Note: Descriptions are shown in the official language in which they were submitted.
5 g
'ritl& of the Invcntion
IMPROVED C~NTROL SYSTEM FOR COLD
DRINK MERC~NDISING MACIIINE
Field of the Invention
Our inve-ntiorl is in the field of cold drink mer- ;
chandising machin~s and more particularly in the field of .
a control system for such a machine which is adapted to
dispense a variety of cold drinks with or without ice
and in which the size of the drink and the amount of ice
delivered with the drink can be varied.
Backqround of the Invention
Tllere are Xnown in the prior art merchandising
machines which, in response to the deposit therein o a
sum of money and the operation of a selecting mech~nism,
deliver to the customer a cold drink which may or may not,
at the customer's option, include a quanti-ty of ice: The
control sys~ems of these machines of the prior art include
an electrormechanical timer and associated clectromechanical
relays for opcrating the various pumps and valves o the
machine.
While the cold drink merchandising machine con-
trol systems of the type described above are gencrally ef-
fective in providing the desired operation of the ~achine,
they suffer from a num~er o~ disadvantages. ~he electro-
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mechanical components are ~elatively expensive. The timing
afforded by the control system is rela~ivcly impreclse.
Many of the settings required to be made in the control systelr
are analogue in nature and thus relatively difficult for the
service personnel. Since the machines operate on a constant
time variable flow rate mode of operation, a change in the
drink size requires a relatively lifficult adjustment of the
valve flow rate. Moreover, changing of a selection amon~
highly carbonated, low carbonated and plain, necessitates a
wiring change.
Summary of the Invention
One ob~ect of our invention is to provide an im-
proved control system for a cold drink merchandising machine
which overcomes the defects of cold drinX merchandising ma-
chine contro~ circuits o the prior art.
Another object o~ our invention is to provide an
improved control system for a cold drink machine which af-
fords a simpler and more expeditious setting o the operating
parameters of,the machine.
Still another object of our invention is to pro-
vide an improved control system for a cold drinX machine which
provides a digital means for setting thc operating paramcterG
of the machine.
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Yet another object of our invention is to proyide
an improved control system for a cold drink ma,chine which is
less expensive than are systems of the prior art.
A further object of our inven-tlon is to provide
an improved control system for a cold drink machine which
is more versatile than are systems of the prior art.
Still another object of our invention is to provide
a control system for a cold drink merchandising machine
which offers precise timing, ye-t is inexpensive in
construction. '
A control system may be provided for a cold drink
merchandising machine which enables an operator quickly and
easily to change khe size of the drink and amount of ice
dispensed. The ,control system may enable the operator to
vary the starting t'ime of each syrup pump to ensure an
adequate drink mix. Further, the control system may
enable the opera-tor to vary the carbonation setting of
each individual selection ln a rapid and expeditious manner.
Briefly stated, the present inven-tion is a control
system for a cold drink merchandising machine adapted to
dispense a variety of drinks, each oE which may be stlll
or relatively highly or lowly carbonated, the rnachine having
actuatable operating elements comprising still water supply
means, carbonated water supply means, various syrup delivery
means and respective selective means corresponding to the
variety of drinks for initiating a cycle of operation of
machine. The control system includes means for proclucing
a first digital signal for determining the syrup delivery
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start time for a selected beverage in the course of the
cycle, means for producing a second digital signal for
determining that a selected beverage is still or highly
or lowly carbonated, and means responsive -to the digi-tal
signals for controlling the operation of the actuatable
operating elements in the course of a cycle of operation
of the machine.
The present invention is also a control system
for a cold drink merchandising machine adapted to
dispense a variety of drinks, the machine comprising
respective syrup delivery means and respective selective
means corresponding to the variety of drinks for
ini-tiating a cycle of operation of the machine. The
control system compri.sing means for producing respective
digital signals corresponding to the drinks for governing
the time in the course of a cycle of operation of the
machine at which operation of the respec-tive syrup delivery
means starts, and means responsive to actuation of one of
the selecting means for polling the digital signal producing
means.
In another embodiment, the present invention is
apparatus ~or a cold drink machine adapted to dispense
a variety of drinks, including in combination a source
of still water, a source of carbona-ted water, a plurali-ty
of manually se-ttable switch means corresponding to the
number of the drinks, each of the switch means adapted
to be set to govern the character of the associated drink
as being still or relatively highly carbonated or
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relatively lowly carbonated, a plurality oE selecting
means corresponding to the drinks, and means responsive
to operation o-E one of the selec-ting means for polling
the switch means to control the flow of water from the
sources in accordance with the setting o~ -the switch
means corresponding to the selec-ted drink.
In a further embodiment, the present invention
is apparatus for a cold drink merchandising machine including
digital switch means adapted to be set to provide a
plurality of binary coded digi-tal outputs, and means
responsive to the setting of the switch for regulating
the size of the drink dispensed.
Brief Description of the Drawings
FIGURE lA is a schematic view of a portion of our
improved control system for a cold drink machine.
FIGURE lB is a schematic view of the remaining
portlon o our improved control system for a cold drink
machine.
FIGURE 2A is a schematic view of a portion of the
microprocessor incorporated in the system sho~n in
FIGURES lA and lB.
FIGURE 2B is a schematic view of the remaining
portion of the microprocessor incorporated in the system
shown in FIGURES lA and lB.
FIGURE 2C is a schematic view of the power supply
o our improved control system for a cold drink machine
shown in FIGURES 1 and 2.
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FIGURE 3 is a schem~-tie view of -the driver circuitry
of our improved eontrol system for a eold drink maehine.
FIGURE 4 is a sehematie view of a water switeh bank
of our improved eontrol system for a cold drink maehine.
FIGURE 5 is a sehematie view of a syrup switeh
bank of our improved control system for a eold drink
machine.
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FIGUR~ ~. is a sehematic view of one of the e1ee-
tronie relays incorporated in our improved control system
for a cold drink machine.
FIGURE 7 is a schematie view of another of the
S eleetronie relays ineorporated in our improved epntrol systc
for a eold drink-maehine.
FIGURE 8 is a schematic view of a furth~r form
of relay which is incorporated in our improved eontrol sys~e
for a eold drink maehine.
FIGURE 9A is a flow ehart of the initial part of
the main pFogram of our improved eontrol system for a cold
drink maehine.
FIGURE 9B is a eontinuation of the flow ehart of
Figure 9A.
FIGURE 9C is a eontinuation of the flow ehart of
FIGURE 9B.
FIGURE (~D is a flow ehart of the terminal part oE
the main program of our improved control system for a eolcl
- clrink maehine.
FIGURE lOA is a flow ehart of the initial portion
of the wait subroutine of the main proc~ram illustrated in
FIGURES 9A to 9D.
FIGURE lOB is a flow ehart of the terminal portion --
; of th~ wait" sui~routine of the main pro~ram illustrated in
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Figures ~A to 9D.
1~IGURE l1 is a flow chart of the "debounce" and
"clear debot1nce" su1>routi~es of the main program illustrated
in FIGUR13S 9~ to 9~.
Descriptlon of the Preferred Embodiment
Referrin~3 now to Figures lA and iB of the draw--
ings, our cold dri~1k merc11andiser control system, indicat~d
generally by tlle re~erence character l0, includes a sourcc of
voltage suc1-, for example, as 120 volt, 60 11Z, having
~l0 terminals 12 and l~. Once the machi1le is plug~ed in, a
normally open switc~ 16 may be closed to cnergize a lamp l~ -
and to supply power to a receptacle ~0, both located within
the machine cabinct for the purpose of facilitating servicin~:
.
of the machine.
Ganged switches 22 and 22a are closed to conn~ct
: the power source to the system l0. Thus power is suppli.ed
directly to the re~rigeration unit 24 which supplies refrige1-
ant to the water rescrvoir cooling coil (not shown) and to
the evaporator coil of tlle icc maker, to ba dc~cribcd here-
inbelow. A normally open manually opcrable switch 26 is
adapted to be closed to provide power for the machine panel
lights 28; for the primary winding 30 of a step-down trans-
former 32, the sccondary winding 34 of which supplies power
to the microprocessor 70 thro~1gh conductors 66 and 68; and
a water level control 36, which, in a manner known to the
art, maintains thc level of water in the machinc water tank
- reservoir ~not shown3 between predetermincd upper and lower
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limits.
Circuit l0 includes a low water level shut off
switch including ganged contact arms 38 and 40 which normally
en~age contacts 38a and 40a and which are adapted to move
into engagement with contacts 38b and 40b when, for example,
thc water supply fails so that the reservoir level falls
below the lower levcl at which control 6 normally wo~ld
turn the water on. In tlle normal position of contact arms
38 and 40, terminal 12 is connected to thc arm 48 of a "cup
10 empty" switch which normally engages a contact 48b and which
moves into engagement with a contact 48a when the sllpply of
cups is depleted. If either the low water level switch 38
or the cup empty switch 48 moves from its normal posit.ion,
a "sold out" lamp 44 is illuminated.
Furth~r, in its normal position, switch 38 supplies
~nabling power to the coin mechanism 46 through a line 50, to
the carbonator 58 through a line 56 ~nd to a manually operablo
normally open switch 'G2 adapted to be closcd to energizc tho
ice maker 42. Tllc coin mecha'ni.sm, whicl- is of any suitablo
type known to the art, includes a "usc exact change" lamp 54.
nespcctivc pairs of conductors 72 and 74, 7fi and
78, 80 and 82, 84 and 86, 88 and 90 and 92 and 94 connect ' - y
customer-accessiblc selection switches SWl to SW6 to the mi-
croprocessor board 70. In onc particular embodim2nt of a
drink machine, switches SWl to SW6 may correspond to drink~ '
of five di.fferent flavors, one of which is availabl~ in car-
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honated and non-carbonated form. Conductors 96 and 98 eon-
nect a "no ice" swiitch to the board 70. ~ "test vend"
switch 100 located within the machine cabinet so as to
be accessiblc only to service personnel may be moved from
its "off" position .illustrated in full lines in Figure lB
to connect either ~ "no cup" line 104 or a "cup" line 102
to a central conductor 103 to set machine test conditions
in a manner to be c~escribed more fully hereinbelow. Con-
duetors 106a to lOGt connect the board 70 to the driver
10 board 108.
A conduetor 110 connects terminaI 14 to board .tO8.
Respective conductors 116, 120, 130 and 134 apply power to ~'
various portions of board 108 to be described in detail
hereinbelow from n~rmally engaged contact 48b, from normally
15 engaged contact 38a~ from switch 26 and from switch 62.
When a sum of money at least equal to the purchaso priee vf
a drink has been de~posited in the eoin mochanlsm 46, it pro-
vides a eredit siynal to boa'rd 108 on line 112. It will
readily be appreeiated that the usual cold drink maehine
sells all drinks at the same price although provision might
be made for multiple pricing.
Whon credit has been established and the machine
is in condition to permit a purchase to be made, board 108
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energi~es a line 118 to illuminate a "make selec~ion"
lamp. When a selection has been made, a line 122 momen-
tarily energizes the cup delivery meehanism which then
eompletes its own holding eircuit by means of a full
cycle swi-tch 166 in a line 12~ from board 108. Similarly,
at an appropriate time in the course of a cycle o opexa-
tion of the maehine, the syrup pump 152 corresponding to
the selected drink is momentarily energized by a line 126
from board 108 and eompletes its own holding cireuit through
a full cycle switch 154 in a line 128 leading to board 108.
For purposes of simplieity, we have shown only one syrup
pump`in Figure 1. It will readily be appreciated that
there are as many syrup pumps 152 as there are flavors of
drinks to be dispensed. Again, at the appropriate time
in the maehine eycle a signal on a line 132 ~rom board 108
energizes the delivery door solenoid ].56 oE the icemaker
to open the door and deliver a eharge of ice to the cup
unless the "no ice" switeh SW7 has been aetivated.
We eonnect a triae 168 between li.ne 120 and a
line 136 which conneets the driver board 108 to a water
pump 158. A eonductor 138 connects the driver board 108
to the gate of tr.iac l.68. Respeetive normally open earbo-
nator relay switehes 170 and 176 eonnect driv~r board line
140 to pump 158 and eonneet a driver board ou-tput line 146a
to another driver board output line 146 leading to a carbo-
nator fill val.ve solenoid winding 164. Respeetive conductors
142 and 144 eouple the driver board 108 to the still water
valve solenoid ~60 and to the carbonated water valve sole-
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noid 162. Manually operated gangcd normally closed and
normally opcn switchcs 172 and 174 respectivcly, connect
line 138 to switch 170 and connect a driver board line
144a to line 1~4.
When the water in the carbonator 58 drops below
a certain level, a ~elay winding (not shown) is e~ergized
to close switches 1~0 and 176, thus activating the w~ter
pump 58 and thc car~onator fill valve 164, filling
the carbonator with water. When the ~lush switch is opcr-
ated by a service person, switch 174 closes to activate
the carbonated wate~ noæzle valve solenoid 162, opening
the valve and allowing the carbonator to empty. Switch
172 opens preventing activation of the water pump 158
upon the closure of switch 170.
lS Referrin~ now to Figures 2A to 2B, the micro-
processor board indicated gencrally by the reference char-
acter 70 includes a controller 200 having a 4-bit input port
comprising pins Pl to P4, an 8-bit input-output port compris-
ing pins Rl to R8, a 9-bit input-output port comprising pins
D0 to D8 and a onc-bit "Into" port. 0, these pins, we
couple pins Pl to P4 to lines 230à to 230d, pins Rl to R8
to line 240a to 2~0h, pins D0 to D8 to lines 250a to 2501
and "Into" pin to lin~ 192.
~ diode 196 connects line 192 to the output pin of
25 N~ND gate 198, one input of which is provided by lina 106b
and the other input to which is from pin 1~1 through lines 7
and 240aO We conncct a resistor 212 and capacitor 210
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in parallel between line 106h and ground line 180, normally
to hold line 106b at a "low~' output state which we have
designated a logic "zero." A pull-up resistor 194, one
terminal of which is connected to a positive DC line 184,
normally holds line 192 at an output high state which we
have designated as logic "one." A diode 202 connects line
192 to thc output pin of N~ND gate 204, one input of which
is provided by line 104 and the other input is from pin ~2
through lines 78 and 240b. A resistor 216 and capacitor
214 connected in parallel between line 104 and ground line
180, normally holds line 104 at logic zero. A diode 206
connects line 192 to the output pin o a NAND gate 208,
the respective inputs to which are from line 98 and from
pin R6 through lines 94 and 240f. A resistor 218 normally
holds line 98 at logic zero. Respective resistors 241 to
246, connected between lines 240a to 240f and ground line
188 normally hold rospective lines 240a to 240f and lines
74, 78, 82, ~6, 90 and 94, connected thereto at logic zero.
As is known in the art, with either or both in~
puts of any of the NAND gates 198, 204 and 208 at logic
zero the output is posi~ive or logic one. If both inputs
of any of the gates 198, 204 and 208 ar~ raised to logic
one,the output is ground or logic zero.
We mount water switch banks W~l to WA6, located
on the microprocessor board and set by a service person.
- Each bank correspondR to a partlcular selcction and may
be set to provide ~ither a high-carbonated, low-carbonated
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or non-carbonated bcverage One terminal of each selection
switch SW1 to Sl~6 is connected to the input pin I of the
corresponding wator switch bank WAl to WA6. When a selec- ~ r
tion switch clo.ses, a high-level signal is placed on the in-
put pin of the corresponding switch bank. If that particular
selection is a high-carbonated beveraye, the signal will be
routed to a first output pin 1 which is connected to line
240g. If the selection is a non-carbonated beverage, the
sighal will be routcd to a second output pin 2 connected to
line 240h~ If th~ selection is set for a low-carbonated
beverage, the signal will appear at both output pins 1 and
2. Respective resistors 224 and 226, respectively connected
between lines 240g al~d 240h and ground line 188, normally
hold respective lines 240g and 240h at logic zero.
Syrup switch banks SYPl to SYP6, each correspond-
ing to a particular selection, are loca~ed on the micropro-
cessor board 70 and are set by a service person. Each syrup
pump, of which only one pump 152 is shown in the drawings,
pumps at the same rate and, for any given drink size, for
the same period of time. Each syrup switch bank determines
at what point, after a selection has been made, the corres-
ponding syrup pump s~arts, thus to assure a complete mi~ of ~ '
syrup and water. T~l s time will vary accordinq to the ~is-
cosity oE the partic~lar syrup. We connect the input pins
I of banks SYPl to 5YP6 to respective pins Rl to R6 through
respective lines 24~ to 240f. Each bank has four pin~
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numbered 1 -to 4 which we connect, respectively -to lines 230a
to 230d to afford 16 different settings Eor each switch.
We mount a swi-tch bank ICE on the microprocessor
board 70 and set by the service person to regulate the
amoun-t of ice to be dispensed with each drink, provided that
the "no ice" switch SW7 is not ac-tivated. The bank has an
input pin I connec-ted by line 250i to pin D8 and four out-
put pins numbered 1 to 4 connected to respective lines 230a
to 230d creating a maximum of 16 settings. Resistor 249
and capacitor 248, connected to respective ground lines 186
and 190, maintain line 250i at logic æero.
Drink-size switch bank DRK, also located on -the
microprocessor board 70 and set by the service person, reg-
ulates the amount of beverage dispensed with each vend. The
bank has an input pin I connected by line 250a to pin DO
and four output pins numbered 1 to 4 connected to respective
lines 230a to 230d creating a maximum of 16 settings. A
resistor 247 normally maintains'iine 250O at logic zero.
We connect respective lines 240a to 240f to re-
spective input pins Dl to D6 of an edge-clocked flip-flop
252. Respective lines 258a to 258f connec-t respective out-
put pins Ql to Q6 oE the flip-1Op 252 to respec-tive input
pins IA to IF of an inverting driver 25~. We connect line
250 i to the clock pin CK of the flip-flop 252. Information
at input ports Dl to D6 of the flip-flop 252 is transferred
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~` to respective outputs Ql to Q6 when a rising edge appears on
line 250i. The clear pin CI,R i5 connec-ted -to reset line 106c
normally held at logic 1 by a power supply 180. Bringing line
106c to logic æero will leave all out-puts ~1 -to Q6 at logic
zero.
We connect line 250a to input pin IG of the in-
verting driver 254 and connect respective output pins OA
to OG to lines 106e to 106k. A high level signal or
logic 1 on any input pin IA to IG drives its corresponding
output pin OA to OG to ground or logic zero, where it is
capable of sinking considerable current. A logic zero on
any input pin IA to IG drives its corresponding output pin
OA to OG to a logic 1,
A diode 260 connects line 106i to line 106;.
Respective diodes 261 to 265 connect lines 106e to 106i -to
one terminal of a resistor 266, the other terminal oE which
is connected to a positive DC line 182 through a light
emitting diode (LED) 268. The LED 268 will be activated
ii any of the outputs OA to OF are grounded, indicating that
power is being supplied to one of the syrup pump relayq,
indicated by blocks 295 to 299. We connect line 106k to a
positive DC line 182 through a resistor 277 and an LED 285,
which is actuated when pin OG of driver 25~ is grounded
(logic 0), indicating that a vend signal is being supplied
to the coin mechanism relay 300.
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We connect lines 250b to 250h to respective input
pins IA to IG of an inverting driver 256 and connect respec-
tive output pins OA to OG to respective lines 106m to 106t,
leading respectively to the light "select" lamp relay 301,
the cup dispensing relay 302, the ice delivery solenoid relay
303, the water pump relay 304, the still water delivery 305,
the carbonated water delivery relay 306 and the carbonator
fill relay 307. When any output terminal OA to OG of
driver 256 goes to a logic ~ero, power is being supplied to
the corresponding relay 301 to 307. A plurality of LEDs
278 to 284 connected in series with respective resistors
270 to 276 between terminal 182 and lines 106~ to 106t
afford a visual indication of the relay or relays to which
power is being supplied.
Referring now to FIGURE 2C, a power supply 180
is adapted to provide the proper potentials for operating
the logic units oE the system Erom a source of alternating
current. More specifically, thb supply 180 provides power for
the controller 200, the drivers 254 and 256, the flip-flop
252 and through llne 106d for the driver board 108. ~n
LED 286 which is connected in series with a resistor 288 be~
tween d.c. line 182 and ground line 186 is activated once line
106d is energized, indicating that power is being supplied to
the driver board 108. In addltion, the power supply maintains
lines 182 and 184 at a positive DC potential, lines 186, 188
and 190 at ground and line 106c at logic 1.
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Referring now to Figure 3, the driver board indi-
cated generally by the reference character 108, includes a
15 volt DC line 106d connected to the collector terminal of
a darlington circui~ 290. we connect reset line 106c to
the base terminal of the input trans.istor of circuit 290
and connect the emitter terminal of the output transistor
to line 292, which supplies a source of direct ~urrent to
the relays 294 to 307. Resistor 308 connects the base
input terminal to the emitter output terminal of circuit
290 in a manner known to the art.
Relay 294 consists of a photo-coupled isolator
which receives a credit or test vend signal from line 112
through a diode 312 and resistor 310 to the input of the
relay LED 294a which is connected to ground line 110.
The relay 294 incLudes a photo-transistor 29~b which is
rendered conducti~re in response to light from diode 294
falling on the base of transistor 29~b to connect line
. 292 to line 106b. Alternatively, if tlle test vend switch
lO0 is placed in either its "cup" 104 or "no cup" 102 po-
sitions, line 106a is coupled by resistor 222 to DC line
184 to apply a signal directly to the base of transistor
294b so that the transistor becomes conductive to connect
line 292 to line lOGb. Capacitor 314 and resistor 316
connect line 106~ to line 106a. ~n isoiating diode 228
connects line 104 to line 106a to prcvent a potential from
being applied to line 104 in t~e "cup" posltion of switc}
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We connect lines 106e to 106i to respective elec-
tronic relays 295 to 299 which control respective syrup
pWTpS correspondinc3 to the various flavor selections. O
The first four syrup pumps, wllicll llave not becn shown in
detail since they are identical to the fifth pump 152
are controlled by output pins OA to OD of driver 254.
Syrup pump motor 152 corresponds to both the fifth and
sixth selections which are controlled by outp-~t pins OE
and OF, offering either a carbonated or a non-carbonated
selection for that flavor. In addition, as relays 295
to 299 are identical, we will describe only the operation
of relay 299.
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Syrup pump motor 152 is provided with a full
cycle switch 154. If either output OE or OF of driver
254 is grounded, the resultant current flow from line 292
to line 106 i causes relay 299 to co~ple a common AC line
130 to line 126, energi~ing the motor 152. Motor 152 illune-
diately closes its full cycle switch 154 which supplies
power to the motor through line 128 after relay 299 is
de-energi;~ed. When delivery of the syrup is completed~
the full cycle switch 154 re-opens, ~hutting off the motor
152.
We connect line 106k to relay 300, which f20ds
an "acccpt" signal to the coin mechanism 46 to permit th~
acceptance of coins in response to grounding of the output
~; OG of driver 254 to cause relay 300 to connect line 116 to
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line 114.
In the manner described hereinabove, lincs 106m
to 106t couple control signals rom output pins OA to OG t
of driver 256 to relays 301 to 307 to energize the respec-
S tive relays. When energized,relay 301 couples line 120
to line 118 to light the "select~' lamp. Relay 302 energi7.cs
the cup delivery mechanism from line 130 to line 122 and
the cup mechanism closes full cycle switch 166 in line
124 to complete its cycle. Relay 303 connects lines 132
and 134 to energize the ice delivery solenoid. In a similar
manner, relays 30a. to 307 provide power from line 120 for
the water pump motor 15a, for the still water valve solenoid
160, for the carhonated water valve solenoid 162 and for
the carbonator fill valve solenoid 164.
Referring now to Figure 4, switch bank Wl~l, to
which switch banks WA2 to WA6 are identical, includes an in~
put linc 320 which connects input pin I to one terminal of
each of a pair of switches 322 and 324. Respective diodes
326 and 328 connect the opposite terminals of respective
switches 322 and 324 to respective output pins 1 and 2.
Each switch bank corresponds to a selection and determlnes
whether the b~vera(Je selccted will be non-carbonated, high
carbonatea or low carbonated. For a high carbonat~d bcvcr-
age, only switch 322 is closed. For a non-carbonated bev-
erage, only switch 324 is closed. For a low carbonated
beverage, both switches 322 and 324 are closed.
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Refe~ring now to Figure 5, switch bank SYP-l,
to which banks S~P-2, SYP-6, ICE and DRK are identical,
includcs an input line 330 which connects input pin I
to one terminal of each of switches 332, 334, 336 and
338. Respective diodes 340, 342, 344 and 346 connect the
opposite terminal~ of switches 332 to 338 respectively to
output pins 1 to 4. Switch banks SYP-l to SYP-6 each
corresponds to a specific selection and dotermines the
time at which the syrup pump for that selection starts.
Switch bank ICE determines the amount of ice to be dispensed
with each beverage and switch banX DRK determines the amount
of beverage. It wilI readiIy be apparent that the times
and amounts correspond to the numbers of switches 332 to
338 which are closed.
L5 Re~erring now to Pigure 6, circuit 302 includes
a photon coupled isolator 350 comprising an LED connected
in series with a resistor 34t3 betw~en lines 292 and 106h or l~,0l).
We connect a silicon controlled rectifier 350b in having
a gate resistor 352 across one set of terminals of a full
wavc rectifier. Normally in the absence of current flow
through 2nd hence, photon emission from the diode 350a,
the SC~ 350b of isolator 350 remains non-conductive, prc-
venting currcnt flow throllgh a full wave rectifier comprisin
diodes 354, 356, 358, and 360. Under thcse conditions, a
triac 362 coupled between lines 130 and 122 is non-conductivc.
In response to current flow through the photon-emltting diode
350a, the SCR 350b becomes conductivc, permittin~ current
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flow from line 122 through resistor 364 and the rectifier
bridge to the gate of the triac 362, turning it on. ~esisto
352 prevents noise from falsely triggerinq the isolator SCR
350a. Resistor 368 and shunt capacitor 366 prevent noise
from falsely triggering the triac 362. ~ resistor 370 and
capacitor 372 couple lines 130 and 122, while line 124 i.5
coupled to line 130 by a resistor 368. Circuit 302 thus
provides AC coupling between lin~s 130 and 122 in response
to a low state on line 106n whenever line 292 carries a high
potential. Circuit 302 also provides AC coupling between
lines 130 and 124. Circuits 295, 296, 297, 298, 299, and
306 are identical to circuit 302, except for resis,tor 370
and capacitor 372 which are eliminated. Circuits 301 and
303 are identical to circuit 302 except for line 124 which
is eliminated. Circuits 300 and 305 ~ro identical to cir-
cuit 302 except for line 124, resistor 370, and eapaeitor
372, which are eliminated.
ReferrincJ now to Figure 7, circuit 304 includes
a photon coupled isolator 376 comprising LED 376a connected
in series with a resistor 374 between lines 292 and 106q
and a silicon-contro~led rectifier (SCR) 376b, having ~
gate rosistor 37E~, connqcted across one set of terminals oE
a full wave rectiier bridge made up of diodes 380, 382, 3E34,
and 386. Normally, in the absence of current flow throu~h
and hence photon emisslon from the diode 376a, the SCR 376b ~ -
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remains non-conductive, preventing current flow through
the full WaVt? rectifier bridge. Under these conditions,
the triac 168 shown in Figure lA, coupled between lines
136 and 120, is non-conductive. In response to current
S flow through ~he photon emitting diode 376a, the SCR 376b
becomes conductive, permitting current flow from line 136
throuqh a resistor 388 and the rectifier bridge to the gate
of the triac 168 through line 140, switch 172 shown in
Figure lB and line 138. Resistor 378 prevents noise from
falsely triggering the i~olator SCR 376b. Resistor 394
and shunt capaci~or 396 prevont noise from falsely trigger1~g
the triac 168. Resistor 390 and capacitor 392 connect line
120 to line 136. Circuit 304 thus pro~ides ~C coupling bc-
tween lines 120 and 136 in response to a low state on line
292 whenever line 106q carries a high potential and switch
172 is closed. In addition, circuit 304 provicles AC coupling
between lines 120 and 136 when both swltches 172 and 170 aro
closcd.
Referring now to Figure 8, circuit 307 includes
a photon coupled isolator 398 comprising an LED 398a connectetl
in series with a resistor 396 between lines 292 and 106s ancl
an associated SCR 398b having a gate resistor 400 and con-
nected across onc pair of terminals of a full wavc r~ctificr
made up of diodes ~02, 404, 406 and 408. Normally, in the
abst-~ncc of current flow through and hencc photon emission
from the diode, the SCR 398b remains non~conductive prcventing
; current flow t~lrough the fulI wave rectifier bridge. Under
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these conditions, a triac 412 coupled between lines 146 and
120 is non-conductive. In response to current flow through
the photon cmitting diode 398a, the SCR 398b becomes conduc-
tive, and, if switch 176 shown in Figure lB is clos~d,
current will flow from line 146a through a resistor 410
and the rectifier bridge to the gate of the triac 412, turn-
ing it on. Resistor 400 prevents from falsely triggering
the isolator SCR 39R. Resistor 416 and shunt capacitor 414
prevent noise from falsely triggerin~ the triac 412. We
connect a resistor 420 and a capacitor 418 in series be-
tween lines 120 and 1~6. Circuit 307 thus provides AC
coupling between lines 146 and 120 in response to a low
state on line 106S whenever line 292 carries a high potential
with switch 176 closcd.
, .
The operation of our control system for a cold
drink machine can best be understood by reference to Figuros
9 to 11. Referring now to Figures 9A and 9B, the main pro-
~ram of our ccntrol circuit for a cold drink vendor starts
when power is first supplied to the machine as indicated by
block 500. As indlcated by block 502, the control circuit
- prepares for normal operation by clearing all storage lo-
cations within the central processing unit (CPU) 200. A
second starting point i5 indicated at block 504, for use
once the machine is opcrational.
:.:
As is shown by block 506, the vending machine is
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prepared for operation by ~nabling the coin mechanism and
the carbonator fill valve, and, if needed, the filling of
the carbonator with water. This is accomplished by main- ,~
taining lines 250a and 250g at a high logic level. Line
250a also providec: an input to the drink size switch bank
DRI~ which is then rcad by scanning lines 230a to 230d.
~lock 508 of the program represents the computation of
drink size and storage in the CPU. As the vending machine
is now operational, block 510 represents the check for a
vend signal, indicating that sufficient money has been
deposited in the coin mechanism or that the test vend
switch 100, used to check the operation of the machine by
simulating the deposit of money, is actuated. To this end,
a high level signal is placed on line 240a causing one in-
put of NAND gate 198 to go positive. If a v~nd signal is
present, line 106b will also be at a high logic level, CAUS-
ing the othcr input of NAND gate 198 to go positive, thus
grounding the output. Diode 196 connects the output to
line 192, which is then scanned by the CPU as represent~3d
by block 512. The grounding of line 192 indîcates the pre-
sence of a vend signal while a high logic level on line 192
indicates the opposite. If the vend signal is not present,;
the program jumps to a "cloar dcbounce" subroutine ~(block
514), to bc explaincd hereinbelow. Line 240 is brought to
a low state and the syrup counts, which determine whels the ,~
syrup pumps are to be activated, are reset to the maximum
`; (block 516~. As a further precaution to prevent fal~e
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triggering of the syrup pumps, lines 240a to 240f are kcpt ~t
logic zero (block ~1~3) and latchcd by flip-flop 2';2 to kocp
syrup pumps off. ~he program then loops back to start.
If thc vcnd signal is rresent, the program jumps
5 to a "D~bouncc" subroutine (block 520) which introduces a
delay into thc program to assure that the machine will re-
spond only to valid inputs and will rcject noise, as will
be more fully explained hereinbelow. When the debounce
time expires, linc 240a is brought to logic zero and a
10 high level signal is placed on line 240b in order to check
the Test Vend swi~ch 100 (block 522~. Line 250a is brou~ht
to losic zcro, dis~bling tlle coin mcchanism to prevent thc
further acceptance of coins (block 524) and the '`no cup"
bit or flag, bit 4, of an ~3 bit ~seloction word" located
15 within the CPU 200, is set to logic 1 (block 526). ~he
program then scans line 192 to determine whether the Test
Vend switch 100 is in the "no cup" position ~block 528j.
If the switch is in the "no cup" position, DC
line 184 will be coupled to line 104. causing one input of
20 NAND gate 204 to go positive. As the othcr input is positiv~
through linc 240b, the output of NAND gate 204, connectcd
by diode 202 to linc 192, is grounded indicatlng that
simulatcd vend is requested without a cup. The program will ~
then jump to a "dcbounce" subroutinc (block 536), to verify - -
25 the signal and then to block 530.
2".
If thc test vend switch 100 is in either the
"Off" or "Cup" positicn, iine 192 will remain positive and
the program will check the "no cup" flag (block 530). If
the flag is clear, the "no cup" bit is at logic zero, the
S operation procee(ls to block 538. If the flag is set, the
"no cup" bit is at logic 1, the program jumps to a "clear
deb~unce" subroutine (block 532), clears the "no cup" bit
(block 534), and loops back to block 528.
At block 53~, a determination is made as to
whether an inter-sale delay, set after the last vend, has
expired before continuing to block 542. If not, the pro-
gram jumps to the "wait" subroutine (block 5'10), to be
described hereinbelow, and loops back to block 538 until
either the intersale delay or a delay within the "wait"
subroutine expires. At this point, a high level signal is
placed on line 250b to illuminate the "make selection" lamp
148, a three bit selection scan register (which may contain
any number from one to six, 001 to 110, corresponding to
pins Rl to R6) is cleared and a number (which varies with
the setting vf the drinX size switchos) is loaded into the
"prescaler count" within the "wait" subroutine (block 542).
The program then determincs whether the "selcction made" Iy
bit, bit 3 of the ~ bit selection word, is set, as repre-
sented by loglc 1~, or is clear, as represented by logic
~ero (block 544). If a selection ha~s been made, the bit is
set and the program will jump to block 572~ If no selecti~n ;
`~ has been made, tlle bit is clear and the progrsm will ~ontisluc~
to block 546 to clear the "selection" bits, which are blts
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O to 2 of the 8 bit .selectio~ word.
Next, as indicated by bloc~s 548, 550 and 552,
the switches 5W-] to S~-6 are scanned until a valid selec-
tion is dctected, as indicated by a high level signal on
S one of the lines 240a to 240f while scanning lines 240g
and 2~0h. If a valid selection is not detected after all
the switches have been scanned, the program jumps to block
578 (block 554). IE a valid selection is detected, it is
verified (block 55G) and the "selection made" bit is set
(block 558).
If the high level signal is detected on line
240g, the "high carb~ bit, bit 7 of the 8 bit selection
word, i9 set, indicatinc3 a high carhonated-selection. If
the signal is detected on 240h, the "no carb" bit, bit 6
of the 8 bit selection word, is set, indicating a non-
carbonated selection. If the signal i5 detected on both
lines 240g and 240h, both bits are set, indicating a low
carbonated selection (block 558). The signal is maintained
on the appropriate line 240a to 240f, while the program
scans lines 230a to 230d to determine the syrup start time . ~-
for this particular selection. Line 250b is then brought
to logic zero, turning off the "make selection" lamp 148
(block 560).
As the program continues, a determination is
made as to whether or not the "no cup" flag is set (block
562). If tlle flag i~ set, the program proceeds to block 566.
If the flag is not set, line 250c i5 brought to logic 1, acti-
vating the cup dispenser 150 (block 564). The program
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waits tblock SGG), assuring activation of the dispenser,
and then brings linc 250c to logic zero (block 568). A
delay is loadcd into the "wait" su~routine (block 570) to
allow the cup to drop into place (block 570). During this
delay the program determines whether the "no ice" flag,
bit 5 of the 8 bit selection word, is set (block 574, 576,
and 578). If this flag is set, the program continues to
block 586. If the "no ice" flag is not set, line 192 i5
scanned while line 240f i9 brougllt to logic 1, causing one
input of NAND gate 208 to go positive. If the "no ice"
switch is closed at this time, the other input of gate
208 will also go positive, grounding the output which lS
connected to line 192 through diode 206. The program will
verify this signal (block 582) and then set the "no ice"
1ag (block 584). If the "no ice" switch is open, the
outp~t will remain posit1ve, and the program will continue
to block 586 from block 58Q.
At block 586 a counter, located within the "De-
bounce" subroutine, is reset. The program then jumps to
the "clear debounce" subroutine and loops back to block544.
Once the delay has expired, linc 250i lS r~lsed
to logic one and lines 230a to 230d are scanned in order
to read the ice amount switch bank IC~ (block 59Q). Thc
"no ice" flag is then checked ~block 592). If the fla~
is clear, line 250d is brought to logic one (block 598),
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opening an icc door which separatcs the ice maker from an
ice chute, allowing ic to fall into the cup.
Next, as represer;.ted by block 598, an "ice door
open time" is calculated and loaded into an ice count lo-
5 cated within ~the "wait" subroutine described in detailhereinbelow. rhis time is determined by the settings of
the ice amount switchbank ICE and the drink si~e switchbank
DR~. When this time expires (block 600),line 250d is brought
to logic zero, closing the ice door. Two delays are then
calculated by the program. A "ma~e-up time", to increase
water to cornpensatc for less ice due to the settir.g of the
ice amount switchbank ICE, is calculated and stored and ~.
"dead time" to delay the program while the ice drops through
the ice chute to the cup, is calculated and set. These de-
lays are also used if the "no ice" flag is set (block 592).The dead time will compensate for the time not used to drop
the ice (block 594), and the make-up time will be used to
increase the water to compensate for the lack of ice (block
596).
The program then waits for the "dead time" to ex-
pire (block 604) and then sèts the "make-up tim~" ~block
606). If the hi~h carb bit is s0t, bit 7 of the 8 bit se-
lectior, word, line 250h is raised to logic one opening
the carbonated water valve ~block 612),filling the cup wi~h
2S carbonated water. If the bit is no~ set, line 250g i9
brought to logic ~ero, disabling ~he carbonator fill valve,
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and lines 250e and 250f a~e raised to logic one, opening
the still water valve and energizing the water pump (block
610), fi.lling the cup wi~h still water. When the cup is
half full, the still water or non-carbonated bit is
checked, bit 6 of the 8 bit selection word (blocks 614 and
616). If the bit is clear, the program finishes filling
the cup (block 620 and 622). If the bit i5 set, lines
250g and 250h are brought to logic zero, disabling the
. carbonator fill valve and closing the carbonated water
valve. Lines 250e and 250f are raised to logic one, open-
ing the still water valve and starting the water pump,
respectively.
Once the cup is filled, lines 250f, 250h, and
250e are brought to logic zero, closing both the still
and carbonated water valves and de-energizing the water
pump. Line 250g is raised to logic one, enabling the car-
bonator fill valve and lines 240a to 240f are brought to logic
zero to prevent the ac-tivation o~ any of the syrup pumps
(block 624). The program then sets an intersale delay
time block 626 and loops back to start block 504.
Referring now to FIGURES 10A and 10B, the "wait"
subroutine, which monitors three delays simultaneously,
begins at block 630. The program loads the accumulator
(block 632) and then waits or 20 milliseconds (blocks
634, 636 and 638) before decrementing the syrup count
(block 640). The number loaded into the syrup count varies
with the setting of the syrup switch bank.for the particular
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selection bcing vcnded, and is based on the viscosity of
the syrup. Until the syrup count is decremented to zero,
the program continues directly to block 646. Once de-
cremcnted to zero, the program wilI start the appropriate
syrup pump by raising to logic one both the corresponding
syrup line (one of the lines 240a to 240f~ and line 250i,
the clock input of tlle ~lip-flop 252 ~blocks 642 and 644).
: .
At block 646, the program decrements a number
loaded into the prescaler, which varies with the setting
of the drink size switches. Until the prescaler is decre-
mented to zero, the program returns to thc main routine
through block 664 (block 648). Once decremented to zero,
the prescaler is reloaded (block 650) and the ice count,
which varies with the settinq of the drink size "DRK" and
ice amount "ICE" switch banks, is decremented (block 652).
The program jumps directly to block 658 until the ice count
is decrementcd to zero (block 654). At that point, line
250e is brought to logic zero causing the ice door to clos2
(block 656).
The program then decrements the cycle count ~block
658~, which varies with th~ delay required at the particular
point in the main program and until the cycle count is de-
cremented to zero, returns to the main routine through
block 664. Once the cycle count is decremented to zero,
2S the: program returns to the main routine through block 662.
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Referring now to FIGURE 11, the "debounce" sub-
routine, which introduces a delay into the program to in-
sure that the machine will respond only to valid inputs
and reject noise, begins at block 670. The program de-
crements a "debounce count" and returns to the main pro~ram
through block 676. ~hen the "debounce _ount" is decremented
to zero ~block 674), the program resets the count (block
680) and returns to the main routine through block 682.
The "clear debounce" subroutine starts at blocX
678, resets the debounce count (bloc~ 680) and returns to
the main routine through block 682.
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It will be seen that we have accomplished the ob-
jects of our invcntion. We have provided an improved con-
trol system for a cold drink merchandising machine which
overcomes the defects of cold drink merchandisiny machine
control circllits of the prior art. Our system affords a
simpler and more expeditious setting of the operating para-
meters of the machine. The settings of the operating para-
meters are digital in nature. Our system is more versatile
than are systems of the prior art. It is less expensive
and easier to operate than are systems of the prior art.
We provide our system with a self-diagnostic feature,
It will be understood that certain features and
subcombinations are of utility and may be employed without !
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reference to other features and subcombinations. This is
contemplated by and i5 within the scope of our claims.
It is further obvious that various changes may be made in
details within thc scope of our claims without departing
from the spirit of OUL- invention. It is, therefore, to be
understood that our invention is not to be limited to the
specific details shown and described.
Having thus described our invention, what we
claim is:
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