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Wednesday, December 27, 2023

SINUDYNE XANTOS N (20036) YEAR 1982

 The SINUDYNE XANTOS N is a heavvy portable compact 20 inches (51cm)color television with 32 Porgrams PLL synthesized 99 channels,

  • It has a 4 digit OSD display for program and channels indications.
  • It has remote and a local right placed  keyboard which is almost replicating all basic functions of the set.
  • These sets were offering ultra bright pictures with very superb colors and sharp pictures.

    • Was a SINUDYNE tv model featuring PLL Synthesizer tuning system (ITT) and was first Italian color television set featuring first time the PLL Synthesizer tuning system, a frequency synthesizer controlled channel selection means which includes a fine tuning arrangement; means for initiating a sweep of available channels by the channel selection means; means for stopping the sweep on reception of a signal and means, operable on cessation of sweeping and responsive to the frequency of the signal, and arranged to control the fine tuning arrangement to compensate for frequency drift of the signal.
    Television receivers of the type under consideration frequently include a frequency synthesizer for tuning the receiver's local oscillator to the nominal carrier frequency of a selected television channel. Generally, the frequency synthesizer compares the local oscillator frequency to a reference frequency associated with the selected channel, and then varies the local oscillator frequency until it equals the reference frequency. Presumably, the receiver will now be correctly tuned to the selected channel.
    This method of tuning the receiver relies, of course, on the frequency of the incoming television signal being equal to its nominal or standard frequency.
    In accordance with the invention, a digital signal representative of the tuner local oscillator frequency is supplied to one input of a comparator with a digital signal representative of a desired channel number being supplied to the other input. The local oscillator frequency and, hence the system tuning, is varied in accordance with a correction signal which is dependent upon the state of the comparator. As a result of the desired channel number input, a driving ramp voltage is applied to the varactor and effectively results in a systematic channel-by-channel search for a predetermined acceptable region of frequencies about the desired channel frequency. The search is carried out at a very high speed, with a repetitive time sampling and comparison technique and, as far as the viewer is concerned, is practically instantaneous. The acceptance region is defined by a "window" which is made narrow enough to define the desired channel without adjacent channel interference, yet broad enough to permit minor deviations in carrier frequency without initiating corrective action.
    In the preferred implementation of the invention, the tuning system incorporates a presettable modular scaler which drives presettable units and tens counters. Any base for the modular scaler may be chosen in conjunction with its preset information and the other counters and their preset information) to provide correct decoding of the oscillator frequency into the corresponding channel number regardless of its frequency band location. Thus, having a predetermined modulus (base), the modular scaler preset determines how many counts are required to provide a pulse to the units counter. The units counter functions in a similar manner to supply pulses to the tens counter. The base of the modular scaler is selected to produce a desired relationship for the intrachannel frequency spacing. Within the frequency window maintained by the tuning system, a normal automatic frequency control (AFC) in the receiver operates to lock the local oscillator frequency to the picture IF carrier. Since the tuning system operates on the local oscillator frequency, there is no dependence on individual characteristics of the varactor other than the requirement that the tuner drive system must be capable of tuning the varactor tuner over all channels.This invention relates to a digitally controlled, electronic tuner that can be tuned to any of several different channels at different frequencies and which includes an automatic fine tuning (AFT) circuit to adjust the tuning precisely when the frequency to which the tuner is tuned is within a predetermined frequency range close to the exact desired frequency. In particular, the invention relates to a television signal tuner for a receiver having an AFT circuit to maintain the tuning at a selected frequency according to one of the available channels and further including means to overcome the effect of the AFT circuit when it is desired to shift the tuner to a different channel.

    • First SINUDYNE using the PHILIPS 30AX 110° CRT TUBE in a 20"  compact tv format !
    The 30AX system, which Philips introduced in 1979, is an important landmark in the development of colour picture systems. With previous systems the assembly technician had to workthrough a large number of complicated setting-up procedures whenever he fitted a television picture tube with aset of coils for deflecting the electron beams. These procedures were necessary to ensure that the beams for the three colours would converge at thescreen for every deflection. They are no longer necessary with the 30AX system: for a given screen format any deflection unit can be combined  with any tube to form a single 'dynamically convergent' unit. A colour-television receiver can thus be assembled from its components almost as easily as a monochrome receiver. The colour picture tube of the PHILIPS 30AX system displays a noticeably sharper picture over the entire screen surface. This will be particularly noticeable when data transmissions such as Viewdata and Teletext are displayed. This has been achieved by a reduction in the size of the beam spot by about 30%. Absence of coma and the retention of the 36.5 mm neck diameter have both contributed to increased picture sharpness. Coma has been eliminated by means of corrective field shapers embedded in the deflection coils which are sectionally wound saddle types. The new deflection unit has no rear flanges. enabling uniform self-convergence to be obtained for all screen sizes. without special corrections, adjustments, or tolerance compensations. Horizontal raster distortion is reduced and no vertical correction is required. One of the inventions in 30AX is an internal magnetic correction system which obviates static convergence and colour purity errors. This enables the usual multiple unit to be dispensed with. together with the need for its adjustment !  New techniques have been employed to achieve close tolerance construction of the glass envelope. In addition, the 30AX picture tube incorporates two features whereby it can be accurately adjusted during the last stages of manufacture. One is the internal magnetic correction system. The other is an array of bosses on the cone that establish a precise reference for the axial purity positioning of the deflection unit on the tube axis and for raster orientation. During its manufacture, each deflection unit is individually adjusted for optimum convergence. The coil carrier also incorporates reference bosses that co-operate with those on the cone of the tube. ' Since every picture tube and every deflection unit is individually pre-aligned, any deflection unit automatically matches with any picture tube of the appropriate size. The deflection unit has only to be pushed onto the neck of the tube unit it seats. Once the reference bosses are engaged, the combination is accurately aligned and requires no adjustment for convergence, colour purity or raster orientation. With no multiple unit and a flangeless deflection unit, there is more space in the receiver cabinet. Higher deflection sensitivity means that less current is consumed, and consequently less heat is produced. This increases the reliability of the TV receiver again. 30AX means simple assembly. Any picture tube is compatible with any deflection unit of the appropriate size and is automatically self-aligning as well as being self-convergent.
    The well-known 20AX features of HI-Bri, Soft-Flash and Quick-vision are maintained in the new 30AX systern.  In their work on the design of deflection coils in the last few years the developers have expanded  the magnetic deflectionfields into 'multipoles', This approach has improved the understanding  of the relations between coil and field and between field and deflection to such an extent that  designing deflection units is now more like playing a difficult but fascinating game of chess than  carrying out the obscure computing procedure once necessary.

    • Was first Sinudyne TV set featuring the Motorola TDA3300 A bipolar linear PAL colour decoder, with provision for multi-standard operation, on-screen display and an automatic C.R.T. current set-up system, is described. This device uses a 40 pin DIL plastic package.This invention relates to a system for stabilizing the cathode emissions from an in-line gun cathode ray tube and for maintaining the ratio of the beam currents in the cathodes within a predetermined desired range. The system includes a subsystem that can be linked to each of the cathodes of an in-line gun or delta gun CRT comprising means for interrupting the flow of a video signal to the cathodes of a cathode ray tube; means for imposing a predetermined test signal on each or any of the cathodes; means for detecting the actual current flowing to each or any of the cathodes of a cathode ray tube independently of the others; means for sampling the actual current; means for detecting the difference between the sampled actual current and a predetermined, desired current; means for developing a signal representing the difference, if any, between the sampled actual current and the predetermined current; and means for using the differential signal to drive the actual current to the predetermined value.Motorola's third generation PAL decoder system (Chroma III) employs a single 40 -pin i.c., type TDA3300. Amongst the features of this i.c. are low dissipation, typically 600mW, with a single 12V supply; a patented 90° phase - shift system requiring no adjustment; and direct inputs for on -screen (data, TV games, etc.) displays, with a complementary fast blanking input. Of particular interest is the beam limiting and automatic black -level adjustment system, the latter making it unnecessary to incorporate preset controls to set up the black level. These arrangements rely on three high -voltage transistors to monitor the beam currents, providing feedback signals for the i.c.  If the reference voltage is exceeded, the beam current limiting action comes into operation, reducing the contrast. The system has been designed to enhance the set's video and digital signal handling capability. During the flyback time the feedback input impedance rises, activating a further internal comparator. This compares the tube's cut-off current (a hot cathode doesn't cut off completely) with another internal reference voltage. The resultant signal is integrated and added to the output (at the output clamp) to provide the automatic black -level correction. Readers may recall that a similar idea, using discrete circuitry, is employed in certain B and 0 colour chassis. The advantage is that the black level is held constant throughout the tube's life, with no grey scale drift.
    In the past, it has been generally necessary to provide separate drive controls for each of the three signal paths in a color video display. Further, inasmuch as the respective guns of a CRT picture tube age differently, it has been necessary to adjust the drive controls of the CRT throughout its life, particularly during the first twenty-four hours. In this respect, it has been necessary to "burn-in" the set to stabilize operation of the guns such that a final manual adjustment could be made of the respective gain controls.
    In this regard, several integrated circuits for television receivers have introduced automatic setting of the CRT operating point, or its dc (black) reference level. However, there has heretofore been no provision for automatic setting of the video gain or contrast (gray) operating point.
    Further, the brightness control of a television or video display receiver is usually accomplished by shifting the bias or dc reference level of the video display. This operation has the effect of changing both the average luminance of the display as well as the contrast ratio of the picture. In like manner, the contrast control is normally an amplitude control, the operation of which will also affect average luminance as well as the contrast ratio. In a color television or data display system, saturation and hue may also be affected. Previously, there has been no provision for compensating the brightness control signal such that the picture black level remains unaffected by the contrast control signal.

    • Was featuring first time the PROFESSIONAL 5000 MODULAR CHASSIS CONCEPT.
    The television receiver also includes a wiring harness including a plurality of wires interconnecting the electronic chassis and picture tube within the cabinet. A plurality of connectors are positioned on the main electronic chassis and are interconnected by the wires within the wiring harness. A plurality of electronic modules are positioned within the electronic chassis with each of the modules having at least one connector thereon. The connectors on the electronic modules care placed so as to mate with the connectors mounted on the electronic chassis for interconnection between the electronic modules and the picture tube. By this means the various electronic modules can be removed by unplugging the connectors and without requiring soldering or unsoldering of any wires in the set.

    • Was first Sinudyne portable TV set featuring a Switching power supply based on SIemens TDA4600. Switching regulators serve as efficient and compact power supplies for instruments such as television receivers. A switching regulator may typically comprise a power transformer having a primary winding coupled to an input voltage source and to a power switch and a secondary winding coupled to a rectifier arrangement for developing a DC supply voltage for the instrument. A regulator control circuit generates pulse width modulated control signals that control the duty cycle of the power switch. A power switch is coupled to an inductance and a source of input voltage. A control circuit is coupled to the power switch for producing the switching thereof to transfer energy from the input voltage source to a load circuit coupled to the inductance. The control circuit is responsive to control voltages for varying the duty cycle of the power switch to control the transfer of energy to the load. A first control voltage representative of a variation in an energy level of the load circuit is developed to control the duty cycle in a manner that regulates the energy level.



    IN general the set is build with a Modular chassis design because as modern television receivers become more complex the problem of repairing the receiver becomes more difficult. As the number of components used in the television receiver increases the susceptibility to breakdown increases and it becomes more difficult to replace defective components as they are more closely spaced. The problem has become even more complicated with the increasing number of color television receivers in use. A color television receiver has a larger number of circuits of a higher degree of complexity than the black and white receiver and further a more highly trained serviceman is required to properly service the color television receiver.
    Fortunately for the service problem to date, most failures occur in the vacuum tubes used in the television receivers. A faulty or inoperative vacuum tube is relatively easy to find and replace. However, where the television receiver malfunction is caused by the failure of other components, such as resistors, capacitors or inductors, it is harder to isolate the defective component and a higher degree of skill on the part of the serviceman is required.
    Even with the great majority of the color television receiver malfunctions being of the "easy to find and repair" type proper servicing of color sets has been difficult to obtain due to the shortage of trained serviceman.
    At the present time advances in the state of the semiconductor art have led to the increasing use of transistors in color television receivers. The receiver described in this application has only two tubes, the picture tube and the high voltage rectifier tube, all the other active components in the receiver being semiconductors.
    One important characteristic of a semiconductor device is its extreme reliability in comparison with the vacuum tube. The number of transistor and integrated circuit failures in the television receiver will be very low in comparison with the failures of other components, the reverse of what is true in present day color television receivers. Thus most failures in future television receivers will be of the hard to service type and will require more highly qualified servicemen.
    The primary symptoms of a television receiver malfunction are shown on the picture tube of the television receiver while the components causing the malfunction are located within the cabinet. Also many adjustments to the receiver require the serviceman to observe the screen. Thus the serviceman must use unsatisfactory mirror arrangements to remove the electronic chassis from the cabinet, usually a very difficult task. Further many components are "buried" in a maze of circuitry and other components so that they are difficult to remove and replace without damage to other components in the receiver.
    Repairing a modern color television receiver often requires that the receiver be removed from the home and carried to a repair shop where it may remain for many weeks. This is an expensive undertaking since most receivers are bulky and heavy enough to require at least two persons to carry them. Further, two trips must be made to the home, one to pick up the receiver and one to deliver it. For these reasons, the cost of maintaining the color television receiver in operating condition often exceeds the initial cost of the receiver and is an important factor in determining whether a receiver will be purchased.
    Therefore, the object of this invention is to provide a transistorized color television receiver in which the main electronic chassis is easily accessible for maintenance and adjustment. Another object of this invention is to provide a transistorized color television receiver in which the electronic circuits are divided into a plurality of modules with the modules easily removable for service and maintenance. The main electronic chassis is slidably mounted within the cabinet so that it may be withdrawn, in the same manner as a drawer, to expose the electronic circuitry therein for maintenance and adjustment from the rear closure panel after easy removal. Another aspect is the capability to be serviced at eventually the home of the owner.

    • Components and Semiconductors parts are naturally from PHILIPS - MOTOROLA -SIEMENS-ITT-THOMSON.

     
    • It has a Transistorized horizontal deflection circuits  made up of a horizontal switching or output transistor, a diode, one or more capacitors and a deflection winding. The output transistor, operating as a switch, is driven by a horizontal rate square wave signal and conducts during a portion of the horizontal trace interval. A diode, connected in parallel with the transistor, conducts during the remainder of the trace interval. A retrace capacitor and the deflection yoke winding are coupled in parallel across the transistor-diode combination. Energy is transferred into and out of the deflection winding via the diode and output transistor during the trace interval and via the retrace capacitor during the retrace interval.
    In some television receivers, the collector of the horizontal output transistor is coupled to the B+ power supply through the primary windings of the high voltage transformer. 

 

 

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