U.S. patent application number 11/449693 was filed with the patent office on 2007-12-13 for electronic control system for a vacuum system.
This patent application is currently assigned to Electrolux Home Care Products Ltd.. Invention is credited to Alan Stimson Foster, Mitchell Wayne Koestner, Mark William Kubovich, Trevor E. Meyer.
Application Number | 20070283521 11/449693 |
Document ID | / |
Family ID | 38820397 |
Filed Date | 2007-12-13 |
United States Patent
Application |
20070283521 |
Kind Code |
A1 |
Foster; Alan Stimson ; et
al. |
December 13, 2007 |
Electronic control system for a vacuum system
Abstract
A programmable control unit for a vacuum cleaning system, such
as central vacuum cleaning system. A control unit is programmed
after manufacture to execute a particular control program for
performing various diagnostic and operational functions including
user interface, voltage level detecting, voltage monitoring,
current monitoring, user interface, power supply control,
temperature monitoring, AC line frequency detection, operation data
recording, speed control program selection, expansion bus interface
and service tool interface. Power control to the vacuum motor is
facilitated by the control unit directly through a triode for
alternating current (TRIAC). Manufacturing costs are reduced by
producing a single programmable control unit that can be programmed
with a control program corresponding to a variety of different
vacuum cleaning devices across a manufacturer's product line.
Inventors: |
Foster; Alan Stimson; (Des
Moines, IA) ; Koestner; Mitchell Wayne; (Webster
City, IA) ; Kubovich; Mark William; (Johnston,
IA) ; Meyer; Trevor E.; (Clive, IA) |
Correspondence
Address: |
HUNTON & WILLIAMS LLP;INTELLECTUAL PROPERTY DEPARTMENT
1900 K STREET, N.W., SUITE 1200
WASHINGTON
DC
20006-1109
US
|
Assignee: |
Electrolux Home Care Products
Ltd.
Bloomington
IL
|
Family ID: |
38820397 |
Appl. No.: |
11/449693 |
Filed: |
June 9, 2006 |
Current U.S.
Class: |
15/314 ;
15/319 |
Current CPC
Class: |
A47L 9/2889 20130101;
A47L 5/38 20130101; A47L 9/2857 20130101; Y02B 40/82 20130101; A47L
9/2805 20130101; A47L 9/2894 20130101; A47L 9/2842 20130101; Y02B
40/00 20130101 |
Class at
Publication: |
15/314 ;
15/319 |
International
Class: |
A47L 5/38 20060101
A47L005/38 |
Claims
1. A vacuum cleaner system comprising: a line power input; a dirt
collection unit; at least one dirty air intake conduit defining an
airflow path to the vacuum unit and terminating in a dirt
collection unit; a vacuum motor adapted to generate a working
airflow from the dirty air intake to conduit to the dirt collection
unit; and a programmable control unit having a power conditioning
module and adapted to be programmed with one or more of a plurality
of different control programs that control the power conditioning
module to provide power from the line power input to drive the
vacuum motor.
2. The vacuum cleaner system according to claim 1, wherein the
programmable control unit comprises a microprocessor-based printed
circuit board (PCB).
3. The vacuum cleaner system according to claim 1, wherein the
power conditioning module is controlled by the programmable control
unit to deliver power to the vacuum motor.
4. The vacuum cleaner system according to claim 1, wherein the dirt
collection unit, at least one dirty air intake, vacuum motor, and
programmable control unit are located in a power unit of a central
vacuum system.
5. The vacuum cleaner system according to claim 1, wherein one of
the plurality of different control programs is stored in memory
structure in the control unit.
6. The vacuum cleaner according to claim 1, wherein each of the
plurality of different control programs is correlated to a
particular feature set.
7. The vacuum cleaner system according to claim 6, wherein each
feature set comprises at least a maximum air watt output level for
the vacuum motor.
8. The vacuum cleaner system according to claim 1, wherein the
control unit is adapted to detect a voltage level of the line power
input.
9. The vacuum cleaner system according to claim 6, wherein
detecting a voltage level comprises measuring the voltage across a
fly back transformer supplying power to the control unit.
10. The vacuum cleaner system according to claim 1, wherein the
control unit further comprises an expansion interface.
11. The vacuum cleaner system according to claim 10, wherein the
expansion interface comprises an electrical connector adapted to
interface with at least one expansion boards utilizing a reciprocal
connector interface.
12. The vacuum cleaner system according to claim 1, wherein the
control unit comprises a memory structure and the control unit is
adapted to record operational data relating to operation of the
vacuum system in the memory structure.
13. The vacuum cleaner system according to claim 12, wherein
operational data consists of information selected from the group
consisting of measured motor current levels, line voltage levels,
faults, motor operation hours, on/off cycles, filter changes and
combinations thereof.
14. The vacuum cleaner system according to claim 1, wherein the
control unit further comprises a service tool interface.
15. The vacuum cleaner system according to claim 14, wherein the
service tool interface comprises an interface selected from the
group consisting of a connector, a wireless interface and
combinations thereof.
16. The vacuum cleaner system according to claim 1, further
comprising a user interface in electrical communication with the
control unit and adapted to receive user inputs and output status
information.
17. The vacuum cleaner system according to claim 16, wherein the
user interface comprises an indicator panel with one or more status
indicators.
18. The vacuum cleaner system according to claim 1, wherein the
control unit is further adapted to execute a power shut off if at
least one error condition is detected from the group consisting of
a detected locked motor rotor, a detected line voltage exceeding a
predetermined threshold, a detected current level exceeding a
predetermined threshold, a detected temperature exceeding a
predetermined threshold, a period of continuous vacuum motor
operation exceeding a predetermined threshold, filter missing,
filter not completely attached, dirt collection reservoir missing,
dirt collection reservoir not complete attached, and combinations
thereof.
19. The vacuum cleaner system according to claim 18, further
comprising a remote user interface in electrical communication with
the control unit and adapted to permit a user of the system to
restart the vacuum system after a power shut off event.
20. The vacuum cleaner system according to claim 1, wherein the
control unit is adapted to perform harmonic emissions
reduction.
21. The vacuum cleaner system according to claim 20, wherein
performing harmonic emissions reduction comprises reducing harmonic
emissions in compliance with European Norm EN61000-3-2.
22. The vacuum cleaner system according to claim 1, wherein the
control unit is further adapted to detect an AC line frequency
connected to the vacuum system and to control the power
conditioning module based on the detected frequency.
23. The vacuum cleaner system according to claim 1, wherein the
programmable control unit is adapted to be programmed with a serial
number of a vacuum cleaner during vacuum cleaner system
assembly.
24. A product line of distinct central vacuums, each central vacuum
in the product line comprising: an integral power unit, comprising:
a line power input; a dirty air intake; a dirt reservoir; a
particulate barrier; an air outlet; a vacuum motor configured on a
side of the particulate barrier fluidly opposite the dirt reservoir
and adapted to generate a working airflow from the dirty air intake
to the particulate barrier, and expect the working airflow out of
the air outlet; and a programmable control unit, including a power
conditioning unit adapted to condition a line power, wherein the
programmable control unit is programmed with a control program
specific to one of the distinct central vacuums for controlling the
power conditioning unit, wherein the control program comprises a
feature set including a maximum power watt output level for the
vacuum motor.
25. A vacuum cleaner system comprising: a line power input; an air
intake; a dirt collection reservoir; a vacuum motor adapted to
generate a working airflow from the dirty air intake to conduit to
the dirt collection unit; and a programmable control unit including
a power conditioning module and adapted to be programmed with one
or more of a plurality of different control programs, wherein each
control program corresponds to a different product in a vacuum
manufacturer's product line and specifies a maximum current level
for the power conditioning module to deliver to the vacuum motor
thereby providing each different product in the product line with
at least one different operational characteristic.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to vacuum cleaner systems and
more particularly to a control system for central vacuum cleaner
systems and other vacuum devices.
BACKGROUND OF THE INVENTION
[0002] Electric vacuum cleaning systems have become ubiquitous as
the preferred method of cleaning carpeted and hard floors. These
devices are manufactured in a variety of configurations including
canister, upright, power wands, power heads, handhelds, etc. These
different vacuum types differ in many design features such nozzle
size and configuration, power agitation, cyclonic airflow and
advanced dust filtering, however, they all share fundamental
components. Vacuum cleaners typically include a handle portion
attached to a cleaning nozzle/attachment, a dirt reservoir and a
vacuum motor--that is, a motor and fan assembly that generates a
working airflow from the nozzle to the dirt reservoir. Depending on
the configuration all these items may be integrated into an upright
or wand unit or the motor and reservoir may be a separate unit
tethered to the cleaning attachment via a flexible vacuum hose.
[0003] Due in part to the inconvenience of pushing an entire vacuum
and also the power, weight and size limitations of the above types
of vacuums, central vacuum systems were developed. Central vacuum
systems use a central power unit with a relatively high power
vacuum motor and large dirt reservoir. Such central vacuums are
typically located outside of the main living area of a home, such
as, for example, in a garage, basement, attic, etc. A network of
conduits hidden below floorboards, above ceilings and between walls
connects wall based vacuum outlets to the central power unit. The
power unit is usually connected to a dedicated 15 amp or larger
power circuit and may run on 240 and 120 volt alternating current
power (AC), but power requirements may vary depending on the
characteristics of the local power system. By isolating the
powerful vacuum motor outside of the primary living area, the
homeowner is able to enjoy strong suction power not typically
available in conventional integrated vacuum cleaning devices
without having to hear the noise that such a high power vacuum
motor generates and without having to physically manipulate such a
unit. Typically, central vacuum systems are equipped with one or
more hose/cleaning attachment modules that connect to wall
connectors located throughout the house. In addition to providing
an airflow path from the cleaning attachment to the dirt canister,
these wall connectors may also provide a power connection to
operate active components of the cleaning attachments and to permit
the user to turn the vacuum unit on or off. U.S. Pat. No. 5,400,463
illustrates an example of a central vacuum system. This patent is
hereby incorporated by reference into the disclosure of this
application in its entirety.
[0004] Though central vacuum systems differ from integrated vacuum
systems in that they are typically more robust and are built into
the house, their basic design has many similarities with
conventional integrated vacuums and therefore, like problems are
often addressed in improving their design. As consumer vacuum
cleaning devices have become more complicated, so too have the
electronic control systems required to facilitate advanced
features. The trend has been to migrate toward microcomputer-based
control. U.S. Pat. Nos. 5,542,146 and 4,654,924 both describe
microcomputer-based control systems for vacuum cleaners and are
hereby incorporated by reference in their entirety.
[0005] Another innovation in vacuum cleaner control system design
is the interchangeable control panel. U.S. Pat. No. 6,360,399
describes an interchangeable control panel that is removably
attached to the housing of a hand-held vacuum cleaner. The
interchangeable control panel can be configured to provide the
feature mix of a given product model without requiring redesign of
the housing of the power unit to accommodate the features mixes of
the different product models. While this solution does have the
potential to reduce manufacturing costs by allowing multiple
products to utilize a common housing, it still suffers from some
significant drawbacks. For example, in this system a unique control
interface must be designed for each product. The control interface,
typically a electronic module with one or more circuit boards,
processors and other electrical circuit components, is typically
the most expensive part of the vacuum to design and manufacture.
Having to design and manufacture a separate one for each product
across a product line only reduces the costs of an inexpensive
component--the housing--and actually limits the configurations and
features that can be installed because they must be compatible with
the physical dimensions of the housing. The housing, which is
typically made of plastic and/or metal, is relatively inexpensive
to design and manufacture because it is merely a passive
"container" to hold the operating parts, such as the vacuum motor,
transformer, filter and control system. Thus, the interchangeable
control system described in this patent system is expected not to
appreciably reduce costs.
[0006] Despite the advent of these computer-based vacuum cleaner
controllers, control systems still suffer from being overly
expensive, complicated and difficult to design. Providing robust,
flexible, scalable control systems remains a technical obstacle for
vacuum cleaning systems--both central vacuums and integrated vacuum
cleaners. Other problems and drawback exist with known systems.
SUMMARY OF THE INVENTION
[0007] According to a first aspect, the present invention provides
a vacuum cleaner system. The vacuum cleaner system according to
this aspect comprises a line power input, a dirt collection unit,
at least one dirty air intake conduit defining an airflow path to
the vacuum unit and terminating in a dirt collection unit, a vacuum
motor adapted to generate a working airflow from the dirty air
intake to conduit to the dirt collection unit, and a programmable
control unit having a power conditioning module and adapted to be
programmed with one or more of a plurality of different control
programs that control the power conditioning module to provide
power from the line power input to drive the vacuum motor
[0008] Another exemplary embodiment according to this invention
provides a product line of distinct central vacuums. Each central
vacuum in the product line of distinct central vacuums according to
this embodiment comprises an integral power unit, comprising a line
power input, a dirty air intake, a dirt reservoir, a particulate
barrier, an air outlet, a vacuum motor configured on a side of the
particulate barrier fluidly opposite the dirt reservoir and adapted
to generate a working airflow from the dirty air intake to the
particulate barrier, and expect the working airflow out of the air
outlet, and a programmable control unit, including a power
conditioning unit adapted to condition a line power, wherein the
programmable control unit is programmed with a control program
specific to one of the distinct central vacuums for controlling the
power conditioning unit, wherein the control program comprises a
feature set including a maximum power watt output level for the
vacuum motor.
[0009] An additional exemplary embodiment according to this
invention provides a vacuum cleaner system. The vacuum cleaner
system according to this embodiment comprises a line power input,
an air intake, a dirt collection reservoir, a vacuum motor adapted
to generate a working airflow from the dirty air intake to conduit
to the dirt collection unit, and a programmable control unit
including a power conditioning module and adapted to be programmed
with one or more of a plurality of different control programs,
wherein each control program corresponds to a different product in
a vacuum manufacturer's product line and specifies a maximum
current level for the power conditioning module to deliver to the
vacuum motor thereby providing each different product in the
product line with at least one different operational
characteristic.
[0010] These and other embodiments and advantages of the present
invention will become apparent from the following detailed
description, taken in conjunction with the accompanying drawings,
illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic diagram of a residential structure
containing a central vacuum system usable with the various
embodiments of the invention and illustrating the various central
vacuum system components.
[0012] FIG. 2 is a plan view of an exemplary central vacuum power
unit of a central vacuum system according to the various
embodiments of the invention.
[0013] FIG. 3 is a cut away plan view of the exemplary central
vacuum power unit illustrated in FIG. 2 illustrating according to
the various embodiments of the invention.
[0014] FIG. 4 is a block diagram of an exemplary digital
microprocessor-based control unit for a vacuum cleaning system
illustrating control unit modules according to various embodiments
of the invention.
[0015] FIG. 5 is an exemplary circuit diagram illustrating a
circuit topology for the vacuum cleaning system control unit
according to at least one embodiment of the invention.
DETAILED DESCRIPTION
[0016] The following description is intended to convey a thorough
understanding of the described exemplary embodiments by providing a
number of specific embodiments and details involving a control unit
for central vacuum cleaning systems. It should be appreciated,
however, that the present invention is not limited to these
specific embodiments and details, which are exemplary only. It is
further understood that one possessing ordinary skill in the art,
in light of known systems and methods, will appreciate the use of
the invention for its intended purposes and benefits in any number
of alternative embodiments, depending upon specific design and
other needs.
[0017] Referring now to FIG. 1, a schematic diagram of a
residential structure employing a central vacuum cleaner system is
illustrated. The residential structure 10 is a multilevel structure
with a primary residential portion 10A and secondary portion 10B.
The central vacuum cleaner of FIG. 1 comprises a power unit 100
located in the second portion 10B, an air intake pipe 120 connected
to an air intake manifold 122 that is connected to a network of
vacuum piping 125 terminating in a plurality of individual wall
connectors 130. In the example of FIG. 1, the vacuum piping is
concealed between the walls of the residential structure 10. In
practical application, the vacuum piping may run under floor
boards, through an attic, over a ceiling, etc., in a manner
analogous to plumbing and electrical lines.
[0018] In the example of FIG. 1, cleaning nozzles 200 are shown
connected to the wall connectors 130 via flexible vacuum hoses 210.
In this way, the operator is only required to move the cleaning
nozzle 200 and hose 210 from room to room rather than transporting
the entire vacuum system to different locations in the structure
10.
[0019] In some systems, the wall connector 130 may have a switch to
turn on the vacuum motor 170 (FIG. 3) located in the power unit
100. Alternatively, the switch may be located on the nozzle 200 or
other power switching devices, such as acoustic, radio or infrared
may be used. In these systems, the wall unit connector may supply a
low voltage connection to power the switch. In most systems, any
powered elements included in the nozzle, such as brushers,
agitators, etc., are powered by a separate connection to a regular
wall power outlet. Alternatively, the wall connector 130 may also
supply power for any powered elements of the nozzle as well as
provide a control signal bus for sending control and/or status
signals between the wall connector 130 and the remote power unit
100. By isolating the power unit 100 in second portion 10B of the
residential structure 10, a relatively large, heavy and loud vacuum
motor may be employed providing suction power that greatly exceeds
that of conventional integrated vacuum systems.
[0020] Referring now to FIG. 2, a plan view of an exemplary central
vacuum power unit 100 of a central vacuum system according to
various embodiments of the invention is illustrated. In the example
of FIG. 2, the power unit 100 has a generally cylindrical shape.
This shape is exemplary only. The power unit 100 may take the form
of a variety of different shapes.
[0021] During operation of the vacuum system, dirty air is drawn
through the air intake pipe 120 in the direction indicated by the
arrow labeled "IN" into the dirt collection chamber 115. The dirt
collection chamber 115 is removably attached to the main body
portion 110 of the power unit 100 via one or more mechanical
fasteners 117. An interface 160 is mounted on a surface of the main
body portion 110. The interface 160 may comprise one or more LEDs
or other status indicator lights and/or a small display screen
and/or user control buttons. The cleaned vacuum air exits the power
unit 100 through an air exit vent 180 in the direction indicated by
the arrow labeled "OUT." Electrical power is supplied through
conventional plug or hardwire connection via a power cord 140.
Also, a power/control cable 142 may run from the power unit 100
along the path defined by the vacuum conduits 125 to supply the
power and/or control interface connection at each wall connector
130. The power unit 100 may be free standing, wall mounted, or
otherwise attached to the residential structure 10.
[0022] Referring now to FIG. 3, a cut away plan view of the
exemplary central vacuum power unit 100 shown in FIG. 2 according
to various embodiments of the invention is depicted. The exemplary
power unit 100 depicted in FIG. 3 includes an air input chamber 119
which receives dirty air input from air intake 120. Solids and
other relatively massive debris fall below the input chamber 119 to
the bottom of the dirt collection chamber 115. An air filter 150 is
mounted between the input chamber 119 and the vacuum motor 170
(which may comprise any combination of a fan and motor adapted to
generate a working airflow) to trap smaller, particulate matter
picked up by the vacuum system and to prevent this matter from
entering the vacuum motor 170 or from being expelled out of the air
output tube 180. The shown configuration may be altered in any way
to provide other dirt collection arrangements, as will be
understood by those of ordinary skill in the art. For example, the
dirt collection chamber 115 may instead comprise a bag filter, or
one or more features may be added to provide a cyclonic air
separation system.
[0023] A control unit 300 provides electrical control signals and
conditioned power to the vacuum motor 170 as well as to the
power/data bus cable 142. Preferably, the control unit 300 is based
on one or more printed circuit boards (PCBs). In a preferred
embodiment, the control unit 300 comprises a single printed circuit
board. Also, in a preferred embodiment, the control unit 300
replaces the necessity of a separate power transformer by including
a triode for alternating current (TRIAC) that can be used to
control the amount of current that flows to the vacuum motor 170.
In this way, the incoming wall power may be directly controlled by
the microprocessor-based control unit 300 via the TRIAC. It should
be appreciated that in other embodiments, a separate power supply
and/ or transformer may be used to condition the line power for use
by the vacuum motor 170. As used herein, the term "power
conditioning module" will be used to refer generally to a feature
of the control unit enabling it to control power to the vacuum
motor 170. As noted above, in a preferred embodiment, this is done
directly through a TRIAC. However, in other embodiments, this may
be done through a control unit 300 interface to a power supply,
transformer or other conventional power conditioning device.
[0024] The power conditioning module of the control unit 300
receives an incoming power supply from the power cord 140 and
conditions the incoming power supply to an output power supply that
drives the vacuum motor 170. This may comprise delivering a
particular current and/or voltage level to the vacuum motor 170, or
changing the power, such as, from alternating current (AC) to
direct current (DC) if so required by the vacuum motor 170. In a
preferred embodiment, the vacuum motor 170 is an AC motor, however,
in various other embodiments, the vacuum motor may be a DC vacuum
motor, that is, run on DC power. The power conditioning module of
the control unit 300 may alternatively condition battery power, or
other AC or DC power, into the necessary output power supply for
the vacuum motor 170. Though not depicted in the figure, the
control unit 300 may also be in electrical communication with a
human interface on an outside surface of the power unit 100, such
as interface 160 depicted in FIG. 2.
[0025] During operation, when a user activates the vacuum system at
the nozzle 200 or wall connector 130, the control unit 300 causes
the power conditioning module to deliver power to the vacuum motor
170, thereby generating a suction force running from the nozzle 200
to the air input chamber 119, through the filter 150, past the
vacuum motor 170 and out the air exit 180. Debris, dust and other
particulate matter are trapped in the filter 150 or in the dirt
collection chamber 115.
[0026] As noted herein, the vacuum motor 170 may comprise any known
vacuum motor, that is, an electric motor fan combination that
generates a working airflow. As discussed above, in a preferred
embodiment, the vacuum motor is an AC motor whose current is
supplied by a TRIAC. However, the various embodiments of the
invention may also be used with a DC motor. Vacuum motors are
usually rated based on the maximum number of air watts they
deliver. An air watt is a mathematical measurement of vacuum
pressure and airflow. Air watt ratings provide a useful cleaning
performance value of a vacuum because they specify the relationship
of lifting ability and dirt moving ability.
[0027] While the air exit 180 may simply be an air conduit exiting
into the ambient air space, in at least one embodiment, the air
output may comprise sound damping apparatus 175 in the power unit
100, such as that disclosed in U.S. Pat. No. 5,737,797 which is
incorporated by reference in its entirety into the disclosure of
this application. In at least one embodiment, the air output may
also comprise a muffler device such as that disclosed in U.S. Pat.
No. 6,052,863, which is also incorporated by reference in its
entirety into the disclosure of this application.
[0028] In various embodiments, the control unit 300 is a unitary
structure, that is, a single, microprocessor-based board. In a
preferred embodiment, the control unit 300 is implemented as an
embedded microprocessor running a programmable, firmware-based
control program for facilitating control, maintenance, service and
other functions, as illustrated in FIG. 5. By consolidating vacuum
control features into a single programmable board, greater
flexibility, lower costs, and enhanced functionality may be
achieved. For example, in at least one embodiment, the control unit
300 can be programmed after manufacture, either before or after
power unit assembly to operate according to a particular operating
program. This allows a single control unit 300 to be manufactured
for vacuum systems across an entire product line and even to
utilize a single motor that is intentionally run at a lower power
level to reserve available power for other devices, reduce power
consumption (either always or intermittently) or to sell the motor
in a device marketed at a price point below higher-end models.
Because of this feature, a single control unit may be used in a
variety of different vacuum cleaners having differing motor sizes
and feature set, or a single motor can be used across a product
line of vacuum cleaners operating at different power levels and
different input power characteristics. This can reduce
manufacturing costs to vacuum manufacturers due to the reduction in
the number of different PCB's that need to be made and the
reduction in the number of motors necessary to developing a
comprehensive product line.
[0029] The present invention also preferably reduces and/or
eliminates the traditional reliance on multiple daughter boards
that have been installed on vacuum cleaners to provide various
additional features. For example, in prior devices, one board may
have been used to control the power supply, another for monitoring
motor performance, another for interfacing with a repair tool, etc.
By developing a single, robust, microprocessor-based platform,
firmware can be developed to allow the processor to perform many or
all control operations. Furthermore, the use of a single platform
allows simple changes and upgrades to the entire system or to
specific system features after board manufacture.
[0030] In a preferred embodiment, the control unit 300 senses a
voltage level (i.e., 220V or 115V) supplied by the power cord 140
to the power conditioning module. Based on the detected value, the
control unit 300 causes the power conditioning module to convert
the power to a predetermined level to deliver to the vacuum motor
170. For example, in at least one embodiment, the control unit 300
determines the voltage level by measuring the voltage across a
flyback transformer (not shown) that is used to supply the low
power for the active electronics in the control unit 300 circuit
while the secondary of the transformer is de-energized.
[0031] As is discussed in greater detail below in the context of
FIG. 4, by utilizing the single board, microprocessor based control
unit according to the various embodiments of the invention,
firmware may be installed that allow the unit to perform many
different functions including voltage monitoring, current
monitoring, soft motor starts, recording of historical performance
data, speed control, human interface, motor lock protection, error
reset, harmonic current emissions reduction, high voltage shut off,
operation timeout and AC line frequency detection.
[0032] Referring now to FIG. 4, a block diagram of an exemplary
single PCB, microprocessor-based control unit for a vacuum cleaning
system according to various embodiments of the invention is
illustrated. The control unit 300 comprises a plurality of
different modules which, in various embodiments, provide
functionality that enable the unit 300 to perform a variety of
different control functions for a vacuum cleaning system, such as,
for example, a central vacuum system, a truck based vacuum system,
a conventional integrated portable vacuum or other vacuum
system.
[0033] In the example of FIG. 4, there are several modules
including a control module 305, a diagnostic module 310, a data
storage module 315, a voltage sensing module 320, a speed setting
module 325, a power conditioning module 330, a timeout module 335,
a control/power bus module 340, a programming module 345, a service
tool interface module 350, an expansion bus module 355, a harmonic
emission reduction module 360, a visual feedback/interface module
365, a frequency detection module 370 and a current monitoring
module 375.
[0034] It should be appreciated that according to various
embodiments of the invention, each of the above-identified modules
may be configured as a software application executing on computer
hardware, an application specific integrated circuit (ASIC),
firmware executing on a microprocessor of a PCB control unit, a
combination of hardware and software, or other suitable
configuration. In a preferred embodiment, each module will be a
routine implemented in firmware and executed on a microprocessor of
a PCB. Moreover, modules may be combined or broken into multiple
additional modules, as desired. For example, the control module 305
may be one or more microprocessors, may be a digital signal
processor (DSP) chip, an embedded processor and/or part of an
embedded operating system (OS). Fewer or more modules may be used,
and different modules than those illustrated in the Figure may be
used as well.
[0035] In at least one embodiment, the diagnostic module 310 will
perform one or more diagnostic functions relating to the operation
of a vacuum cleaner control unit. For example, in at least one
embodiment, the diagnostic module may monitor the operation of the
motor through a sensor or other interface to determine if a locked
rotor condition has occurred. If the rotor becomes locked, damage
to the windings of the electric motor can occur. Thus, in this
embodiment, if the controller detects a locked rotor condition, the
diagnostic module 310 will cause the power conditioning module 330
to issue an instruction to the power conditioning module 330 to cut
off power to the vacuum motor for a predetermined time period--for
example, for 15 seconds. No power will be supplied during this time
period, thereby making it impossible for a user to turn the vacuum
motor back on. At the end of the 15 seconds, the user may then
manually restart the vacuum motor. In at least one embodiment, the
diagnostic module 310 may also cause the visual feedback module 365
to activate a visual indicator, such as a warning or error
indicating LED to provide visual notification to the user of the
temporary error condition--either by specifically identifying the
condition or by generally indicating that a fault is detected.
[0036] In at least one embodiment the diagnostic module 310 may
also perform a thermal shutdown function. In this embodiment, the
diagnostic module 310 may be connected to a thermocouple or
thermometer measuring the ambient temperature in the power unit. In
a preferred embodiment, part of the flyback transformer circuit
that supplies power to the control unit 300 includes an integrated
thermal shut down function that is based on the current die
temperature. When the flyback transformer shuts off power to the
control unit 300, the control unit 300, including the power
conditioning module 330, can no longer cause current to be
delivered to the vacuum motor. Thus, the system is effectively shut
off. In some embodiments this may comprise the flyback transformer
may remain off until a predetermined time period has expired. In
other embodiments, this the flyback transformer may remain off
until the overheat condition is no longer detected, or until the
temperature drops below another predetermined threshold. In
embodiments in which a separate temperature sensing device is used,
shutoff may also occur for a fixed time period, or until the
temperature in the power unit has dropped below an acceptable
threshold.
[0037] Still another function performed by the diagnostic module
310 in at least one embodiment of the invention is remote error
condition reset. If an error condition occurs during operation of a
central vacuum system, it is likely that the user is located away
from the power unit. Therefore, via a control/power bus connection
to each wall connector 130, the diagnostic module 310 may permit
the operator restart operation by selecting a control on the wall
unit or on the cleaning nozzle, without having to travel to the
location of the power unit. In a preferred embodiment, the nozzle
handle includes a fault indicator light or display to inform the
operator of the fault condition and a reset switch that interfaces
with the control unit 300 via the control/power bus module 340
connection at the wall connector 130. Alternatively, the wall
connector itself 130 may include a reset switch to accomplish this,
and may also include a fault indicator light or display.
[0038] Yet an additional function performed by the diagnostic
module 310 is sensor monitoring. The control unit 300 may be
connected to a variety of different sensors in the power unit 100
interfaced via the diagnostic module 310. For example, a sensor may
notify the diagnostic module 310 that the dirt reservoir 115 is
either detached from or insecurely attached to the power unit 100.
The diagnostic module 310 may cause the visual feedback module 365
to display a message or activate an indicator to alert a user of
this condition.
[0039] Another sensor may notify that the diagnostic module 310
that the filter 150 is either absent or loosely attached to the
power unit 100. In various embodiments, this may be facilitated
through vacuum pressure sensors that detect a pressure differential
across the filter. A lack of differential or small differential may
indicate that no filter is present or that it is improperly
mounted. The occurrence of this condition may also cause the
diagnostic module 310 to display a message, activate an indicator
to alert a user as to the existence of this condition, or disable
operation. Alternatively, a physical switch that is engaged with
the filter when it is fully attached may be used to detect the
presence of a filter.
[0040] Still another sensor may notify the diagnostic module 310 of
variances in the pressure differential across the filter, which may
indicate that the filter 150 needs to be cleaned or changed, that
an obstruction such as a rag, plastic bag or other piece of debris
is overly restricting air flow through the filter 150 or that the
filter 150 is missing. As noted above, in addition to indicating
when no filter is present, pressure differential sensors can also
detect when the filter is clogged or blocked as indicated by a
large pressure differential across the filter. Detection of a large
pressure differential may also cause the diagnostic module 310 to
display a message or activate an indicator to alert a user as to
the existence of this condition, such as, a "Check Filter" message
and/or indicator, and/or disable the device.
[0041] As noted above, in at least one embodiment, the diagnostic
module 310 will shut off power to the vacuum motor and other
electrical circuits upon the detection of certain error conditions.
In at least one embodiment, the diagnostic module will impose a
minimum shut off time, such as, for example, 15-30 seconds. By
imposing a minimum shut off time, the diagnostic module will
prevent the operator from damaging the system during a rotor jam by
thermal runaway--a condition that occurs when over current causes
the motor to rapidly overheat faster than the thermal sensor can
monitor the temperature.
[0042] In at least one embodiment according to this invention, the
control unit 300 also comprises a data storage module 315. The data
storage module 315 stores data regarding the vacuum system's
performance, such as time usage data and data obtained by the
various other modules including line voltage levels, current
levels, error condition occurrences, etc. The data storage module
315 preferably comprises a non-volatile memory structure such as
flash memory, NAND memory or other non-volatile semiconductor
memory, or alternatively, a magnetic storage device such as a hard
drive.
[0043] In at least one embodiment of the invention, the control
unit 300 also performs voltage sensing of the line voltage supplied
to the power unit's conditioning module. In this embodiment, a
voltage sensing module 320 measures the voltage across a flyback
transformer while the secondary portion of the transformer is
de-energized. Because the control unit 300 is already connected to
the flyback transformer to receive its own power, sensing the
voltage can be implemented without requiring additional components
and prior to delivering power to the vacuum motor. In one sense,
voltage sensing is done as a precaution to monitor the line voltage
conditions. If dangerously high spikes in the line voltage are
detected, the voltage sensing module 320 will cause the control
module to instruct the power conditioning module 330 to shut off
power to the vacuum motor to prevent damage to the motor 170 or the
control unit 300. The voltage sensing module 320 may also record
detected voltage levels, either periodically, or above or below
predetermined thresholds, in the data storage module 315 so that a
technician who later accesses the data in the data storage module
315 can be alerted as to the line voltage conditions under which
the vacuum system has been operated.
[0044] Another feature provided by the voltage sensing module 320
of the control unit 300 is the ability to detect the type of line
voltage and frequency to which the power unit is
connected--typically 120 V or 240V. This enables a single PCB-based
control unit to be used in heavy duty, high voltage models and
regular duty lower voltage models, thereby eliminating the excess
manufacturing costs of having to produce separate control units for
each. This also allows a single motor to be used in international
products, where the supply voltage may be different from the United
States.
[0045] Similarly, the control unit 300 also may include an AC line
frequency detection module 370. Different countries and regions
around the world utilize different AC line frequencies. For
example, some countries' power systems are based on 60 Hz and
others on 50 Hz alternating current power. As a result,
manufacturers must make different systems intended for different
geographic markets. The programmable PCB-based control unit 300
according to one embodiment of the present invention detects the
local AC line frequency and makes any necessary adjustments to the
control program. This detection may also be performed through the
flyback transformer interface.
[0046] In at least one embodiment of the invention, the control
unit 300 also comprises a speed setting module 325. The speed
setting module 325 receives a user input selection from either the
user interface control/power bus module 340 connected nozzle or the
visual feedback/interface module 365 on the power unit itself. As
will be discussed in greater detail in the context of the
programming module 345, the speed setting module 325 may comprise a
plurality of different speed setting programs. Once a particular
program has been programmed into the control unit 300 via the
programming module 345, the speed setting module 325 will allow the
vacuum motor 170 to be operated at any of the selected speeds
available in the current program. In a preferred embodiment, once a
user selects a speed setting via the control/power bus module 340,
the control unit causes the power conditioning module 330 to
perform phase control via that TRIAC--that is, pulsing current to
the vacuum motor a predetermined frequency.
[0047] Another feature of the control unit 300 according to at
least one embodiment of the invention is a timeout module 330.
Instead of using a separate circuit or timer to keep track of
current continuous operating time, the timeout module 330 utilizes
the existing functionality of the microprocessor based control unit
300 to track time. In at least one embodiment, this may be
implemented by monitoring zero line crossings of the line voltage
once the vacuum motor is engaged--each 120 or 100 crossing is
equivalent to one second in 60 Hz and 50 Hz systems respectively.
Alternatively, timeout may facilitated through a system clock or
other timing device. When the time equals or exceeds a
preprogrammed threshold, such as 30 minutes, the timeout module 335
will cause the power conditioning module 330 to cut off power to
the vacuum motor 170. In various embodiments, the user may be able
to override the cutoff by manually restarting the vacuum motor 170
with a switch. In various other embodiments, the timeout module 335
prevents the system from being restarted for a predetermined period
of time, such as 10 minutes, to allow the motor, control unit and
other internal circuits and system components to cool off. If
desired, the user may also be able to select the timeout time
setting with the interface 160.
[0048] Yet another feature of the control unit 300 according to
various embodiments of the invention is a control/power bus module
340. In a preferred embodiment, the control/power bus module 340
supplies low voltage power to the nozzle via the wall connector to
power a switch on the nozzle that activates the power unit. In such
embodiments, power for indicators, interfaces and motor-driven
components of either the connector 130 or nozzle 200 is supplied
via a standard wall connector in the residential structure via a
separate power supply cord integral to the nozzle. In addition to a
physical interface to the nozzle, the control/power bus module 340
may also comprise a wireless interface. In such embodiments, the
nozzle functions as a wireless remote control for passing control
signals to the power unit and to receive signals such as status
indicators and other messages. In various embodiments this may be
performed using a standard wireless protocol such as ZigBee, R F,
IrdA, 802.11x, etc. The control/power bus module 340 may also
supply one or more two-way communication lines between the user end
(i.e., wall connector 130 or nozzle 200) and the power unit end for
issuing commands to the power unit 100 and for sending status and
other signals to the user end. User end-generated commands to turn
on the vacuum systems are received by the control/power bus module
340. In turn, based on the user command, the control/power bus
module 340 causes the power conditioning module 330 to deliver
power to the vacuum motor 170 and to the wall connector 130 through
the power cable 142 of the control/power bus module 340.
[0049] Another novel feature of the control unit 300 according to
one or more embodiments of the invention is its programmability.
The programming module 345 permits the control unit 300 to be
programmed with an appropriate control program after the power unit
100 is manufactured but before it is shipped to the consumer. This
feature increases the flexibility to manufacturers and eliminates
the costs of manufacturing separate control units for each product
in a manufacturers' product line. The control unit 300 may also be
set up to be programmable even after it is delivered to the
customer or installed in a home, which can be useful for service
and to add features or upgrade the device's performance. The
programming module 345 permits program information to be written to
the control unit 345, where, in at least one embodiment, it is
stored in a memory structure. The transfer can be through any known
means, such as a physical connector, a standard serial, parallel,
USB or IEEE1394 connector, a proprietary, non-standardized
connector, a wireless link such as IrDA, 802.11x, BlueTooth, UWB,
ZigBee (802.15.4), or other wireless communication link, and so on.
In various embodiments, the program information is stored as
firmware in flash memory, or other non-volatile electronic data
structure. In various other embodiments, the program information is
stored in the data storage module 315.
[0050] In at least one embodiment, the manufacturer may not know
the particular model of vacuum cleaning system that the control
unit 300 will be installed in at the time the control unit 300 is
manufactured. Thus, the control unit 300 can be made without being
tied to a particular model. After the manufacturer determines the
particular product, including motor and feature set, the
programming module 345 is used to "upload" the designated control
program from a computer or programming tool that interfaces with
the control unit 300 via the programming module's communication
interface.
[0051] In at least one other embodiment, the programming module 345
may be used to specify additional late-stage product information.
For example, in certain segments of the vacuum market, a
manufacturer may desire to sell two or more vacuums with the same
vacuum motor but at different price points. Thus, although the
vacuums are capable of outputting the same level of air watts, 600
air-watts for example, one is sold as being lower power. In various
embodiments, this is facilitated by programming the control unit
300 with different performance levels. That is, the high powered
model is programmed with a control program specifying a performance
level that allows the vacuum motor to be turned up fully to 600 air
watts, while the other model is programmed with a control program
specifying a performance level that allows the vacuum to be turned
up to only 450 air watts. The programmable performance levels
facilitated by the programming module 345 permit a manufacturer to
create market differentiated products using only a single vacuum
motor. This reduces manufacturing costs because fewer motor types
are utilized without reducing the breadth of the product line. For
a large, multinational product line, this can reduce the number of
required motors from dozens to just a few, or even one.
[0052] Still another feature of the control unit 300 according to
the various embodiments of the invention is a service tool
interface module 350. The service tool interface module 350
provides an interface for a diagnostic/service tool of a repair
person to electronically communicate with the control unit 300 of
the power unit 100 of the vacuum system, and to access the
performance information recorded by the control unit 300 in the
data storage module 315. In at least one embodiment, the service
tool interface module 350 includes a physical connector on the
power unit that is mated with a reciprocal connector attached to or
integral with a service tool device. In at least one other
embodiment, the service tool interface module 350 includes a
wireless transceiver based on IrDA, 802.11x, BlueTooth, ZigBee
(802.15.4) or other suitable standard-based or proprietary wireless
communication protocol that can be used to facilitate two-way
communication between the power unit and the service tool. In still
an additional embodiment, the service tool interface module may
include a modem that is connected to a standard RJ-11 residential
telephone connector. In this embodiment, the service tool interface
module 350 may periodically send information to a service tool data
server over a residential telephone line. Alternatively, a
technician may be able to "call" into the power unit via the modem
and facilitate transfer of performance information and automated
analysis of this information. Also, the service interface tool
module 350 and the programming module 345 may be utilized to
perform control program updates, diagnostics, upgrades, expansions,
and so on.
[0053] Another feature of the control unit 300 according to the
various embodiments of the invention is an expansion control bus
355. In at least one embodiment, the expansion bus module 355 is a
electrical pin, cartridge or plug-type bus connector that can be
used to add additional user interface and accessory features. In at
least one embodiment, the expansion bus module 355 is used to
connect the user interface 160 or another user interface device to
the control unit 300, thereby enabling bidirectional communication
between the control unit 300 and user interface 160 and also
enabling output of status and other information to the user via the
interface 160.
[0054] An additional novel feature provided by control unit
according to one or more embodiments of the present invention is
harmonic emission reduction. The harmonic emissions reduction
module 360 insures that the power conditioning module performs
power factor correction according to the relevant standards.
Harmonic emissions reduction shapes the input current of off-line
power supplies to maximize the real power available from the power
supply. Ideally, from the perspective of the line power, the vacuum
cleaning system should present a load that emulates a pure
resistor, in which case the reactive power drawn by the device is
zero. Inherent in this scenario is the freedom from input current
harmonics. The current is a perfect replica of the input voltage
(usually a sine wave) and is exactly in phase with it. In this case
the current drawn from the supply is at a minimum for the real
power required to perform the needed work, and this minimizes
losses and costs associated not only with the distribution of the
power, but also with the generation of the power and the capital
equipment involved in the process. The freedom from harmonics also
minimizes interference with other devices being powered from the
same source.
[0055] Another reason for employing harmonic emissions reduction
(also known as "power factor correction") in electrical consumer
products is to comply with regulatory requirements. Currently,
electrical equipment in Europe must comply with the European Norm
EN61000-3-2, which requires that the current harmonics of all
line-connected equipment stay below prescribed limits. This
requirement applies to most electrical appliances with input power
of 75 W or greater, and it specifies the maximum amplitude of line
frequency harmonics up to and including the 39.sup.th harmonic.
While this requirement is not yet in place in the United States,
equipment manufacturers attempting to sell products worldwide are
designing for compliance with this requirement.
[0056] In various embodiments, performing harmonic emissions
reduction may comprise performing a method similar to that
disclosed in U.S. patent application Ser. No. 11/243,918, which is
hereby incorporated by reference in its entirety into the
disclosure of this application.
[0057] In various embodiments, when the control unit 300 is
programmed with the control program using the programming module
345, a data field or bit may be used to designate whether or not to
activate the harmonic emissions reduction module 360.
[0058] In addition to the optional user interface 160 connectable
to the expansion bus module 355, the control unit 300 according to
one or more embodiments of the invention comprises a visual
feedback module 365 adapted to provide status, error and other
messages to the user. In one embodiment, the visual feedback module
365 displays messages on an LED panel or display screen located on
an outer surface of the power unit of the vacuum cleaning system.
Alternatively, or in addition, the visual feedback module 365 may
cause the control/power bus module 340 to send a signal to each
wall connector 130 and or vacuum nozzle 200 to illuminate a status
indicator or display a message on an integral display screen
regarding a current status of the vacuum system. For example, a
green LED may be illuminated on the wall connector when the vacuum
is ready for use. A red LED may be illuminated if an error has
occurred. Also, a yellow LED may be illuminated if a condition
exists that requires the user to check the power unit, such as, for
example, if the dirt collection unit is full or has not be securely
attached to the main body of the power unit.
[0059] Yet another feature of the control unit 300 according to at
least one embodiment of the invention is a current monitoring
module 375. The current monitoring module 375 comprises a current
measuring device supplying current reading measurements to the
control unit 300. If an overcurrent condition is detected, such as
may occur in a rotor jam, transformer failure or other breakdown,
the current monitoring module 375 causes the power conditioning
module 330 to shut off power to the vacuum motor 170 for a
predetermined period of time. The current monitoring module 375 may
also cause the visual feedback module 365 to display an error
message or illuminate an error status indicator to inform a user of
the occurrence of the error condition. The current monitoring
module 375 may also record detected current conditions in the data
storage module 315 so that if an overcurrent condition occurs, a
service technician will be made aware of this when viewing the
historical performance data in the data storage module 315.
[0060] Referring now to FIG. 5, an exemplary circuit diagram
illustrating a circuit topology for the vacuum cleaning system
control unit according to at least embodiment of the invention is
provided. The circuit diagram illustrates a single
microprocessor-based PCB controller 400. Power is supplied by AC
line voltage via IEC320 connector 405. Low voltage DC power for the
circuit 400 is provided by the universal power supply. The power
supply feeds the transformer 415. The IEC320 connector 405 is a
modular AC socket that is an international standard, and allows
different cord sets to be used with the same product. This DC power
is used by the microprocessor 410 and other digital components. The
microprocessor may be any suitable embedded processor containing a
programmable flash memory module. The control circuit's control
program is written via the programming connector 435. In the
exemplary embodiment of FIG. 5 this is a pin connector. However, as
noted herein, a wireless transceiver may be utilized to facilitate
control program upload. Optocoupler 425 receives digital control
signals from the microprocessor 410, and in response sends low
current signals to the TRIAC 430 that dictate the phase control
performed by the TRIAC. The TRIAC is also connected the AC line
power (L). Based on a current level received from the optocoupler
425, it controls the percentage of line current that flows through
the TRIAC to the vacuum motor. Low-voltage connection to the wall
connectors is provided via a low voltage connector 420. Connector
440 provides an expansion connector interface.
[0061] It should be appreciated that the various circuit elements
illustrated in the control unit circuit 400 of FIG. 5 are exemplary
only. More or fewer elements may be utilized as well as completely
different elements than those shown in the Figure, without
departing from the spirit or scope of the invention.
[0062] The embodiments of the present inventions are not to be
limited in scope by the specific embodiments described herein. For
example, although many of the embodiments disclosed herein have
been described in the context of a programmable, PCB-based control
unit for a central vacuum cleaning system, other embodiments, in
addition to those described herein, will be apparent to those of
ordinary skill in the art from the foregoing description and
accompanying drawings. Thus, such modifications are intended to
fall within the scope of the following appended claims. Further,
although some of the embodiments of the present invention have been
described herein in the context of a particular implementation in a
particular environment for a particular purpose, those of ordinary
skill in the art will recognize that its usefulness is not limited
thereto and that the embodiments of the present inventions can be
beneficially implemented in any number of environments for any
number of purposes. For example, as the control unit or other
features described herein can be used with integrated vacuums, such
as canister vacuums and upright vacuums, in addition to the being
useful with the illustrated central vacuum. Many modifications to
the embodiments described above can be made without departing from
the spirit and scope of the invention. Accordingly, the claims set
forth below should be construed in view of the full breath and
spirit of the embodiments of the present inventions as disclosed
herein. Also, while the foregoing description includes many details
and specificities, it is to be understood that these have been
included for purposes of explanation only, and are not to be
interpreted as limitations of the present invention.
* * * * *