radio nếu bỗng dưng ta chán nhau

... Trang 1 RADIO_CASSETTESơ đồ khối Radio – Cassette Nội dung : Phân tích sơ đồ khối của Radio - Cassette, các biểu hiện khi hư hỏng các khối chức năng 1 Sơ đồ khối của Radio - Cassette ... trên loa, nếu có tiếng sột sột và đo thấy trở kháng báo từ 4Ω - 8Ω là loa còn tốt Trường hợp loa bị dè => thường do loa bị chạm côn, ta thử bằng cách ấn nhẹ tay lên màng loa, nếu loa bị ... thanh , cả Radio và Cassette đều mất • Hỏng đầu từ : Radio nói bình thường , cassette nói nhỏ và chỉ còn tiếng trầm , mất tiếng thanh • Hỏng tầng khuếch đại đầu từ (Head amply ) : Radio nói bình

Ngày tải lên: 16/12/2019, 11:51

... undergoing twostages of amplification The first stage, known as channel amplification is used to ensure thatthe input power level to the second stage high power amplification remains at a constant level.The ... Pb¼ Q ffiffiffiffiffiffi2Eb N0 ð5:33ÞThe value of Q(x), also known as the complementary error function, can be obtained fromstandard tables or alternatively can be approximated when x 3 using the equation: ... the received phase angle can bederived by obtaining the arctangent of the ratio of quadrature to in-phase components, fromwhich a phase angle is obtained This is then compared with the anticipated

Ngày tải lên: 14/09/2012, 11:26

... higher data rates, while maintaining GMSK for lower rates The new modulation scheme allows data rates of up to 59.2 kbps per time slot, using a combination of link adaptation and incremental redundancy ... Communications; GPRS – General Packet Radio Services; HSCSD – High Speed Circuit Switched Data, EGPRS – Enhanced GPRS; ECSD – Enhanced Circuit Switched Data; PDC – Pacific Digital Cellular; UMTS – Universal ... Variable mean lognormal C/I distribution with standard deviation of 7 dB Single - slot mobile stations Single Packet Data Channel (SPDC) dedicated to data traffic Traffic model: Poisson distribution

Ngày tải lên: 26/04/2013, 11:15

... giám sát: Có nhiều cách khác nhau để giám sát, đo đạc mạng GSM Dữ liệu chất lượng dịch vụ QoS có thể được xây dựng từ các nguồn thông tin khác nhau và bổ sung lẫn nhau như: ¾ Các bộ đếm OMC_R ... hay công cụ của Aircom Nếu cần, đo kiểm tần số bằng TEMS trong khu vực bị nhiễu để xác định cell gây nhiễu Thay đổi tần số cell phục vụ hoặc tần số cell gây nhiễu hoặc nếu có thể, giới hạn vùng ... có thể ảnh hưởng đến cảm nhận khách hàng như sau: o Không thiết lập được cuộc gọi nếu sau 3 lần nghẽn liên tục o Nếu không, thời gian thiết lập cuộc gọi bị kéo dài không như mong đợi • Tỉ lệ nghẽn

Ngày tải lên: 26/04/2013, 11:16

... crystal radio in Chapter 4 Generally crystal radios are only thought of as simple AM radios which can only pickup local broadcast stations But did you know that you can build crystal radios which ... how AM radio is broadcast, from a radio station to a receiver in your home, and how to build your own TRF or Tuned Radio Frequency AM radio receiver In Chapter 6, we will discover how FM radio ... terminals and fitted with a rotary control shaft which varies the resistance as it isrotated A metal wiping contact rests against a circularcarbon or wire wound resistance track As the wiperarm

Ngày tải lên: 17/03/2014, 17:58

... 6RCC7K11 2 Front Wheel Bars 6RCC7K12E 1 Battery Contact, + 6RCC7K13E 1 Battery Contact, – 6RCC7K14E 2 Battery Contact, + – 6RCC7K15E 1 Battery Contact, – + 6RCC7K16E 1 Transmitter Antenna 484010E ... Cover Back of Bottom Frame NOTE: Slide the contacts into the slots and then fold back the tabs on the top side to hold Trang 9Interior Tab:Bend Tab 90O,but don’t shortto motor shell Motor Gear ... ft.Obstacles such as walls, furniture, and trees will degrade the radio signal’s ability to travel through air andreduce operating range, but will never block it completely In some cases more radio

Ngày tải lên: 30/03/2014, 10:20

... data over the data lines In our application, there are multiple sets of data (three radio channels, and up to four wheel speed signals) and insufficient I/O ports to give each set its own data ... to handle data acquisition from the radio receiver It sets the eight lower bits of the digital I/O address to input and the eight upper bits to output All eight lower bits serve as data lines from ... The three blocks at the left represent incoming data from the sensors and radio receiver The data is processed if necessary and output to a data file In addition, this model outputs signals to

Ngày tải lên: 30/03/2014, 10:20

... TAG n ANTENNA LOOP ANTENNA CIRCUIT TAG 1 CIRCUIT (CHIP) TAG 1 ANTENNA LOOP TAG 1 ANTENNA CIRCUIT RWD antenna unit Tag n antenna unit ( critical constant:Bmin) x y z Z R M 2 (x 2 ,y 2 ,z 2 ) TAG ... the tag takes place (Jankowski-M & Kalita, 2008) The minimum value of magnetic induction required in the process of writing data to the Trang 10Radio Frequency Identification Fundamentals ... carried out simultaneously with multiple RFID tags In this process, the algorithms of multi-access to the radio channel are used, what provides an effective way to distinguish simultaneously between

Ngày tải lên: 21/06/2014, 11:20

... Reference time interval for a data-0 in Reader-to-Tag signaling TARI 12.5us Time interval for a data-0 in Time interval for a data-1 in Tag-to-Reader calibration Reader-to-Tag calibration Number of ... chapter we focus exclusively on it Reader Tag 1 Tag 2 Tag N Query (Q) Slot 0 Query Rep Slot 1 ID=0 Ack EPC Slot 2 Query Tag 3 Identification cycle Slot 0 Tag Identified New cycle t Packet error ... from the initial state, X 0 =N The transitions between states represent the probability to identify a certain quantity of tags t or, in other words, the probability to have (N-t) tags still unidentified

Ngày tải lên: 21/06/2014, 11:20

... latter case, tags depend on energy provided by the tag reader through its queries (Want, 2006) For this reason, active tags can have some data processing ability, while passive tags are limited ... elementary operations and replying to the reader’s queries An important issue in Radio Frequency Identification systems concerns the reading of co-located tags, that must be managed through suitable ... some advantages and disadvantages binary tree (BT) protocols have the advantage of very low tag complexity, since there is no need of implementing pseudo-random number generators within tags (except

Ngày tải lên: 21/06/2014, 11:20

... of RFID tags contained in each data set, the results are recorded and averaged with the 100 data sets 4.2 The accuracy of RFID tag population estimations To find the accuracy for RFID tag population ... different number of RFID tags is shown in Table 2 RFID Tag Optimal Frame Length 16 32 64 128 256 Table 2 Optimal Frame Length for the Identification of Different Number of RFID tags Trang 84.4 Simulation ... identification of t RFID tags 3.5 The deployment of multiple RFID readers Usually in a dense RFID tag environment, multiple RFID readers are deployed to facilitate the RFID tag identification cycle

Ngày tải lên: 21/06/2014, 11:20

... environmental conditions and using various positions for the tags Before starting the measurement session the receiver itself must be calibrated using, as recommended by the producer, an active tag ... were made in an open area, with no obstacles between the antenna system and the tags, using a tag placed at 10 meters in front of the antenna The results obtained (Figure 10) are much better than ... from one transponder takes 2.66 ms Trang 5Fig 5 Header data with one active transponder As one can see in Figure 6, a bit is transmitted every 26 microseconds Fig 6 Every bit takes about 26 µs to

Ngày tải lên: 21/06/2014, 11:20

... that key to obtain the metaID value The tag then has to compare the metaID with its current metaID value If both values match, the tag is unlocked Once the tag is in an unlocked state, it can ... identify the tag k is on its tag's ID list (i.e tag authentication) The reader will then transmit the IDk value to the tag for unlocking Once the tag is in an unlocked state, the reader can obtain its ... reserved memory (i.e a metaID value), the tag then enters into a locked state automatically To unlock the tag, the reader transmits the original key value to the tag, and the tag performs a hash function

Ngày tải lên: 21/06/2014, 11:20

... Floors Walls Entrances Interrogators Visitors Table 1 Model parameters Trang 6START GOAL START GOAL START GOAL START GOAL GOAL STA RT GOAL GOAL STA RT START GOAL Model 4 Fig 5 Types of shopping mall ... preparation stage If the two RFID passwords are the same, the RFID tag will change to the secured state When the RFID tag changes to the secured state, the user can read or write to the data in the ... interrogator RFID tag 1 password X RFID tag 2 password X RFID tag 3 password X password X (a) Common RFID Password RFID tag group1 password A RFID tag group2 password B RFID tag group3 password

Ngày tải lên: 21/06/2014, 11:20

... data are specific to individual items There are two types of active data: instance data such as serial number and date of manufacture, and temporal data such as observations, location and containment ... programs Data modelling doesn't want these "ugly" data; rather, data modelling wants data that is all made up in a nice, neat package for processing by a database So in a way, data modelling ... variable length EPC data generator i.e 64, 96, 1128, 256, 512 etc But, we have generated 64-bit data as show in table 4 Time Reading_of _Tag_1 Reading_of_Tag_2 Reading_of_Tag_3 100 FF3CD4FB8ED4FB8E

Ngày tải lên: 21/06/2014, 11:20

... an RFID tag Chapter 9 discusses active RFID tags system energy analysis as excitable linear bifurcation system In Chapter 10, several types of tag antennas which are mountable on metallic platforms ... known that metallic objects strongly affect the antenna performance by lowering the efficiency of tags Therefore tag antennas have to be designed to enable tags to be read near and on metallic objects ... combination of Wi-Fi Trang 7 VII radio and measurement capabilities for sensors and actuators that generate output as voltage, current, or digital signal Tag4M is suitable for prototyping wireless

Ngày tải lên: 21/06/2014, 14:20

... for both a data-0 and a data-1 As shown in Fig 3, in order to transmit a data-0, T H is set so that T S =Tari In order to transmit a data-1, T H is set so that 1.5·Tari ≤T S ≤2·Tari Fig 3 PIE ... Architecture of the low power C1G2 digital core Working state STRTP STDBY RX CNTRL TX Table 1 Working states of the digital core transmission In this state only the symbol detector is active ... be detected is a data-1, then we need that n data-1 >n pivot Taking from (4) the minimum number of samples for n data-0 and the maximum number of samples for n RTcal, we obtain the third constraint:

Ngày tải lên: 21/06/2014, 14:20

... geometry is shown in Fig.13 Fig 13 Standard Koch fractal dipole antenna Table 1 summarizes the standard Koch fractal dipole antenna properties with different fractal iterations at reference port ... calculated using SWR between the tag antenna and the tag input impedance: 211 The transmitted power (P EIRP) is attenuated by reader-tag distance, and the available power at the tag is: Trang 5PG P d λπ ... is added to obtain additional inductance This antenna can be easily tuned by trimming Lengths of meander trace and loading bar can be varied to obtain optimum reactance and resistance matching

Ngày tải lên: 21/06/2014, 14:20

... imaginary part of the impedance within reactance part, but not in resistance. According to all of these OCA resistance can be designed equally to the Tag resistance, formula 14. R OCA = R RC = ... signal, after rectifier stage, supplied to the subsequent circuit will be stable for establishing and mainteinance a communication between reader and Tag within a near field. 5. Tag antenna geometry ... the entire Tag, which describe the same behaviour, working at the ressonant frequency and delivering enough voltage to feed the Chip (wake-up voltage claimed by producer into datasheet is 1.4V).

Ngày tải lên: 21/06/2014, 14:20

... power The disadvantages of an active RFID TAGs are: The TAG cannot function without battery power, which limits the lifetime of the TAG The TAG is typically more expensive The TAG is physically ... Passive RFID TAG since the battery has a very high serial resistance – disconnected status 4 Active RFID TAG as a dynamic energy analysis Active RFID equivalent circuit total TAG power is a ... specialized tasks By By contrast, passive RFID TAGs do not have a power supply and must rely on the power emitted by a RFID Reader to transmit data There is an arbitration while reading TAGs (TAGs anti

Ngày tải lên: 21/06/2014, 14:20