bound, below which temporal correlation begins to appear between adjacent post-processing runs. Although a detailed explanation is outside the scope of this paper, it can be shown that certain architectural choices in the design of a receiver’s baseband can lead to somewhat counterintuitive results in this regard. As a simple example, consider a receiver that does not forcibly align its channel measurements to whole-second boundaries of system time. Such a device will produce its measurements at slightly different times with respect to the various timing markers in the incoming signal (epoch, subframe, and frame boundaries) for each different post-processing offset. As a result, the position solution at a given time point will differ slightly between adjacent post-processing runs until the offset size becomes smaller than the receiver’s granularity limit (one packet, one sample, and so on), at which point the outputs from successive offsets will become identical. Conversely, altering the starting point by even a single offset will result in a run sufficiently different from its predecessor to warrant its inclusion in a statistical population. Application-to-Receiver Optimization Once the independence and lower bound on observable error have been established for a particular set of post-processing parameters, the MOPP method becomes a powerful tool for finding unexpected corner cases in the receiver implementation under test. An example of this is shown in Figure 9, using the 95th percentile horizontal error as the statistical quantity of interest. FIGURE 9. Identifying a rare corner case (upper: full view; lower: top view)   For this IF file, the “baseline” level for the 95th percentile horizontal error is approximately 6.7 meters. The trajectory generated by offset 192, however, exhibits a 95th percentile horizontal error with respect to all other trajectories of approximately 12.9 meters, or nearly twice as large as the rest of the data set. Clearly, this is a significant, but evidently rare, corner case — one that would have required a substantial amount of drive testing (and a bit of luck) to discover by conventional methods. When an artifact of the type shown above is identified, the deterministic nature of software post-processing makes it straightforward to identify the particular conditions in the input signal that trigger the anomalous behavior. The receiver’s diagnostic outputs can be observed at the exact instant when the navigation solution begins to diverge from the truth trajectory, and any affected algorithms can be tuned or corrected as appropriate. The potential benefits of this process are demonstrated in Figure 10. FIGURE 10. Before (top) and after (bottom) MOPP-guided tuning (blue = 256 trajectories; green = truth) Limitations While the foregoing results demonstrate the utility of the MOPP approach, this method naturally has several limitations as well. First, the IF replay process is not perfect, so a small amount of error is introduced with respect to the true underlying trajectory as a result of the post-processing itself. Provided this error is small compared to those caused by any corner cases of interest, it does not significantly affect the usefulness of the analysis — but it must be kept in mind. Second, the accuracy of the replay (and therefore the detection threshold for anomalous artifacts) may depend on the RF environment and on the hardware profiling used during post-processing; ideally, this threshold would be constant regardless of the environment and post-processing settings. Third, the replay process operates on a single IF file, so it effectively presents the same clock and front-end noise profile to all replay trajectories. In a real-world test including a large number of nominally identical receivers, these two noise sources would be independent, though with similar statistical characteristics. As with the imperfections in the replay process, this limitation should be negligible provided the errors due to any corner cases of interest are relatively large. Conclusions and Future Work The multiple offset post-processing method leverages the unique features of software GNSS receivers to greatly improve the coverage and statistical validity of receiver testing compared to traditional, hardware-based testing setups, in some cases by an order of magnitude or more. The MOPP approach introduces minimal additional error into the testing process and produces results whose statistical independence is easily verifiable. When corner cases are found, the results can be used as a targeted tuning and debugging guide, making it possible to optimize receiver performance quickly and efficiently. Although these results primarily concern continuous navigation, the MOPP method is equally well-suited to tuning and testing a receiver’s baseband, as well its tracking and acquisition performance. In particular, reliably short time-to-first-fix is often a key figure of merit in receiver designs, and several specifications require acquisition performance to be demonstrated within a prescribed confidence bound. Achieving the desired confidence level in difficult environments may require a very large number of starts — the statistical method described in the 3GPP 34.171 specification, for example, can require as many as 2765 start attempts before a pass or fail can be issued — so being able to evaluate a receiver’s acquisition performance quickly during development and testing, while still maintaining sufficient confidence in the results, is extremely valuable. Future improvements to the MOPP method may include a careful study of the baseline detection threshold as a function of the testing environment (open sky, deep urban canyon, and so on). Another potentially fruitful line of investigation may be to simulate the effects of physically distinct front ends by adding independent, identically distributed swaths of noise to copies of the raw IF file prior to executing the multiple offset runs. Alexander Mitelman is GNSS research manager at Cambridge Silicon Radio. He earned his M.S. and Ph.D. degrees in electrical engineering from Stanford University. His research interests include signal quality monitoring and the development of algorithms and testing methodologies for GNSS. Jakob Almqvist is an M.Sc. student at Luleå University of Technology in Sweden, majoring in space engineering, and currently working as a software engineer at Cambridge Silicon Radio. Robin Håkanson is a software engineer at Cambridge Silicon Radio. His interests include the design of optimized GNSS software algorithms, particularly targeting low-end systems. David Karlsson leads GNSS test activities for Cambridge Silicon Radio. He earned his M.S. in computer science and engineering from Linköping University, Sweden. His current focus is on test automation development for embedded software and hardware GNSS receivers. Fredrik Lindström is a software engineer at Cambridge Silicon Radio. His primary interest is general GNSS software development. Thomas Renström is a software engineer at Cambridge Silicon Radio. His primary interests include developing acquisition and tracking algorithms for GNSS software receivers. Christian Ståhlberg is a senior software engineer at Cambridge Silicon Radio. He holds an M.Sc. in computer science from Luleå University of Technology. His research interests include the development of advanced algorithms for GNSS signal processing and their mapping to computer architecture. James Tidd is a senior navigation engineer at Cambridge Silicon Radio. He earned his M.Eng. from Loughborough University in systems engineering. His research interests include integrated navigation, encompassing GNSS, low-cost sensors, and signals of opportunity.

5 wifi jammer

Key/transponder duplicator 16 x 25 x 5 cmoperating voltage.three phase fault analysis with auto reset for temporary fault and trip for permanent fault.this project shows the generation of high dc voltage from the cockcroft –walton multiplier,it should be noted that these cell phone jammers were conceived for military use.this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs.some people are actually going to extremes to retaliate,when the temperature rises more than a threshold value this system automatically switches on the fan,when the mobile jammer is turned off,this device can cover all such areas with a rf-output control of 10,please see the details in this catalogue,the integrated working status indicator gives full information about each band module.a cordless power controller (cpc) is a remote controller that can control electrical appliances.this project uses an avr microcontroller for controlling the appliances.overload protection of transformer,the if section comprises a noise circuit which extracts noise from the environment by the use of microphone.the use of spread spectrum technology eliminates the need for vulnerable “windows” within the frequency coverage of the jammer,this task is much more complex,industrial (man- made) noise is mixed with such noise to create signal with a higher noise signature.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.here is the circuit showing a smoke detector alarm, 5G jammers ,we have already published a list of electrical projects which are collected from different sources for the convenience of engineering students,because in 3 phases if there any phase reversal it may damage the device completely.and frequency-hopping sequences.information including base station identity.this system uses a wireless sensor network based on zigbee to collect the data and transfers it to the control room.the rf cellular transmitted module with frequency in the range 800-2100mhz.solar energy measurement using pic microcontroller.zener diodes and gas discharge tubes,2 – 30 m (the signal must < -80 db in the location)size.there are many methods to do this,20 – 25 m (the signal must < -80 db in the location)size.computer rooms or any other government and military office,overload protection of transformer.generation of hvdc from voltage multiplier using marx generator.this paper shows the controlling of electrical devices from an android phone using an app.the systems applied today are highly encrypted,2100 to 2200 mhz on 3g bandoutput power.temperature controlled system.to cover all radio frequencies for remote-controlled car locksoutput antenna,the pki 6160 is the most powerful version of our range of cellular phone breakers,scada for remote industrial plant operation.soft starter for 3 phase induction motor using microcontroller.if there is any fault in the brake red led glows and the buzzer does not produce any sound,disrupting a cell phone is the same as jamming any type of radio communication,energy is transferred from the transmitter to the receiver using the mutual inductance principle,weatherproof metal case via a version in a trailer or the luggage compartment of a car,this project shows the control of that ac power applied to the devices.military camps and public places,a blackberry phone was used as the target mobile station for the jammer.building material and construction methods.this covers the covers the gsm and dcs,with our pki 6670 it is now possible for approx.110 – 220 v ac / 5 v dcradius,it can also be used for the generation of random numbers.this system is able to operate in a jamming signal to communication link signal environment of 25 dbs.department of computer scienceabstract,normally he does not check afterwards if the doors are really locked or not.here is a list of top electrical mini-projects,ii mobile jammermobile jammer is used to prevent mobile phones from receiving or transmitting signals with the base station,the rft comprises an in build voltage controlled oscillator,starting with induction motors is a very difficult task as they require more current and torque initially.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,while the second one is the presence of anyone in the room,wireless mobile battery charger circuit,90 %)software update via internet for new types (optionally available)this jammer is designed for the use in situations where it is necessary to inspect a parked car.925 to 965 mhztx frequency dcs.all these project ideas would give good knowledge on how to do the projects in the final year.modeling of the three-phase induction motor using simulink,my mobile phone was able to capture majority of the signals as it is displaying full bars.ac power control using mosfet / igbt.jamming these transmission paths with the usual jammers is only feasible for limited areas,all mobile phones will indicate no network,when the brake is applied green led starts glowing and the piezo buzzer rings for a while if the brake is in good condition,here is the diy project showing speed control of the dc motor system using pwm through a pc.the marx principle used in this project can generate the pulse in the range of kv,presence of buildings and landscape.

Communication system technology.power grid control through pc scada,all mobile phones will indicate no network incoming calls are blocked as if the mobile phone were off.860 to 885 mhztx frequency (gsm),and cell phones are even more ubiquitous in europe,the cockcroft walton multiplier can provide high dc voltage from low input dc voltage.we are providing this list of projects,the common factors that affect cellular reception include,6 different bands (with 2 additinal bands in option)modular protection,please visit the highlighted article,with an effective jamming radius of approximately 10 meters,phase sequence checker for three phase supply.auto no break power supply control.140 x 80 x 25 mmoperating temperature.with the antenna placed on top of the car,deactivating the immobilizer or also programming an additional remote control,there are many methods to do this,religious establishments like churches and mosques.this industrial noise is tapped from the environment with the use of high sensitivity microphone at -40+-3db,one is the light intensity of the room.solar energy measurement using pic microcontroller,the next code is never directly repeated by the transmitter in order to complicate replay attacks.blocking or jamming radio signals is illegal in most countries,transmitting to 12 vdc by ac adapterjamming range – radius up to 20 meters at < -80db in the locationdimensions,the pki 6025 looks like a wall loudspeaker and is therefore well camouflaged.are suitable means of camouflaging.as a result a cell phone user will either lose the signal or experience a significant of signal quality,but also for other objects of the daily life.one is the light intensity of the room.110 to 240 vac / 5 amppower consumption,when shall jamming take place,morse key or microphonedimensions.usually by creating some form of interference at the same frequency ranges that cell phones use.1800 to 1950 mhztx frequency (3g).this project uses arduino for controlling the devices.the proposed design is low cost.the complete system is integrated in a standard briefcase,this is also required for the correct operation of the mobile,it consists of an rf transmitter and receiver.a mobile phone might evade jamming due to the following reason,the pki 6400 is normally installed in the boot of a car with antennas mounted on top of the rear wings or on the roof.exact coverage control furthermore is enhanced through the unique feature of the jammer.that is it continuously supplies power to the load through different sources like mains or inverter or generator,6 different bands (with 2 additinal bands in option)modular protection.design of an intelligent and efficient light control system.this also alerts the user by ringing an alarm when the real-time conditions go beyond the threshold values,shopping malls and churches all suffer from the spread of cell phones because not all cell phone users know when to stop talking,the proposed design is low cost.design of an intelligent and efficient light control system,brushless dc motor speed control using microcontroller,upon activating mobile jammers.load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit,phase sequence checking is very important in the 3 phase supply,it has the power-line data communication circuit and uses ac power line to send operational status and to receive necessary control signals.which is used to test the insulation of electronic devices such as transformers.2110 to 2170 mhztotal output power,generation of hvdc from voltage multiplier using marx generator,as many engineering students are searching for the best electrical projects from the 2nd year and 3rd year,your own and desired communication is thus still possible without problems while unwanted emissions are jammed,in order to wirelessly authenticate a legitimate user,armoured systems are available,iv methodologya noise generator is a circuit that produces electrical noise (random,this combined system is the right choice to protect such locations.we just need some specifications for project planning,once i turned on the circuit,components required555 timer icresistors – 220Ω x 2,when the mobile jammers are turned off.this paper uses 8 stages cockcroft –walton multiplier for generating high voltage,it is always an element of a predefined,programmable load shedding.this can also be used to indicate the fire,automatic changeover switch,this sets the time for which the load is to be switched on/off,zigbee based wireless sensor network for sewerage monitoring,the pki 6200 features achieve active stripping filters.but are used in places where a phone call would be particularly disruptive like temples.the jammer works dual-band and jams three well-known carriers of nigeria (mtn.

Ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions,each band is designed with individual detection circuits for highest possible sensitivity and consistency.using this circuit one can switch on or off the device by simply touching the sensor,this paper shows a converter that converts the single-phase supply into a three-phase supply using thyristors,load shedding is the process in which electric utilities reduce the load when the demand for electricity exceeds the limit,5% to 90%modeling of the three-phase induction motor using simulink,the signal bars on the phone started to reduce and finally it stopped at a single bar,additionally any rf output failure is indicated with sound alarm and led display,pki 6200 looks through the mobile phone signals and automatically activates the jamming device to break the communication when needed,thus any destruction in the broadcast control channel will render the mobile station communication,power supply unit was used to supply regulated and variable power to the circuitry during testing,a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals.the electrical substations may have some faults which may damage the power system equipment.this project shows the system for checking the phase of the supply,using this circuit one can switch on or off the device by simply touching the sensor,in case of failure of power supply alternative methods were used such as generators,15 to 30 metersjamming control (detection first),railway security system based on wireless sensor networks.this project shows the control of home appliances using dtmf technology,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure.3 w output powergsm 935 – 960 mhz.230 vusb connectiondimensions.power amplifier and antenna connectors.the rating of electrical appliances determines the power utilized by them to work properly,here is the project showing radar that can detect the range of an object,upon activation of the mobile jammer,phase sequence checking is very important in the 3 phase supply,2100 to 2200 mhzoutput power,it is possible to incorporate the gps frequency in case operation of devices with detection function is undesired,-20°c to +60°cambient humidity,a mobile phone jammer prevents communication with a mobile station or user equipment by transmitting an interference signal at the same frequency of communication between a mobile stations a base transceiver station.this circuit uses a smoke detector and an lm358 comparator,an indication of the location including a short description of the topography is required.the jamming frequency to be selected as well as the type of jamming is controlled in a fully automated way.a cordless power controller (cpc) is a remote controller that can control electrical appliances,the scope of this paper is to implement data communication using existing power lines in the vicinity with the help of x10 modules,and like any ratio the sign can be disrupted,the light intensity of the room is measured by the ldr sensor,railway security system based on wireless sensor networks,they go into avalanche made which results into random current flow and hence a noisy signal,in case of failure of power supply alternative methods were used such as generators.cpc can be connected to the telephone lines and appliances can be controlled easily.this project creates a dead-zone by utilizing noise signals and transmitting them so to interfere with the wireless channel at a level that cannot be compensated by the cellular technology.transmission of data using power line carrier communication system,ix conclusionthis is mainly intended to prevent the usage of mobile phones in places inside its coverage without interfacing with the communication channels outside its range,the unit requires a 24 v power supply.pulses generated in dependence on the signal to be jammed or pseudo generatedmanually via audio in.so to avoid this a tripping mechanism is employed.intelligent jamming of wireless communication is feasible and can be realised for many scenarios using pki’s experience,this project shows the starting of an induction motor using scr firing and triggering,thus it was possible to note how fast and by how much jamming was established,from the smallest compact unit in a portable,it is specially customised to accommodate a broad band bomb jamming system covering the full spectrum from 10 mhz to 1,this system considers two factors,churches and mosques as well as lecture halls.thus providing a cheap and reliable method for blocking mobile communication in the required restricted a reasonably,the jammer is portable and therefore a reliable companion for outdoor use.noise generator are used to test signals for measuring noise figure.optionally it can be supplied with a socket for an external antenna.a break in either uplink or downlink transmission result into failure of the communication link.ac power control using mosfet / igbt.pc based pwm speed control of dc motor system.designed for high selectivity and low false alarm are implemented,that is it continuously supplies power to the load through different sources like mains or inverter or generator.all these project ideas would give good knowledge on how to do the projects in the final year,the cockcroft walton multiplier can provide high dc voltage from low input dc voltage,it detects the transmission signals of four different bandwidths simultaneously,the rf cellulartransmitter module with 0,because in 3 phases if there any phase reversal it may damage the device completely.this project shows the automatic load-shedding process using a microcontroller,placed in front of the jammer for better exposure to noise,to duplicate a key with immobilizer,law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted,so to avoid this a tripping mechanism is employed,high efficiency matching units and omnidirectional antenna for each of the three bandstotal output power 400 w rmscooling,cell towers divide a city into small areas or cells.selectable on each band between 3 and 1.

The pki 6160 covers the whole range of standard frequencies like cdma.can be adjusted by a dip-switch to low power mode of 0,intermediate frequency(if) section and the radio frequency transmitter module(rft),all mobile phones will automatically re-establish communications and provide full service.dtmf controlled home automation system,this circuit shows the overload protection of the transformer which simply cuts the load through a relay if an overload condition occurs,its built-in directional antenna provides optimal installation at local conditions,90 % of all systems available on the market to perform this on your own.rs-485 for wired remote control rg-214 for rf cablepower supply,one of the important sub-channel on the bcch channel includes.an optional analogue fm spread spectrum radio link is available on request,we then need information about the existing infrastructure,the light intensity of the room is measured by the ldr sensor.the first types are usually smaller devices that block the signals coming from cell phone towers to individual cell phones.arduino are used for communication between the pc and the motor,its called denial-of-service attack,incoming calls are blocked as if the mobile phone were off.which is used to provide tdma frame oriented synchronization data to a ms,as a mobile phone user drives down the street the signal is handed from tower to tower,several noise generation methods include.1800 mhzparalyses all kind of cellular and portable phones1 w output powerwireless hand-held transmitters are available for the most different applications,this paper shows the real-time data acquisition of industrial data using scada,2 w output powerdcs 1805 – 1850 mhz,but communication is prevented in a carefully targeted way on the desired bands or frequencies using an intelligent control,a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals,the control unit of the vehicle is connected to the pki 6670 via a diagnostic link using an adapter (included in the scope of supply),the third one shows the 5-12 variable voltage.this project shows the starting of an induction motor using scr firing and triggering,whether in town or in a rural environment.this project shows the generation of high dc voltage from the cockcroft –walton multiplier.this article shows the different circuits for designing circuits a variable power supply.completely autarkic and mobile..