US Patent Class 340
COMMUNICATIONS: ELECTRICAL




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Current as of: June, 1999
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  DF  CLASS NOTES
850  DF  UNDERWATER
851  DF  .~ Ship guidance system
852  DF  .~ Electrodes and electrode systems
853.1  DF  WELLBORE TELEMETERING OR CONTROL (E.G., SUBSURFACE TOOL GUIDANCE, DATA TRANSFER, ETC.)
853.2  DF  .~ Diagnostic monitoring or detecting operation of communications equipment or signal
853.3  DF  .~ Selective control of subsurface equipment
853.4  DF  .~.~ In horizontal or inclined drilling or passage
853.5  DF  .~.~.~ Control of drilling apparatus using magnetic field
853.6  DF  .~.~ Control of drill bit or apparatus (e.g., steering, speed, etc.)
853.7  DF  .~ Repeater in subsurface link (e.g., cable, etc.)
853.8  DF  .~ With orientation sensing of subsurface telemetering equipment (other than drilling equipment)
853.9  DF  .~ Including detail of subsurface signal storage (e.g., memory, recorder, register, etc.)
854.1  DF  .~ With position or depth recording (e.g., line payout, equipment locator, etc.)
854.2  DF  .~.~ Location of collar or stuck tool
854.3  DF  .~ Using a specific transmission medium (e.g., conductive fluid, annular spacing, etc.)
854.4  DF  .~.~ Drill string or tubing support signal conduction
854.5  DF  .~.~ Wellbore casing or ground
854.6  DF  .~.~ Electromagnetic energy (e.g., radio frequency, etc.)
854.7  DF  .~.~.~ Optical link (e.g., waveguide, etc.)
854.8  DF  .~.~.~ Near field coupling (e.g., inductive, capacitive, etc.)
854.9  DF  .~.~ Cable or wire (e.g., conductor as support, etc.)
855.1  DF  .~.~.~ Coupling connection structural feature
855.2  DF  .~.~.~ Single conductor cable or wire
855.3  DF  .~ Multiplexed signals
855.4  DF  .~ Pulse or digital signal transmission
855.5  DF  .~.~ Digital signal processing in subsurface transmitter
855.6  DF  .~.~.~ Having acoustic sensor
855.7  DF  .~ Modification of signal bandwidth, frequency, or circuit impedance at subsurface location
855.8  DF  .~ Including specified power transmission feature or source (e.g., battery, etc.)
855.9  DF  .~.~ Specified alternating current (A.C.) circuit feature
856.1  DF  .~ In horizontal or inclined passage arrangement
856.2  DF  .~ With expandable or inflatable sensor element or mounting
856.3  DF  .~ Including particular sensor
856.4  DF  .~.~ Acoustic or vibratory (e.g., sonic, fluidic, etc.)
870.01  DF  CONTINUOUSLY VARIABLE INDICATING (E.G., TELEMETERING)
870.02  DF  .~ With meter reading
870.03  DF  .~.~ Having plural transmitters
870.04  DF  .~ With calibration
870.05  DF  .~ With calculation
870.06  DF  .~.~ Plural transmitters (e.g., ratio)
870.07  DF  .~ Combined (TM system with other system)
870.08  DF  .~.~ Radio dial
870.09  DF  .~.~ With alarm or annunciator (concurrent with TM)
870.1  DF  .~ For radio sonde
870.11  DF  .~ Plural transmitters
870.12  DF  .~.~ Frequency division multiplex
870.13  DF  .~.~ Time division multiplex
870.14  DF  .~.~.~ Using particular sync
870.15  DF  .~.~ With plural receiver
870.16  DF  .~ Condition responsive
870.17  DF  .~.~ Temperature
870.18  DF  .~ Using a particular modulation (e.g., phase, frequency, or amplitude)
870.19  DF  .~.~ Pulse
870.2  DF  .~.~.~ Pulse repetition
870.21  DF  .~.~.~ Analog to digital function converter
870.22  DF  .~.~.~ Permutation code
870.23  DF  .~.~.~ Increase pulses plus decrease pulses
870.24  DF  .~.~.~ Pulse duration (e.g., pulse train)
870.25  DF  .~ Phase variation
870.26  DF  .~ Frequency variation
870.27  DF  .~ Plural circuits, each for particular magnitude
870.28  DF  .~ Via radiant energy beam (via particular energy)
870.29  DF  .~.~ Photoelectric cell pickup
870.3  DF  .~ With particular transmitter (e.g., piezoelectric, dynamo)
870.31  DF  .~.~ Inductive transmitter
870.32  DF  .~.~.~ Mutual inductance
870.33  DF  .~.~.~.~ Flux valve type (e.g., with movable saturating magnet)
870.34  DF  .~.~.~.~ Self-synchronous type
870.35  DF  .~.~.~.~ Differential type
870.36  DF  .~.~.~.~.~ Linear variable differential transformer (LVDT)
870.37  DF  .~.~ Capacitive transmitter
870.38  DF  .~.~ Resistive transmitter
870.39  DF  .~ With supply voltage regulation or compensation
870.4  DF  .~ With particular receiver (e.g., ratiometer)
870.41  DF  .~.~ Plural receivers
870.42  DF  .~.~ With feedback (e.g., reflex along line)
870.43  DF  .~.~.~ Follow-up (e.g., circuit rebalanced when upset)
870.44  DF  .~.~ With discharge device (e.g., CRT)
901  DF  EXTERNAL CONDITION VEHICLE-MOUNTED INDICATOR OR ALARM
902  DF  .~ Transmitter in another vehicle (e.g., emergency vehicle)
903  DF  .~.~ Relative distence between vehicles (e.g., collision alert)
904  DF  .~ Transmitter in one vehicle only
905  DF  .~ Highway information (e.g., weather, speed limits, etc.)
906  DF  OVERRIDE OF TRAFFIC CONTROL INDICATOR BY COMMAND TRANSMITTER
907  DF  TRAFFIC CONTROL INDICATOR
908  DF  .~ Portable
908.1  DF  .~.~ Barricade marker
909  DF  .~ Plural intersections under common central station control
910  DF  .~.~ Central station responsive to traffic detectors
911  DF  .~.~.~ Central station controls offset (time between beginning of same phase at adjacent intersections)
912  DF  .~.~ Standby cycling implemented if invalid transmission received or loss of transmission occurs
913  DF  .~.~ Offset control
914  DF  .~.~ Split control
915  DF  .~.~ Central station includes display of status of indicators
916  DF  .~ Intersection normally under local controller
917  DF  .~.~ Controller responsive to traffic detectors
918  DF  .~.~.~ Controller, when changing right of way, alters or skips normal "go" cycle of street having no traffic detected
919  DF  .~.~.~ Plural cross highways at intersection each have traffic detectors
920  DF  .~.~.~.~ Density determines split
921  DF  .~.~.~.~.~ Extension of time
922  DF  .~.~.~ Density determines split
923  DF  .~.~.~ Extension of time
924  DF  .~.~ Local controller can be superceded by central station controller
925  DF  .~.~ Pedestrian control
926  DF  .~.~ Manual setting of cycle length and split times
927  DF  .~.~ Rotating cam structure (specific structure required)
928  DF  .~ Combined (e.g., toll systems, one-way)
929  DF  .~ Indication of time remaining before change of phase
930  DF  .~.~ Electromechanical movable auxiliary indicator
931  DF  .~ Traffic control or local controller failure indicator
932  DF  .~ Pacing (e.g., vehicle keeps pace with sequentially activated lights)
932.1  DF  .~ Pivoted
932.2  DF  VEHICLE PARKING INDICATORS
933  DF  VEHICLE DETECTORS
934  DF  .~ Density
935  DF  .~ Discriminates vehicle direction
936  DF  .~ Speed and overspeed
937  DF  .~ With camera
938  DF  .~ Compensation for vehicle remaining at sensor position
939  DF  .~ Environmental or drift compensation
940  DF  .~ With pneumatic
941  DF  .~ Inductive
942  DF  .~ Photoelectric
943  DF  .~ Sonic or ultrasonic
944  DF  PEDESTRIAN GUIDANCE
945  DF  AIRCRAFT ALARM OR INDICATING SYSTEMS
946  DF  .~ Nonairplane (e.g., balloon or helicopter)
947  DF  .~ Land-based landing guidance
948  DF  .~.~ Aircraft actuation of land-based landing guides
949  DF  .~.~ Wind direction
950  DF  .~.~ Movable (e.g., rotatable) guides
951  DF  .~.~ Phased landing guidance (e.g., runway approach, landing, touchdown)
952  DF  .~.~ Particular energy guide source (e.g., sound, electric field, radio)
953  DF  .~.~.~ Visual source
954  DF  .~.~.~.~ Alignment of plural sources
955  DF  .~.~.~.~ Plural colors
956  DF  .~.~.~.~ Modulated light source
957  DF  .~.~.~ Magnetic field guide
958  DF  .~ Docking guidance
959  DF  .~ Takeoff indicator
960  DF  .~ Landing gear indicator
961  DF  .~ Potential collision with other aircraft
962  DF  .~ Icing indicator
963  DF  .~ Flight alarm
964  DF  .~.~ Phased warnings for same flight condition
965  DF  .~.~ Tactile
966  DF  .~.~ Stall
967  DF  .~.~ Attitude (including yaw, angle of attack, roll, pitch, glide slope)
968  DF  .~.~ Wind shear
969  DF  .~.~ Speed
970  DF  .~.~ Altitude
971  DF  .~ Nonalarm flight indicator
972  DF  .~.~ Runway presentation
973  DF  .~.~ Indicator of at least four flight parameters (altitude, speed, etc.)
974  DF  .~.~ Attitude
975  DF  .~.~.~ Roll or pitch
976  DF  .~.~.~ Glide slope or path
977  DF  .~.~ Altitude
978  DF  .~.~ Speed
979  DF  .~.~ Heading (includes deviation from desired course)
980  DF  .~.~ Indicator visible in pilot's line of sight through windscreen
981  DF  .~ Aircraft beacons
982  DF  .~.~ Lights communicate (e.g., direction, altitude, reference position to observer)
983  DF  .~ Obstruction beacon
984  DF  WATERCRAFT ALARM OR INDICATING SYSTEMS
985  DF  .~ Navigation guides (e.g., channel lights)
986  DF  .~ Anchor movement
987  DF  .~ Rudder position indicator
988  DF  VEHICLE POSITION INDICATION
989  DF  .~ At remote location
990  DF  .~.~ With map display
991  DF  .~.~ Position indication transmitted by vehicle after receipt of information from local station
992  DF  .~.~ Position indication transmitted at periodic intervals (e.g., distance travelled)
993  DF  .~.~ Position indication transmitted by local station to remote location
994  DF  .~.~ Vehicle's arrival or expected arrival at remote location along route indicated at that remote location (e.g., bus arrival systems)
995  DF  .~ Map display
996  DF  .~ Prerecorded message describes position
425.5  DF  LAND VEHICLE ALARMS OR INDICATORS
426  DF  .~ Of burglary or unauthorized use
427  DF  .~.~ Of motorcycles or bicycles
428  DF  .~.~ Responsive to changes in voltage or current in a vehicle electrical system
429  DF  .~.~ Responsive to inertia, vibration, or tilt
430  DF  .~.~ With entrance/exit time delay
431  DF  .~ For trailer
432  DF  .~ For bicycle
433  DF  .~ For school bus
434  DF  .~ For taxi
435  DF  .~ Of relative distance from an obstacle
436  DF  .~ Of collision or contact with external object
437  DF  .~.~ Curb
438  DF  .~ Internal alarm or indicator responsive to a condition of the vehicle
439  DF  .~.~ Operation efficiency (e.g., engine performance, driver habits)
440  DF  .~.~ Tilt, imbalance, or overload
441  DF  .~.~ Speed of vehicle, engine, or power train
442  DF  .~.~ Tire deflation or inflation
443  DF  .~.~.~ By indirect detection means (e.g., height measurement)
444  DF  .~.~.~.~ Relative wheel speed
445  DF  .~.~.~ With particular telemetric coupling
446  DF  .~.~.~.~ Acoustic wave
447  DF  .~.~.~.~ Radio wave
448  DF  .~.~.~.~ Inductive
449  DF  .~.~ Temperature
450  DF  .~.~ Fluid level
450.1  DF  .~.~.~ Of hydraulic brake fluid
450.2  DF  .~.~.~ Of fuel
450.3  DF  .~.~.~ Of lubricant (e.g., engine oil)
451  DF  .~.~ Fluid pressure
452  DF  .~.~.~ Of brake fluid
453  DF  .~.~ Brake or clutch condition
454  DF  .~.~.~ Wear
455  DF  .~.~ Battery charging system condition
456  DF  .~.~ Gear position
457  DF  .~.~ Reminder
457.1  DF  .~.~.~ Of seat belt application
457.2  DF  .~.~.~ Of headlight energization
457.3  DF  .~.~.~ Of parking brake application
457.4  DF  .~.~.~ Of service interval expiration
458  DF  .~.~ Lamp or lamp circuit condition
459  DF  .~.~ Plural conditions
460  DF  .~.~.~ With voice warning
461  DF  .~.~.~ With particular display means
462  DF  .~.~.~.~ Digital
463  DF  .~ External alarm or indicator of movement
464  DF  .~.~ Plural indications (e.g., go, slow, stop)
465  DF  .~.~ Turning or steering
466  DF  .~.~ Speed
467  DF  .~.~ Acceleration or deceleration
468  DF  .~ External signal light system
469  DF  .~.~ With two or more intensity levels (e.g., day or night)
470  DF  .~.~ Pass - no pass
471  DF  .~.~ Hazard warning or distress signalling
472  DF  .~.~.~ Auxiliary signal permanently attached to vehicle
473  DF  .~.~.~ Portable signal
474  DF  .~.~ With audible signal
475  DF  .~.~ Turn signal
476  DF  .~.~.~ With automatic cancelling
477  DF  .~.~.~.~ By predetermined time interval or distance
478  DF  .~.~.~ With plural bulbs sequentially flashed
479  DF  .~.~ Brake light
480  DF  .~ Electromagnetically actuated mechanical signal
481  DF  .~.~ Wigwag type
482  DF  .~.~ Normally encased
483  DF  .~.~.~ Plural concurrent indicators
484  DF  .~.~.~ Sliding sign or shutter
485  DF  .~.~.~ Window exhibited sign or shutter
486  DF  .~.~.~.~ Drum
487  DF  .~.~ Pivoting
488  DF  .~.~.~ Multiple indicators
489  DF  .~.~.~ Three or more positions
490  DF  .~.~.~.~ Vertical axis
146.2  DF  DIGITAL COMPARATOR SYSTEMS
500  DF  CONDITION RESPONSIVE INDICATING SYSTEM
501  DF  .~ With particular system function (e.g., temperature compensation, calibration)
502  DF  .~.~ Acknowledgement
503  DF  .~.~.~ With ringback
504  DF  .~.~ Answer-back
505  DF  .~.~ Interrogator-responder
506  DF  .~.~ Alarm system supervision
507  DF  .~.~.~ Fail-safe
508  DF  .~.~.~ Redundant (e.g., added circuit or loop)
509  DF  .~.~.~ Plural or diverse current sources
510  DF  .~.~.~ Bridge or potential divider
511  DF  .~.~.~ Threshold or window (e.g., of analog electrical level)
512  DF  .~.~.~ Pulse
513  DF  .~.~.~ Diode
514  DF  .~.~ Testing
515  DF  .~.~.~ Simulation of condition
516  DF  .~.~.~ Automatic (e.g., periodic, start-up)
517  DF  .~.~ Selection from a plurality of sensed conditions
518  DF  .~.~.~ Scanning
519  DF  .~.~.~ Worst condition
520  DF  .~.~.~ First sensed exclusively indicated
521  DF  .~.~.~ Plural diverse conditions
522  DF  .~.~.~.~ Combined for response
523  DF  .~.~.~ Particular sequence of conditions
524  DF  .~.~.~ Condition position indicator
525  DF  .~.~.~.~ Display board
526  DF  .~.~ Predetermined rate of occurrence
527  DF  .~.~ Time delay
528  DF  .~.~.~ Entrance/exit
529  DF  .~.~.~ Condition persistence
530  DF  .~.~.~.~ Capacitor
531  DF  .~ With particular coupling link
532  DF  .~.~ Having particular safety function
533  DF  .~.~ Wired
534  DF  .~.~.~ Coded message
535  DF  .~.~.~.~ Mechanical code means (e.g., coded disc)
536  DF  .~.~.~ Noninterfering
537  DF  .~.~.~ With impedance level coding
538  DF  .~.~.~ Combined with power line
539  DF  .~.~ Radio
540  DF  .~ Specific condition
541  DF  .~.~ Intrusion detection
542  DF  .~.~.~ Lock
543  DF  .~.~.~.~ Permutation
544  DF  .~.~.~ Disturbance of fluid pressure
545.1  DF  .~.~.~ Door or window movement
546  DF  .~.~.~.~ Portable
545.2  DF  .~.~.~.~ Specified sensor
547  DF  .~.~.~.~.~ Magnetic sensor
548  DF  .~.~.~.~.~ Plug or cord tension sensor
549  DF  .~.~.~.~.~ Rotatable sensor
545.3  DF  .~.~.~.~.~ Sensing of electromagnetic energy (e.g., light, infrared, or microwave)
545.4  DF  .~.~.~.~.~ Sensing of electrical parameter (e.g., piezoelectricity or capacitance)
545.5  DF  .~.~.~.~.~ Inertia-type sensor (e.g., mercury or pendulum switch)
545.6  DF  .~.~.~.~ Door, cover, or lid for self-contained article (e.g., refrigerator, mailbox, drawer, cabinet, or box)
545.7  DF  .~.~.~.~ Specified door or window portion (e.g., doorknob)
545.8  DF  .~.~.~.~ Specified door or window attachment (e.g., shade or blind)
545.9  DF  .~.~.~.~ Plural doors or windows
550  DF  .~.~.~ Partition penetration
551  DF  .~.~.~ Disturbance of magnetic field
552  DF  .~.~.~ Disturbance of electromagnetic waves
553  DF  .~.~.~.~ Standing waves
554  DF  .~.~.~.~ Doppler effect
555  DF  .~.~.~.~ Light
556  DF  .~.~.~.~.~ Beam
557  DF  .~.~.~.~.~.~ Laser
561  DF  .~.~.~ Disturbance of electric field
562  DF  .~.~.~.~ Capacitance
563  DF  .~.~.~.~.~ With bridge
564  DF  .~.~.~.~.~ Fence
565  DF  .~.~.~ Responsive to intruder energy
566  DF  .~.~.~.~ Vibration
567  DF  .~.~.~.~ Electromagnetic energy
568.1  DF  .~.~ Article placement or removal (e.g., anti-theft)
568.2  DF  .~.~.~ Signal-carrying conduit between sensor and article (e.g., cable, power cord, or data link)
568.3  DF  .~.~.~.~ Power cord
568.4  DF  .~.~.~.~ Specified connector (e.g., phone jack-type plug)
568.5  DF  .~.~.~ Shopping cart or item thereon
568.6  DD  .~.~.~ Sporting equipment (e.g., golfbag, club, cart, or skis)
568.7  DF  .~.~.~ Currency, credit card, or container therefor (e.g., wallet or handbag)
568.8  DF  .~.~.~ Article on pedestal, in display case, or mounted on wall (e.g., work of art)
569  DF  .~.~.~ Mailbox
570  DF  .~.~.~ Drawer
571  DF  .~.~.~ Alarm on protected article
572.1  DF  .~.~.~ Detectable device on protected article (e.g., "tag")
572.2  DF  .~.~.~.~ Specified relationship between field and detection frequencies (e.g., nth order harmonics)
572.3  DF  .~.~.~.~ Deactivatable by means other than mere removal
572.4  DF  .~.~.~.~ Specified processing arrangement for detected signal
572.5  DF  .~.~.~.~ Having tuned resonant circuit
572.6  DF  .~.~.~.~ Having "soft" magnetic element (e.g., Permalloy)
572.7  DF  .~.~.~.~ Specified antenna structure
572.8  DF  .~.~.~.~ Specified device housing or attachment means
572.9  DF  .~.~.~.~.~ Having means locking device to article
573.1  DF  .~.~ Human or animal
574  DF  .~.~.~ Holdup
575  DF  .~.~.~ Sleep
576  DF  .~.~.~ Drive capability
573.2  DF  .~.~.~ Nondomestic animal (e.g., for hunting, fishing, or repelling)
573.3  DF  .~.~.~ Domestic animal training, monitoring, or controlling
573.4  DF  .~.~.~ House arrest system, wandering, or wrong place
573.5  DF  .~.~.~ Incontinence or enuresis alarm
573.6  DF  .~.~.~ Water safety alarm
573.7  DF  .~.~.~ Posture alarm
577  DF  .~.~ Flame
578  DF  .~.~.~ By radiant energy
579  DF  .~.~.~ By ionization or conductivity
580  DF  .~.~ Ice formation
581  DF  .~.~.~ Thermal
582  DF  .~.~.~ Vibratory
583  DF  .~.~.~ Photoelectric
584  DF  .~.~ Thermal
585  DF  .~.~.~ Refrigerated storage
586  DF  .~.~.~ Portable
587  DF  .~.~.~ False alarm resistant
588  DF  .~.~.~ Time-temperature relationship (e.g., overtemperature exceeds predetermined interval or time-temperature integral)
589  DF  .~.~.~.~ Rate of temperature change
590  DF  .~.~.~ Fusible, frangible, or destructible sensor
591  DF  .~.~.~.~ Containing pressurized fluid
592  DF  .~.~.~ Expanding fluid sensor
593  DF  .~.~.~ Switch sensor
594  DF  .~.~.~.~ With bimetallic element
595  DF  .~.~.~ Current modifier or generator
596  DF  .~.~.~.~ Cable or elongated probe
597  DF  .~.~.~.~ Curie point sensor
598  DF  .~.~.~.~ Barrier-layer sensor
599  DF  .~.~.~.~ Bridge circuit
600  DF  .~.~ Radiant energy
601  DF  .~.~ Meteorological condition
602  DF  .~.~.~ Moisture or humidity (e.g., rain)
603  DF  .~.~ Fluent material
604  DF  .~.~.~ Wetness
605  DF  .~.~.~ Leakage
606  DF  .~.~.~ Flow rate
607  DF  .~.~.~.~ Filter clogging
608  DF  .~.~.~.~ Stoppage
609  DF  .~.~.~.~ Counting
610  DF  .~.~.~.~ Vane in flow path
611  DF  .~.~.~.~ Pressure
612  DF  .~.~.~ Material level
613  DF  .~.~.~.~ Weight in container
614  DF  .~.~.~.~ Pressure
615  DF  .~.~.~.~ Moving sensor (e.g., impeller)
616  DF  .~.~.~.~ Overflow
617  DF  .~.~.~.~ Pulverant material (e.g., bin)
618  DF  .~.~.~.~ Liquid
619  DF  .~.~.~.~.~ Optical sensor
620  DF  .~.~.~.~.~ Electrode probe
621  DF  .~.~.~.~.~ Having sonic sensor
622  DF  .~.~.~.~.~ Having heat sensor
623  DF  .~.~.~.~.~ Float sensor
624  DF  .~.~.~.~.~.~ Vertically reciprocable
625  DF  .~.~.~.~.~.~ Pivoted arm
626  DF  .~.~.~ Pressure
627  DF  .~.~.~ Particle suspension in fluid
628  DF  .~.~.~.~ Smoke
629  DF  .~.~.~.~.~ Ionization
630  DF  .~.~.~.~.~ Photoelectric
631  DF  .~.~.~.~ Lubricant
632  DF  .~.~.~ Gas
633  DF  .~.~.~.~ Catalytic detector
634  DF  .~.~.~.~ Semiconductor detector
635  DF  .~.~ Condition of electrical apparatus
636  DF  .~.~.~ Battery
637  DF  .~.~.~ Watt-hour meter
638  DF  .~.~.~ Fuse or circuit breaker
639  DF  .~.~.~.~ Plural
640  DF  .~.~.~ Heater element
641  DF  .~.~.~ Signalling light element
642  DF  .~.~.~.~ Plural bulbs or filaments
643  DF  .~.~.~.~ Thermal or magnetic current sensors
644  DF  .~.~.~ Switch or relay
645  DF  .~.~.~ Rectifier
646  DF  .~.~.~ Transformer
647  DF  .~.~.~ Insulation
648  DF  .~.~.~ Motor
649  DF  .~.~.~ Condition of intentional grounding circuit
650  DF  .~.~.~ Undesired circuit ground or short
651  DF  .~.~.~.~ For plural circuit conductors
652  DF  .~.~.~ Breaking of circuit continuity
653  DF  .~.~.~ Electronic circuit or component
654  DF  .~.~.~ Circuit energization
655  DF  .~.~.~.~ Heating circuit
656  DF  .~.~.~.~ Electrical socket
657  DF  .~.~ Electrical characteristic
658  DF  .~.~.~ Phase or frequency
659  DF  .~.~.~ Pulse or surge
660  DF  .~.~.~ Voltage
661  DF  .~.~.~.~ Comparison
662  DF  .~.~.~.~ Overvoltage
663  DF  .~.~.~.~ Undervoltage
664  DF  .~.~.~ Current
665  DF  .~.~ Force or stress
666  DF  .~.~.~ Weight
667  DF  .~.~.~.~ On seat
668  DF  .~.~.~ Tension
669  DF  .~.~ Acceleration
670  DF  .~.~ Velocity
671  DF  .~.~.~ Angular
672  DF  .~.~.~.~ Direction of shaft rotation
673  DF  .~.~ Article transport
674  DF  .~.~.~ Discrete articles
675  DF  .~.~.~ Web, film, or strip
676  DF  .~.~.~.~ Conveyor belt
677  DF  .~.~.~ Strand
678  DF  .~.~ Of geometrical gauge
679  DF  .~.~ Machine condition
680  DF  .~.~.~ Machine tool
681  DF  .~.~.~ Synchronization
682  DF  .~.~.~ Bearing
683  DF  .~.~.~ Vibration
684  DF  .~.~.~ Agricultural
685  DF  .~.~.~ Cranes
686.1  DF  .~.~ Position responsive
687  DF  .~.~.~ Connected or disconnected
688  DF  .~.~.~ Meter dial
689  DF  .~.~.~ Tilt
690  DF  .~.~.~ Geophysical (e.g., fault slip)
686.2  DF  .~.~.~ Alignment or misalignment
686.3  DF  .~.~.~ Shaft or rotary element
686.4  DF  .~.~.~ One article inserted into another
686.5  DF  .~.~.~ Workpiece
686.6  DF  .~.~.~ Proximity or distance
691.1  DF  .~ Specified indicator structure
691.2  DF  .~.~ Simulated effect
691.3  DF  .~.~ Degree or urgency
691.4  DF  .~.~ Plural
691.5  DF  .~.~.~ Diverse
691.6  DF  .~.~ Information display
692  DF  .~.~ Sound reproducer
691.7  DF  .~.~ Mechanical
691.8  DF  .~.~ Control circuit detail
693.1  DF  .~ Specified power supply
693.2  DF  .~.~ Substitute or emergency source (e.g., back-up battery)
693.3  DF  .~.~ Having reduced power consumption (e.g., intermittent power)
693.4  DF  .~.~ Having specified voltage regulator
693.5  DF  .~ Specified housing
693.6  DF  .~.~ Configured to promote sensing capability (e.g., smoke detector)
693.7  DF  .~.~.~ Inserted battery required for housing closure
693.8  DF  .~.~ Simulation
693.9  DF  .~.~ Having specified mounting structure
693.11  DF  .~.~.~ To wall or ceiling
693.12  DF  .~.~.~ Within another housing
825  DF  SELECTIVE
825.01  DF  .~ Spare channel
825.02  DF  .~ Tree or cascade
825.03  DF  .~ Channel selection
826  DF  .~.~ Plural stage matrix system (e.g., path finding)
827  DF  .~.~.~ Alternate routing
825.04  DF  .~.~ Code or pulse responsive
825.06  DF  .~ Monitoring and control (e.g., supervisory)
825.07  DF  .~.~ With addressing
825.08  DF  .~.~.~ Polling or roll call
825.09  DF  .~.~ Quiescent
825.1  DF  .~.~ Scanning
825.11  DF  .~.~.~ Continuous
825.12  DF  .~.~.~ Interrupted
825.13  DF  .~.~.~.~ Automatic
825.14  DF  .~.~ Synchronization
825.15  DF  .~.~ With storage or recording
825.16  DF  .~.~ Fault condition
825.17  DF  .~.~ With indicator
825.18  DF  .~.~ Relay
825.19  DF  .~ Communication or control for the handicapped
825.2  DF  .~ Synchronizing
825.21  DF  .~.~ With addressing
825.22  DF  .~ Program control
825.23  DF  .~.~ Machine tool
825.24  DF  .~.~ Of audio system
825.25  DF  .~ Audio system (e.g., by pulse signal)
825.26  DF  .~ Stock quotation
825.27  DF  .~.~ With information storage
825.28  DF  .~ Space allocation (e.g., vehicle seat, hotel reservation)
825.29  DF  .~.~ Remote terminal
825.3  DF  .~ Intelligence comparison
825.31  DF  .~.~ Authorization control (e.g., entry into an area)
825.32  DF  .~.~.~ With alarm or indication of improper access
825.33  DF  .~.~.~ Credit
825.34  DF  .~.~ Authentication (e.g., identity)
825.35  DF  .~.~ Commodity (e.g., vending)
825.36  DF  .~ Having indication or alarm (e.g., location indication)
825.37  DF  .~.~ Additional to other selective control
825.38  DF  .~.~ Party line
825.39  DF  .~.~.~ Selection by means of frequency
825.4  DF  .~.~.~ Selector or indicator, per se
825.41  DF  .~.~.~ Step-by-step impulse
825.42  DF  .~.~.~.~ Polarity controlled
825.43  DF  .~.~.~ Amplitude or polarity controlled
825.44  DF  .~.~ Code responsive (e.g., paging)
825.45  DF  .~.~.~ Distress signal alarm
825.46  DF  .~.~.~ Vibratory (tactual) alarm
825.47  DF  .~.~.~ Group call
825.48  DF  .~.~.~ Tone code
825.49  DF  .~.~ Location indication
825.5  DF  .~ Lockout or priority (programmed or variable)
825.51  DF  .~.~ Designated priority
825.52  DF  .~ Addressing
825.53  DF  .~.~ Plural part (e.g., digit) or repetitions
825.54  DF  .~ Interrogation response
825.55  DF  .~.~ Printout (e.g., logging) or display
825.56  DF  .~ With multidigit encoder
825.57  DF  .~ Pulse responsive actuation
825.58  DF  .~.~ Phase or frequency shift keying
825.59  DF  .~.~ Polarity
825.6  DF  .~.~ Pulse pairs
825.61  DF  .~.~ Having delay line
825.62  DF  .~.~ Serial
825.63  DF  .~.~.~ Pulse width
825.64  DF  .~.~.~ Pulse spacing (e.g., pulse repetition rate)
825.65  DF  .~.~.~ Counting
825.66  DF  .~.~.~.~ Relay
825.67  DF  .~.~.~.~ Counting chain
825.68  DF  .~.~.~ Shift register
825.69  DF  .~.~.~ Radio link
825.7  DF  .~ Phase responsive actuation
825.71  DF  .~ Frequency responsive actuation
825.72  DF  .~.~ Wireless link
825.73  DF  .~.~ Plural frequencies
825.74  DF  .~.~.~ Simultaneous
825.75  DF  .~.~.~ Permutation
825.76  DF  .~.~.~ Corresponding to distinct functions
825.77  DF  .~ Amplitude responsive actuation
825.78  DF  .~.~ Divided resistor
825.79  DF  .~ Matrix
825.8  DF  .~.~ Plural stage
825.81  DF  .~.~ Electroluminescent elements
825.82  DF  .~.~.~ Light-emitting diode
825.83  DF  .~.~ Programmable
825.84  DF  .~.~.~ Having fusible element
825.85  DF  .~.~ Semiconductor crosspoint
825.86  DF  .~.~.~ Integrated circuit
825.87  DF  .~.~.~ Logic
825.88  DF  .~.~.~ Bistable
825.89  DF  .~.~.~ Switching element
825.9  DF  .~.~.~ Transistor
825.91  DF  .~.~.~.~ Field effect transistor
825.92  DF  .~.~.~.~ Four or more elements
825.93  DF  .~.~.~.~ Plural
825.94  DF  .~.~.~ Diodes
825.95  DF  .~.~.~.~ Charge storage
825.96  DF  .~.~.~.~ Plural diodes at crosspoint
825.97  DF  .~ Having electron beam device
825.98  DF  .~ System having rectifier
286.01  DF  SYSTEMS
286.02  DF  .~ Network signaling
286.03  DF  .~.~ Speaking tube including circuit
286.04  DF  .~ Manual alarm telegraph; e.g., other than signal box type
286.05  DF  .~.~ Fire
286.06  DF  .~ Call station
286.07  DF  .~.~ Hospital
286.08  DF  .~.~ Hotel
286.09  DF  .~.~ Restaurant
286.11  DF  .~ Annunciator
286.12  DF  .~.~ Drop annunciator
286.13  DF  .~ Mimic
286.14  DF  .~.~ Mapping
287  DF  .~ Signal box type (e.g., to call messenger, plural fire alarm boxes)
288  DF  .~.~ Combined (e.g., alarm circuit over power line)
289  DF  .~.~.~ With fire extinguisher (e.g., CO2)
290  DF  .~.~.~ Engine house apparatus controlling (e.g., releases horses, starts motor)
291  DF  .~.~ Repeaters (e.g., from central to plural fire houses or to siren)
292  DF  .~.~ Circuit maintenance (e.g., fault alarm, faulty circuit substitution)
293  DF  .~.~ Variable signal (e.g., police and fire, first and third alarm)
294  DF  .~.~.~ Dial selector for variable signal
295  DF  .~.~ Noninterfering (prevents break-in by another box during transmission)
296  DF  .~.~.~ Key obstruction type
297  DF  .~.~ With signal at box (e.g., preliminary signal to combat false alarms)
298  DF  .~.~.~ Answer back signal acknowledges transmitted signal
299  DF  .~.~.~ Simultaneous (e.g., actuated by transmitted signal)
300  DF  .~.~.~ Lamp at box (e.g., to call patrolman)
301  DF  .~.~ Portable box actuating key (e.g., key must be released by signal from central)
302  DF  .~.~.~ Frangible guard or protector for key
303  DF  .~.~ Frangible element must be broken to send signal
304  DF  .~.~ False alarm combating (e.g., detention devices)
305  DF  .~.~ Local circuit to actuate box
306  DF  .~.~.~ Watchman's local circuit
307  DF  .~.~ Transmitters
308  DF  .~.~.~ Controlled by door of signal box
309  DF  .~.~.~ With make and break wheel
309.15  DF  .~ Timer controlled
309.2  DF  .~.~ With nonelectrical indicator or exhibitor
309.3  DF  .~.~ With diversely controlled indicator
309.4  DF  .~.~ Selectively or sequentially actuated indicators
309.5  DF  .~.~.~ With independent manual controller
309.6  DF  .~.~ Circuit maker-breaker in series
310.01  DF  .~ Signal over power line
310.02  DF  .~.~ Modulation technique
310.03  DF  .~.~ Noise reduction (e.g., filtering)
310.04  DF  .~.~.~ Zero crossing
310.05  DF  .~.~ Impedance matching (e.g., Y-match or delta match)
310.06  DF  .~.~ Bidirectional (e.g., with transceiver)
310.07  DF  .~.~ With inductive coupling (e.g., transformer or torroid)
310.08  DF  .~.~ With coupling plug
311.1  DF  .~ Paging
313  DF  .~ Answer back
314  DF  .~.~ Noncorrespondence alarm (e.g., if acknowledgement is incorrect)
315  DF  .~ Selsyn type
316  DF  .~ Rebalancing at receiver
317  DF  .~.~ Automatic rebalancing
318  DF  .~ Synchronous distributor at transmitter and receiver
319  DF  .~ Plural electromagnets or plural motors receiver
320  DF  .~ Via fluid conduit (e.g., fire hose)
321  DF  .~ Portable self-contained (e.g., movie usher's signalling flashlight)
322  DF  .~ Self-cancelling after fixed time
323 R  DF  .~ Game reporting
323 B  DF  .~.~ Bowling
326  DF  .~ Plural (e.g., concurrent auxiliary) single indications (e.g., light flashes when bell rings)
327  DF  .~.~ With sounder signal cut-off
328  DF  .~ Audible signals (e.g., bell rings softly first and then loudly)
329  DF  .~.~ Intermittent
330  DF  .~ In and out indicators (e.g., doorbell button flashes "out" sign)
331  DF  .~ Periodic or flashing
332  DF  .~ Signal light systems
333  DF  .~ With specific power supply (e.g., power substitution)
425.1  DF  REPEATER IN UNSPECIFIED TYPE COMMUNICATIONS LINE OR CHANNEL (E.G., RELAY STATION)
425.2  DF  .~ Power control
407.1  DF  TACTUAL INDICATION
407.2  DF  .~ With input means (e.g., keyboard)
815.4  DF  VISUAL INDICATION
815.41  DF  .~ False signal prevention (anti-sunlight)
815.42  DF  .~ Having light piping
815.43  DF  .~.~ With specified colors
815.44  DF  .~ Seven-segment indicator
815.45  DF  .~ Using light emitting diodes
815.46  DF  .~ Audio responsive lamp
815.47  DF  .~ Switchboard or panel type (e.g., bullseye)
815.48  DF  .~.~ Pushbutton
815.49  DF  .~.~ Housing
815.5  DF  .~.~.~ Including optical means
815.51  DF  .~.~.~ Including spring
815.52  DF  .~.~ With details of energizing circuit
815.53  DF  .~ Lighted alphanumeric or character indicator matrix
815.54  DF  .~.~ Having optical means in viewing path
815.55  DF  .~ Transparent or translucent indicator with means for blocking light
815.56  DF  .~.~ Color
815.57  DF  .~.~ Having optical device
815.58  DF  .~ Step by step positioner
815.59  DF  .~.~ Having resetting device
815.6  DF  .~.~ Remote controller
815.61  DF  .~.~ Drum indicator
815.62  DF  .~ Electromagnetic actuator for indicator matrix
815.63  DF  .~ Binary indicator
815.64  DF  .~ Electromagnetic rotator for indicator wheel
815.65  DF  .~ Multiple colors
815.66  DF  .~.~ By light signal
815.67  DF  .~.~.~ Plural
815.68  DF  .~.~.~ With movable optical means
815.69  DF  .~ Diverse indications
815.7  DF  .~.~ Having percussion type indication (e.g., electric bells, chimes)
815.71  DF  .~.~.~ Electromagnetic
815.72  DF  .~.~ Having pneumatic type indication
815.73  DF  .~ With lamp enclosed in transparent housing
815.74  DF  .~.~ Combined
815.75  DF  .~.~ Light source modifier
815.76  DF  .~.~.~ Lens type
815.77  DF  .~.~ Relatively movable light source
815.78  DF  .~ Pointer indicator
815.79  DF  .~.~ Annunciator
815.8  DF  .~.~.~ Having electromagnetically releasable latch
815.81  DF  .~ Grouped drop annunciators
815.82  DF  .~.~ Support
815.83  DF  .~ Movable
815.84  DF  .~.~ Semaphore
815.85  DF  .~.~ Self restoring type annunciator
815.86  DF  .~.~ Rotary
815.87  DF  .~.~.~ Rotor driven
815.88  DF  .~.~.~ Vane indicator
815.89  DF  .~.~ Circuit closing type
815.9  DF  .~.~ By electromagnetically releasable latch
815.91  DF  .~.~.~ Having restoring means
815.92  DF  .~.~.~ Gravity operated drop annunciator
384.1  DF  AUDIBLE INDICATION
384.2  DF  .~ Ultrasonic pest control
384.3  DF  .~ Simulation
384.4  DF  .~ Electronic siren (e.g., wail tone or yelp tone warning device)
384.5  DF  .~ With computer element
384.6  DF  .~ Piezoelectric
384.7  DF  .~ Electronic
384.71  DF  .~.~ Timing
384.72  DF  .~.~ Plural generators
384.73  DF  .~.~ With sound transducer details
385.1  DF  .~ Explosive
387.1  DF  .~ Weatherproofing
388.1  DF  .~ Diaphragm (e.g., horn or buzzer)
390.1  DF  .~.~ Rotary actuator
390.2  DF  .~.~.~ Having spring
388.2  DF  .~.~ Alternating current
388.3  DF  .~.~ With auxiliary flexible membrane
388.4  DF  .~.~ With resonance chamber
388.5  DF  .~.~ Armature support
388.6  DF  .~.~.~ Having spring
388.7  DF  .~.~ Interrupter
388.8  DF  .~.~.~ Having spring
391.1  DF  .~.~ Housing or mounting
392.1  DF  .~ Percussion-type sound producer (e.g., signal chimes or bells)
392.2  DF  .~.~ Rotary actuator
393.1  DF  .~.~ Plural armatures
393.2  DF  .~.~ Battery operated
393.3  DF  .~.~ Pushbutton
393.4  DF  .~.~ Including timer
392.3  DF  .~.~ Volume control
401.1  DF  .~.~ Alternating current
398.1  DF  .~.~ Nonelectrical driving means (e.g., spring or weight)
398.2  DF  .~.~.~ With electromagnetic control
398.3  DF  .~.~.~.~ Including circuit breaker
392.4  DF  .~.~ Tubular sound producer (e.g., signal chimes)
392.5  DF  .~.~ Resonator (e.g., signal chimes)
395.1  DF  .~.~ Suspended (e.g., locomotive bell)
397.1  DF  .~.~ Armature support
397.2  DF  .~.~.~ Having spring
397.3  DF  .~.~ Interrupter
397.4  DF  .~.~.~ Having spring
397.5  DF  .~.~ Polarized
396.1  DF  .~.~ Housing or mounting
404.1  DF  .~ Pneumatic-type sound producer (e.g., whistle or siren)
404.2  DF  .~.~ Rotary actuator
404.3  DF  .~.~ With valve
999  DF  MISCELLANEOUS
*********************************
FOREIGN ART COLLECTIONS
*********************************
*  DD  CONDITION RESPONSIVE INDICATING SYSTEM (340/500)
*  DD  .~ Specific condition (340/540)
*  DD  .~.~ Intrusion detection (340/541)
FOR 100  DF  .~.~.~ Door or window movement (340/545)
*  DD  CONDITION RESPONSIVE INDICATING SYSTEM (340/500)
*  DD  .~ Specific condition (340/540)
FOR 101  DF  .~.~ Article placement or removal (340/568)
FOR 102  DF  .~.~.~ Detectable device on protected article (340/572)
*  DD  CONDITION RESPONSIVE INDICATING SYSTEM (340/500)
*  DD  .~ Specific condition (340/540)
FOR 103  DF  .~.~ Human or animal (340/573)
*  DD  CONDITION RESPONSIVE INDICATING SYSTEM (340/500)
*  DD  .~ Specific condition (340/540)
FOR 104  DF  .~.~ Position responsive (340/686)
*  DD  CONDITION RESPONSIVE INDICATING SYSTEM (340/500)
FOR 105  DF  .~ Specified indicator structure (340/691)
*  DD  CONDITION RESPONSIVE INDICATING SYSTEM (340/500)
FOR 106  DF  .~ Specified power supply or housing (340/693)
FOR 107  DD  .~ Loop (340/825.05)