U.S. patent application number 10/973573 was filed with the patent office on 2005-03-10 for positive station module locking mechanism for expandable irrigation controller.
Invention is credited to Anuskiewicz, Ronald H., Beutler, Matthew G., McKnight, James F., Uccello, Santo.
Application Number | 20050055106 10/973573 |
Document ID | / |
Family ID | 33416346 |
Filed Date | 2005-03-10 |
United States Patent
Application |
20050055106 |
Kind Code |
A1 |
Beutler, Matthew G. ; et
al. |
March 10, 2005 |
Positive station module locking mechanism for expandable irrigation
controller
Abstract
A modular expandable irrigation controller has controls for
manual entry or selection of a watering program and a memory for
storing the watering program. A processor executes the stored
watering program and controls one or more station modules each
including a station module circuit for energizing at least one
solenoid actuated valve in accordance with the watering program.
The irrigation controller has a plurality of receptacles for each
removably receiving a station module and for providing an operative
connection to the processor. A manually movable locking member is
grasped and moved between UNLOCKED and LOCKED positions to
positively secure each station module in a corresponding
receptacle.
Inventors: |
Beutler, Matthew G.;
(Temecula, CA) ; Anuskiewicz, Ronald H.; (San
Diego, CA) ; McKnight, James F.; (San Diego, CA)
; Uccello, Santo; (San Marcos, CA) |
Correspondence
Address: |
ATTN: Michael H. Jester
A PROFESSIONAL LAW CORPORATION
505 D Grand Caribe Causeway
Coronado
CA
92118
US
|
Family ID: |
33416346 |
Appl. No.: |
10/973573 |
Filed: |
October 26, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10973573 |
Oct 26, 2004 |
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10430929 |
May 5, 2003 |
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6842667 |
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Current U.S.
Class: |
700/11 ; 700/19;
700/2; 700/282; 700/284 |
Current CPC
Class: |
A01G 25/165 20130101;
Y10T 137/86389 20150401 |
Class at
Publication: |
700/011 ;
700/002; 700/019; 700/282; 700/284 |
International
Class: |
G05B 019/18; G05B
011/01; G05D 007/00; G05D 011/00 |
Claims
We claim:
1. A modular expandable irrigation controller, comprising: control
means for manual entry or selection of a watering program; means
for storing the watering program; processor means for executing the
stored watering program and controlling one or more station modules
each including a station module circuit for energizing at least one
solenoid actuated valve in accordance with the watering program;
means for providing a plurality of receptacles for each removably
receiving a station module and for providing an operative
connection to the processor; and means, including a manually
movable locking member, for securing each station module in a
corresponding receptacle.
2. The controller of claim 1 wherein the movable locking member is
a rotating lever.
3. The controller of claim 1 wherein the movable locking member is
a slide bar.
4. The controller of claim 1 wherein the station module circuit
includes at least one switching device.
5. The controller of claim 1 wherein the securing means further
comprises UNLOCKED and LOCKED indicia and the securing means
includes a pointer on the movable locking member that moves between
first and second positions adjacent the UNLOCKED and LOCKED
indicia, respectively.
6. The controller of claim 1 wherein the means for providing an
electrical connection includes a female electrical connector in
each of the receptacles.
7. The controller of claim 1 wherein the means for providing an
electrical connection includes a card edge connector in each of the
receptacles.
8. The controller of claim 1 wherein the movable locking member is
a rotating lever that is connected to a shaft that moves a locking
tab underneath a portion of a back panel in which the receptacles
are located.
9. The controller of claim 1 wherein the movable locking member is
a slide bar having a plurality of locking elements that move into
and out of obstructing relationship with at least one projection on
each of the station modules to simultaneously prevent and permit
the removal of a plurality of station modules from their
corresponding receptacles, respectively.
10. The controller of claim 1 and further comprising means for
providing a receptacle for removably receiving a power module and
for providing an electrical connection to the processor means.
11. A modular expandable irrigation controller, comprising: means
for entry or selection of a watering program; a memory that stores
the watering program; a processor that executes the stored watering
program and controls one or more station modules each including a
station module circuit for opening and closing at least one valve
in accordance with the watering program; a plurality of receptacles
each configured to removably receive a station module and provide a
connection to the processor; and a locking member mounted adjacent
the receptacles and manually moveable from an UNLOCKED position to
a LOCKED position to positively secure the station modules in the
receptacles.
12. The controller of claim 11 wherein the locking member is a
rotating lever.
13. The controller of claim 11 wherein the locking member is a
slide bar.
14. The controller of claim 11 and further comprising a pointer on
the locking member that moves between positions adjacent UNLOCKED
and LOCKED indicia formed adjacent at least one of the
receptacles.
15. The controller of claim 11 wherein each of the receptacles
includes a female electrical connector.
16. The controller of claim 11 wherein each of the receptacles
includes a card edge connector.
17. The controller of claim 11 wherein the locking member is a
rotating lever that is connected to a shaft that moves a locking
tab underneath a portion of a back panel in which the receptacles
are located.
18. The controller of claim 11 wherein the locking member is a
slide bar having a plurality of locking elements that move into and
out of obstructing relationship with at least one projection on
each of the station modules to simultaneously prevent and permit
the removal of a plurality of station modules from their
corresponding receptacles, respectively.
19. The controller of claim 18 wherein the locking elements and the
projection are configured so that they will collide and move the
slide bar to its UNLOCKED position if a user plugs the station
module into an empty receptacle when the slide bar is in its LOCKED
position.
20. A method of expanding a modular irrigation controller,
comprising the steps of: providing a microprocessor based
irrigation controller with a plurality of receptacles for each
receiving a station module that is controlled by the microprocessor
to open and close at least one solenoid actuated valve operatively
connected to the station module; inserting a module into one of the
receptacles; and manually gripping and moving a locking member
mounted adjacent the receptacle from an UNLOCKED position to a
LOCKED position to positively secure the station module in the
adjacent receptacle.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to electronic irrigation
controllers that control valves which supply water to sprinklers,
and more particularly, to modular expandable irrigation
controllers.
BACKGROUND OF THE INVENTION
[0002] In many parts of the world due to inadequate rainfall it is
necessary at some times during the year to artificially water turf
and landscaping. An ideal irrigation system for turf and
landscaping should utilize a minimum number of valves, supply lines
and sprinklers. Preferably the valves should be turned ON and OFF
by an inexpensive, yet reliable electronic irrigation controller
that is easy to program and can carry out a wide variety of
watering schedules. The goal is to uniformly distribute the optimum
amount of water over a given area. Rotor type sprinklers have
largely displaced older impact type sprinklers in applications
where large expanses of grass are watered, such as golf courses,
due to the fact that the former are more reliable, quieter, and
distribute water on a uniform and controlled basis. Spray type
sprinklers, rotary stream sprinklers, bubblers and drip irrigation
devices are also frequently used in residential and commercial
irrigation systems. When an irrigation system is designed and/or
installed the type, placement and precipitation rates for each of
the sprinklers are pre-selected. The optimum precipitation rate
provided by each sprinkler should preferably fall within plus or
minus one-quarter gallons-per minute (GPM). The amount of water
supplied by each sprinkler is largely determined by the size and
configuration of its nozzle orifice(s), although variations result
from fluctuations in water pressure that cannot be fully negated
with regulators.
[0003] Preferably an irrigation controller should have the
capability of temporarily terminating its watering program if
sufficient rain occurs based on signals inputted from a rain
sensor. See for example, U.S. Pat. No. 5,097,861 granted Mar. 24,
1992 of Hopkins et al. entitled IRRIGATION METHOD AND CONTROL
SYSTEM, assigned to Hunter Industries, Inc., the assignee of the
subject application, the entire disclosure of which is hereby
incorporated by reference. On suitable rain sensor for this purpose
is disclosed in pending U.S. patent application Ser. No. 10/053,100
filed Oct. 26, 2001 of Paul A. Klinefelter et al. entitled QUICK
SHUT-OFF EXTENDED RANGE HYGROSCOPIC RAIN SENSOR FOR IRRIGATION
SYSTEMS, also assigned to Hunter Industries, Inc., the entire
disclosure of which is hereby incorporated by reference.
[0004] Residential and commercial irrigation systems typically
include one or more solenoid operated valves that are turned ON and
OFF by an electronic irrigation controller. The valves admit water
to various subterranean branch lines usually made of PVC pipe that
typically have several sprinklers connected to risers coupled to
the branch lines at spaced intervals. Each combination of a
solenoid valve and its associated sprinklers is referred to in the
irrigation industry as a station or zone. A modern electronic
irrigation controller typically includes a microprocessor and
separate memory, or a micro-computer with on-chip memory, that
stores and executes one or more watering programs. The watering
programs can be pre-programmed by the user via push button and/or
rotary controls. The controller usually has an LCD or other display
to facilitate programming by the user. Often the controller will
revert to a default watering program in the case of a power
failure. The microprocessor controls the solenoid valves via
suitable drivers and switching devices. The valves are opened and
closed by the microprocessor in accordance with the pre-programmed
run and cycle times for each of the stations.
[0005] Over the past decade, modular expandable irrigation
controllers have gained increasing popularity. In these
controllers, the base portion of the system contains the
microprocessor and user actuated controls. Each station is then
controlled by a corresponding station module which comprises a
plastic housing that encloses and supports a station module
circuit, as well as wire connection terminals for connecting wires
to a plurality of solenoid actuated valves. Typically each station
module can independently control more than one solenoid actuated
valve, i.e., station. The station modules contain pins, sockets,
card edge connectors or some other standard form of
electro-mechanical connectors for allowing them to be inserted into
slots or receptacles in either the housing that contains the
microprocessor or a separate back panel hinged to the
microprocessor housing. The advantage of this configuration is that
the controller need only be equipped with the minimum number of
station modules that can control the total number of stations.
Thus, for example, an irrigation system may have only three zones,
requiring only a single station module, while another may have
twelve stations which might require four station modules.
Considerable cost savings are thus achieved. Moreover, if an
irrigation system expands after initial installation because the
landscaping has increased, additional station modules can be added.
In some modular expandable irrigation systems the base unit is
capable of controlling a minimal number of stations without
requiring the addition of any station modules. In others, such as
the ICC.TM. and Pro C.TM. irrigation controllers manufactured and
sold by Hunter Industries, Inc., at least a power module and one
irrigation station module must be plugged into the controller in
order to operate any stations or zones.
[0006] When the station modules are plugged into the receptacles of
a modular expandable irrigation controller they are mechanically
supported and an electrical connection is made between the
microprocessor and the driver. The station modules can be removed
and replaced if damaged, for example, during a lightening strike.
It has been conventional to use plastic spring members or elements
to hold the station modules in place in their respective
receptacles or slots. However, such springs often require
considerable force to be exerted by the user, both during
installation and withdrawal of the station modules. The spring
members can also break and difficulties have been encountered in
ensuring that a complete and positive electrical connection is both
achieved and maintained. In some cases, station module installation
can lead to breakage in the metal pins or metal leaf spring
contacts used to make the electrical connection.
[0007] Accordingly, it would be desirable to provide a modular
expandable irrigation controller with improved station module
mating to minimize or eliminate the foregoing problems.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention a modular
expandable irrigation controller has controls for manual entry or
selection of a watering program and a memory for storing the
watering program. A processor executes the stored watering program
and controls one or more station modules each including a station
module circuit for energizing at least one solenoid actuated valve
in accordance with the watering program. The irrigation controller
has a plurality of receptacles for each removably receiving a
station module and for providing an operative connection to the
processor. A manually movable locking member secures each station
module in a corresponding receptacle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an enlarged perspective view of a station module
of a first embodiment of our invention.
[0010] FIG. 2 is a fragmentary perspective view of the station
module of FIG. 1 inserted into a back panel of the first
embodiment.
[0011] FIG. 3 is an enlarged fragmentary perspective of the rear
side of the back panel illustrating the engagement of locking tab
of the first embodiment with the back panel.
[0012] FIG. 4 is a top plan view of a second embodiment of the
present invention.
[0013] FIG. 5 is a vertical sectional view taken along line 5-5 of
FIG. 4.
[0014] FIG. 6 is an enlarged fragmentary perspective view
illustrating the relationship of the locking slide bar of the
second embodiment to four modules installed side-by-side in its bay
when the locking slide bar is in its UNLOCKED position.
[0015] FIG. 7 is an enlarged fragmentary perspective view similar
to FIG. 6 but taken from a different angle and illustrating the
relationship of the locking slide bar of the second embodiment to
four modules installed side-by-side in its bay when the locking
slide bar is in its LOCKED position.
[0016] FIG. 8 is an enlarged vertical sectional view of the locking
slide bar taken along line 8-8 of FIG. 5.
[0017] FIG. 9 is a greatly enlarged fragmentary view of the portion
of the locking slide bar circled in FIG. 8.
[0018] FIG. 10 is a block diagram of the overall irrigation
controller circuit that may be used in either of the first or
second embodiments.
[0019] FIG. 11 is a schematic diagram of an exemplary circuit for
one of the station modules of the irrigation controller circuit of
FIG. 10.
[0020] FIG. 12 is a schematic diagram of an alternate circuit for
one of the station modules.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Referring to FIGS. 1-3, in accordance with a first
embodiment of our invention, a rectangular station module 10 has a
pair of rigid (non-resilient) wedge-shaped tabs 12 and 14 that
project from one end and a pivotable locking lever 16 that is
mounted at the opposite end. The station module 10 is inserted into
a receptacle such as 18 (FIG. 2) formed in the back panel 20 that
is hinged to a separate housing (not shown) that contains the
microprocessor. During the insertion of the station module 10 into
the receptacle 18, the left end of the station module is first
lowered into the receptacle 18 so that the wedge-shaped tabs 12 and
14 are inserted into corresponding side-by-side rectangular
apertures in one end wall of the receptacle 18, which are similar
to the two apertures 24 and 26 in the opposite end wall. The right
end of the station module 10 is then lowered into the receptacle
18. At this time pins (not shown) on the back side of the station
module 10 are plugged into corresponding holes in a female
electrical connector 22 to establish connection with a serial
bus.
[0022] Once the station module 10 has been fully inserted into the
receptacle 18, the locking lever 16 is swung or pivoted ninety
degrees from its extended (unlocked) position illustrated in FIG. 1
to its retracted (locked) position illustrated in FIG. 2. This
motion is translated via a drive shaft (not illustrated) journaled
in a bearing sleeve in the end wall of the station module 10 to
move a planar locking tab 28 (FIG. 3) underneath the back panel 20.
The various parts are dimensioned to provide a snug or tight fit
when the locking lever 16 is moved to its locked position. Thus,
the station module 10 is locked and held in place within the
receptacle 18 via the wedge-shaped tabs 12 and 14 and the planar
locking tab 28. The station module 10 can be removed from the
receptacle 18 by swinging the locking lever 16 to its unlocked
position and first lifting the right end of the station module to
unplug its pins from the connector 22 and then lifting the left end
of the station module to remove the wedge-shaped tabs 12 and 14
from their corresponding apertures in the left end wall of the
receptacle 18. An important aspect of the controller illustrated in
FIGS. 1-3 is that the station module 10 will fit in the receptacles
of an older design. In other words, the station module 10 is
backward compatible with an original commercial design of the
controller.
[0023] A second embodiment of our invention is illustrated in FIGS.
4-9. Referring to FIG. 7, female electrical connectors 29 in the
ends of three box-like station modules 30, 32 and 34 receive
corresponding card edge connectors such as 36 (FIG. 5) with mating
electrical contacts. The station modules 30, 32 and 34 are received
in side-by-side fashion in a bay formed in a rectangular back panel
38 (FIG. 4) that is separate from the housing (not illustrated)
that encloses the microprocessor. A larger, fourth box-like power
module 40 (FIG. 6) plugs into the bay onto its own card edge
connector and drives the pump master valve and the first three
station modules 30, 32 and 34. The upper sides of the modules 30,
32, 34 and 40 each have an upstanding projection 42 (FIG. 6). A
locking slide bar 44 (FIG. 8) with a V-shaped gripping member 46
extends above the bay and may be slid laterally (left and right)
between an unlocked position illustrated in FIG. 6 and a locked
position illustrated in FIG. 7. A V-shaped bump 48 (FIG. 9) on the
underside of the locking slide bar 44 can alternately register with
different V-shaped detents 50 and 52 formed in a cover 54 to hold
the locking slide bar 44 in its locked and unlocked positions. A
pointed tab 56 (FIG. 4) extending from the gripping member 46
alternately points to UNLOCKED and LOCKED indicia molded into the
adjacent back panel structure to indicate the module connection
status to the user.
[0024] When the locking slide bar 44 is moved to the right in FIG.
4 to its locked position, downwardly extending locking elements 58
(FIG. 5) move behind the upstanding projection 42 on each of the
modules 30, 32, 34 and 40 to mechanically lock the modules in the
bay and prevent their withdrawal. Any or all of the modules can be
removed from the bay by moving the locking slide bar 44 to the left
in FIG. 4 to its unlocked position so that the locking elements 58
are cleared from behind the projections 42 to permit the modules to
be pulled off of their corresponding card edge connectors. The new
modules 30, 32, 34 and 40 of the controller of FIGS. 4-9 are
backward compatible with an earlier original design of the
controller because they simply plug into the card edge connectors
which hold them in place. The old modules of the original
controller are also forward compatible with the re-designed
controller. FIGS. 6 and 7 also illustrate the upstanding projection
60 of the old modules which is spaced laterally with respect to the
upstanding projection 42 of the newer modules. The locking slide
bar 44 has alternate downwardly extending locking elements 62 (that
are laterally displaced from the locking elements 58) and move
behind the upstanding projections 60 of the older modules to lock
them in place. The old modules only have the upstanding projection
60 and the new modules only have the upstanding projection 42, but
both are shown in FIGS. 6 and 7 at the same time in order to
illustrate the backward and forward compatibility.
[0025] Referring to FIG. 6, the upstanding projections 42 and 60
have a triangular cross-section the downwardly extending locking
elements 58 and 62 have a rectangular cross-section. The
projections 42 and 60 are oriented so that if a user tries to
insert a module, such as 32 into a vacant receptacle in the bay
formed in the rectangular back panel 38 when the slide bar 44 is in
its locked position, the slide bar 44 will be forced to its
unlocked position. This takes place as a result of the angled
surfaces on the projections 42 and 60 colliding with and sliding
the locking elements 58 and 62 laterally. This automatic unlocking
feature prevents breakage of the projections 42 and 60 and/or the
locking elements 48 and 62.
[0026] Thus both embodiments of our invention each have a locking
member that is manually movable in the sense that it has with an
outer portion that is ergonmicially configured to be grasped by a
user's hand and pivoted or slid to positively lock one or more
station modules in place. The locking lever 16 has an enlarged
outer portion 16a (FIG. 1) that snaps over a small projection 17 in
a cut-out corner 10a of the station module 10 to hold the lever in
its locked position illustrated in FIG. 2. The V-shaped gripping
member 46 (FIG. 7) of the second embodiment is readily grasped
between the user's thumb and index finger. The positive module
locking mechanism of our invention guards against partial or
incomplete insertion of a station module that could lead to shorts
that would make the station or zone inoperable. The user is given
visual and tactile feedback indicating that a positive lock has
been established in the sense that each module has been fully
inserted. In the case of the first embodiment illustrated in FIGS.
1-3 each station module 10 is independently locked and unlocked. In
the case of the second embodiment illustrated in FIGS. 4-9, a
plurality of modules 30, 32, 34 and 40 are simultaneously locked
and unlocked with respect to their respective receptacles.
[0027] The back panel 20 (FIGS. 2 and 3) of the first embodiment is
typically mounted on a vertical wall of a building structure so
that each station module 10 is plugged in an removed in a generally
horizontal direction away from the user, and toward the user,
respectively. The back panel 38 (FIG. 4) of the second embodiment
is also typically installed on a vertical wall of a building
structure so that the modules, such as 30 (FIG. 6) are plugged in
and removed in a horizontal direction, lateral relative to the
user. In other words, the back panel 38 is oriented so that the
modules are in a vertical column with the station module 34 on top
and the power module 40 on the bottom. In both the first and second
embodiments the weight of the modules cannot tend to unplug the
same.
[0028] FIG. 10 is a simplified block diagram of the electronic
circuit 100 that may be used with either of the preferred
embodiments just described. Briefly, a microprocessor 102 executes
a selected watering program stored in ROM 104 using RAM 106. The
microprocessor 102 is coupled through an optional electro-optic
isolator 108 and a serial bus 110 to one or more removable station
modules 112 each including a station module circuit 114 for
energizing and de-energizing the solenoid of a valve (not
illustrated) connected thereto via insulated wires (not
illustrated). The electro-optic isolator 108 protects the
microprocessor 102 from damage if lightening should destroy one or
more of the station modules 112, but it may be eliminated for cost
savings.
[0029] The stripped inner ends of the wires that lead to the
solenoid valves are securred to conventioinal screw terminals 115a
(FIG. 1) on each of the modules 10 of the first embodiment or 115b
(FIG. 6) of the second embodiment. The screw terminals 115a are
separated by upstanding divider walls 11 (FIG. 1) to prevent
contact between adjacent wires. Similarly, the screw terminals 115b
are separated by upstanding divider walls 41 (FIG. 6) to prevent
contact between adjacent wires.
[0030] The valves may be of the type disclosed in U.S. Pat. No.
5,996,608 granted Dec. 7, 1999 of Richard E. Hunter et al. entitled
DIAPHRAGM VALVE WITH FILTER SCREEN AND MOVABLE WIPER ELEMENT, Inc.;
U.S. Pat. No. 6,079,437 granted Jun. 27, 2000 to Mathew G. Beutler
et al. entitled DIAPHRAGM VALVE WITH FLOW CONTROL STEM AIR BLEED;
and U.S. Pat. No. 5,979,482 granted Nov. 9, 1999 of Loren W. Scott
entitled REMOVABLE CAPTIVE PLUNGER WITH CONTAMINATION PROTECTION,
all assigned to Hunter Industries, Inc., the entire disclosures of
which are hereby incorporated by reference.
[0031] The term "solenoid actuated valve" shall also encompass
valves used in irrigation systems in which a pilot valve is not
directly opened and closed by a solenoid. These include
hydraulically or pneumatically actuated valves which have a
solenoid or its electrical equivalent somewhere in the fluid
system, and not necessarily next to the gating valve, for
controlling the fluid pressure to open and close the valves.
[0032] A power supply 116 (FIG. 10) supplies the power needed to
run the microprocessor 102 and energize the solenoids of the
valves. A removable power module 117 contains current sensing
resistors and has pump output terminals. Power is routed from the
power supply 116 through the power module 117 to the microprocessor
102 and to the station modules 112. The DC power to run the
microprocessor 102 and the logic circuitry inside the station
modules 112 is supplied by the power supply 116 through the power
module 117 to the microprocessor 102 and then back through the
power module 117 to the station modules 112. The AC power for
switching the solenoid actuated valves ON and OFF is supplied from
the power supply 116 through the power module 117 to the station
modules 112. A set of manually actuated controls 118 are connected
to the microprocessor 102 for allowing a watering program to be
entered, selected, altered, etc. with the aid of graphic and/or
alphanumeric symbols shown on LCD 120. The controls may include a
rotary switch, one or more pushbuttons, one or more slide switches,
one or more membrane switches, one or more toggle switches, one or
more insertable pins, a DIP switch, etc. Instead of using separate
microprocessor 102, ROM 104 and RAM 106, a single micro-computer
with on-chip memory may be utilized. The preferred configuration of
our irrigation controller includes a main PC board (not
illustrated) which supports the microprocessor 102, ROM 104, RAM
106, electro-optic isolator 108, serial bus 110 manual controls 118
and LCD 120. This main PC board is mounted inside a housing (not
illustrated) which is connected via ribbon cable to a back panel
such as 20 (FIG. 2) or 38 (FIG. 4) that is hinged to the housing.
The back panel 20 or 38 provides the receptacles for removably
receiving the station modules 10 or 30, 32, 34.
[0033] A port (not illustrated) may be connected to the
microprocessor 102 for downloading a watering program that has been
created on a personal computer and downloaded into a smart card,
portable data shuttle or other removable media. See for example
U.S. Pat. No. 6,088,621 granted Jul. 11, 2000 of Peter J. Woytowitz
et al. entitled PORTABLE APPARATUS FOR RAPID RE-PROGRAMMING OF
IRRIGATION CONTROLLERS, also assigned to Hunter Industries, Inc.,
the entire disclosure of which is hereby incorporated by reference.
Alternatively, the microprocessor could receive programming and/or
commands from a master computer via hard-wired or wireless
connection. The programming executed by the microprocessor 102 can
include a cleaning cycle which momentarily turns on each valve
after completion of a run cycle to flush debris away from the valve
seat. See U.S. Pat. No. 5,829,678 granted Nov. 3, 1998 of Richard
E. Hunter et al. entitled SELF-CLEANING IRRIGATION REGULATOR VALVE
APPARATUS, also assigned to Hunter Industries, Inc., the entire
disclosure of which is hereby incorporated by reference.
[0034] The microprocessor 102 controls a plurality of solenoid
actuated valves via the corresponding station module circuit 114
(FIG. 11) which is mounted on a small PC board contained within the
plastic housing of each station module 112. The station module
circuit 114 includes a microcontroller 122 that drives a switching
device in the form of a triac 124 through a diode 126 and resistor
128. The triac 124 comprises two silicon controlled rectifiers
(SCRs) connected in parallel and oppositely oriented to allow
bi-directional control of a standard twenty-four volt AC signal
sent to the solenoid of a valve via terminal 130. The control
signal from the serial bus is applied to the microcontroller 122
via serial data lead 132 while a nominal DC voltage signal, such as
five volts, is applied via another lead 134. Synchronous serial
data is clocked into the microcontroller 122 from the
microprocessor 102 via clock lead 136. Twenty-four volt AC power is
supplied from the power module 116 to the triac 124 via lead 138.
In the preferred embodiment of the station module circuit 114 triac
124, diode 126 and resistor 128 are duplicated eight times so that
one station module 112 can independently control up to eight
solenoid actuated valves (stations). The valves that supply water
to the sprinklers can thus be independently opened and closed by
the microprocessor 102 utilizing the station module circuits 114 in
accordance with the selected and/or pre-programmed run and cycle
times for each of the stations. See also U.S. Pat. No. 5,444,611
granted Aug. 22, 1995 of Peter J. Woytowitz et al. entitled LAWN
AND GARDEN IRRIGATION CONTROLLER, also assigned to Hunter
Industries, Inc., the entire disclosure of which is hereby
incorporated by reference.
[0035] FIG. 12 is a schematic diagram of an alternate circuit 140
for one of the station modules 112'. Each station module 112' has
its own power supply 142 that supplies a five volt DC signal to a
microcontroller 144 that can switch a triac 146 through diode 148
and resistor 150. The station modules 112' each have three sets of
the triac 146, diode 148 and resistor 150 (not illustrated) for
independently actuating three stations. The alternate station
module circuit 140 (FIG. 12) receives asynchronous serial data on
serial data line 152. In other words, the microcontroller 144 of
the station module 112' derives its clock signal from the serial
data signal. Twenty-four volt AC power is supplied to each power
supply 142 inside each station module 112' via lead 154.
[0036] Those skilled in the art will recognize that besides
providing a new irrigation controller, we have also provided a
novel method of expanding a modular irrigation controller. Our
method includes the step of providing a microprocessor based
irrigation controller with a plurality of receptacles for each
receiving a station module that is controlled by the microprocessor
to open and close a solenoid actuated valve connected to the
station module. Our method further includes the step of inserting a
module into one of the receptacles. Our method involves the final
step of manually moving a locking member mounted adjacent the
receptacle from an UNLOCKED position to a LOCKED position to secure
the station module in the adjacent receptacle.
[0037] While we have described two different preferred embodiments
of our modular expandable irrigation controller with improved
station module locking means, and a method of expanding a modular
irrigation controller, it will be apparent to those skilled in the
art that our invention can be modified in both arrangement and
detail. For example, each station module 112 or 112' could be
configured for controlling only a single station. Therefore, the
protection afforded our invention should only be limited in
accordance with the following claims.
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