Note: Descriptions are shown in the official language in which they were submitted.
CA 02833938 2013-11-20
,
,
_
_ - 1 -
CENTRAL VACUUM CLEANER WITH
SWITCHED-MODE POWER SUPPLY
FIELD
[0001] This disclosure relates to a central vacuum cleaning system, in
particular to a central vacuum cleaning system having a control circuit using
a switched-mode power supply.
BACKGROUND
[0002] A central vacuum cleaning system often has a vacuum motor
placed in an isolated area of a building, such as a garage, basement,
mechanical room, or other room. The motor is isolated, thereby reducing the
noise from the motor in the living areas of the building; thus a more powerful
motor may be used. However, the isolated motor is also less accessible to a
user; thus more difficult to control. Various control systems can be used to
control the central vacuum system.
SUMMARY
[0003] In one aspect of the disclosure, a circuit for
controlling an
alternating current motor of a central vacuum system is disclosed. The
circuit includes an alternating current input for receiving the alternating
current; a wide input voltage range switched-mode power supply (SMPS) for
converting the alternating current to a direct current, the SMPS having an
alternating current input terminal and a direct current output terminal; and a
control switch coupled to the direct current output terminal, wherein only
when the control switch is closed is the alternating current received at the
motor.
CA 02833938 2013-11-20
- 2 -
-
[0004] In one aspect of the disclosure, the circuit also
includes a relay
_
coupled to the control switch and to the motor, such that when the control
switch is closed the relay is energized and connects the motor to the
alternating current. The circuit may also include a sensor, an indicator and a
controller for receiving information from the sensor and providing an
indication on the indicator in correspondence with the information. Each of
the sensor, the indicator, the controller and the control switch may be
connected in parallel to the direct current output terminal of the SMPS.
[0005] In another aspect of the disclosure, the circuit also
includes a
TRIAC coupled to the motor for controlling the alternating current received at
the motor; and a controller coupled to the control switch. The controller is
configured to send a signal to the TRIAC to allow the alternating current to
flow to the motor when the control switch is closed. The circuit may also
include a potentiometer to allow for a plurality of motor control speed
settings coupled to the controller. The signal to the TRIAC indicates a
selected motor control setting, and the TRIAC controls the flow of alternating
current to the motor in dependence on the signal to the TRIAC. The circuit
may also include a sensor and an indicator, wherein the controller is
configured for receiving information from the sensor and providing an
indication on the indicator in correspondence with the information. The
controller may be configured to control the motor in dependence on the
received information from the sensor. Each of the sensor, the indicator, the
controller and the control switch may be connected in parallel to the direct
current output terminal of the SMPS. The control switch, the potentiometer
and the direct current output terminal of the SMPS may be connected in
series to one another.
[0006] In another aspect of the disclosure, a central vacuum
system is
disclosed, including a motor coupled to an alternating power source; a
CA 02833938 2013-11-20
,
- 3 -
conduit defining an airflow path to the motor; and a circuit for controlling
the
motor.
[0007] According to one aspect there is provided a method of
controlling application of power to a motor of a central vacuum cleaning
system comprising: receiving an AC power signal at a switched-mode power
supply (SMPS);providing a DC power signal from the SMPS to a switch; and
monitoring for switching of the switch into or out of a predetermined state
and causing the AC power signal to be supplied to operate the motor of the
central vacuum cleaning system when the switch is switched into the
predetermined state and casing the AC power signal to cease being supplied
to operate the motor when the switch is switched out of the predetermined
state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Reference will now be made, by way of example, to the
accompanying drawings which show example embodiments of the present
application, and in which:
[0009] Figure 1 shows a cross-section of a building incorporating a
central vacuum system;
[0010] Figure 2A shows in block-diagram form a first example circuit
for use with the central vacuum system of Figure 1; and
[0011] Figure 2B shows in block-diagram form a second example
circuit
for use with the central vacuum system of Figure 1.
[0012] Similar reference numerals may have been used in different
figures to denote similar components.
CA 02833938 2013-11-20
'
- - 4 -
-
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0013] A control subsystem for controlling a central vacuum
cleaning
system is disclosed. The control subsystem is an "always-on" control
subsystem; thus requiring a constant supply of electrical power. The control
subsystem allows for convenient remote control of the central vacuum
cleaning system, as an operator does not need to switch the system on from
an isolated area in the building. Additionally, the control subsystem provides
for optional continuous monitoring of the building for added safety.
[0014] Referring to FIG. 1, a central vacuum cleaning system 201
incorporating a control subsystem 219 will be further described. The system
201 is installed in a building 203. The building 203 is shown as a residence;
however, the system 201 could be installed in other buildings, such as
commercial or industrial buildings.
[0015] The system 201 has a central vacuum unit 204 in an isolated
location which houses a vacuum motor 205 and includes a dirt receptacle or
canister 206. The vacuum unit 204 is connected through pipes 207, or other
conduits in walls, floors or ceilings of the building 203, which define an
airflow path to the unit 204. Alternatively, the pipes 207 may be exposed.
During operation, the vacuum motor 205 generates suction through the pipes
207 to draw cleaning air through the canister 206. The pipes 207 terminate
at valves 209 throughout the building 203 to which a flexible hose 211 may
be connected. The hose 211 terminates in a handle 213 that is held by an
operator 215. Various cleaning attachments, such as a carpet brush 216, are
connected to the handle 213.
[0016] The motor 205 is coupled to an alternating current
(AC) source
114 (shown in Figures 2A and 2B). To provide sufficient power to generate
CA 02833938 2013-11-20
,
. - 5 -
an effective vacuum, the motor 205 is configured to operate using a high
power source, typically from an electrical outlet providing an alternating
current (AC) source. The output of electrical current from the electrical
outlet is typically in the 5-30A range at a voltage in the 100-240V (root mean
square voltage) range having a frequency of 50-60Hz. It is thus apparent
that the electrical current needed to operate the motor 205 is at an unsafe
level for the operator 215.
[0017] A control subsystem 219 is thus used to electrically
isolate the
operator 215 from the motor 205. Control signals, such as ON/OFF, from the
operator 215 are provided through a user-control panel 218, typically
provided in the handle 213, communicating the control subsystem 219
(example embodiments of the control subsystem 219, 219A and 219B are
provided in Figures 2A and 2B respectively). The control subsystem 219 is
typically located near the motor 205, as illustrated. When the operator 215
turns on the system 201, dirt is drawn by a vacuum created by the motor
205 through the attachment 216, handle 213, hose 211, and pipes 207, and
into canister 206.
[0018] The user-control panel 218 (example embodiments of the
user-
control panel 218, 218A and 218B are provided in Figures 2A and 2B
respectively) is included in the system 201 to allow the operator 215 to
interface with the control subsystem 219 safely and conveniently. The user-
control panel 218 is this desirably located at a convenient location for the
operator 215, such as in the handle 213. The user-control panel 218 is
electrically coupled to the control subsystem 219 via electrical lines (not-
shown), for example in the handle 213, the hose 211, the valves 209 and the
pipes 207. In some embodiments, the electrical lines run through the handle
213 and the hose 209 and interface with electrical terminals in the valves
209 when the hose 209 is connected to the valves 209. The electrical lines in
the pipes 207 may be included on an outer edge of the pipes 207 or may be
CA 02833938 2013-11-20
. .
_
.- - 6 -
internal to the pipes 207. Typically only two electrical lines are used
between
the user-control panel 218 and the control subsystem 219, providing positive
and negative terminals for both power and communication signals. Addition
electrical lines may also be added.
[0019] Reference is now made to Figure 2A, showing, in block-diagram
form, an example circuit 200A for use with the central vacuum cleaning
system 201. The circuit 200A includes a control subsystem 219A, a user-
control panel 218A, the motor 205, an AC source 114 (i.e. an electrical
outlet) and a circuit breaker 116. The AC source 114 is coupled to the circuit
breaker 116 for added safety, and to the motor 205 to provide AC power to
the motor. The circuit 200A provides AC power to the motor 205, DC power
to the control subsystem 219A and the user-control panel 218A. The motor
205 is under direct control of the control subsystem 219A and under indirect
control of the user-control panel 218A, as will be explained.
[0020] The control subsystem 219A is electrically coupled to the AC
source 114, the motor 205 and the user-control panel 218A. The control
subsystem 219A receives control signals from the user-control panel 218A
and controls the motor 205 in accordance with the received control signals.
To protect the operator 215 from the high-power electrical energy of the AC
source 114, the control subsystem 219A receives the high-power alternating
current of the AC source 114 and converts the alternating current to a low-
power direct-current (DC). The operator only interfaces with the user-control
panel 218A, which is only coupled to the DC power. The DC current is
typically in the 1,000-42mA (milliamp) range, at a voltage of 3-24V (DC
volts). The DC power is thus safer for the operator 215 to handle than the
AC power.
[0021] The control subsystem 219A includes a switched-mode
power
supply (SMPS) 110 for converting alternating current to direct current, a
CA 02833938 2013-11-20
- 7 -
relay 112 and optionally, a controller 102, one or more sensors 106, and one
or more indicators 104. In some embodiments, the SMPS 110 is a wide input
voltage range SMPS. In some embodiments, the components or some of the
components of the control subsystem 219A are coupled to a printed circuit
board (PCB) having electrical traces. The components are electrically
coupled to one another using the electrical traces of the PCB or alternatively
using wires. The SMPS 110 has alternating current input terminals for
receiving AC power from the AC source 114 and direct current output
terminals for outputting DC power to the user-control panel 218A, the
controller 102, the sensor 106 and the indicator 104.
[0022] The SMPS 110 rectifies the AC power input to DC power (i.e.
converts AC power to DC power). During power conversion, the SMPS 110
switches between "on" and "off" states, but dissipates power mainly during
"on" states; thereby providing for a more efficient power conversion. In the
central vacuum cleaning system 201, the control subsystem 219 is ideally
always powered for greater convenience to the operator 215; allowing the
operator to control the motor 205 at any time without requiring the operator
to be in the same physical location as the motor 205. The enhanced
efficiency in power conversion thus allows for convenience in controlling the
motor 205, but at lower electrical costs.
[0023] An example of a SMPS 110 employed in the control subsystem
219A is a single output SMPS, having part-number ZPOlS and provided by
ZETTLER Magnetics , receiving an alternating power input having an AC
voltage in the range of 90-264V, oscillating at 47-63Hz with a maximum
current input of 25A, and providing a one Watt power output having a DC
voltage in the range of 3.3-24V at a current level in the range of 300-42mA.
Another example of a SMPS 110 employed in the control subsystem 219A is
a single output SMPS, having part-number ZPO3S and provided by ZETTLER
Magnetics , receiving an alternating power input having an AC voltage in
CA 02833938 2013-11-20
- - 8 -
=
the range of 90-264V, oscillating at 47-63Hz with a maximum current input
of 25A, and providing a three Watt power output having a DC voltage in the
range of 3.3-24V at a current level in the range of 900-125mA. Although
specific examples of SMPSs have been provided, any number of suitable
solid-state, low power consuming SMPS devices could be used to implement
SMPS 110.
[0024] The user-control panel 218A includes a switch 132,
and is
electrically connected in series with a relay 112 in the control subsystem
219A. The switch 132 is coupled to the DC output terminals of the SMPS 110
and the relay 122. The relay 112 is coupled to the DC output terminals, the
switch 132, the AC source 114 and the motor 205. When the switch 132 is
closed, for example by the operator 215, the relay 112 is energized and
closes the circuit providing the AC power to the motor 205, thereby
connecting the motor 205 to the AC source 114 and turning on the motor.
When the switch 132 is opened by the operator 215, the relay 112 opens the
circuit providing the AC power to the motor 205, thereby disconnecting the
motor 205 from the AC source 114 and turning off the motor.
[0025] Optionally connected in parallel to the DC output
terminals of
the SMPS 110, and in parallel to the switch 132 and the relay 112, and in
parallel to one another are controller 102, sensor(s) 106 and indicator(s)
104. The controller 102 may include a microprocessor or a field-
programmable gate array (FPGA) circuit, which receives and sends
communication and control signals to and from the sensor 106 and the
indicator 104. The controller 102 may include a clock for synchronizing
communications and operations of the sensor 106 and the indicator 104. The
controller 102 is typically centrally located near the motor 205 at the
central
vacuum unit 204.
CA 02833938 2013-11-20
_
_
. - 9 -
[0026] One or more sensors 106 may be positioned at the
handle 213,
_
in the pipes 207, in the hose 211, or the valves 209, and may communicate
with the controller 102 via a serial communication protocol over the
electrical
lines used for powering the user-control panel 218A. Serial communication
protocols can be implemented using one electrical wire (such as 1-Wire ), or
using two electrical wires (such as I2C ); thus no additional electrical lines
are needed. Additionally, one or more sensors 106 may be positioned at
central vacuum unit 204 and may communicate with the controller 102 via
the same serial communication protocols, however; due to their proximity to
the motor 205, other more complex communication protocols requiring more
communication lines (e.g. RS 232, using three or five wires) can also be
implemented to provide faster and less error prone communication. The
sensors 106 include, without limitation, any one of: (1) an oxygen sensor,
(2) an air contaminant sensor, measuring the level or dust and other
particles in the air, (3) an airflow sensor, measuring airflow through the
pipes 207, and (4) a dust level sensor, measuring the level of dust in a dust
storage area coupled to the motor.
[0027] The controller 102 receives information from the
sensor(s) 106,
processes the information, and provides a signal to one or more indicators
104 to provide an indication to the operator 215 (or other person) in
correspondence with this information. One or more indicators 104 may be
positioned at the handle 213 or at the central vacuum unit 204, and may
receive communication and control signals from the controller 102 via the
same protocols used for sensor communication. The indicators 104 include,
without limitation, any one of: (1) a display, (2) one or more light-emitting
diodes (LED), including multi-color LEDs, where each color represents a
sensor state, and (3) a speaker.
[0028] In some embodiments, the controller 102, the one or
more
sensors 106 and the one or more indicators 104 are only active when the
CA 02833938 2013-11-20
- - 10 -
=
motor 205 is active, while in other embodiments they are active at all times.
_
Continuous operation of the controller 102, the sensors 106 and the
indicators 104 helps improve the safety levels associated with the system
201. For example, continuous monitoring can be performed to determine if
the level of contaminants in the air in the building 203 is at an unsafe level
due to the vacuuming process unsettling contaminants and releasing the
contaminants into the air (or other reasons unrelated to vacuuming), thus
putting any person in the building 203 is at risk. In such as case an audible
warning is ideally provided through an indicator 104 until the level of
contaminants in the air is at a safe level. Thus, continuous operation of the
controller 102, sensors 106 and indicators 104 is desired. In example
embodiments, the SMPS 110 efficiently provides a constant DC power supply
to the sensors 106, controller 102, and the indicators 104 even when relay
112 is open; thereby allowing for efficient continuous operation of the
sensors 106 and indicators 104.
[0029] Reference is now made to Figure 2B, showing, in block-
diagram
form, an example circuit 200B for use with the central vacuum cleaning
system 201. The circuit 200B includes a control subsystem 219B, a user-
control panel 218B, the motor 205, the AC source 114 and the circuit breaker
116. The circuit 200B provides AC power to the motor 205, DC power to the
control subsystem 219B and the user-control panel 218B. The motor 205 is
under direct control of the control subsystem 219B and under indirect control
of the user-control panel 218B.
[0030] The control subsystem 219B is electrically coupled to
the AC
source 114, the motor 205 and the user-control panel 2188. The control
subsystem 219B receives control signals from the user-control panel 218B
and controls the motor 205 in accordance with the received control signals.
To protect the operator 215 from the high-power electrical energy of the AC
source 114, the control subsystem 219B receives the high-power alternating
CA 02833938 2013-11-20
- 11 -
current of the AC source 114 and converts the alternating current to a low-
power direct-current (DC). The operator only interfaces with the user-control
panel 218B, which is only coupled to the DC power.
[0031] The control subsystem 219B includes a SMPS 110 for converting
alternating current to direct current, a controller 102, a triode for
alternating
current (TRIAC) 120 and optionally, one or more sensors 106, and one or
more indicators 104. In some embodiments, the components or some of the
components of the control subsystem 219B are coupled to a printed circuit
board (PCB) having electrical traces. The components are electrically
coupled to one another using the electrical traces of the PCB or alternatively
using wires. The SMPS 110 has alternating current input terminals for
receiving AC power from the AC source 114 and direct current output
terminals for outputting DC power to the user-control panel 218B, the
controller 102, the sensor 106 and the indicator 104. The SMPS 110 of
Figure 2B functions similarly to the SMPS 110 of Figure 2A.
[0032] The TRIAC 120 includes a gate, and two anodes. The TRIAC
120 conducts current between the two anodes. The amount of current
allowed to flow through the anodes is variable in dependence on the input at
the gate. The anodes of the TRIAC 120 are connected in series to the motor
205; therefore, the TRIAC 120 controls the amount of current allowed to flow
to the motor 205, in dependence on the input at the gate. The speed of the
motor 205 varies in dependence on the amount of current at the motor 205.
The controller 102 is electrically coupled to the gate; thereby the controller
102 is able to control the speed of the motor 205 by varying the input at the
gate. The output signal from the controller 102 is typically a digital signal,
thus a digital-to-analogue convertor (DAC) may be used to convert the
output signal to an analogue signal to interface with the gate of the TRIAC
120.
CA 02833938 2013-11-20
_
_
- - 12 -
=
[0033] The user-control panel 218B includes a switch 132 and
optionally a potentiometer 134 electrically connected in series with one
another and to the DC output terminals of the SMPS 110. When the switch
132 is closed, for example by the operator 215, the controller 102 instructs
the TRIAC 120 to close the circuit providing the AC power to the motor 205,
thereby connecting the motor 205 to the AC source 114 and turning on the
motor. When the switch 132 is opened by the operator 215, the controller
102 instructs the TRIAC 120 to open the circuit providing the AC power to
the motor 205, thereby disconnecting the motor 205 from the AC source 114
and turning off the motor.
[0034] The potentiometer 134 allows the operator 215 to
select a
motor control setting for the motor 205 from several motor control settings.
The motor control settings may include, without limitation settings for
varying the speed of the motor 205. The potentiometer 134 is
communicatively coupled to the controller 102, and may communicate with
the controller 102 via a serial communication protocol over the electrical
lines
used for powering the user-control panel 218B. In some embodiments, the
potentiometer 134 includes a knob that adjusts a variable resistor
electrically
coupled in series to the switch 132; thereby varying the DC voltage at the
potentiometer 134. The potentiometer also includes an analogue-to-digital
convertor (ADC) for converting the DC voltage at the potentiometer 134 to a
digital value, and a transmitter for sending the digital value to the
controller
102. In other embodiments, a digital potentiometer is used, and may include
several push buttons, each selecting a speed of the motor (for example,
"low", "medium" and "fast" speed settings). The controller 102 will adjust
the speed of the motor 205 in correspondence with the selected setting of
the potentiometer 134 by sending a signal to the TRIAC 120 corresponding to
the selected setting.
CA 02833938 2013-11-20
_
- - 13 -
=
[0035] Optionally connected in parallel to the DC output
terminals of
the SMPS 110, and in parallel to the switch 132 and the potentiometer 134,
and in parallel to the controller 102, and in parallel to one another are one
or
more sensors 106 and one or more sensors indicators 104. The controller
102, the sensors 106 and the indicators 104 of the control subsystem 219B
function similarly to the controller, sensors and indicators of the control
subsystem 219A in providing information to the operator 215. However, in
some embodiments, in addition to providing information to the operator 215,
the sensors 106 and the controller 102 of the control subsystem 219B are
also used to control the speed of the motor 205, via the TRIAC 120.
[0036] In one embodiment, the handle 213 is equipped with an
orientation sensor such as an accelerometer sensor. The accelerometer
sends real-time data to the controller 102 when the motor 205 is turned on.
The controller 102 is configured to analyze the accelerometer data and in
particular to detect when the data is indicative of the operator 215 lifting
the
handle 213 in an upwardly direction; indicating that the cleaning attachment
216 is no longer touching the ground. At that point in time, the motor 205 is
active, thereby consuming electrical power, but does not provide any useful
result; as the cleaning attachment 216 is off the ground. The controller 102
therefore upon detecting that the cleaning attachment 216 is no longer
touching the ground reduces the speed of the motor 205, or turns off the
motor 205. The controller 102 then analyzes the accelerometer data to
detect when the data is indicative of the operator 215 lifting the handle 213
in a downwardly direction; indicating that the cleaning attachment 216 is
touching the ground. When the controller 102 detects the handle 213 is
moved in a downwardly direction, the controller 102 then returns the motor
205 to the selected speed setting.
[0037] In another embodiment, a proximity sensor is
installed in the
cleaning attachment 216, to detect when the cleaning attachment 216 is
CA 02833938 2013-11-20
. - 14 -
touching the ground. The speed of the motor 205 is then varied by the
controller in dependence on the input the proximity sensor to help reduce
power consumption by the motor 205.
[0038] In another embodiment, an air contaminant sensor is
used to
determine if the level of contaminants in the air in the building 203 is at an
unsafe level, thus putting any person in the building 203 is at risk. If an
unsafe level is detected, the controller 102 (via the TRIAC) turns off the
motor 205 and sounds an audible alert.
[0039] Certain adaptations and modifications of the
described
embodiments can be made. Therefore, the above discussed embodiments
are considered to be illustrative and not restrictive.
