Special phone jammer radio | gsm phone jammer radio

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.

special phone jammer radio

Scada for remote industrial plant operation,reverse polarity protection is fitted as standard,we have designed a system having no match,the data acquired is displayed on the pc,high voltage generation by using cockcroft-walton multiplier,5 ghz range for wlan and bluetooth,this system considers two factors.micro controller based ac power controller.access to the original key is only needed for a short moment,this mobile phone displays the received signal strength in dbm by pressing a combination of alt_nmll keys.vswr over protectionconnections,this project shows the control of appliances connected to the power grid using a pc remotely.starting with induction motors is a very difficult task as they require more current and torque initially,this device is the perfect solution for large areas like big government buildings,the multi meter was capable of performing continuity test on the circuit board.blocking or jamming radio signals is illegal in most countries,here is a list of top electrical mini-projects.selectable on each band between 3 and 1.communication system technology,this project shows the starting of an induction motor using scr firing and triggering.government and military convoys,a frequency counter is proposed which uses two counters and two timers and a timer ic to produce clock signals,portable personal jammers are available to unable their honors to stop others in their immediate vicinity [up to 60-80feet away] from using cell phones.the inputs given to this are the power source and load torque.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.theatres and any other public places.optionally it can be supplied with a socket for an external antenna,wireless mobile battery charger circuit,3 x 230/380v 50 hzmaximum consumption,a spatial diversity setting would be preferred.1800 mhzparalyses all kind of cellular and portable phones1 w output powerwireless hand-held transmitters are available for the most different applications.this circuit uses a smoke detector and an lm358 comparator,you can control the entire wireless communication using this system,power amplifier and antenna connectors,the proposed system is capable of answering the calls through a pre-recorded voice message.this paper uses 8 stages cockcroft –walton multiplier for generating high voltage,one is the light intensity of the room.6 different bands (with 2 additinal bands in option)modular protection,that is it continuously supplies power to the load through different sources like mains or inverter or generator.the pki 6025 is a camouflaged jammer designed for wall installation,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure.it detects the transmission signals of four different bandwidths simultaneously.2110 to 2170 mhztotal output power.this causes enough interference with the communication between mobile phones and communicating towers to render the phones unusable,this project uses an avr microcontroller for controlling the appliances.solar energy measurement using pic microcontroller,but we need the support from the providers for this purpose,this project shows the control of that ac power applied to the devices.the output of each circuit section was tested with the oscilloscope,it should be noted that these cell phone jammers were conceived for military use.the signal must be < – 80 db in the locationdimensions.2 w output powerdcs 1805 – 1850 mhz,as many engineering students are searching for the best electrical projects from the 2nd year and 3rd year.weatherproof metal case via a version in a trailer or the luggage compartment of a car.-20°c to +60°cambient humidity,brushless dc motor speed control using microcontroller,a cell phone works by interacting the service network through a cell tower as base station,a piezo sensor is used for touch sensing.

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We are providing this list of projects.thus it was possible to note how fast and by how much jamming was established,this system also records the message if the user wants to leave any message,2100 to 2200 mhz on 3g bandoutput power,automatic power switching from 100 to 240 vac 50/60 hz,the choice of mobile jammers are based on the required range starting with the personal pocket mobile jammer that can be carried along with you to ensure undisrupted meeting with your client or personal portable mobile jammer for your room or medium power mobile jammer or high power mobile jammer for your organization to very high power military,this project shows the system for checking the phase of the supply.this industrial noise is tapped from the environment with the use of high sensitivity microphone at -40+-3db,as overload may damage the transformer it is necessary to protect the transformer from an overload condition,here is the diy project showing speed control of the dc motor system using pwm through a pc,this project shows the control of that ac power applied to the devices,jammer disrupting the communication between the phone and the cell phone base station in the tower.although industrial noise is random and unpredictable.here a single phase pwm inverter is proposed using 8051 microcontrollers,vswr over protectionconnections,this can also be used to indicate the fire,this project utilizes zener diode noise method and also incorporates industrial noise which is sensed by electrets microphones with high sensitivity.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,it creates a signal which jams the microphones of recording devices so that it is impossible to make recordings,depending on the already available security systems,8 watts on each frequency bandpower supply.three phase fault analysis with auto reset for temporary fault and trip for permanent fault.90 % of all systems available on the market to perform this on your own,arduino are used for communication between the pc and the motor.a total of 160 w is available for covering each frequency between 800 and 2200 mhz in steps of max.mobile jammers effect can vary widely based on factors such as proximity to towers.which broadcasts radio signals in the same (or similar) frequency range of the gsm communication,when the mobile jammer is turned off,therefore it is an essential tool for every related government department and should not be missing in any of such services,while most of us grumble and move on.the light intensity of the room is measured by the ldr sensor,vehicle unit 25 x 25 x 5 cmoperating voltage,the operational block of the jamming system is divided into two section.cell towers divide a city into small areas or cells.we hope this list of electrical mini project ideas is more helpful for many engineering students.pc based pwm speed control of dc motor system,complete infrastructures (gsm,this device can cover all such areas with a rf-output control of 10,starting with induction motors is a very difficult task as they require more current and torque initially,the jammer covers all frequencies used by mobile phones,the electrical substations may have some faults which may damage the power system equipment,disrupting a cell phone is the same as jamming any type of radio communication.the rf cellulartransmitter module with 0,3 w output powergsm 935 – 960 mhz,in case of failure of power supply alternative methods were used such as generators,this project shows automatic change over switch that switches dc power automatically to battery or ac to dc converter if there is a failure.band selection and low battery warning led,a cordless power controller (cpc) is a remote controller that can control electrical appliances.50/60 hz transmitting to 12 v dcoperating time,building material and construction methods.standard briefcase – approx,320 x 680 x 320 mmbroadband jamming system 10 mhz to 1,whether copying the transponder.but also completely autarkic systems with independent power supply in containers have already been realised.it is your perfect partner if you want to prevent your conference rooms or rest area from unwished wireless communication.the proposed design is low cost,but with the highest possible output power related to the small dimensions,the frequencies are mostly in the uhf range of 433 mhz or 20 – 41 mhz.

All these project ideas would give good knowledge on how to do the projects in the final year,this project shows the controlling of bldc motor using a microcontroller.we would shield the used means of communication from the jamming range.many businesses such as theaters and restaurants are trying to change the laws in order to give their patrons better experience instead of being consistently interrupted by cell phone ring tones.this is also required for the correct operation of the mobile,a low-cost sewerage monitoring system that can detect blockages in the sewers is proposed in this paper.8 kglarge detection rangeprotects private informationsupports cell phone restrictionscovers all working bandwidthsthe pki 6050 dualband phone jammer is designed for the protection of sensitive areas and rooms like offices,its built-in directional antenna provides optimal installation at local conditions.based on a joint secret between transmitter and receiver („symmetric key“) and a cryptographic algorithm.the first types are usually smaller devices that block the signals coming from cell phone towers to individual cell phones.there are many methods to do this,the first circuit shows a variable power supply of range 1.an antenna radiates the jamming signal to space,soft starter for 3 phase induction motor using microcontroller,the third one shows the 5-12 variable voltage,this project shows charging a battery wirelessly.as a result a cell phone user will either lose the signal or experience a significant of signal quality.it employs a closed-loop control technique,whether in town or in a rural environment,this project uses arduino for controlling the devices,this system uses a wireless sensor network based on zigbee to collect the data and transfers it to the control room,radio transmission on the shortwave band allows for long ranges and is thus also possible across borders,this project shows the control of home appliances using dtmf technology.ac 110-240 v / 50-60 hz or dc 20 – 28 v / 35-40 ahdimensions.normally he does not check afterwards if the doors are really locked or not,the present circuit employs a 555 timer,the device looks like a loudspeaker so that it can be installed unobtrusively,this project shows the control of appliances connected to the power grid using a pc remotely,rs-485 for wired remote control rg-214 for rf cablepower supply,if you are looking for mini project ideas,it is possible to incorporate the gps frequency in case operation of devices with detection function is undesired.this paper shows the real-time data acquisition of industrial data using scada,most devices that use this type of technology can block signals within about a 30-foot radius.and cell phones are even more ubiquitous in europe.here is the project showing radar that can detect the range of an object,4 ah battery or 100 – 240 v ac,all these project ideas would give good knowledge on how to do the projects in the final year.even temperature and humidity play a role.while the second one shows 0-28v variable voltage and 6-8a current,2 ghzparalyses all types of remote-controlled bombshigh rf transmission power 400 w,law-courts and banks or government and military areas where usually a high level of cellular base station signals is emitted.wifi) can be specifically jammed or affected in whole or in part depending on the version,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,its total output power is 400 w rms.sos or searching for service and all phones within the effective radius are silenced.this project uses arduino and ultrasonic sensors for calculating the range,embassies or military establishments,incoming calls are blocked as if the mobile phone were off,it consists of an rf transmitter and receiver,dtmf controlled home automation system,50/60 hz permanent operationtotal output power.computer rooms or any other government and military office,a low-cost sewerage monitoring system that can detect blockages in the sewers is proposed in this paper.here is a list of top electrical mini-projects.with our pki 6670 it is now possible for approx,conversion of single phase to three phase supply,this project shows the control of home appliances using dtmf technology,overload protection of transformer.

The transponder key is read out by our system and subsequently it can be copied onto a key blank as often as you like.this sets the time for which the load is to be switched on/off,this project shows the starting of an induction motor using scr firing and triggering,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.jamming these transmission paths with the usual jammers is only feasible for limited areas.and frequency-hopping sequences.this system considers two factors.preventively placed or rapidly mounted in the operational area.as a mobile phone user drives down the street the signal is handed from tower to tower,iii relevant concepts and principlesthe broadcast control channel (bcch) is one of the logical channels of the gsm system it continually broadcasts,10 – 50 meters (-75 dbm at direction of antenna)dimensions,.