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BACKGROUND OF THE INVENTION
A large percentage of the adult United States population is overweight or
is prone to be overweight. Bookstores carry entire sections devoted to
books which their readers hope will provide an easy solution to their
weight problems. Dietetic foods, drugs, weight reducing programs, machines
and treatments abound, and millions of dollars are spent in an effort by
overweight persons to solve their weight problems.
Competent medical specialists who have studied the problems of obesity
generally are convinced, however, that the only effective method of
controlling weight is to balance the intake of energy in the form of food
with the expenditure of energy in the form of activity. Whenever an
imbalance exists in the form of a greater energy intake than is expended,
an increase in weight results. In theory, the maintenance of a balanced
caloric intake/expenditure should be easily established. Readily available
charts have been published which provide accurate data on the caloric
content of all types of foods and beverages. In addition, caloric
expenditures of a wide range of human activities from sleep through
strenuous exercise have been measured and charted. Many thousands of
individuals have succeeded in achieving their desired weight and
maintaining that weight by balancing their caloric intake with
expenditure. Many persons carry calorie counter charts with them wherever
they go to limit their caloric intake in a given day to some maximum
amount which they or their doctors have determined should not be exceeded
if a weight loss is to be attained or maintenance of a given weight is to
be established.
Some persons appear to have a built-in ability to strike the right balance
between caloric intake and expenditure. For a large number of persons
however, perhaps the vast majority, it is necessary to keep a record of
the calories consumed and the activities performed and the duration of
such performance in order to maintain an effective caloric balance. To be
truly effective, data of this type must be accurate and must be
continuously accounted for 24 hours of every day.
Anyone who has observed a person on a diet is well aware of the
inconvenience of the collection and recording of such data and performing
the addition, subtraction and multiplication required to produce
meaningful information relative to caloric intake, expenditure, and
remaining unexpended calories. This inconvenience most likely is
responsible for the fact that only a relatively small number of persons
use this technique, even though it is an effective solution to the
widespread problem of calorie control.
Solid-state battery-powered electronic wristwatches utilizing digital
displays in the form of light-emitting diodes or liquid crystals are
enjoying increasing popularity. A typical watch of this type is disclosed
in U.S. Pat. No. 3,803,827 to Dennis A. Roberts, issued Apr. 16, 1974. The
electronic wristwatch of that patent is provided with a master time
reference in the form of a high frequency oscillator connected to the
watch display through suitable divider circuits to provide indicia of the
time on demand by operation of a switch to energize a plurality of
light-emitting diodes. The time computer portion of the watch circuit
continuously keeps the time although it is only displayed upon demand. The
display and the driver circuits for the display also are shared by a
calendar calculating circuit which may be coupled to the display diodes
upon demand by operation of a calendar display switch.
Digital electronic wristwatches have been combined in a single housing with
a miniature calculator in which the calculator output display also shares
the display elements which are used to display the time or calendar
information. Thus, techniques presently are available in improved
electronic watch constructions which permit sharing of the time display
elements for other purposes.
It is desirable to incorporate a calorie counter into an electronic
wristwatch which will enable the user to readily enter caloric intake
information into the wristwatch/calorie calculator, determine a caloric
rate expenditure, and have readily available on a continuous basis data
indicative of the excess of calorie intake over calorie expenditures. This
then would provide the user, at any time, the data necessary to see the
state of his calorie intake/expenditure account; so that he can modify his
future calorie intake or his activity or both to achieve the results he
wants with his own diet program.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved calorie counting
system.
It is another object of this invention to provide an improved electronic
timepiece with additional data handling capabilities.
It is an additional object of this invention to provide an improved calorie
calculator-chronometer system.
It is a further object of this invention to provide an electronic
wristwatch having a digital display with additional circuitry to permit
the use of the watch as a calorie calculator.
An electronic timepiece, which includes a source of constant frequency
signal pulses, a time computing circuit coupled to the source of pulses
where the time computing circuit produces time information in binary coded
form to a decoder which couples the time computing circuit to an
electro-optical digital display, also includes an auxiliary data system.
The auxiliary data system has a storage counter in it for storing
numerical data indicative of preestablished information. A manually
operated switch is coupled with the storage counter and is used to effect
the storage of data in it. A circuit couples the counter with the source
of constant frequency signal pulses to change the numerical data stored in
the counter at a preestablished rate, and a circuit including an
additional manually operated switch is used to couple the counter with a
decoder circuit for energizing the digital display from the counter in
response to operation of the additional switch.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a wristwatch incorporating a preferred
embodiment of the invention;
FIG. 2 is a block diagram of a circuit implementing a preferred embodiment
of the invention; and
FIGS. 3 and 4 are more detailed block diagrams of a portion of the circuit
shown in FIG. 2.
DETAILED DESCRIPTION
In the drawings, the same reference numbers are used throughout the several
figures to designate the same or similar components. Referring to FIG. 1,
there is shown a perspective view of a wristwatch generally indicated at
10. The watch comprises a case 11 having a viewing window 13 in it for
viewing a typical digital display, comprising four seven-segment display
elements, the middle two of which are separated by a colon or other
symbol. These display elements may be light-emitting diodes, liquid
crystal elements or some other suitable conventional display devices.
Typically, in an electronic wristwatch of this type, particularly when the
display elements are in the form of light-emitting diodes, the display is
not energized during normal operation of the watch. The time computer
circuit of the watch, however, continuously computes the current time; and
upon depression of a time pushbutton 15, the display is energized to
indicate the current time in hours and minutes. In addition, the continued
depression of a time pushbutton 15 may be used to effect a display of
seconds information, if desired. Many watches of this type include an
additional display energizing pushbutton 16 which is used to activate a
calendar computing circuit within the watch and connect it to the display.
When the button 16 is depressed, the display is illuminated with the
current month and date information. Since the display in the window 13 is
only activated when specific information is demanded, it may be shared
with both the time computing circuit and the calendar circuit since only
one or the other of these is activated at any one time to provide the
desired information. The manner in which such a display is shared is
conventional and well known and simply utilizes a multiplexing gate
decoder arrangement to drive the display from the selected one of the data
input circuits, that is, either the time computing circuit or the calendar
circuit.
The watch shown in FIG. 1 has been further modified to operate as a calorie
calculator system; and for this purpose it includes additional
pushbuttons. A pushbutton 19 is activated to enter calorie intake
information in response to internal timing circuitry within the wristwatch
case 11. As this information is being entered, the display in the window
13 shows the accumulating count of the calorie intake entry. In the system
described more fully in conjunction with FIGS. 2 and 3, a second
depression of the pushbutton 19 terminates the entry of further calorie
input data and sets up a transfer of the input data to a main calorie
counter which continuously provides a count of the accumulated calories
which have not been expended by the user. Since calories are expended by a
person at different rates depending upon his physical activity, a calorie
rate expenditure pushbutton 20 is used to enter calorie rate expenditure
data into another portion of the calorie calculator circuitry. This again
is done in conjunction with the timing circuitry already available within
the wristwatch for running the time computer circuitry; and the display in
the window 13 indicates the accumulation of the calorie expenditure per
hour entry as it is made. A second depression of the pushbutton 20
transfers this information to another portion of the calorie computer
circuitry where it is utilized to control the operation of the main
calorie counter.
Any time the user of the calorie computer wristwatch shown in FIG. 1
desires to know his net calorie count, representative of the excess of
calorie intake over calories expended which he has for the time interval
under consideration, he depresses a pushbutton 22 which couples the output
of a net main calorie counter to the display to give the desired reading.
In addition, if at any time the user is uncertain as to the calorie
expenditure rate which he has set into the calorie computer portion of his
wristwatch, a pushbutton 23 is depressed to provide a reading of the
current calorie expenditure rate stored within the calorie computer
section of the watch.
Finally, in order to reset the operation of the system for the entry of new
data, a reset pushbutton 26 is provided. The various pushbuttons for
controlling the display in the window 13 conveniently may be located about
the periphery of the watch case as illustrated in FIG. 1. The particular
location of the pushbuttons is not important, however; and if desired,
some of them or all of them could be located directly on the watch case
face. In addition to the control pushbuttons which have been shown in FIG.
1, there generally are pushbuttons or controls to enable setting of the
current time and data in the watch initially and whenever a battery
replacement is made or if the watch should fail to keep correct time for
any reason.
Reference now should be made to the circuit of FIG. 2 which illustrates the
addition of the calorie computer to a conventional electronic digital
watch circuit. The watch function is similar to existing units, such as
the type disclosed in U.S. Pat. No. 3,803,827, to which reference
previously has been made. The conventional watch circuit 30 is shown
within the dashed lines on the righthand side of the drawing of FIG. 2.
The circuit 30 typically includes a stable high-frequency oscillator 31
which operates as the source of constant frequency signal pulses used in
the time computing circuitry 30 of the watch, the calendar computing
circuitry, and in the calorie computer circuitry forming the remainder of
the circuit of FIG. 2.
As shown in FIG. 2, the conventional time computer watch circuitry divides
down the output frequency of the oscillator 31 to produce output pulses at
different frequencies. Three of these frequencies are utilized in the
calorie computer portion of the circuit shown in FIG. 2. The highest
frequency is one-half the basic oscillator frequency and appears on a lead
33. As illustrated, this frequency is slightly more than one-half
megahertz, namely 524.288 kilohertz. Two other frequencies are supplied
from the frequency divider chain in the watch circuit 30 and these are a 2
Hertz frequency supplied on a lead 34 and 1 Hertz frequency supplied on a
lead 35. Pulses at these three different frequencies are continuously
supplied on the leads 33 through 35.
In the calorie computer portion of the circuit, three digital counters
function as the primary control elements of the circuit. The first of
these counters is a reversible main calorie counter 36 which is the
counter in which the net calorie information is continuously stored and
updated. At any time the net calorie pushbutton 22 is depressed, it
enables coincidence gate circuitry in a conventional multiplexer gate and
output driver circuit 38 to display on the digital display in the window
13 the calorie count then present in the counter circuit 36. This display
exists as long as the button 22 continues to be depressed.
The multiplexer and output driver circuit 38 is a conventional one and
merely is a straightforward expansion of the comparable circuit which is
used to share the same display and output drivers of a conventional
wristwatch between the time computer section of the watch and the calendar
computer section of the watch. Typically, this circuitry includes
coincidence gates which are enabled by depression of the selected
pushbutton to connect the driver and decoder circuitry for the display
with the appropriate inputs supplied by the selected circuit.
The main calorie counter 36 is designed to provide a running algebraic
total of calories which have been added to and subtracted from the system
for display at any given time. Calories are added to the system by
depressing the Calorie In pushbutton 19, as stated previously, releasing
the button when the desired number of calories have been entered, and then
depressing the button 19 a second time to enter the data into the main
calorie memory 36.
The Calorie In pushbutton 19 operates an up/down control circuit 40 which
in turn controls the entry of clock pulses into an auxiliary binary
counter 41 at a 2 Hertz rate to increment the counter 41 by a count of +10
calories each one-half second. So long as the pushbutton 19 is depressed,
the "Enable 1" input to the multiplexer gate and output driver circuit 38
is enabled; so that the outputs of the counter 41 are used to drive the
display 13. Once the desired calorie count for the input is indicated in
the display 13, the pushbutton 19 is released. The pushbutton 19 then is
depressed a second time to cause the total count in the auxiliary counter
41 to be transferred under control of high speed clock signals applied
over a lead 43 to increment the main counter 36 by the amount of the count
stored in the counter 41. This same source of clock pulses is used to
drive the counter 41 in its reverse direction; and when it is emptied, a
carryout pulse is applied over a lead 45 to the control circuit 40 to
terminate the transfer operation. At this point, a count corresponding to
the additional calories has been added to the count in the counter 36; and
the counter 41 is cleared.
The basic circuitry of FIG. 2 is designed to decrease the count in the main
calorie counter 36 approximately one calorie per minute. This represents
the basal fraction expended in sustaining body functions at rest. However,
not all persons have this same basal fraction; so an adjustment may be
effected by a divide-by-"N" counter 47, the division ratio of which is
varied by the setting of an adjustable switch 49. This type of counter is
well known in the art, and the manner of changing or adjusting its
division number or ratio may be readily effected. In the circuit of FIG.
2, the adjustment is made to adjust the basal fraction rate applied to the
input of the first stage of the counter 36 from approximately -0.5
calories per minute to -1.5 calories per minute. This permits the calorie
calculator operation to be tuned or adjusted to the particular metabolic
rate of the user. This adjustment and the minute and hour setting controls
for the watch preferably are located on the back of the case of the watch
since these controls are infrequently used.
As illustrated, the pulses which are used to decrement the counter 36 are
obtained from the lead 33 and are applied through the variable
divide-by-"N" counter 47 to one input of an OR gate 48. The pulses then
are passed through a divide-by-3600 circuit 50 which applies the resultant
pulses through an OR gate 51 to the input stage of the counter 36. The
particular frequencies which have been shown and the divider circuits are
selected so that pulses applied from the output of the OR gate 51 to the
counter 36 occur at the basal fraction rate of approximately one pulse per
minute (.+-.0.5 pulses per minute).
Normally the counter 36 is operated in its count down mode of operation,
that is each pulse applied to the input of the first stage causes a
decrease in the binary count of the counter by one unit. The direction of
count of the counter 36, which can count in either direction, however, is
controlled by the signal on a lead 53 from a rate controller circuit 54.
At the time the transfer clock pulses are applied over the lead 43 through
the OR gate 51 to increase the count in the counter 36, the same clock
pulses are applied to the rate controller 54 to cause it to apply an "up"
count signal on the lead 53 to the counter 36. Thus, whenever pulses are
being transferred over the lead 43, indicative of the transfer of calorie
input information from the counter 41 to the counter 36, the rate
controller 54 provides an output on the lead 53 to cause the counter 36 to
count in its "up" direction. At all other times, the counter 36 counts in
its down direction in response to the pulses applied to it from the output
of the OR gate 51.
In addition to the basal calorie expenditure which is set or controlled by
the variable counter 47, activity in addition to the basal rate results in
increased expenditure or consumption of calories. The calorie expenditure
rate varies in accordance with the activity, as is readily apparent.
Charts are available which provide fairly accurate representations of the
rates of expenditure or burning of calories for different activities. When
the user of the calorie calculator-chronometer circuit shown in FIG. 2
changes his activity from any previous activity to a new one, it is
necessary to adjust the basal calorie expenditure provided by the output
of the counter 47 by the new activity. This is accomplished by depressing
the calorie expenditure pushbutton 20. As stated previously, this causes
the Enable 1 display output to drive the display 13 from the output of the
auxiliary counter 41. At the same time, the up-down control signal from
the control circuit 40 applied over the lead 44 cuases the counter 41 to
be placed in its "up" mode of operation.
A "jam" input to the counter 41 is applied over a lead 57 to the counter to
cause it to increase its count by 50 each time a clock pulse is applied to
the counter over the lead 58. The circuit is set up to apply clock pulses
at one second intervals over the lead 58 when the button 20 is depressed,
so that the display in the display window 13 changes by a count of 50 each
time a pulse appears on the lead 58. When the desired calorie expenditure
rate is displayed in the window 13, the pushbutton 20 is released. The
button 20 then is depressed a second time, and this causes the circuit 40
to shift the count now representative of the calorie expenditure rate in
the counter 41 to a latch memory circuit 60. Here the count is stored
indefinitely until a new calorie expenditure rate is placed in the counter
41 and transferred to the latch memory 60. Once this transfer has been
effected, the counter 41 again may be used to enter new calorie input data
into the system, as described previously, without disturbing the calorie
expenditure rate which is stored in the latch memory 60.
Once the calorie expenditure rate is stored in the memory 60, the current
rate at which calorie expenditure information is supplied from the rate
controller 54 to the counter 36 may be read out by pushing the calorie
rate pushbutton 23. This causes the "Enable 2" signal to be applied to the
multiplexer gate and output driver circuit 38 to cause the output of the
latch memory circuit to be displayed in the display 13. Depressing the
rate key 23 at any time causes the display 13 to indicate the current
calorie expenditure rate programmed into the calorie computer.
The output of the latch memory 60 is used in conjunction with a third
digital down counter 62 to control the rate at which pulses are applied to
the main counter 36 through the OR gate 51 in addition to those supplied
by the basic basal rate circuit from the output of the counter 47. Once
per second, the output of the latch memory 60 is jam fed to change the
count of the counter 62 which then stores the new rate input. The counter
62 then is operated in a count "down" mode by a high speed clock on a lead
64 from the rate controller circuit 54 until it is emptied. A carryout
pulse then is applied to the rate controller 54 from the counter 62 over a
lead 65.
During the time interval from the time the information is first jam set
into the counter 62 until the pulse is obtained on the carryout lead 65,
pulses are applied through the OR gate 48, the divide circuit 50, and the
OR gate 51 to decrement the main counter 36. The number of these pulses
adjusts the calorie-per-hour information stored in the counter 62 to
calories-per-second expended during the one second time interval between
the successive resettings of the counter 62. Thus, the calorie expended
rate set into the system by the operation of the pushbutton 20 continues
to supplement the basal rate supplied through the OR gate 48 from the
output of the counter 47 to control the net calorie expenditure which is
continuously monitored by the counter 36.
In the event that the calories expended should equal the calorie input over
the time interval being measured, the counter 36 is reset to its zero
count and produces a carryout pulse on a lead 67. This pulse is applied to
the rate controller 54 to terminate its operation. As soon as any new
calorie input data is transferred to the main counter 36, the rate
controller is free to operate to permit pulses to pass through it
corresponding to the rate selected by the information which is updated
each second in the calorie rate down counter 62. Alternatively, the
circuit may continue to operate to count negative calories, i.e. the
excess of calorie expenditure over calorie intake. In such an event, the
carryout pulse from the counter 36 would not be applied to the gate 91
(which then would be eliminated), but instead could be used to indicate
the negative count. This may be accomplished, for example, by pulsing the
colon between the center two digits on the display. Once the calorie
intake again exceeds the negative amount, such an indication would be
removed. The technique used is conventional and of the type commonly used
in hand-held electronic calculators.
For a better understanding of the operation of the controller circuit 40,
reference now should be made to FIG. 3. The control circuit 40 comprises
two toggle flip-flops 71 and 72 and two direct set/reset flip-flops 74 and
75 as its primary circuit components. Normally all four of these
flip-flops are in their "reset" condition or state.
Assume now that the user of the system has just eaten an item of food
representing a calorie intake of 80 calories. He wishes to enter this
information into the calorie computer system. To do this, the Calorie In
pushbutton 19 is depressed. This causes the toggle flip-flop 71 to change
its state from its "reset" condition to its "set" condition. As a result,
its "Q" output goes high and its "Q" output goes low. As soon as the
flip-flop 71 is set, its Q output causes the flip-flop 74 to change from
its "reset" state to its "set" state causing its Q output to go high. When
the Q output of the flip-flop 74 goes high, it enables an AND gate 75 to
pass the 2 Hertz clock pulses appearing on the lead 34 to the input of an
INHIBIT gate 77.
At the time the flip-flop 71 switched to its "set" state, the INHIBIT gate
77 was enabled by the removal of an inhibiting input applied to it from
the Q output of the flip-flop 71. Thus, the clock pulses appearing on the
lead 34 pass through an OR gate 78 to the lead 58 to advance the counter
41 one count for each pulse. As shown in FIG. 2, the counter 41 counts by
tens; so that each time a pulse on the lead 34 is passed by the gates 75,
77 and 78, the cumulative total count in the counter 41 is increased by
ten. This increase occurs once each one-half second. Thus, to add 80
calories to the system, the Calorie In key 19 is held depressed for 31/2
seconds, at which time the display in the window 13 indicates 80. The
pushbutton 19 then is released and depressed again to clear the display
and enter the count 80 in the counter 41 into the main memory 36.
The second depression of the pushbutton 19 after its release toggles the
flip-flop 71 to place it back in its "reset" state of operation. This
causes the INHIBIT gate 77 to block the passage of any further pulses from
the output of the gate 75. At the same time, both of the upper two inputs
to an AND gate 80 are now high or enabling inputs; so that the high speed
clock pulses appearing on the lead 33 are now passed by the gate 80. These
pulses are applied directly over the lead 43 to the OR gate 51 and the
rate controller 54. As described previously, the rate controller causes
the counter 36 to be placed in its "up" count direction and the pulses
then passed by the OR gate 51 advance the count in the counter 36 one
count (one calorie) for each pulse.
Since the counter 36 counts units and the counter 41 has a minimum count of
10, a divide-by-10 circuit 81 is connected to the output of the AND gate
40 to supply pulses to the OR gate 78. These pulses, as described
previously, appear on the lead 58 to operate the counter 41. The direction
of count of the counter 41 is controlled by the signal on the lead 44
which in turn is produced by signals applied to an OR gate 83. The counter
44 counts in its up direction whenever the toggle flip-flop 41 is in its
"set" state, with the Q output high. Thus, the counter adds to its count
during the time that the 2 Hertz clock pulses on the lead 34 are operating
the counter to add calorie information to it.
When the toggle flip-flop 71, however, is in its reset condition, as is now
the case, the up-down control signal on the lead 44 changes to cause the
counter 41 to count in its down or reverse direction. Thus, the previously
entered calorie input information is removed from the counter 41 under the
control of the clock pulses passed by the gate 80.
When the counter 41 reaches its zero count, a carryout pulse is applied
from the counter over the lead 45. This pulse is passed through an OR gate
85 to the reset inputs of the toggle flip-flops 71 and 72 to set these
flip-flops to their reset state if this already has not been accomplished.
In addition, the carryout pulse is applied to a second OR gate 86, the
output of which is connected to the reset input of flip-flop 74 to reset
the flip-flop 74 to its "reset" state. When this occurs, the AND gate 80
no longer is enabled since the Q output of the flip-flop 74 goes low.
Thus, no more pulses are applied over the lead 43 to the rate controller
54 and the OR gate 51. The number of pulses required to do this is
precisely equal to the count which was entered originally into the counter
41. Thus, the calorie input information has been transferred to the main
calorie counter 36.
The operation of the control circuitry to establish the calorie expenditure
rate also may be understood by reference to FIG. 3. When an entry is to be
made into the counter 41 indicative of a calorie expenditure rate, the
pushbutton 20 is depressed as described previously. This causes the state
of the toggle flip-flop 72 to change from its "reset" state to its "set"
state. Thus, the Q output of the flip-flop 72 goes high to cause the
up/down control on the lead 44 to the counter 41 to operate the counter 41
in its "up" direction. At the same time, a "preset enable" signal is
applied over the lead 57 to the counter 41 to force the counter to
increase its count by 50 instead of 10 for the application of each clock
pulse to the counter, so long as the signal is present on the present
enable lead 57.
When the flip-flop 72 is set to its "set" state, the high Q output also
causes the direct set flip-flop 75 to be set from its "reset" to its "set"
state of operation. This causes the Q output of the flip-flop 75 to go
high, enabling an AND gate 88 to pass the 1 Hertz clock pulses on the lead
35 through the OR gate 78 to the clock input 58 of the counter. Thus, each
time a 1 Hertz pulse is applied over the lead 58 to the counter, the count
in the counter increases by 50. So long as the pushbutton 20 is depressed,
the display in the display window 13 indicates the output condition of the
counter to show the calorie rate expenditure being entered into the
counter 41.
When the desired rate is reached, the pushbutton 20 is released and then
depressed again. This causes the toggle flip-flop 72 to change its state
from its "set" state to its "reset" state, at which time the present
enable signal on the lead 57 is removed. At the same time, the flip-flop
75, which is coupled directly to the outputs of the flip-flop 72, is set
to its "reset" condition, causing the AND gate 88 to be disabled. When the
Q output of the flip-flop 72 first goes high, it produces a signal to the
latch memory circuit 60 to cause it to store the information present on
the outputs of the counter 41. This is the condition described previously
which permits the data in the latch memory 60 to be continuously jam fed
or set into the counter 62 under operation of the rate controller circuit
54.
To insure that the system is cleared prior to the entry of any calorie
input data or calorie expenditure data, a reset pushbutton 26 is provided.
This pushbutton provides signals to the OR gates 85 and 86 to result in a
resetting of all of the flip-flops 71 to 75 to their "reset" state of
operation. It may not be necessary to operate the reset pushbutton, but
its operation insures that the circuit is in its proper state of operation
prior to the entry of any new data under the control of the pushbutton 19
or 20.
Reference now should be made to FIG. 4 which is a detailed circuit diagram
of the rate controller circuit 54. As stated previously, the rate
controller circuit 54 controls the direction of the count of the counter
36 through a signal applied over the lead 53. Normally the lead 53
produces an output which causes the counter 36 to count in its down
direction. However, whenever input pulses continuously appear on the lead
43, representative of the transfer of calorie input information to the
counter 36, the signal on the lead 53 causes the counter 36 to count in
its up direction. This is controlled or accomplished by applying the
pulses on the lead 43 to a retriggerable one-shot multivibrator circuit or
missing pulse detector circuit 90 which is held in its astable output
state so long as the high frequency pulses appear on the lead 43. The
time-out period for the circuit 90 is selected to be only slightly longer
than the time interval between successive pulses at the high frequency
rate on the lead 43. As described previously, unless data is being
transferred from the counter 41 to the main counter 36, no pulses
whatsoever appear on the lead 43; so that the retriggerable one-shot
multivibrator circuit 90 normally remains in its stable state.
So long as some count is stored in the counter 36, the signal on the
carryout lead 67 is a low signal which enables an INHIBIT gate 91 to pass
the 1 Hertz clock pulses appearing on the lead 35 to the set input of a
direct set flip-flop 94. Assume initially that the flip-flop 94 is in its
"reset" state of operation. In this state, the Q output of the flip-flop
is low and the Q output is high; so that an AND gate 96, which has the
high frequency clock pulses on the lead 33 applied to its other input, is
normally disabled.
The next 1 Hertz clock pulse appearing on the lead 35 then passes through
the enabled INHIBIT gate 91 to set the flip-flop 94 from its "reset" to
its "set" condition of operation. When this occurs, the Q output of the
flip-flop goes high and the Q output goes low; so that the AND gate 96 is
opened to pass pulses from the lead 33 to the OR gate 48, described
previously in conjunction with FIG. 2.
These pulses also are applied to a divide-by-10 circuit 98 and appear as
the clock pulses on the lead 64 used to operate the count down counter 62.
The reason the divider 98 is used is that the minimum count or lowest
increment of count in the counter 62 is 10 whereas the count in counter 36
is 1. Thus, the divider 98 is necessary to maintain the proper ratio
between the pulses appearing at the output of the OR gate 48 and those
appearing on the lead 64.
As described previously, the rate which is stored in the counter 62 is an
hourly rate, so that the divide-by-3600 divider 50 is interposed between
the output of the gate 48 and the input to the counter 36. The number of
pulses required to drive the counter 62 to its zero count then is directly
proportional to a calorie per second consumption rate represented by the
pulses applied to the counter 36 from the OR gate 51. As soon as the
counter 62 is cleared, a carryout pulse is produced on the lead 65 to
reset the flip-flop 94 to its original condition. This removes the
enabling input for the AND gate 96, and no further pulses are passed by
that gate.
At this time, however, the Q output of the flip-flop 94 goes high to apply
a pulse over the set enable lead 99 to the counter 62 to cause the counter
62 again to be jam set with the count stored at that time in the latch
memory 60. This readies the circuit for the next operation. Subsequently,
when the next pulse appears on the lead 35, the sequence of operation is
repeated. The number of pulses which are passed by the AND gate 96 duri | | |
