U.S. patent number 3,683,357 [Application Number 05/012,651] was granted by the patent office on 1972-08-08 for battery operated scoreboard.
This patent grant is currently assigned to Olympian Scoreboard Division, Metatronics Manufacturing. Invention is credited to Everett Penn, John Piorek, Michael C. Presnick.
United States Patent |
3,683,357 |
|
August 8, 1972 |
BATTERY OPERATED SCOREBOARD
Abstract
The present invention relates to the battery operation of
display devices d the like, including scoreboards for sports
events. More particularly, the invention is directed to a unique
circuit for efficiently operating a bank of display lamps in a
display board with extra light output and for operating the lamps
for comparatively lengthy durations without recharging of the
batteries. The new and improved operation of remotely situated
display boards is effected through the novel manner in which the
lamps, of a predetermined voltage rating, are energized with excess
voltage or "overenergized." The display lamps are divided into two
separate loads, and the "overenergization" of the overall display
is alternated rapidly between the two loads of the divided display
at a frequency (i.e., 50-70 Hz) carefully selected to provide
adequate and regular cooling of the "overenergized, extra intensely
burning" lamps while providing the appearance to the eye of being
constantly energized. The desired display of information is
obtained by a novel "scintillating" energization of the lamps of
the board, which energization is effected through a new circuit
which includes an oscillator circuit, a switching circuit, and a
guard circuit for automatically terminating operation of the board
when the DC battery source has reduced itself to a predetermined
level or when the oscillator is not properly functioning.
Inventors: |
Michael C. Presnick (New York,
NY), Everett Penn (Los Angeles, CA), John Piorek
(Westbury, NY) |
Assignee: |
Olympian Scoreboard Division,
Metatronics Manufacturing (N/A)
|
Family
ID: |
21756019 |
Appl.
No.: |
05/012,651 |
Filed: |
February 19, 1970 |
Current U.S.
Class: |
340/323R;
315/201; 340/332; 345/73; 345/211 |
Current CPC
Class: |
G08B
5/36 (20130101); A63B 71/06 (20130101) |
Current International
Class: |
G08B
5/22 (20060101); G08B 5/36 (20060101); G08b
005/22 () |
Field of
Search: |
;340/323,335,334,331,332,324 ;315/201,322,217 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: John W. Caldwell
Assistant Examiner: Michael Slobasky
Attorney, Agent or Firm: Mandeville and Schweitzer
Claims
1. A portable scoreboard comprising a. a display panel including a
plurality of selectively lightable incandescent lamps divided into
first and second lamp loads; b. a portable battery providing a DC
voltage source of predetermined value; c. scintillating circuit
means for alternatingly applying said DC voltage to each of said
lamp loads for durations of approximately 5-12 milliseconds; d.
said lamps are of predetermined voltage rating substantially less
than the DC voltage source; e. whereby the lamps of the first load
are non-energized and free to cool down during the energization of
the second load and vice versa, whereby the lamps of the entire
display panel provide an appearance of constantly being lighted,
and whereby said lamps are overenergized when said voltage
2. The scoreboard of claim 1, in which a said scintillating circuit
means include a generator of timing pulses and means switching the
delivery of DC voltage from said first load to said second load at
a rate determined by the frequency of said timing pulses.
3. The scoreboard of claim 2, which further includes a. guard
circuit means in association with said scintillating circuit means
to prevent the energization of said lamps by said DC source in the
absence
4. The scoreboard of claim 3, in which a. said guard circuit means
includes means to prevent the energization of said lamps upon the
predetermined dimunition of voltage of said DC source.
5. A circuit for energizing a plurality of display lamps from a DC
voltage source, including a. means dividing said plurality of lamps
into two groups; b. means generating a train of timing pulses; c.
switching means alternately and mutually exclusively applying the
voltage from said DC source to said two groups of lamps at a
frequency and for durations determined by said timing pulses; d.
the frequency of the application of said voltage to said lamps
being high enough to provide the optical illusion that both groups
of lamps are lighted at the same time and said frequency being low
enough to provide each group of lamps sufficient time for cooling
of its filaments while the other group of lams is being energized;
and d. said lamps being overenergized by said DC source to provide
extra light
6. The circuit of claim 5, which includes a. guard circuit elements
for opening the lamp energizing circuit upon the failure of said
means generating a train of timing pulses or upon the
7. The circuit of claim 6, in which a. the timing pulses are
generated by a UJT relaxation oscillator means; b. said switching
means includes a commutated pair of silicon controlled rectifiers;
c. said guard circuit includes relay means having switch contacts
in series with said DC source and said lamp groups and a latching
coil in series with a guard silicon controlled rectifier; d.
sampling means for detecting the voltage at the gates of the
commutated pair of silicon controlled rectifiers; e. said guard
silicon controlled rectifiers being fired in the absence of the
detection of a pulsating voltage by the voltage sampling means.
Description
With the ever increasing proliferation of sports activities and
spectator interest therein, there has been a concomitant
requirement for the provision of adequate scoreboard displays to
apprise participants and spectators of the essential particulars at
any time. To that end, there have been a substantial number of
improvements in the design and operation of scoreboards and, more
particularly, of electric scoreboards of the type utilizing
matrixes of lamps which are selectively lighted to indicate game
scores; game times; game conditions (balls, strikes, period, etc.);
and the like. Heretofore, virtually all of these electric
scoreboards have been placed in permanent or relatively permanent
installations, such as gymnasiums and stadiums, where a readily
available AC power source exists. However, with the increase of the
number of small neighborhood playing fields on which well attended
athletic contests take place, on which fields the installation of
conventional AC operated scoreboards is impracticable or is unduly
expensive, there has been a growing need for a more portable type
of display board which can be used at a plurality of locations and
which may be used independently of the degree of accessibility of
an AC power source. Accordingly, it is to the end of providing a
readily portable scoreboard having an especially visible display,
which scoreboard may be used at remote locations (independently of
an AC supply) by operation of the same from a portable DC storage
battery source, that the present invention is directed.
SUMMARY OF THE PRESENT INVENTION
In accordance with the principles of the present invention, a
portable scoreboard having an electrical load essentially
comprising a large plurality of comparatively low voltage lamps (14
volts) may be readily, efficiently, and reliably operated for
extended periods of time from a comparatively high voltage DC
battery source (24 volts) by the "scintillating, overenergization"
thereof. Specifically, the load of a portable scoreboard comprises
several banks or matrixes of lamps which are used to indicate the
score for the home team and the visiting team, and sets of lamps
which are used to indicate game conditions, such as "at bat";
"balls"; "strikes"; period of play; and the like, which load is
divided into two or more load segments, as required. The load
segments are sequentially energized at a frequency which permits
the lamps to cool sufficiently between each applied pulse to extend
filament life and which frequency is great enough to give the lamp
the appearance of being steadily energized but which is not so
great as to cause an apparent dimming of the lamps. For ease of
description, the invention will be described hereinafter in terms
of two load segments which are alternately energized, although it
is to be understood that more segments may be employed.
Scintillating frequencies of 50-70 Hz are suitable for the purposes
of this invention. This type of alternate DC energization of two
load segments enables smaller and cheaper power supplies to be
used, since the power requirements are substantially reduced (e.g.,
halved for two load segments; quartered for four load
segments).
In accordance with a specific aspect of the invention, the lamps
are selected for "overenergization" so that they produce more light
and are therefore more readily visible outdoors. The overenergizing
of 14 volt lamps with a 24 volt source has been found particularly
advantageous in limiting the effect of sunlight and increasing the
visibility and readability of the information displayed by the
lamps.
Advantageously, the individual lamps are energized by DC pulses
delivered at a rate of approximately 60 Hz. This is very important,
since pulses supplied at a rate substantially slower than 60 Hz,
i.e., below 50, are observable through the lamps as a disconcerting
"flicker", and pulses provided at a substantially greater rate than
60 Hz, i.e., above 70 Hz, result in the lamps having a "dimmed"
appearance. The 60 Hz pulses, in accordance with the principles of
the invention, are scintillated or alternated between each of the
two load segments so that a portion of the board (advantageously
approximately "half") is energized while the other portion or
"half" cools off and vice versa. With 60 Hz scintillation, and in
accordance with the invention, the entire board always appears
lighted due to optical illusory effects.
As a more specific aspect of the present invention, the
scintillating circuitry includes associated guard circuitry which
removes the lamp loads from the energizing circuit if the
generation of scintillation pulses should cease or if the battery
voltage drops below a predetermined level, e.g., 22 volts for a 24
volt battery source.
DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 1a are schematic, perspective views of a portable
scoreboard and control console therefor (drawn to a larger scale)
embodying the principles of the present invention; and
FIG. 2 is a circuit diagram for operating a portable scoreboard or
the like in accordance with the principles of the present
invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
Referring now to FIG. 1, a portable scoreboard 10, designed for
battery operation in accordance with the principles of the
invention and adapted for use in the scoring of "Little League"
baseball contests, includes an information display panel 11 having
three matrixes of lamps 12-14 to indicate the "guest score";
"inning"; and "home score", respectively, as well as groups of
lamps 15-17 to indicate, respectively, "balls", "strikes", and
"outs"; and a pair of lamps 18 to indicate the team at bat. In
accordance with common practice, these lamps are remotely
controlled from appropriate switches 19 on a control console 20
(FIG. 1a) connected to the scoreboard by a cable 21. To enhance its
portability, the display panel and its associated circuitry are
enclosed in an aluminum frame 22 of reduced size, e.g.,
approximately 38 by 38 by 6 inches. To facilitate the handling of
the scoreboard, the frame includes a carrying handle and removable
tubular aluminum legs which advantageously may be stored within
hollow lower portions of the scoreboard frame when the scoreboard
is not in use. Advantageously, the scoreboard frame 22 includes
hinged display panel cover members 23, 24 which protect the lamps
and the face of the scoreboard when the board is being carried or
is otherwise not in use. The hinged covers 23, 24 may be opened, as
shown in FIG. 1, with the upper cover supported by brackets 25 in a
sunshading relationship to the face of the scoreboard. The cover 23
is most useful, as will be appreciated, for those occasions when
the scoreboard is operated in bright sunlight, and it greatly
contributes to enhancing the visibility of the lighted lamps. The
lower cover 24 depends generally downwardly from the scoreboard
frame and may be used to advantage to carry an advertising message
or the like. The scoreboard is, of course, powered from a DC
battery source 26, e.g., a pair of lightweight, rechargeable 12
volt storage batteries, connected thereto by a short cable 27.
As an important aspect of the present invention, the scoreboard
lamps 12-18 are 14 volt lamps which are energized at a
substantially greater voltage, i.e., approximately 24 volts, than
the normal voltage rating for which the lamps are designed to
operate to ensure that the filaments of the lamps produce more
light than they would otherwise produce if energized at rated
voltage. This enhances visibility in the daylight environment in
which the portable scoreboard 10 is most often to be used. However,
as will be understood, the mere "overenergization" of a DC lamp
will ordinarily tend to so overheat the lamp filament that it will
be destroyed in very short order. The 14 volt DC lamps of the type
contemplated for use in the present invention, when constantly or
steadily energized by a 24 volt source, tend to have a life of
approximately 5 minutes. On the other hand, when such a lamp is
intermittently energized in accordance with the principles of the
invention with short pulses and allowed to cool down between the
application of pulses, the lamp life will be extended to
approximately 300 hours, a lamp life of more than a typical "Little
League" season, for example. Thus it should be appreciated that
intermittent "overenergization" is of substantial importance to the
efficacy of the present invention, and the "overenergization" of
the 14 volt lamps with 24 volts provides a display having "extra
light" which is very readily visible in sunlight and pronouncedly
more visible than would be the case if the lamps were energized by
rated voltage or even if higher voltage lamps, e.g., 24 volt lamps,
were "properly" or conventionally energized by a 24 volt
source.
More specifically and in accordance with the principles of the
present invention, the lamps 12-18 of the portable scoreboard may
be "overenergized" safely and extremely efficiently in the
following manner. The entire lamp load, e.g., 83 lamps for for a
scoreboard of the type illustrated, is divided into two
approximately equal loads, "load segment I" and "load segment II",
and each of which is alternately "overenergized" with pulses from a
24 volt DC source. Current in the "worst case" (all lamps of a
"load segment" on) reaches approximately 3.6 amps. Thus, one
portion or "half" of the entire scoreboard display will always be
energized while the other "half" is cooling down and vice versa. It
has been determined that by applying "overenergizing" pulses to the
lamps at approximately 60 Hz (the lamps in each "load segment" of
the scoreboard will be cooled for approximately one one hundred
twentieth of a second after the termination of each applied
energizing pulse of approximately one one hundred twentieth of a
second) in accordance with the principles of the invention, the
complete face of the whole board will always appear to be lighted
in the eyes of a viewer (although only a portion of the board is
actually energized at any instant) due to the optical illusory
effects. It is physically impossible for the eyes to notice the
extinguishing and relighting of the lamps in each portion of the
scoreboard when the lamps in the other portion are also alternating
from "off" to "on" at approximately 60 Hz.
Appropriate circuitry for operating a portable scoreboard in
accordance with the principles of the invention is shown in FIG. 2.
As indicated and in accordance with the invention, the entire
scoreboard load is divided and includes load segment I comprising,
for example, the lamps used for indicating the guest score and the
inning, and into load segment II which comprises the lamps used for
indicating home team score, balls, strikes, out, and at bat.
Individual ones of the plural lamps 12-18 are controlled (on-off)
by switches from the control console, to form lighted numerals for
inning and score and to indicate balls, strikes, etc., as should be
understood. In accordance with the principles of the invention, the
loads I, II are alternatingly energized with DC pulses at a rate of
approximately 60 Hz, although frequencies ranging from as low as 50
Hz to as high as 70 Hz may be employed.
The new and improved "scintillating" circuitry for efficiently
operating a portable scoreboard in accordance with the inventive
principles generally includes a 24 volt DC battery source 26; the
load segment I (comprising lamps 12, 13); and the load segment II
(comprising lamps 14-18) connected to the battery through relay
contacts 80a, 80b, respectively; power switching circuitry
including a pair of silicon controlled rectifiers (SCR's) 51, 52
for delivering pulses alternately to the two loads I, II; timing
circuitry of the relaxation oscillator type including unijunction
transistor (UJT) 53 for generating timing trigger pulses for
operating the power SCR's 51, 52; and guard circuitry for
disconnecting the lamps from the power source in the event the
oscillator fails to deliver trigger pulses to the gates of the
power SCR's or in the event the power source 26 is reduced to an
unsatisfactory level, e.g., 22 volts.
In accordance with the principles of the invention, the timing
circuit for the generation of lamp energizing pulses at the desired
rate of approximately 60 Hz is a relaxation oscillator comprising
the unijunction transistor 53 in association with resistors 55, 56
and 57 and a capacitor 58. The bases B1 and B2 of the UJT 53 are
connected across the 24 volt battery source through the resistors
56 and 57, while its emitter is connected between the resistor 55
and capacitor 58, as shown. The parameters of resistor 55 and
capacitor 58 are appropriately selected for the specific pulse
width desired. For example, with a 0.12 microfarad capacitor 58 and
a 58 kilohm resistor 56, the positive trigger pulses generated at
the base B1 will be approximately 7 milliseconds, thereby providing
a scintillating pulse rate of approximately 70 Hz; while if the
resistor 56 is increased to approximately 100 kilohms, the pulse
duration will be 12 milliseconds, thereby providing a pulse rate of
approximately 50 Hz. For a scintillating rate of approximately 60
Hz requiring a pulse duration of approximately 8 milliseconds, the
resistance of resistor 56 is 68 kilohms.
The generated pulsing output of the timing circuit is applied to
the gates of the SCR's through diodes 61 and 62 which function to
block the passage of positive signals from the gate of one SCR to
the gate of the other SCR, as will be understood. Thus, the time
base for the scintillating circuit is established by the
combination of UJT, resistors 55-57, and capacitor 58 which form a
conventional relaxation oscillator.
The generated positive pulses are used in accordance with the
invention to trigger alternately the firing of the pair of SCR's
51, 52 in order to switch the overenergization of the scoreboard
lamps alternately between load I and load II. More specifically, a
resistor 63 is included to provide blocking diode 61 with back bias
when the SCR 51 is not fired, thus removing the trigger pulse from
the gate of the SCR 52 and forcing the SCR 51 to fire first. Thus,
when the SCR 51 fires, its anode is at minus potential, therefore
removing the back bias on the blocking diode 61. The next pulse
generated by the relaxation oscillator will therefore fire the SCR
52. As will be understood, the SCR 52 commutates the SCR 51 by
grounding the capacitors 74a and 74b to complete one switching
cycle. The capacitors 74a and 74b are wired back-to-back to form a
non-polarized capacitor of one-half the rated value of the
capacitors. The resistors 70 and 71 are included in parallel with
loads I, II to provide loads to the SCR's 51 and 52 during
switching of the lamp patterns and therefore ensure that the SCR's
will not be artificially unlatched at any time (such as, for
example, when "guest score" and "inning" are being changed).
As an important aspect of the present invention, guard circuitry is
associated with the scintillating circuitry to remove the power
source from the lamps and thereby prevent the burning out of the
lamps if the timing circuit should fail to generate a train of
pulses for any reason. Additionally, the guard circuitry provides
for the removal of the source from the lamp load when the battery
has substantially run down to a predetermined weakened level, e.g.,
22 volts. The guard circuit includes the operating coil of a safety
relay 80 which is controlled by an SCR 81. The latching of the
relay 80 through the energization of its coil will open contacts
80a, 80b to remove the power from the lamps 12-18. The SCR 81 is,
itself, controlled by a unijunction transistor 82, which in turn is
controlled by a guard capacitor 83, which in turn is controlled by
a guard transistor 85. The guard circuitry ensures longer battery
life, as should be understood.
As long as the SCR's 51 and 52 are firing properly, the transistor
85 will saturate with every other pulse generated by the UJT 53 and
will discharge the guard capacitor 83 through the resistor 89 as
well as its own collector-emitter junction. However, should SCR 52
for any reason cease to fire in its order and at the predetermined
rate, in this example 60 Hz, the guard transistor 85 will not fire
and will, therefore, allow the capacitor 83 to charge to the peak
voltage of the UJT 82. When this point is reached, the UJT 82
itself will fire and will cause the SCR 81 to fire, thereby
energizing the coil 80 and causing it to open its associated
contacts 80a, 80b, thereby removing both the loads I and II from
the voltage source. As an important aspect of the invention,
resistors 88 and 89 as well as the capacitor 82 cooperate to form a
time constant of approximately four seconds, which will provide a
safety factor to allow occasional short term (less than 4 seconds)
failures of the generation of a pulse train to be non-effective in
initiating the firing of the SCR 81.
The back-to-back wiring of the capacitors 74a and 74b provides a
point 74c (the junction of the two capacitors) which can be
employed to drive the guard transistor 85, when desired or found
necessary. In this case, the conditions of both SCR 51 and SCR 52
will be sensed rather than the condition of just SCR 52, as in the
circuit arrangement illustrated in FIG. 2. Thus, with this
modification of the circuit, there will be a signal at every timing
pulse instead of every other timing pulse, as with the FIG. 2
circuit. Accordingly, when the guard transistor 85 is driven from
point 74c, it would be switching at twice the rate at which it
switches in the FIG. 2 circuit, and this arrangement would reduce
the size requirement of the guard capacitor 83 from that of the
FIG. 2 circuit.
A zener diode 90 is included in the guard circuit, as shown, and it
functions to sense constantly the battery voltage. Should the
battery voltage drop below a predetermined value, i.e., 22 volts,
the zener diode 90 will block the transistor from firing, a
condition which will therefore permit the capacitor 83 to
accumulate sufficient charge to fire the UJT 82 which in turn will
fire the SCR 81 and thereby energize the safety relay coil 80.
By way of an example, the parameters for the circuit of FIG. 2 for
operating a scoreboard having 83 lamps (14 volts DC) from a 24 volt
storage battery source are tabulated hereinbelow. Reference Circuit
Element Numeral Specification Resistors 55 68 Kohms .5 watt 56 220
ohms .5 watt 57, 86 47 ohms .5 watt 63, 87 4.7 Kohms .5 watt 64 2.2
Kohms .5 watt 65 470 ohms .5 watt 66 15 ohms .5 watt 70, 71 125
ohms 10 watt 84 390 ohms .5 watt 88 6.8 Kohms .5 watt 89 1.5 Kohms
.5 watt 91 3.3 Kohms .5 watt 92 15 Kohms .5 watt 93 100 ohms .5
watt Capacitors 58 .12 MFD-75VDC 67 .22 MFD-75VDC 74a, 74b 50
MFD-50VDC 83 500 MFD-25VDC 93 .68 MFD-75VDC 95 .056 MFD-100VDC
silicon Controlled Rectifiers 51, 52 MCR 2818R-1 81 MOT 430 or MOT
2N5060 transistor 85 2N3705 Unijunction Transistors 53, 82 2N2646
or 2N4871 Relay 80 Guardian 9152 C-24v Reset Switch 49 Guardian
9152 C-24 v DC Source 26 Two 12 volt batteries
_________________________________________________________________________
_
As should be appreciated, the new and improved portable scoreboard
of the present invention may be easily carried from playing field
to playing field and quickly placed into reliable operation from a
readily portable DC source, such as a pair of 12 volt storage
batteries. The alternate energization of each half of the display
board by a square wave of DC power pulses, of course, reduces the
power requirement for operating the entire board, thereby
contributing to the reduction in size of the power source and
contributing to the ease with which the power source may be moved
from site to site. Moreover, the alternate energization of the
halves of the display board at 50-70 Hz provides intermittent
cooling periods, and thereby enables the display lamps to be
overenergized for enhanced visibility, while not distracting from
the overall scoreboard display, which appears to be constantly
lighted (without "flicker" or "dimming") due to the advantageous
use of optical illusory effects on the unaided eye.
As the most important advantage of the invention, a portable
scoreboard can be successfully and reliably operated from a readily
available rechargeable battery source for extended periods, i.e.,
several hours without recharging. Absent the new circuitry,
operation of a battery powered conventional scoreboard would cause
the battery to run down in an unacceptably short period of time.
Thus, it should be appreciated that the new and improved guard
circuitry, which ensures the conservation of battery energy, and
the new and improved scintillating circuitry, which reduces the
battery load, effectively extend battery life from the unacceptably
short period of time obtained with a conventional board directly
powered by a battery to the acceptable and comparatively long life
of many, many hours.
It should be understood that the new and improved circuitry and the
scoreboard operated thereby have been disclosed herein by way of
example and not limitation of the present invention. Those skilled
in the art will appreciate that many other practical uses of the
inventive principles are apparent, including, for example,
"standby" or "emergency" power source applications. Accordingly,
reference should be made to the appended claims in ascertaining the
scope of the invention.
* * * * *