Video Signals And Slip Rings White Paper - Moog Inc.
White PaperKey Messages Slip rings are often part ofcompact assemblies that requirede-rotation of multiple power,signal, data, and video channelsVideo Signals and Slip Rings The problem of designing sliprings for video applicationsis addressed by combiningbroadband electricalinterconnect solutions withoptimized sliding contactsGlenn DorseyMoog Inc.Business Development Specialist The bandwidth challenges oftransmitting video signalsthrough slip rings present issuessimilar to any interconnectproblem -- control of theimpedance, attenuation, anddispersion are all critical issuesIntroductionOne of the most common questions asked of a slip ringsupplier is “Will your slip rings handle video signals?”The short answer is “Yes, there is a slip ring solutionfor every rotating video problem.” The long answer getsto the purpose of this application note. What are theimportant parameters to understand when specifyinga slip ring for video applications, and what slip ringfeatures ensure specification compliance? Even moreimportantly, how should a slip ring to be used in a videoapplication be specified?Slip rings are required to “de-rotate” a signal comingfrom a rotating platform, such as a rotating gimbalof a scanning vision system. CCTV is one commonapplication, but sophisticated multi-spectralsurveillance vision systems also require slip rings tocarry signals from infrared (IR), day, and night camerasfrom a rotating to a stationary platform. As thesedesigns continue to transition from standard or analogvideo to high definition (HD) digital video, slip ringdesigns have kept up with the increased bandwidthrequirements.example, 75Ω coaxial cable). But perfect transmissionline matching is difficult, so slip rings do not look exactlylike a piece of wire. Transmission line qualities such asimpedance matching and shielding effectiveness are theprimary parameters of interest.Slip rings are often part of compact assemblies thatrequire de-rotation of multiple power, signal, data, andvideo channels. The size constraints that normally resultfrom limited system space place challenges on circuitperformance in terms of matching impedance andcontrolling crosstalk isolation. Slip rings use continuousrings and sliding electrical contacts, or brushes, tomaintain electrical continuity during rotation. There arethree basic slip ring configurations shown in Figure 1a-c.A decision on which of these design approaches to use isnormally driven by mechanical considerations regardingavailable space or system design, but each of thesedesigns comes with its own electrical advantages anddisadvantages in regards to video transmission.Slip Ring ConfigurationSlip rings operate on the physical layer (PHY), sotransmission line qualities are the parameters ofinterest. Ideally any device such as a connector or slipring that is inserted into a transmission line shouldhave the properties of the transmission media (forwww.moog.comFigure 1a: Capsule assemblies
bandwidth cannot be avoided however, so jitter control isthe primary challenge with digital video.Figure 1b: Through-bore assembliesIt is important to understand the role and impact of thesliding electrical contacts (the ring-brush interface) inthe quality of video signals transmitted through a slipring assembly. These sliding contacts are typically thefirst area of concern when slip rings are included into avideo transmission line. There is some variation in contactresistance produced at the slip ring contacts duringrotation, and there is logical concern that this variationin resistance will produce video noise. In fact in properlydesigned slip rings, the sliding contacts themselves haveminimal impact on the performance of video signalsthrough slip rings.Sliding Contact IntegrityFigure 1c: Platter style assembliesCapsule Assemblies (Figure 1a)Slip rings are often put on the center axis of rotation ofan assembly, and this real estate near the centerline isusually valuable. Miniature capsule assemblies are usedin these designs. Since space is very limited in theseminiature assemblies, crosstalk isolation is usually themost critical design issue in the transmission of video.Through-bore Assemblies (Figure 1b)These slip rings are designed to provide a through-borefor a shaft, sub-assembly, or assembly clearance. Theincreased diameter changes the focus to impedancematching and jitter control as the most critical electricalparameters, especially with digital video. Moog’sApplication Note #228, High Speed Data and CommercialSlips (Dorsey, 2009) provides additional details on thediameter effect on slip rings.Platter Style Assemblies (Figure 1c)Moog’s patented broadband platter design uses microstrip design techniques with platter assemblies toprovide a low profile, high bandwidth option for slip ringpackaging. The improvements yielded by this micro-stripprinted board design improve the bandwidth of slip ringsrequiring a through bore. The slip ring diameter effect on2 Video Signals and Slip RingsSlip rings used to transmit sensitive signals have evolvedfrom designs used for very low level analog signals in the“pre-digital” age. The precious metal contact materials,the design parameters, and manufacturing techniqueswere all developed for negligible contact resistance, lowresistance variation with rotation, and long life. Theseanalog applications were very noise sensitive and oftenrequired noise levels measured in the μv range. In fact thecontact noise requirements of these slip rings 50 yearsago were much more stringent than required for videoand digital applications. But it is not just these provenmaterials that make the difference. Recent work in thefield of nano-tribology (the study of friction and wear onthe nano scale) has provided new lubricants, materials,and design insight into improved sliding contact designs.Recent research (Dorsey, Coleman et al. 2012) hasshown that sliding contacts do not limit the bandwidth ofsignals transmitted through properly-designed preciousmetal contacts. This is to say that there is no criticalfrequency or bandwidth for which sliding contacts arenot appropriate. Slip ring design for analog video, aswell as digital video, revolves around inserting theseoptimized sliding contacts into a transmission linedesign that minimizes the effects of transmission lineperturbations. So the problem of designing slip rings forvideo applications is addressed by combining broadbandelectrical interconnect solutions with optimized slidingcontacts.Standard VideoStandard or analog video is known as NTSC in NorthAmerica, Western South America, and parts of Asia
and PAL in Europe and the rest of the world. Thecorresponding component video formats are RS 170(NTSC) and CCIR (PAL). The composite formats providefor video carrying luminance (Y) and chrominance (C) ina single signal with a bandwidth of 6 MHz (allocated asshown in Figure 2), while component video carries thisinformation on separate lines. The precise bandwidthallocation for a complete color signal is complex, but it issafe to assume that good performance across a 6 MHzbandwidth is the critical PHY specification for specifyinga slip ring to carry standard video. Figures 3 and 4illustrate this 6 MHz bandwidth with time and frequencydomain plots of NTSC video. It is important that a slip ringhave sufficient bandwidth to transfer a DC-6 MHz signaland sufficient crosstalk isolation within this bandwidthto maintain the required signal-to-noise ratio. A crosstalkspecification that ensures a noise floor of 10 mV iswell under the NTSC signal to noise requirement. This istypically 40 dB for most potentially noisy data signalsmeasured within the DC-6 MHz band. Signals with thegreatest potential for a deleterious effect are high speeddata channels including digital video channels.Standard composite video is carried on coaxial cable, andslip rings carry the coax cable through on multiple rings;typically one ring is dedicated to the center conductor ofthe coax and the shield is carried through on one ring orboth of the rings on either side of the center conductorring. In many cases, the coax conductor cannot becarried inside the slip ring due to space constraints, andterminations are made to the shield and center conductoroutside the slip ring. This termination technique isusually acceptable when internal leads can be physicallyseparated, but in the case of small slip rings where leadsare closely packed, care must be exercised to minimizethe length of unshielded conductors to avoid crosstalkissues.It is in this transition from an unbalanced coaxial cable toa balanced ring configuration that determines successfulslip ring performance in video transmission. Good slipring design minimizes the effective electrical length ofthis transition, controls the differential impedance of thecenter conductor to ground as closely as possible to thenominal impedance of the channel, and controls the noiseintroduced on the circuit.Figure 2: Standard video frequency partitionFigure 3: NTSC time domainIt is important to stress that modern slip ring designtechniques provide sufficient bandwidth and crosstalkisolation to provide good video performance with allthree design configurations (i.e., capsule, through-bore,and broadband platter) with slip ring diameters up to 1meter or more. The primary risk is appropriate crosstalkisolation. Crosstalk, the result of capacitive coupling fromone channel to another, can occur in a slip ring from ringto-ring coupling as well as coupling of the internal as wellas external wiring. It is important to isolate video channelsfrom “noisy” circuits (e.g., noisy power or digital data) bothinternal to the slip ring as well as any external wiring.3 Video Signals and Slip Rings
In the case of slip rings, the coaxial cable is terminated todiscrete rings producing an unbalanced to balanced linetransition. Proper slip ring design avoids this ghostingproblem by minimizing the length of the impedancemismatch among other strategies. This ghosting is nota common problem, but is worth mentioning in case theproblem must be corrected. Standard analog video isnormally carried without problems on slip ring assemblieswhen properly wired. A slip ring that is supplied pre-wiredwith the proper impedance value coaxial cable is normally“good to go” with analog NTSC or PAL video. In caseswhere coaxial cable must be terminated outside the slipring or when especially noisy signals must be transmittedthrough the slip along with the analog video, specialprecautions might be required to avoid image ghosting ornoise coupling.Figure 4: NTSC frequency domainA phenomena known as “video ghosting” can occurwhenever the unbalanced configuration (center conductorsurrounded by a shield) of the transmission line isdisturbed. Figure 5 illustrates this ghosting effect whichis the result of signal reflections generated at impedancediscontinuities of a coaxial transmission line. Typicallythese reflected signals, carried on the shield layer, arewell down under the noise floor, but in some cases underthe right combination of cable length and impedancediscontinuity length, these reflected signals can causevisible ghosting.One solution to the ghosting problem is to use a balun, adevice that handles the BALanced to Unbalanced energytransfer. The simplest balun is an RF choke placed aroundthe coax to increase the impedance of the outside surfaceof the coax. At this point, the energy that escapes frominside the coax and travels on the outside of the shieldcan be partly absorbed and partly reflected back towardthe discontinuity, where it can rejoin the original signalwith only a small displacement in time and negligibleghosting. The distance between the RF choke and theend of the open coax shield determines the temporaldisplacement of the signal those image. The energy thattravels past the RF choke is strongly attenuated, as is theresidual reflection. The RF choke has the added effect ofameliorating the effects of an impedance mismatch at theslip ring and the ensuing reflection. Simple ferrite beadsplaced around the coaxial cable are a common method ofintegrating an RF choke.4 Video Signals and Slip RingsFigure 5: Video ghosting as the result of signal reflectionsfrom impedance mismatchesDigital Video - SPMTE StandardsThe transition from analog to digital video is movingquickly in order to achieve an improvement in overallimage quality by improving the signal-to-noise ratio withdigital signal processing (DSP). There are a number ofdigital video formats that are being used to transmitdigital data. Probably the most common are the seriesof serial digital interface (SDI) standards defined bythe Society of Motion Picture and Television Engineers(SMPTE). Table 1 shows the controlling standards for SDIvideo along with their common names, serial bit rates,and the vertical spatial resolution. There are a numberof other SMPTE standards that fall under each of theseindividual standards that control digitizing parametersfor video and audio, encoding schemes, and ancillary datapackets.
StandardMainBitrates (Mbps)VideoFormatsSMPTE 259MSD-SDI143, 177, 270,360480i, 576iSMPTE 344SD-TI540480p, 576pSMPTE 292HD-SDI1485,1485/1001720p,1080iSMPTE 372DualLinkHD-SDI2970 AND2970/1001in two parallelchannels1080pSMPTE 4243G-SDI2970 and2970/10011080pTable 1: SMPTE serial digital interfaces (SDI) standardsThe top-level SDI standards shown in Table 1 relate todigital signals carried on coaxial cable. In addition SMPTE297 defines the fiber optic interface for the receptionand transmission of SDI signals (SMPTE 259, 344, 292and 424). Important system performance parameters oftransceivers, transmitters, and the overall system suchas the optical loss budget are provided in SMPTE 297.Figures 6 and 7 illustrate how SMPTE specifications worktogether to define SD and HD video data streams.Figure 7: HD-SDI standardsAs digital video has progressed from SDI to HD-SDIand 3G-SDI, the move has been towards greater spatialresolution as shown in Figure 8. This increased samplingrate has led to a resultant increase in digital bitratesnecessitating increased attention to the quality ofthe transmission line that carries the signal and itsbandwidth. It is at this point we ask the question, “Whateffect does the insertion of a slip ring in a digital videotransmission line have on the quality of the video signal?”In terms of physical media considerations, these digitalvideo signals, defined by a complex set of interrelatedformat standards, are simply 800 mV serial datastreams. However there are some specifics of the videoformats that require specific attention when specifyingtransmission line properties.Figure 6: SD-SDI standardsFigure 8: Spatial resolution boundaries of SDI video5 Video Signals and Slip Rings
To examine these special signal properties, SMPTE 292,HD-SDI will be used as an example. In the case of SMPTE292, Section 8.1 defines the transmission line propertiesor signal level and specifications. Paragraphs 8.1.1through 8.1.7 define the quality of the signal producedby the generator and paragraphs 8.1.9 through 8.1.11 thequality of the signal that the receiver can recover, (i.e.,signal to noise ratio evaluation criteria). Although specifictransmission line quality metrics are not given, they canbe inferred from the difference between the receiver andgenerator signal quality metrics.The SMPTE standards all define coaxial transmissionlines (i.e. single-ended). Most other high speed digital dataformats are differential in order to achieve good commonmode noise rejection. However, the advantage of installingdigital video on existing coaxial cable infrastructureoverrode this noise rejection consideration when definingthe standard. This single-ended characteristic of SDIdoes pose the critical problem of ensuring adequate noiserejection. The earlier discussion about the criticalityof control of the unbalanced to balanced transitionat the slip ring interface is relevant in discussions ofthe signal to noise ratio of SDI signals, and the sameparameters (electrical length of the transition, value ofthe impedance, and noise introduction) are important.However, the problem is exacerbated by the higher signalbandwidth. The primary issue, just as in analog video,is still the reflections caused on the line by the cablingtransitions. The amplitude and phase characteristics ofthese reflections can be controlled (not eliminated) bygood slip ring design practices. These reflections resultin noise, or jitter, on the receiver end of the transmissionline. As in the case of analog video, this deterministicjitter is a much more critical issue than the very nondeterministic jitter caused by contact noise.Jitter is the most common metric used to define thequality of the digital transmission line. SMPTE standardsRP 184 and 192 address the Specification of Jitter inBit-Serial Digital Systems and the Jitter MeasurementProcedures in Bit-Serial Digital Interfaces respectively.SMPTE 184 defines the input jitter allowed by theequipment as well as the intrinsic jitter at the equipmentoutput in the absence of input jitter (i.e., the jitter fromthe transmission line and system electronics downstreamfrom the input). This amplitude and phase jitter is definedin terms of Unit Interval (UI) which normalizes the jittervalues to the period of one clock cycle (or the nominalminimum time between transitions of the serial signal).6 Video Signals and Slip RingsSMPTE 292 provides a detailed breakdown of the jitterrequirements of HD-SDI which is replicated in Table2. Timing jitter is defined in RP 184 as the variationin position of a signal’s transitions occurring at a rategreater than a specified frequency (typically 10 Hz, B1of table 2). Variations occurring below this specifiedfrequency are termed wander and are not addressed bythis practice. Alignment jitter is the variation in positionof the signal’s transitions relative to those of a clockextracted from that signal and is typically the primaryconcern of the video performance.B110 HzTiming jitter lowerband edgeB2100 kHzAlignment jitterlower band edgeB3 1/10 the clock rateUpper band edgeA11 UITiming jitter(Note 1)A20.2 UIAlignment jitter(UI Unit Interval)Test Signal Color bar test signaln10 (preferred)(Note 2)Serial clock divided(Note 3 )Notes:1. Designers are cautioned that parallel signalscould contain jitter up to 2 ns p-p. Directconversion of such signals from parallel to serialcould result in excessive serial signal jitter.2. Color bars are chosen as a non-stressing testsignal for jitter measurements. Use of a stressingsignal with long runs of zero could give misleadingresults.3. Use of serial clock divider value of 10 could maskword correlation jitter components.4. See SMPTE RP 184 for definition of terms.Table 2: From SMPTE ST 292-1: 2012
It is important to note that these jitter budgets are totalacceptable values at the receiver, and the output jitterfrom the transmitter must be added to overall jitter fromthe transmission line. Since the output jitter from mostSDI transmitters is around 0.1 UI, the total alignmentjitter allocated to the transmission line by the standardcan be assumed to be around 0.1 UI. Figure 8 shows thejitter of a fairly simple SMPTE 292 channel in a gimbaledvideo application with no slip ring. This jitter was partof a study to show the effect of adding a slip ring intothe transmission line. As it can be observed, since thetransmission line without the slip ring has alignment jitterof 0.16, the contribution of the slip ring to jitter must beless than 0.04 UI to maintain the 0.2 UI alignment jitterspecification.Figure 9 - Eye pattern of HD-SDI. The alignment jitter(0.16) and timing jitter (0.65 UI) are shown at the top ofthe graph. This trace shows jitter produced by transmitter,connectors, and miniature coaxial cable.This 0.2 UI alignment jitter specification is a prettytough requirement in many of the rotating systems thatuse slip rings. As can be seen from Figure 9, much of thejitter budget is “used up” by the transmitter, connectors,cables, etc. These components quickly erode the 0.2 UIalignment jitter especially in the case of digital data about1 GHz (i.e., SMPTE 292 and 424). A significant part of thedegradation of the signal waveform (alignment jitter) canbe compensated for by the use of transmit pre-emphasisand receive equalization (Zhang and Wong 2002). Infact, many of the SDI receivers have built in equalizationcircuitry making them much more forgiving of alignmentjitter than suggested by the specification. Figure 11 (fromZhang and Wong) shows the effect of this equalizationon jitter caused by signal dispersion on a printed circuitboard.7 Video Signals and Slip RingsRise time and fall time (20% and 80% of the amplitudepoints) are parameters that are addressed in paragraph8.1.5. These values should be “no greater than 270 psand shall not differ by more than 100ps.” Figure 10ashows rise and fall times that do not meet the standard’srequirement for rise and fall times (as seen by the redvalues—304 and 291 ps) due to the sharp knees in bothrise and fall time curves.Slip rings designed for SDI video are a subset of highspeed data slip rings. The primary difference is the levelof standardization imposed by the SMPTE standardscompared to many other data formats. High speeddata slip rings utilize design strategies to minimize theproblems of impedance mismatching, crosstalk, andattenuation to expand the bandwidth. To enable properrecovery of serial data, a system from the transmitterto detector should have a frequency response that isnearly flat to at least 1/2 of the clock rate (fundamentalfrequency) and the roll-off should be reasonably gentleout to three times the clock rate (TECHNICAL 2011). Inthe case of SMPTE 292, this means that the transmissionline, including the slip ring, should have a bandwidth of atleast 2.25 GHz (i.e, 3 x 750 MHz).The SMPTE standards were developed around a systemthat is composed of a signal generator, a length of coaxialcable, and a receiver. SMPTE 292 suggests that themaximum signal attenuation from cable can be in therange of 20 dB at 1/2 the clock frequency. This equatesto around 100 m of coaxial cable (depending on thecable specification). The specification also allows for awide variety of receiver re-clocking and signal recoverycapabilities. Non-standard transmission line featuressuch as slip rings, non-standard connectors, PC boards,and non-standard cable that are often used in customvideo or vision systems are not adequately covered inthe specification. Signal pre-emphasis and equalization,robust receiver technology, and short cable runs all serveto significantly improve the jitter margin of these systemsand system tests are required to accurately assess thesystem capability. In the ideal situation, the slip ringshould pass all the SMPTE requirements as demonstratedby the slip ring signal shown in Figure 10a. However, 100%compliance is not required for a slip ring to perform wellin a transmission line. Figure 10b shows the waveform ofa slip ring that fails to satisfy the rise time and fall timerequirement of the SMPTE requirement. In systems withrelatively low attenuation (less than the 100m of thecable allowed), this slip ring should perform adequately.Slip ring suppliers can provide data on video slip ringsthat can help the system architect determine if the end-
to-end transmission line has sufficient margin to reliablytransmit video data, but in some cases engineeringjudgment and/or testing is required to make the finalassessment.of the Channel Link chipset (the National Semiconductorbuilding block of Camera Link) is up to 2.38 Gbps or 595Mbps per twisted pair. The advantage is that the datarate for HD video is decreased per channel compared toHD-SDI, and the data is transmitted differentially forbetter noise rejection. The disadvantage is that a singlecoaxial connector is replaced with a 26 pin connector toaccommodate the image and control signals. Not all pinsare used on the base configuration, but the configurationis more complex than a single coaxial lead. In addition,cable length is limited to 10 meters without repeaters orfiber converters and a frame grabber is required.Figure 10a: Fully compliant SMPTE 292 waveformFigure 11: Effect of equalization at the receiver on 3.125Gbps data (SMPTE 424). The data shows the effect of a 40inch printed circuit board trace on the alignment jitter ofhigh speed data. From (Zhang and Wong 2002)Figure 10b: SMPTE 292 waveform that fails to satisfy therise time and fall time requirementsDigital Video - Other StandardsThere are a number of other HD digital data formatsthat were developed to address some of the issuessurrounding the SMPTE standards, most particularlyrelated to single-ended high-speed data transmission.Cameralink was developed by an industry consortiumof companies who produce cameras and frame grabberswith the goal of standardizing communications betweencameras and frame grabbers. Image data is transmittedon four parallel LVDS (low-voltage differential signaling)per ANSI/TIA/EIA-644 and the LVDS clock is transmittedon a separate pair. The maximum data transmission rate8 Video Signals and Slip RingsGigE Vision takes advantage of the popular andinexpensive Gigabit Ethernet PHY (physical layer) andinternet protocol (IP) to transport image data with CAT 5or CAT 6 cable. This is another standard introduced by aconsortium of camera manufacturers and is maintainedby AIA (Automated Imaging Association). The advantageof GigE Vision is that it takes advantage of the uniqueIEEE 802.3 encoding scheme to achieve a bi-directionalaggregate data speed of up to 1.0 Gbps on four twistedpairs with a bit rate of only 125 Mbps on each twisted pairat up to 100 m of cable length. (Dorsey 2012) discussesthe transmission of Ethernet signals through slip rings.An upgrade to 10 Gbps can be achieved by the use of CAT6a cable. The additional networking capability is an addedadvantage.DVI (Digital Visual Interface) is an HD display formatused to send graphics data to HD monitors (HDMIadds audio). It is not a true video camera format, butthe transmission line issues are the same. DVI uses atransition minimized differential signaling (T.M.D.S.)technique to transmit the pixel data on 3 twisted pairand a clock. A single-link DVI connection consists of fourTMDS links; each link transmits data from the source
to the device over 1 twisted wire pair. Three of thelinks correspond to the RGB components of the videosignal: red, green, blue (for a total of 24 bits per pixel.)The fourth link carries the pixel clock. Each TMDS linkcarries binary data at ten times the pixel clock referencefrequency, for a maximum data rate of 1.65 Gb/s 3 data pairs for single-link DVI. The maximum pixelclock speed is 165 Mbps for a maximum data rate pertwisted pair of 1.65 Gbps. DVI is a very robust format asdefined in Section Four of the DVI Standard. Slip ringsthat can handle SMPTE 292 can transmit DVI data ifcare is exercised to avoid channel to channel crosstalk.However, DVI does require a pin connector which uses up24 slip ring circuits making it a fairly impractical methodof transmitting HD video through slip rings.SummaryThe bandwidth challenges of transmitting videosignals through slip rings present issues similar toany interconnect problem. Control of the impedance,attenuation, and dispersion are all critical issues, andthe rotation of the slip ring does cause additional timevariable parametric changes. These RF transmission lineproperties are more important than the sliding contactsthemselves in good signal transmission; however, thecontacts do need to provide good contact resistanceover the total life of the ring. There are designs thatprovide solutions to all rotating video problems. It isimportant to understand the effect the slip ring has onthe overall quality of the transmission line (PHY layer)but some judgment is required when applying videospecifications to non-traditional applications to avoidunnecessary constraints on performance.www.moog.com 2020 Moog, Inc.Moog is a registered trademark of Moog, Inc. All trademarks as indicated herein arethe property of Moog Inc. and its subsidiaries. All rights reserved.Moog Video Signals and Slip Rings White PaperMS335103/20www.moog.comReferencesDorsey, G. (2009) “High Speed Data and Commercial Slip Rings.” Moog Inc Application Note#228.Dorsey, G. (2012) “When Ethernet Rotates: Ethernet and Slip Rings.” Moog Inc White Paper#311.Dorsey, G., et al (2012) High Speed Data Across Sliding Electrical Contacts. Proceedings 59thIEEE Holm Conference, Portland, OregonTECHNICAL (2011). “Advice on 3G-SDI Interfaces for 1080p HDTV & 3DTV.” EBU TechnicalReport 002-V1.0.Zhang, J. and Z. Wong (2002). “White paper on transmit pre-emphasis and receiveequalization” Mindspeed Technologies–A Conexant Business.GigE Vision and Camera Link are registered trademarks of the American ImagingAssociation (AIA).Figure 1aSlip ring capsule assembly image provided by Moog.Figure 1bThrough-bore assembly image provided by Moog.Figure 1cPlatter style assembly image provided by Moog.Figure 2Standard video frequency partition data provided by Moog.Figure 3NTSC time domain data provided by Moog.Figure 4NTSC frequency domain data provided by Moog.Figure 5Video ghosting example image provided by Moog.Figure 6SD-SDI standards illustration provided by Moog.Figure 7HD-SDI standards illustration provided by Moog.Figure 8Spatial resolution boundaries of SDI video provided by Moog.Figure 9Eye pattern of HD-SDI image provided by Moog.Figure 10aFully compliant SMPTE 292 waveform data image provided by Moog.Figure 10bSMPTE 292 waveform data image provided by Moog.Figure 11Effect of equalization at the receiver on 3.125 Gbps data image providedby Moog.
Video Signals and Slip Rings Glenn Dorsey Moog Inc. Business Development Specialist www.moog.com Figure 1a: Capsule assemblies. 2 Video Signals and Slip Rings Capsule Assemblies (Figure 1a) Sli
2.4 Homomorphism and quotient rings 28 2.5 Special rings 30 2.6 Modules 34 2.7 Rings with chain conditions 35 3. Smarandache rings and its properties 3.1 Definition of Smarandache ring with examples 38 3.2 Smarandache units in rings 41 3.3 Smarandache zero divisors in rings 46
Heavy Duty Back-Up Rings Heavy Duty back-up rings are configured with a greater axial thickness (T) dimension. The extra thickness provides more extrusion protec-tion for O-Rings. These rings are interchange-able with MS27595, MS28774, MS28782 and MS28783 back-up rings used in MIL-G-5514 packing glands. Heavy duty rings are available
7. COMPONENT VIDEO IN jacks: Input AV component video signals with a component video cable. (Compatible only with 480i or 576i resolution.) 8. HDMI OUT jacks: Transmit video signals and audio signals with an HDMI cable connected to a TV. 9. HDMI IN jacks: Transmit video signals and audio signals with an HDMI cable connected to an AV component. 10.
Signals And Systems by Alan V. Oppenheim and Alan S. Willsky with S. Hamid Nawab. John L. Weatherwax January 19, 2006 wax@alum.mit.edu 1. Chapter 1: Signals and Systems Problem Solutions Problem 1.3 (computing P and E for some sample signals)File Size: 203KBPage Count: 39Explore further(PDF) Oppenheim Signals and Systems 2nd Edition Solutions .www.academia.eduOppenheim signals and systems solution manualuploads.strikinglycdn.comAlan V. Oppenheim, Alan S. Willsky, with S. Hamid Signals .www.academia.eduSolved Problems signals and systemshome.npru.ac.thRecommended to you based on what's popular Feedback
gear, slip-rings, external rotor resistances etc. A squirrel cage motor is thus preferred to a slip-ring motor. A slip-ring motor also requires a larger space for the motor and its controls. 5.2 Starting of slip-ring motors These can be started by adopting either a ‘current limiting’ .
MOOG COMMERCIAL - INDUSTRIAL SLIP RINGS Moog SRA-73540 Compact Slip Ring Capsule Moog SRA-73625 Compact Slip Ring Capsule Moog AC6373 Compact Slip Ring Capsule Moog SRA-73762 Compact Slip Ring In Various Circuit Configurations P r o d u c t s & S e r v i c e s. MOOG
Using Cross Products Video 1, Video 2 Determining Whether Two Quantities are Proportional Video 1, Video 2 Modeling Real Life Video 1, Video 2 5.4 Writing and Solving Proportions Solving Proportions Using Mental Math Video 1, Video 2 Solving Proportions Using Cross Products Video 1, Video 2 Writing and Solving a Proportion Video 1, Video 2
Army training centers, and other training activities under the control of Headquarters (HQ), TRADOC and to all personnel, military and civilian, under the control of HQ TRADOC, to include Army elements stationed within Interservice Training Review Organizations (ITRO) for AIT, who interact with Trainees/Soldiers undergoing IET conducted on an installation, the commander of which is subordinate .
