U.S. patent number 3,854,123 [Application Number 05/347,289] was granted by the patent office on 1974-12-10 for remotely controllable tuning system for television tuners.
This patent grant is currently assigned to Zenith Radio Corporation. Invention is credited to Frank G. Banach.
United States Patent |
3,854,123 |
Banach |
December 10, 1974 |
REMOTELY CONTROLLABLE TUNING SYSTEM FOR TELEVISION TUNERS
Abstract
A television receiver has its usual plurality of different
functions which are to be controlled. These may include the
selection of different channels and/or the adjustment of different
performance parameters such as volume, brightness, contrast, color
quality, muting and on-off. A plurality of operators are
individually spaced successively apart to control the different
functions upon receipt of an appropriate impulse which may be
either mechanical or electrical. To deliver such an impulse, an
apparatus is movable to different positions that correspond to the
different operators. External command signals are used to
selectively control movement of the apparatus between the different
positions and to effect delivery of the impulse at any given
position.
Inventors: |
Banach; Frank G. (Oak Lawn,
IL) |
Assignee: |
Zenith Radio Corporation
(Chicago, IL)
|
Family
ID: |
23363109 |
Appl.
No.: |
05/347,289 |
Filed: |
April 2, 1973 |
Current U.S.
Class: |
348/731;
340/12.22; 348/734 |
Current CPC
Class: |
H03J
5/0209 (20130101) |
Current International
Class: |
H03J
5/00 (20060101); H03J 5/02 (20060101); H04b
001/16 () |
Field of
Search: |
;340/171R ;178/DIG.15
;325/393,391 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pitts; Harold I.
Attorney, Agent or Firm: Camasto; Nicholas A. Pederson; John
J.
Claims
I claim:
1. A television function-selection system comprising:
a television receiver having a plurality of different functions to
be controlled;
a corresponding plurality of operators individually spaced
successively apart and each responsive to an impulse for
individually operating respective different ones of said
functions;
movable means, including a selectively rotatable lead screw and a
nut movable along said lead screw upon rotation thereof, movable to
selected different ones of a plurality of different positions
individually corresponding to respective different ones of said
operators and, at each position, selectively delivering said
impulse to the corresponding operator;
and means responsive to external command signals for selectively
controlling movement of said movable means between said different
positions and delivery of said impulse to said operators.
2. A system as defined in claim 1 further includes an actuator
carried by said lead screw for movement to said different positions
to deliver said impulse.
3. A system as defined in claim 1 in which at least one of said
operators is a movement responsive switch, and in which said
movable means includes a solenoid having a plunger that moves to
actuate said switch.
4. A system as defined in claim 3 which further includes means for
also manually actuating said switch.
5. A system as defined in claim 1 in which at least one of said
operators includes a rotatable shaft having a shaft rotator, and in
which said movable means includes a solenoid having an armature
that moves to actuate said shaft rotator.
6. A system as defined in claim 5 in which movement of said movable
means to one of said positions enables actuation of said shaft
rotator in one direction and movement of said movable means to
another of said positions enables actuation of said shaft rotator
in the opposite direction.
7. A system as defined in claim 1 in which said operators
individually include respective different ones of a plurality of
voltage-responsive sensors and in which said movable means includes
means for developing a plurality of different voltages in
correspondence with respective different ones of said positions
and, at each different position, supplying the corresponding
voltage to the respective sensor.
8. A system as defined in claim 1 in which said operators
individually include respective different ones of a plurality of
voltage-responsive sensors, in which said system includes a voltage
divider, and in which said movable means includes a tap movable
among different positions on said divider to feed respective
different voltages to said sensors.
9. A system as defined in claim 8 in which said system further
includes means separate from said movable means and said voltage
divider for enabling operation of said sensors.
10. A system as defined in claim 1 which further includes a scale
distributed in correspondence with said different positions and in
which an indicator is moved along said scale by said movable means
to indicate the one of said operators to which said impulse is
delivered.
11. A system as defined in claim 1 in which said movable means
includes function-selection means for selectively controlling
movement of said movable means to the different ones of said
positions and actuation-selection means for selectively controlling
the delivery of said impulse to the one of said operators
corresponding to the selected one of said positions.
12. A system as defined in claim 1 in which said movable means
includes means for automatically enabling operation of said
operator to said impulse upon location of said movable means at the
corresponding position.
13. A system as defined in claim 1 in which said operators are
distributed into two groups in each of which a respective plurality
of the operators individually are spaced successively apart, in
which each of said different positions individually corresponds to
a respective one operator in each of said groups, and which
includes means for selectively delivering an impulse to either one
of the pair of operators corresponding to the selected one of said
positions.
14. A system as defined in claim 13 in which one of said two groups
of operators functions to select channels of television channels
and the other of said two groups of operators functions to control
reproduction qualities of said television receiver.
Description
BACKGROUND OF THE INVENTION
The present invention pertains to television function-selection
systems. More particularly, it relates to such systems which are
particularly adapted for remote control.
Since first offered in a customer-acceptable form, the remote
control of television receivers has proven to be a most attractive
feature. Many viewers have enjoyed being able to change channels,
mute the audio signal from the receiver, and adjust volume or the
like directly from their viewing position remote from the receiver
itself. While the remote like may be accomplished by a variety of
different systems, including wires, light-operated photocells and
radio signals, probably the most widely acclaimed television remote
control system is that which was so successfully introduced by the
assignee of the present application and which involved the use of
ultrasonic signals. In that approach, manually-operable pushbuttons
in a hand-held transmitter unit activate respective mechanical
vibrators which, in turn, generate ultrasonic signals of respective
different frequencies that are projected to the television
receiver. At the receiver, those signals are segregated with
respect to their different frequencies and utilized to develop
respective different function-control signals. Typifying such a
transmitter are the embodiments disclosed in U.S. Pat. No.
2,821,955 issued in the name of R. C. Ehlers et al., on Feb. 4,
1958. A highly advantageous receiver approach is that disclosed in
U.S. Pat. No. 2,821,954 issued in the name of R. Adler also issued
on Feb. 4, 1958.
Initially, it was customary to employ the remote control system for
the purpose of changing channels, adjusting volume, turning the
television receiver off and on and muting the audio, the latter
especially to eliminate annoying commericals. Subsequently, other
control functions were added. These included the control of such
parameters as hue and saturation of color receiver displays. To
accomplish the inclusion of these additional control functions
without having to add a corresponding number of different control
frequencies, one approach has been to use combinations of a basic
set of control signals, transmitted either in certain sequences or
coincidentally. In this way, for instance, four basic control
signals may be utilized to control a larger number of specific
different function. However, this has led to significant complexity
at the receiver, while at the same time allowing for the
possibility of greater confusion of the inexperienced user.
Moreover, the recent expansion in usage of the many UHF channels,
as compared to the original common usage in a given area of only a
few VHF channels, has greatly increased the problems connected with
selecting a desired channel, both manually at the receiver itself
and remotely from a distant point.
OBJECTS OF THE INVENTION
It is, accordingly, a general object of the present invention to
provide a new and improved television function-selection system
which aids in alleviating the complexities and problems noted
above.
It is another object of the present invention to provide a new and
improved television function-selection system which enables the
selection and control of a very large number of functions while
requiring but a comparatively small number of command signals or
command operations.
A further object of the present invention is to provide a new and
improved television function-selection system in which a
significant portion of the apparatus utilized to achieve selection
from among the different available channels also is utilized, in an
alternative mode, to control the operation or selection of a
variety of other functions.
SUMMARY OF THE INVENTION
A television function-selection system constructed in accordance
with the present invention includes a television receiver that has
a plurality of different functions to be controlled. A
corresponding plurality of operators individually are spaced
successively apart with each being responsive to an immpulse for
individually operating respective different ones of those
functions. Included are means movable to selected different ones of
a plurality of different positions individually corresponding to
respective different ones of the operators and, at each position,
selectively delivering the impulse to the corresponding operator.
Finally, means respond to external command signals for selectively
controlling movement of the movable means between the different
positions as well as controlling delivery of the impulse to the
operator.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of this invention which are believed to be novel are
set forth with particularity in the appended claims. The invention,
together with further objects and advantages thereof, may best be
understood, however, by reference to the following description
taken in conjunction with the accompanying drawings, in the several
figures of which like reference numerals identify like elements,
and in which:
FIG. 1 is a block diagram of a remotely-controlled color television
reproducer;
FIG. 2 is a front-elevational view of a function-control panel
utilized in the system of FIG. 1;
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG.
2;
FIG. 4 is a fragmentary cross-sectional view taken of a portion of
the apparatus in FIG. 2 with its front panel removed;
FIG. 5 is a fragmentary cross-sectional view taken along the lines
5--5 in FIG. 4; and
FIG. 6 is a schematic diagram of an arrangement alternative to the
electro-mechanical approach particularized in FIGS. 3-5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates an exemplary overall arrangement that includes a
remotely-controlled television receiver. Thus, a color television
reproducer 10 is shown as having means to control or adjust a
variety of different functions. These include an on/off switch 11,
a volume control 12, a hue control 13, a saturation control 14, a
brightness control 15, a contrast control 16 and a mute switch 17.
Each of the names of these controls is used herein in accordance
with its ordinary terminology. For example, the hue control
determines the emphasis within the color spectra which generally
runs from purple to green. Saturation, on the other hand, refers to
the level of color. Each of function controls 11-17 is individually
governed by operation of a selection system 19. In addition to
control of the various functions specifically illustrated,
selection system 19 also serves to control operation of the tuner
(not shown) in reproducer 10 so as to select among the number of
different television channels; the channel-selection signal is fed
to reproducer 10 from selection system 19 over a path 20.
To the extent desired, selection system 19 may include manually
operable elements, such as pushbuttons or knobs, for directly
controlling the different functions at the television receiver. In
themselves, these different controls may be entirely conventional.
In addition, however, the arrangement of FIG. 1 includes a remote
control system capable of also selectively governing operation of
the different control functions. To that end, a remote control
transmitter 22 includes four different manually-operable
pushbuttons 23, 24, 25 and 26 respectively labeled "up", "down",
"channel" and "function." While any of the different modes of
remote control signal transmission mentioned in the introduction
may be utilized, as herein contemplated transmitter 22 is of the
ultrasonic type such as disclosed in the Ehlers, et al., patent
mentioned above. Correspondingly, the system includes a
remote-control receiver 28 of the kind disclosed in the
aforementioned Adler patent. Accordingly, receiver 28 segregates
the four different signals of which transmitter 22 is capable of
generating into a corresponding number of control paths 29, 30, 31
and 32. The signals corresponding to up or down commands, obtained
respectively by depressing pushbuttons 23 or 24, are routed over
corresponding paths 29 and 30 to a reversible motor 34; depression
of pushbutton 23 causes reversible motor 34 to rotate its shaft in
one direction, while depression or actuation of pushbutton 24
causes motor 34 to rotate its shaft in the opposite direction. That
shaft movement is fed into selection system 19 as indicated by a
path 35. Depression of channel pushbutton 25 results in
energization of a channel actuator 36 which, in turn, is coupled to
selection system 19 over a path 37. Finally, actuation of function
pushbutton 26 results in the energization of a function actuator 38
which governs certain operations within selection system 19 by way
of a path 39.
As labeled in FIG. 1, channel actuation has for convenience been
separated from what is denominated as function actuation. It is to
be understood, however, that the selection from among different
channels is also a matter of one variety of function selection. In
any event, the overall manner of operation of the system of FIG. 1
is such that pushbutton 23 and 24 effect operation of motor 34 in a
manner to enable the selection of any one of a possible number of
different channels. When the desired channel has been enabled,
subsequent depression of pushbutton 25 then effects the actual
selection of that channel for reception by the television receiver.
Alternatively, or at the same time, pushbuttons 23 or 24 are
utilized again to operate reversible motor 34 in a manner so as to
enable the selection of any one of the several different available
ones of controls 11-17. Subsequently, when the desired control has
thus been enabled, pushbutton 26 is depressed as a result of which
function actuator 38 causes that particular specific function to be
operated or controlled. The manner in which these different
selections may be achieved in practice will become more apparent
following discussion of the subsequent figures.
In the United States, standard television stations are each
assigned a specific one of the different available channels which
are numbered from 2 to 83. Even in most large metropolitan areas,
however, the number of satisfactorily-receivable stations usually
is limited to about five or six. At most, the viewer is probably
able to receive no more than about 12 stations. In any event, the
number of stations which a viewer may receive in any given
geographical area is much less than the maximum 82 channels
assignable to broadcasters. Accordingly, a number of different
television tuning systems have been produced which allow the user
or installer to preset the television receiver so that, at least
upon any kind of automatic or remote-controlled tuning, selections
may be made from only among those channels which are utilized
locally. This permits skipping the unused channels entirely.
However, present regulations in the United States complicate the
design of such tuning systems. For example, the tuning mechanism
must accommodate both UHF and VHF channels, and it must be
approximately as easy to tune a UHF channel as it is to tune a VHF
channel. With any repeated access system, there must be a minimum
of six UHF channels. In the case of a single-control tuning system,
there must be a total of at least 11 discrete channel positions,
any of which is readily adjustable without tools, to receive any
UHF channel.
The arrangement of FIG. 2 enables satisfaction of such
requirements. It involves the use of a limited number of possible
receiving channels which may be preset to the different local
channels. In more detail, that which is shown in FIG. 2 includes a
selector panel 40 that desirably is mounted upon the external front
surface of the cabinet which houses reproducer 10. Projecting
through panel 40 are a plurality of pushbuttons 42 respectively
designated by the individual different channel numbers to which
each is assigned for purposes of selection. Without more, these
different pushbuttons may be manually depressed just for that
purpose as in any other conventional pushbutton tuning mechanism.
For example, depression of the pushbuttons 42 designated by the
numeral four causes the tuner associated with reproducer 10 to
select the station on channel four for viewing and listening. Thus,
and in a manner well known as such, each different pushbutton
permits a respective different frequency-selective element to
become operative within the television tuner. Typically, that
element might be a resistor controlling a varactor, a capacitor or
an inductor.
Also spaced along panel 40, in this case in a column parallel to
that formed by pushbuttons 42, are a series of labels 44 each of
which includes a designation of a respective different operational
parameter to be controlled in the television receiver. In
themselves, the different designations are self-explanatory. It may
be noted, however, that in some cases, such as an on/off and mute,
a single label is assigned. In others, such as volume or hue, one
label indicates control of that function in one direction while an
immediately adjacent label designates control of that function in
the opposite direction.
Also included in panel 40 are a pair of elongated translucent
windows 46 and 47 respectively aligned alongside the column of
pushbuttons 42 and the column of labels 44. At a particular
position within each of the windows are respective light spots 48
and 49 which serve to indicate the corresponding functions enabled
for selection at any given light. That is, the position of light
spots 48 and 49 as drawn in FIG. 2 indicate to the viewer, who may
be located a number of feet from the television receiver, that
channel seven is enabled for selection by use of his remote control
transmitter or that, alternatively, use of his remote control
transmitter will enable him to reduce the volume. Also shown in
FIG. 2 is reversible motor 34 the shaft of which depends downwardly
from the motor generally between the respective columns of
pushbuttons 42 and labels 44 as well as between windows 46 and 47.
In this particular embodiment, the motor shaft is in the form of a
lead screw 50.
Referring to FIG. 3 for more detail, pushbutton 42 is movably
carried within a slide 52 affixed to the back side of panel 40.
Depression of the illustrated one of pushbuttons 42 results in the
corresponding depression of the plunger 53 of an on-off switch 54
mounted in a bracket 55 affixed to a stationary support 56. A pair
of leads 58 and 50 are electrically connected upon depression of
plunger 53. Accordingly, leads 58 and 59 when electrically
connected serve to complete an electrical circuit for the
appropriate frequency-determining element in the television tuner.
For example, a simple resistance may be connected in a varactor
energization network to change the capacitance of the varactor to
the desired frequency-determining value.
Driven along lead screw 50 is a nut 60 on one side of which is
affixed an operator in the form of a solenoid 62 having an armature
63. Upon energization of solenoid 62, plunger 63 is driven
rearwardly of panel 40 so as to urge against a lug 64, projecting
laterally from the rear end portion of pushbutton 42, and thereby
electro-mechanically depress pushbutton 42 against plunger 53. That
is, plunger 53 of switch 54 may be operated either by manual
depression of pushbutton 42 or by energization of solenoid 62.
Affixed to the opposite side of nut 60 is another solenoid 66 from
which projects an armature 67. As shown, armature 67 is aligned
with the plunger 68 of a switch 69 which in this case serves the
function of on-off switch 11 in FIG. 1. That is, each successive
depression of plunger 68 alternatively opens and closes the
connection between a pair of leads 71 and 72 in order to govern
that function of reproducer 10. Switch 69 is mounted from the back
side of panel 40 by a bracket 74. Another switch, identical to
switch 69, is included in back of the mute position at the bottom
of panel 40 and opposite the channel designated 53. Thus, when lead
screw 50 is rotated so as to move solenoid 66 to the lower-most
position in back of panel 40, energization of solenoid 66 serves
instead to control the mute function. At the same time, alternative
or simultaneous energization of solenoid 62 would effect depression
of the pushbutton designated 53 so that channel would be
selected.
Mounted on the casing of solenoid 62 and facing window 48 is an
indicator lamp 76. Similarly mounted on solenoid 66 and facing
window 49 is another indicator lamp 77. When desired, only one
window and the corresponding indicator lamp are all that is
necessary. As illustrated, however, the use of the two different
light spots 48 and 49 assists the viewer in determining from a
distance the parameter or function enabled for control.
For the purpose of constraining rotation of the assembly including
nut 60 and solenoids 62 and 66, and thus causing that assembly to
traverse lead screw 50 as the latter rotates, angle-shaped guide
rails 80, 81, 82 and 83 are located at the respective four corners
of the assembly. While guide rails 80-83 might also serve as
electrical connective elements, in this case the leads for
energizing the indicator lights and the solenoids are in the form
of a simple flexible cable.
In the particularized example of FIG. 4, motor 34 has been
energized and the nut and solenoid assembly is positioned adjacent
to the label designating a change of volume in the up, or louder
direction. In this case, plunger 67 is aligned with an anvil 90
slidably received in a journal 91 carried by a rigid support 92;
anvil 90 is biased toward plunger 67 by a spring 90a. Projecting
outwardly from anvil 90 is a flexible stem 93 which serves in
operation to drive an opposed cog in a ratchet wheel 94 mounted on
the shaft 95 of a potentiometer 96 as shown in FIG. 5. Thus, each
energization of solenoid 66 causes plunger 67 to strike anvil 90
and thus move stem 93 to effect rotation of shaft 95 by one ratchet
notch. In turn, each such advance in rotation of the ratchet wheel
results in a stepped increase in volume by a preselected amount.
Also affixed to shaft 95 is a second ratchet wheel 97 which has its
cogs oriented for rotation of the shaft in the opposite direction
by means of a stem 98 affixed to an anvil 99 located in the next
position below anvil 90. That is, in order to lower the volume, it
is only necessary to command motor 34 to move the nut and solenoid
assembly to the next lower position adjacent the label designating
volume down, whereupon energization of solenoid 66 causes the
volume to be lowered one step. Of course, ratchet wheels 94 and 97
are each mounted upon or coupled to shaft 95 by a suitable ratchet
clutch so that either wheel is able to drive the shaft in its
respective direction of control. Similar ratchet wheel assemblies
are located at each of the other function positions that require a
rotary action.
Of course, different mechanical arrangements may be utilized to
achieve the specific operations illustrated. For example, a geneva
drive may be substituted for lead screw 50. In that case, movement
of solenoids 62 and 66 will occur in discrete steps from one
position to the next. As an added feature, shaft 95, and the
analogous ratchet wheel shafts at others of the control positions,
may extend through the front panel and have knobs affixed to permit
manual control of the different functions. As an alternative to the
use of rotary action in connection with any function, pushbutton
switches may be used in association with stepping circuits.
Considering FIGS. 1 through 5 together, the overall principle of
operation may be reviewed. Upon operation of transmitter 22, by
depression of either of pushbuttons 23 and 24, motor 34 is
energized in the appropriate direction to cause solenoid 62 and 66
effectively to scan, from one channel number to the next, while at
the same time scanning the locations corresponding to the different
other parameters that may be controlled. When the solenoids reach
the position corresponding to the desired function the viewer
simply presses either pushbutton 25 or pushbutton 26 to effect
operation of the corresponding channel actuator 36 or function
actuator 37. That is, channel actuator 36 in this case is solenoid
62, while function actuator 38 is solenoid 66. Thus, the same
apparatus which is utilized to achieve selection from among the
different available channels also is utilized to enable selection
of any one of the other parameters to be controlled. As
illustrated, 12 different parameters are each separately
controllable in addition to channel selection in either an up or
down direction. Yet, all this is accomplished with but four
different remote control signals. Another advantage, as compared
with some prior systems, is that actual channel selection occurs
only after the channel has been enabled; that is, there is no need
to sequence through a number of undesired successive channels to
reach a desired channel.
In contrast with the primarily electro-mechanical approach detailed
in FIGS. 3-5, FIG. 6 illustrates a system which is primarily
electrical. In this case, reproducer 10 is again subject to both
local and remote control of a plurality of functions 11-17 the same
as in the case of FIG. 1. Its tuner 100 is specifically of the type
in which a varactor 101 is the primary frequency-determining
element.
Varactor-controlled tuners are now commerically available and
require no operational description. It will, therefore, suffice
merely to maintain that the varactor exhibits a change in
capacitance in response to a change in the potential applied across
its terminals. By using the varactor to establish the capacitance
in a frequency-selective circuit, it thus becomes necessary only to
adjust the level of the applied potential in order to change the
selected frequency.
shaft 50, in this case, is shown more completely as being journaled
at its lower end in a stationary bearing 103. A nut 105 is suitably
constrained to ride up or down lead screw 50 as the latter is
rotated. Projecting outwardly from one side of nut 105 is a tap or
contact 106 movable by the nut to successively electrically wipe
different ones of a plurality of fixed contacts 107. Fixed contacts
107 are respectively connected to individual different junctions
between a series of resistors 108 which together form a voltage
divider connected between a source of positive potential B+ and
ground. Movable contact 106 is connected by a lead 110 to channel
actuator or switch 36 which, in turn, is operable to supply the
potential on movable contact 106 to varactor 101 by way of a lead
112.
In operation, pushbuttons 23 and 24 of transmitter 22 are used as
before to command energization of reversible motor 34 and
consequent rotation of shaft 50. Each of fixed contacts 107
corresponds to a specifically assigned one of the respective
different channels. Thus, movement of nut 105 in response to the up
or down command signals serves to select from the appropriate one
of fixed contacts 107 a channel-determining potential that may be
fed to tuner 100 to control the tuning capacitance presented by
varactor 101. When nut 105 has been positioned to the desired
channel position, subsequent depression of channel-selection
pushbutton 25 effects switch closure in channel actuator 36 to feed
the frequency-determining potential to the varactor. As illustrated
in FIG. 6, the voltage divider network has been simplified for
convenience of illustration. In actual practice, where tuner 100
may have entirely separate portions for respective receiving
channels in the VHF and UHF portions of the spectrum, it is
contemplated that the system would also include a suitable
arrangement, which may be as simple as a switch operated upon the
passage of nut 105 past a selected position, to enable changing
between VHF and UHF operation of the tuner.
A more sophisticated voltage-divider arrangement, which
accommodates different voltage ranges required in view of unequal
frequency spacings between different ones of the channels, is
described and claimed in the copending application of Melvin C.
Hendrickson, Ser. No. 331,921, filed Feb. 12, 1973 (1,728), and
assigned to the same assignee as the present application. Also
featured is a means for achieving a fine-tuning voltlage adjustment
without altering the voltage distribution within the divider
itself. Such features of that application may be adapted to the
embodiment of FIG. 6.
Selection from among the different other control parameters is
achieved in an analogous matter. Thus, another movable contact 120
is carried by nut 105 in a location to wipe successively across a
plurality of fixed contacts 121. Contacts 121 are individually
connected to respective different junctions between a corresponding
plurality of resistors 122 again connected in series to form a
voltage divider which extends between B+ and ground. In this case,
the potential derived by movable contact 120 at any given time is
fed by a lead 125 to each of a plurality of voltage sensors
126--132 associated respectively with function controls 11-17. As
will be apparent, each voltage sensor responds only to a
corresponding level of voltage on the voltage divider selected by
movable contact 120. Each of sensors 126-136 also is enabled to
operate only in response to energization of function actuator 38.
Thus, the only one of voltage sensors 126-132 which will operate at
any given time is the one corresponding to the input voltage level
selected by movable contact 120 from the voltage divider composed
of resistors 122. Moreover, that particular voltage sensor is only
armed by the appropriate voltage until such time as pushbutton 26
is depressed so as to energize actuator 38. When both armed and
enabled to operate, the particular voltage sensor fires or operates
the associated control function. Alternatively, any one or more of
sensors 126-132 may be chosen so as to operate automatically upon
application of the proper voltage but without enabling by actuator
38.
A variety of known control circuits are available which may be
utilized in the place of any of voltage sensors 126-132 or controls
11-17. The sensors need only function as gates that have upper and
lower thresholds. In principle, the controls may be stepping or
ramp circuits that respond to the gate voltage. A variety of
voltage or current responsive control circuits are known that may
be employed to adjust a resistance or capacitance in a variable
gain stage for governing the function being controlled.
Whatever specific approach is followed as to any of the different
details and alternatives, it will be observed that the system
described and illustrated enables control of a large multiplicity
of functions with but a few control signals. At the same time, the
addressing is such as to avoid any necessity of sequencing through
different successive functions. Moreover, the very same system used
for the purpose of addressing different channels to be selected
also may be utilized to address a number of different control
functions or parameters. In all cases, the general approach affords
a wide flexibility of design to the manufacturer. That is, the
manner of construction and assembly of the different parts in the
electro-mechanical version detailed in FIGS. 3-5 may vary widely in
correspondence with the economics of component and fabrication
costs. Analogously, the primarily electrical approach of FIG. 6
also affords a great degree of flexibility. As one example, the
linear motion of the lead screw and its nut as illustrated may
readily be replaced by a rotary switch. Presently available
techniques permit printing of the different fixed contacts in an
annular array for access by a circularly movable contact. Resistors
108 and 122 may be printed and interconnected directly on the
substrate carrying the fixed contacts. An example of such an
arrangement is included in the aforementioned Hendrickson
application.
While particular embodiments of the present invention have been
shown and described, it is apparent that changes and modifications
may be made therein without departing from the invention in its
broader aspects. The aim of the appended claims, therefore, is to
cover all such changes and modifications as fall within the true
spirit and scope of the invention.
* * * * *