Engineering, Polytechnic and Vocational Training Equipment-> Dynamic Demonstrators

[1]   Click to Enlarge Colour Television Dynamic Demonstration. Model CTV-1 Technical Specifications: I. CCIR Standards : Lines : 625 Picture IF : 38.90 MHz Sound IF : 33.40 MHz Video Bandwidth : 6 MHz Inter carrier sound IF : 5.5 MHz Channels : Band I : 1,3 and 4 Band III : 5 to 12 Aspect Ratio : 4:3 Type of Modulation : Negative Picture : Amplitude modulation. Sound : Frequency modulation. II. No.of Stages: 1. Power supply (SOPS type) 2. Carrier IF with Hyper band Electronic Tuner 3. Sound IF 4. Sound Output 5. Video Processor 6. EHT Unit 7. Video Output 8. Sync Separate: Video Indent: (1) Separate vertical and horizontal signals. (2) Using for mute. 9. Vertical Section: Generate Ramp 50 Hz. Generate Blanking for Blank the Retrace lines. 10. Color Section: Crystal Oscillation:- Color system : 4.43 MHz. Pal. Method of Demodulation : Phase shift 90? and 180? Demodulation as : R - Y and B - Y signals Luminance: : Y amp. 11. Video Output as: 1. Red 2. Green 3. Blue. 12. BCL or ABL section: Automatic bright level. This section adjusting focuses and beam lines. III. Types of circuits used: PUPC Microprocessor : ST (4A - ST) EPROM : 24CO2 Vision IF IC : TA 7680 Sound IF IC : TA 7680 Sound Output IC : TDA 2611 Video Processor : TA 7698 Vertical Output : Push pull type with Transistor A940 Transistor C2078 Color Demodulate : Delay Line PF Type Crystal : 4.43 MHz IV Power supply : Mains transformer type V Picture Tube : 20? Color Fault Creating Points : 26 fault creating switches provided with LED indication at fault sections. VI Cabinet : Metal cabinet. Control panel and picture tube are Connected through cable. Size : 60 cm (H) x 60 cm(W) x 15 cm(D) Weight : 8 Kg (approx.) Fault Creating Points at Various Stages. 1. AFT DETECTOR AFT SWITCH. 2. AGC CIRCUIT GAIN CONTROL. 3. SOUND IF 5.5 MHz. MUTE. 4. AUDIO AMP. AF SIGNAL 5. VIDEO AMPLIFIER BUFFER 6. VIDEO AMPLIFIER BLANKING. 7. SYNC SEPARATOR TOTAL SYNC. 8. VERTICAL SYNC. VERTICAL SYNCHRONIZING. 9. VERTICAL OSCILLATOR HEIGHT CONTROL 10. VERTICAL OSCILLATOR LINEARITY CONT. 11. VERTICAL OSCILLATOR RAMP GENERATOR 12. VERTICAL OUTPUT BLANKING. 13. VERTICAL OUTPUT INVERTER. 14. VERTICAL OUTPUT VERTICAL FAILURE. 15. HORIZONTAL SYNC. COINCIDENCE 16. WITH OSCILLATOR. DETECTOR. 17. HORIZONTAL OUTPUT INVERTER. 18. HORIZONTAL OUTPUT HORIZONTAL FAILURE. 19. LUMINANCE Y-AMP. 20. LUMINANCE CONTROL CIRCUIT. 21. CHROMINANCE ACC DETECTOR. 22. CHROMINANCE KILLER DETECTOR. 23. CHROMINANCE SATURATION CONTROL. 24. PEAK AMPLIFIER RED-Y-OUT. 25. PEAK AMPLIFIER GREEN-Y-OUT 26. PEAK AMPLIFIER BLUE-Y-OUT. 27. 4.43 MHz. OSCILLATOR CHROMO DEMODULATOR. See Enlarge Click to Enlarge CLOSE CIRCUIT TELEVISON TRAINER. MODEL IBL-CCTV-1 This trainer is intended to demonstrate how a CCTV works. This trainer has 4 cameras with electronic shutters. Picture from each camera can be viewed on a 14? monitor. The picture from each camera can be switch selected to view the captured image from each camera. Each camera is fixed and can be fixed at any predefined angle for image capture. Optionally PAN and TILT can be provided. Maximum distance of monitor from the camera is 100feet. The system consists of 1) 4 cameras with fixed aperture, 2) 14? B/W monitor, 3) 8 channel switcher, 4) 50 meters single Co-Axial cable, which you have to splice and join during installation. See Enlarge Click to Enlarge AM RADIO RECIEVER DEMOSTRATOR. MODEL IBL-RRD-1 The main purpose of a radio receiver is to intercept and decode the radio waves. All radio receivers MUST contain at least these, 1.Antenna system, 2.Tuned circuit, 3.Detector 4.Transducer When the sound signal is mixed with the carrier frequency then the frequency of the carrier wave remains the same but the amplitude of the carrier changes with the amplitude of the signal. In this case when the amplitude of the carrier waves changes with the amplitude of the sound signals, then the modulation is said to be the Amplitude Modulation or AM. This type of amplitude modulation is characterized by a lot of disturbance and noise. Consequently, the quality and clarity of the transmitted sound is not quite good. When these AM signal is received on the radio receivers then the quality of the sound reproduced also remains poor. The main objective of the Super heterodyne receiver is to produce an intermediate frequency (IF) by the process of heterodyne or beating. This can be accomplished when two frequencies are mixed to produce the beat frequency .In superhets, the IF is usually 455 kHz which is selected because the broadcast band begins above that frequency. So if we imagine a situation when the RF amplifier is tuned to receive a 800KHz broadcast signal the local oscillator must be tuned to 1255 kHz which will result in an IF of 455KHz(1255-800 kHz). Since we have to tune the RF amplifier section throughout the entire broadcast band, the frequency of the local oscillator must also vary in a manner that it always maintains a gap of 455kHz. To achieve this condition, the local oscillator and the RF amplifier section are ?ganged ?, i.e., their tuning condensers are connected /ganged mechanically in such a way that when we tune the variable capacitor in the RF section, the variable capacitor in the local oscillator also changes its value it ?tracks? the frequency to which the ?aerial circuit ?is tuned and remain separated from the tuned frequency by 455kHz up. The intermediate frequency (IF), which is considerably low frequency is being used, because it is a suitable The demonstrator has several test points for observations. Using these test points, waveforms of incoming signals can be observed using a high frequency oscilloscope. The test points brought out for observations are: Modulated RF waveform Output of the mixer stage RF amplifier stage Second intermediate frequency stage Detector stage Input of the Power amplifier stage See Enlarge Click to Enlarge FM RADIO RECEIVER DEMONSTRATOR. MODEL IBL-RRD-2 Frequency Modulation: Frequency modulation is specially known for its good clarity of sound. When the sound signal and the carrier waves mixed in such manner that the amplitude of the carrier waves remains unchanged but its frequency changes with the amplitude of he sound signal then this type of modulation is called the frequency modulation or more commonly as FM. The rate at which the frequency of the carrier waves changes depends on the frequency of he sound signal. Thus the frequency of the carrier waves depends on both the amplitude and the frequency of the sound signal in this type of frequency modulation. Clarity of transmitted sound signal and low noise is the benefit of the frequency modulation technique. It is necessary to keep the frequency of the carrier waves at a very high level in the FM transmission. The FM range for radio broadcast is from 88MHz-108MHz. In FM the total transmitted power always remains constant and useful. Frequency Modulation is a non-linear modulation process. Consequently the spectrum of a FM wave is not related in a simple manner to that of the modulating wave. Several Test points are available for waveform observations. They are Modulated RF waveform Intermediate Frequency signal of the FM i.e. 100.7MHz Discriminator output Oscillator signal Amplified output of the oscillator Pure AF signal The final output of the whole circuit. See Enlarge Click to Enlarge CORDLESS TELEPHONE DEMONSTRATOR. MODEL IBL-CDLT-1 The Cordless Telephone supplied here is only a demonstrator. The front panel of the kit has the following a) Charge/Line Indicator b) Supply ON/OFF Switch c) Telephone Line Adapter The Charge / Line Indicator will glow when the kit is in function. Also the LED glows if charging is done. The kit can be switched ON or OFF by the supply switch. The telephone line is connected to the jack provided. The Cordless Telephone operates at a frequency that may cause interference to nearby TVs and VCRs; the base unit should be placed near or the top of the TV or VCR and, if interference is experienced, moving the Cordless Telephone farther away from the TV and VCR will often reduce or eliminate the interference. See Enlarge Click to Enlarge TAPE RECORDER TRAINER. MODEL IBL-TRD-2 The magnetic tape-recording works on the principle of storing sound signals by magnetizing the ferromagnetic tape in proportion to audio signals. The tape is moved through a magnetic field produced in a small gap of the recording head when audio signals are applied. As a result, the ferromagnetic coating of the tape gets magnetized in proportion to the intensity and polarity of the magnetizing field. The tape moves past the recording head-gap at a uniform speed and presents a clean unrecorded medium across the recording head-gap on which information is recorded instant by instant. During replay, the recorded tape is passed across the replay head-gap at the same speed and direction as used in recording. Some of the magnetic flux lines from the elemental magnets in the tape pass around the laminations of the replay-head as these tiny magnets pass across the gap, because the core of the head provides a low reluctance path as compared to the air gap. Since different sections of tape have different magnetization's, the magnetic field in the core of the replay-head will be continuously changing, causing an induced e.m.f. in the replay-coil wound on the core of the head. This e.m.f. is proportional to the rate of change of flux-linkage and, therefore, gives the audio-signal that has been recorded on the tape. A magnetic tape-recorder consists of three main parts: a) Tape transport mechanism commonly known as Tape deck. b) Record, Replay and Erase heads. c) Record, Replay amplifier and bias oscillator. See Enlarge Click to Enlarge AUTOMATIC TELEPHONE EXCHANGE DEMONSTRATOR. MODEL IBL-TELE - 1 The Automatic Telephone Exchange Demonstrator is state of art Microprocessor Technology. It has user friendly commands and is simple to operate. Each function is programmable through the telephone several built-in functions and readily usable. The instrument is housed in an elegant one panel with four wall mountable telephone instruments, with on main and four extensions. These telephone instruments can be used as normal telephone lines through the exchange including intercom facilities. The instruments are normal decade type push-button telephones. All blocks of the instrument are marked and printed on the protective acrylic panel. Various functional blocks EPABX are marked. They are Relay bank for external communication for line calls), relay bank for internal communication (intercom facility), display the current user/users of the exchange. Opto-isolator section, switching section, tone generator/ringer, ringer amplifier, Line coupler/relay/drivers, MICROPROCESSOR, EPROM RAM, buffer section, connection for 4 internal instruments and one external line. Features: Intercommunication facilities between instruments. Call conference Call forwarding Call transfer Call back Call consult & hold Call pick-up Auto call back Direct dialing Different ring tones Ring polling Music on hold Call restrict local /STD Specifications: No of lines: one trunk and 4 extensions. Instruments: normal decade dial with 9-11 PPS. See Enlarge Click to Enlarge VCR TRAINER. MODEL IBL-VCR -1 Video Cassette Recorder is a highly complex electro mechanical system. Most of the time, it can be repaired by visually inspecting the mechanism. A reason can be a worn-out rubber wheel can be the cause for a bad picture. A simple cleaning procedure can set right a visible fault. It is necessary to understand that all modern tape recorders use dedicated electronics parts, like controllers, power device, active and passive components, all made of them may be surface mounted devices. However a formal education in this will help a technician to be more proficient in troubleshooting techniques. While it is difficult to trouble shoot electronic parts, namely surface mounted devices (SMDs), it certainly provides necessary skills identify which part to be replaced. This demonstrator provides such skills. Before you begun to study about VCR, you need to understand its territory. This section deals with how a VCR's mechanical deck is laid out, the individual parts and what they do. Developing an understanding of how it all works together goes a long way towards acquiring successful knowledge of VCR. It is possible to view the following components in the trainer. They are Supply Reel Table Supply Reel Brake P1 Post Tape Tension Arm P2 Post Full Erase Head Roller Guide (supply) V-stop (supply) Video Drum V-stop (Take-up) Roller Guide (Take-up) ACE Head P3 Post Capstan Shaft Pinch Roller Take-up Reel Brake Take-up Reel Table Now that you understand the individual parts and what they do, it is time to know how they work. The VCR Demonstrator is supplied with the following. Video Cassette Recorder Demonstrator with various faults introduced in them by switch mechanism. They are: Record Channel UP Channel Down Record Reset Rewind Stop Play Forward and Eject. Hand held Remote control unit Partly recorded VHS cassette AV-RF Cable set assembly. See Enlarge Click to Enlarge CD PLAYER TRAINER. MODEL IBL-CDT-1 This trainer is a dynamic demonstrator. It is intended to study how various activities are performed inside a CD player system. While it is difficult to demonstrate all the above mentioned principles, because of the presence of the surface mounted devices, Principle block signals are displayed for waveform observations only. Various faults are introduced in this trainer, wherever possible, like PLAY/PAUSE, FORWARD, SKIP, REVERSE, OPEN and CLOSE, POWER SUPPLY, SMPS etc. In addition to this a hand-held remote control will also be provided. How CD (Compact Disk) player works: Converting sound into numbers: In a digital recording system, sound is stored and manipulated as a stream of discrete numbers. A microphone connected to a circuit generates the numbers. Each number is called a SAMPLE, and the number of samples taken per second is the SAMPLE RATE. Ultimately, the numbers will be converted back into sound by a DIGITAL TO ANALOG CONVERTER or DAC, connected to a loudspeaker. Once the waveform is faithfully transformed into bits, it is recorded on a Compact Disc. The bits are represented as microscopic pits burned into the plastic by a laser. To read the data, light from a gentler laser is reflected off the surface of the into a light detector. Digital circuits are complex, but very few of the components must be precise; most of the circuitry merely responds to the presence or absence of current. This system is mounted in an ergonomically designed cabinet. All the moving parts are visible for observation. It works on 230V AC power inlet. See Enlarge Click to Enlarge PAGER TRAINER. MODEL IBL-PT-1 The basic signaling pattern used in this pager is a sequence of coded binary data using the Post Office Code Standardization Advisory Group (POCSAG) code. The POCSAG code is a synchronous paging format that allows pages to be transmitted in a simple batch structure. The code accommodates both tone-only. The POCSAG code also provides improved battery-saving capability and an increased code capacity. The negative logic convention (?0?= high, ?1? =low) is used in this system. The POCSAG code format consists of a preamble and one or more batches of code words. Each batch comprises a 32-bit frame-synchronization code and eight 64-bit addresses frames of two 32-bit addresses or idle code words each. The frame-synchronization code makes the start of the batch code words. The pager is a localized instrument. It means the pager instrument accepts the, paged information from the transmitter. The effective of range of reception is usually in the range of 25 to 40KM from the transmitter. So it can be termed as a localized instrument. Another example of a localized instrument is a FM transmitter and receiver. The front panel of this pager trainer has all the important and necessary blocks of a pager. This contains several test points for waveform observations only. This has an alphanumeric LCD panel for displaying the incoming message. NOTE: You must send a pager instrument duly registered with a service provider in your area, while placing the purchase order. The scope of usage of this trainer is restricted to the extent of observing the waveforms only. There should be a transmitter and a service provider available in your area for actual demonstration and waveform observations. See Enlarge Click to Enlarge OSCILLOSCOPE DYNAMIC DEMONSTRATOR TRAINER. MODEL IBL-CRO-1 The oscilloscope is basically a graph-displaying device - it draws a graph of an electrical signal. In most applications the graph shows how signals change over time: the vertical (Y) axis represents voltage and the horizontal (X) axis represents time You can determine the time and voltage values of a signal. You can calculate the frequency of an oscillating signal. You can see the "moving parts" of a circuit represented by the signal. You can tell if a malfunctioning component is distorting the signal. You can find out how much of a signal is direct current (DC) or alternating current (AC). You can tell how much of the signal is noise and whether the noise is changing with time. This is a dynamic demonstrator. It is intended to study how the oscilloscope works. Signals from various blocks of the oscilloscope are terminated on different terminals terminated on the front panel of the demonstrator. Since longer lengths of wires are used for terminating the test points, performance of the oscilloscope will be degraded. See Enlarge Click to Enlarge DIGITAL MULTI-METER DYNAMIC DEMONSTRATOR. MODEL IBL-DMM-1 This trainer is intended to demonstrate the principles of Voltage, Resistance and current measurements. The fundamental principles of measurement are displayed here. A LCD or LED indicators are used to display the actual values. Importance is given for qualitative measurements rather than quantitative measurements while explaining the principles of measurements. See Enlarge Click to Enlarge AUTOMATIC VOLTAGE STABILIZER DYNAMIC DEMONSTRATOR . MODEL IBL-AVS-1 This trainer is intended to demonstrate the principles of Voltage stabilizer. The essential parts of controlling BUCK ? BOOST, Lower voltage and upper voltage settings etc are demonstrated in this trainer. See Enlarge Click to Enlarge FAX MACHINE DEMONSTRATOR. MODEL IBL-FAX-1 FAX is the abbreviation of facsimile process. A FAX machine is highly elector-mechanical machine. A FAX machine can send or receive pictures and text over a telephone line. The principle of FAX machine is by digitizing an image dividing it into a grid of DOTS (One) and NO DOTS (Zero) at high resolution. This is called as bitmap. This works more on the principle of photo imaging. Each dot is either ON or OFF. The transmission of these bits is transmitted like normal computer data over telephone lines. The received data is Re-translated in the form of DOTS and NO DOTS. A FAX machine consists of (a) an optical scanner for digitizing images on paper, (b) a printer for printing incoming FAX messages, and (c) a telephone for transmission and reception. The received data is printed on thermal paper. Some of the features that differentiate one FAX machine from another include the following: Modem Speed: FAX machines transmit data at different rates, from 4,800 bps to 28,800 bps. A 9,600-bps FAX machine typically requires 10 to 20 seconds to transmit one page. Printer Type: A thermal printer recognizes Dots and NO dots. Wherever there is a DOT, by thermal action, it generates a Dot. Paper Cutter: This is usually an optional facility. Paper Feed: The paper from the thermal paper roles are advanced step by step, after getting a synchronizing pulse from the transmitter. The distance to which it moves horizontally and vertically is standardized. Auto dialing and time dialing: These are facilities that vary from manufacturer to manufacturer. The FAX Machine Demonstrator Model FAX-1 is intended to demonstrate the principles of FAX transmission and reception. This demonstrator can be connected to normal telephone lines for actual transmission and reception. The front panel consists of various blocks to broadly indicate the system configuration. Test points (TP) are provided wherever necessary for waveform observations using an oscilloscope. Specifications: Transmission compatibility: ITU-T/CCITT Group 3 Scanner: Flatbed scanning with CCD type image sensor Document size: Max - 257mm X 1000mm (with operator assistance) Min ? 148mm X 105 mm Effective scanning width: 208mm Recording: Thermal print head Print media: High sensitivity thermal recording paper Resolution: Horizontal ? 203 pixels / Inch Coding scheme: MH, MR (conforms to ITU-T/CCITT) Modem type: ITT-T/CCITT V.29 Modem speed: 300, 2400, 4800, 7200 or 9600 bps Power supply: Mains operated 230V AC @ 50Hz. See Enlarge [1] Go to Top