Note: Descriptions are shown in the official language in which they were submitted.
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Title VACUUM CLEANER HAVING A PLURALITY OF POWER
MODES
FIELD OF THE INVENTION
This invention relates to power control systems and methods of
delivering power to a mechanical or a fluid mechanical system. In particular,
this invention relates to the use of impulsed power.
BACKGROUND OF THE INVENTION
Power control systems are used to control the rate of delivery of power
to a member which requires power or which performs work. For example,
power control systems are used to control the delivery of electrical power to
a
load (eg. a motor or other electromechanical devices which produce work
such as solenoids, loudspeakers, florescent lights, incandescent lights and
sodium lamps). The load may also be a battery wherein the power control
system is used to control the charging and/or the discharging of the battery.
Power control systems are also used in mechanical systems such as to
control the delivery of power from an internal combustion engine. Examples of
power control systems for such mechanical systems include governors and
regulators for power generators.
Historically, power control systems have been designed to provide a
uniform flow of power. For example, in the case of electrical motors, power
delivery systems have been developed so as to ensure a continuous flow of
electricity to a motor so that the drive shaft driven by the motor runs at a
constant rate of revolution. In this way, the motor operates smoothly (i.e.
without any vibrations). Similarly, even in mechanical systems, such as the
use of an internal combustion engine to drive a vehicle (e.g. a car, train,
airplane or the like), the power control systems have been developed so as to
ensure that the engine provides smooth acceleration to the vehicle.
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More recently, developments have been directed also towards decreasing the
power requirements of a system. Typically, such work has been developed to
reduce the actual amount of power required to operate the system while still
maintaining a uniform flow of power. Examples of such developments include
improved laminations and wiring for motors and generators to reduce power
lost as heat.
There are also many applications wherein no power control system is
utilized. An example of this is lighting. Fundamentally, an incandescent fight
bulb has a filament, usually contained within a glass enclosure, filled with a
gas selected to maximize filament life. In use, an electric current is passed
through the filament and simply serves to heat the filament to a very high
temperature. The effect of this is to cause the filament to radiate
electromagnetic radiation. It is well known that the spectrum of radiation
produced is dependent upon the temperature of the filament. The filament is
designed to reach temperatures such that a significant proportion of the
radiation falls within the visible band of the electromagnetic spectrum.
Unfortunately, the electromagnetic spectrum produced by a heated object,
such as a filament, is necessarily broad, and much of the radiation falls
either
in the infrared or ultraviolet bands. This is highly undesirable. However,
conventionally, it has simply been accepted that the physics of radiation or a
heated body necessarily determines characteristic. Accordingly, this is simply
accepted, and common incandescent light bulbs have a relatively low
efficiency.
Similarly, a fluorescent light bulb typically has a gas, eg. mercury
vapour, contained within a glass enclosure. In use, an electric current is
passed through the mercury vapour to ionize the vapour. This in turn excites
a fluorescent coating on the glass, to produce visible light as well as
electromagnetic radiation outside the visible spectrum.
Another example are electric motors and other devices which are
powered by batteries or cells. Batteries or cells are commonly classified into
two types, namely: primary cells, which are single use cells and, after
discharge, cannot be recharged for further use; and secondary cells or
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batteries, which are subjected to a large number of charge and discharge
cycles. Commonly, the current or energy drain from a battery or cell,
whether this be a primary cell or secondary cell, is determined solely by the
characteristics of the load. While there are a number of concepts employing
pulse width modulation which are used to control the power consumption of
electric motors, these known techniques are directed solely to controlling the
motor, without regard to the effect on the energy source, and in particular
without regard to any impact on the drain from a battery source.
Secondary batteries or cells deliver a DC current. Accordingly,
charging of such secondary cells is commonly done by connection to a
suitable, fixed DC potential. Current flow into the cell is then determined by
the electrical characteristics of the cell, including the internal resistance
of the
cell. Practically, when charging the cell, the current initially has a
relatively
high value, and then reduces down, in some approximate exponential fashion.
When a secondary battery is recharged, heat is produced. This heat is a
byproduct of the recharging process and constitutes a loss of energy when a
battery or cell is recharged. The speed at which a secondary battery or cell
can be recharged is generally governed by the temperature to which the
battery may be raised without degradation of the battery occurring.
Despite the advances which have been made in recent years in power
control systems, a need still exists to increase the energy efficiency of
electrical and mechanical devices as well as the speed and efficiency of
battery recharging.
SUMMARY OF THE INVENTION
In the research which has been undertaken by the inventor, it has
surprisingly been found that the objective of providing a uniform flow of
power
to a system results in inefficiencies. Various systems operate on a cyclical
basis which is not uniform. In accordance to the instant invention, in order
to
increase the energy efficiency of a system, the power is provided to, or
withdrawn from, the system so as to operate a system in a regime in which it
operates more efficiently. These systems include transmitting motive force
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between a fluid and an apparatus (eg. a fan blade or turbine) positioned in
the
fluid flow path, the production of light and other forms of radiation
(including in
particular infrared and x-ray radiation) and the charging and discharging of
batteries. In each of these systems, the input of power results in the
creation
of work (eg. a fluid is moved, radiation is produced, electricity is generated
or
a battery is charged). However, the systems perform more work than is
required. For example, in the case of light bulbs, lights bulbs will emit
light
(visible radiation), as well as radiation in band widths which are not visible
(ancillary work). By reducing the non-visible radiation emitted by a light
bulb,
the same amount of visible light may be produced using less power. By
providing pulsed power to the system, the system may be driven to perform
the required work (eg. the production of light) and at least a reduced amount
of ancillary work (eg. the production of non-visible radiation).
In accordance with the Instant invention, a method of controlling the
electrical power applied to a load comprises the steps of producing a pulse
train comprising a series of pulses defining a cycle in which a portion of the
pulse train having a duration of 10% of the cycle delivers more than 20% of
the total power to the load which the Load receives each cycle, and, supplying
the pulse train to the load to supply power to the load. Accordingly, a
portion
of pulse train having a duration of 10% or less of the time of a cycle
deliveries
20% or more of the power.
In one embodiment, the method further comprises the step of providing
an electric power supply and the pulse train is produced by modulating the
electric power supply to produce the pulse train.
In accordance with another aspect of the instant invention, a method of
controlling the mechanical power applied to a load, the method comprises the
steps of producing changes in the acceleration of a mechanical member
whereby a series of differing accelerations are applied in a repeating pattern
to produce the mechanical power, a portion of the series having a duration of
10% of the pattern delivers more than 20% of the total power to the load
which the load receives during the repetition of each period and, supplying
the
mechanical power to the load to supply mechanical power to the load.
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In one embodiment, the load comprises an impact member and the
mechanical power is modulated to reduce degradation of a Prandtl layer
which forms on the Prandtl layer as fluid travels over the impact member.
In another embodiment, the mechanical member comprises an impact
member and the mechanical power is modulated to reduce degradation of a
Prandtl layer which forms on the Prandtl layer as fluid travels over the
impact
member.
Preferably, the portion provides 30% - ?0%, more preferably 40 - 60%
and most preferably 45% - 55% of the total power the load receives each
second.
The frequency of the pulse train may vary from 6 - 20Hz and
preferably 9 - 15 Hz. It will be appreciated that if mechanical power is being
applied to a load, then the series of pulses are efFectively applied in a
cycle
which is preferably of the same frequency as an electrical signal as taught
herein. Further, each cycle may contain from 1 - 20, preferably 5 - 20, more
preferably 5 - 15 and most preferably 9 - 13 pulses or differing
accelerations.
For example, the pulse train may be produced by providing a constant power
supply to the load (eg. a constant DC or AC signal) and superimposing on the
signal which is supplied to the load one or more pulses. Thus, if a single
pulse
is superimposed, the load will receive a signal providing a continuous power
level and, once a cycle, a signal at a higher power level. Preferably, in the
case of an electric signal, the increased power is provided by increasing the
voltage of the signal supplied to the load. It will be appreciated that a
power
control system for a mechanical system may be operated in the same
manner.
Further, it is also preferred that the signal is non-uniform. For example,
the signal is not synchronized to occur at the same point in each rotation or
series of rotations of the motor and hence is not designed to maintain a
uniform angular velocity or uniform momentum or uniform power input or
distribution.
Referring to Figure 1, a plurality of different wave forms are shown.
These include DC (Figure 1 a), AC (Figure 1 b), pulsed DC (Figure 1 c) and a
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pulse width modulated signal (Figure 1d). The power transfer spectrum of
each of these signals is substantially uniform. By this, it is meant that over
a
given period of time, a relatively uniform amount of power is delivered by a
signal to a load. In the case of DC, it is understood that a uniform amount of
power is effectively continuously provided to a load. In the case of AC or
pulsed DC power, over each cycle, the same amount of power is provided.
For example, in the case of a 60 Hz signal, the same amount of power is
provided each 1160 of a second. The power transfer spectrum of a pulse width
modulated system delivers substantially less than 20% of the power in 10% of
the time. Therefore, measuring the cycle from one point to another, the same
amount of power is provided during each cycle. A pulse width modulated
signal, if provided to a motor, typically provides power to the motor at the
same point in each rotation. All of these signals are designed so that the
output of a device driven by these signals appears to be constant. In
contrast,
a pulse string according to the instant invention is shown in Figure 1(e). As
can be seen, the amount of power which is provided per unit time is non-
uniform. In particular, in this example, most (e.g. 50%) of the power
delivered
to a load is provided in 0.006 seconds and each cycle or period lasts .08
seconds. The output of a device driven by such a signal does not appear to
be constant. For example, in the case of a motor, a person may perceive
vibrations produced by the operation of the motor.
There are many applications today in which electric motors are
employed. The energy consumption of motors for pumping gases and liquids
accounts for over one-quarter of all electricity consumed in the world today.
There are known a number of techniques employing pulse width modulation
to control the power consumption of motors. Such techniques have had
modest success and generally are provided to control motor power or speed
with little or, no regard for improving motor efficiency. While the power is
pulsed, the pulses are symmetrical (i.e. the pulses are designed to provide
about the same amount of power so that the motor receives a uniform supply
of power).
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In accordance with the present invention, the power consumption of
electric motors, particularly in such applications as the movement of air and
pumping of liquids is substantially reduced while stilt performing the same
level of work. Research by the inventor has found that these types of
electromechanical assemblies have a natural resonance. Additionally, it has
been found that when the electrical signal or power supplied to the device is
conditioned, so as to provide energy in synchronism with natural resonant
frequencies of the motor and associated equipment, the power required to
produce the desired work is significantly reduced.
Additionally, this invention has general applicability to any electrical
power consuming circuit or device which shows similar characteristics. That
is, it is applicable to any device which shows some resonant characteristics,
and where providing the power signal as a pulse train with suitable
characteristics of voltage, frequency and pulse width, can improve the
efficiency of'the circuit by, in effect, coupling the electrical power supply
to the
circuit or device so that the circuit or device performs the desired work and
a
reduced amount of ancillary work. This in turn can reduce the power energy
required to deliver the desired work.
In accordance with another aspect of the instant invention, the present
inventor has realized is that it is possible to modulate or modify the signal
supplied to a light bulb such as an incandescent light bulb, to improve its
performance. This modulation can be applied to either an alternating current
or a direct current signal.
In effect, it has been discovered that if the power supplied to the light
bulb is supplied as a train of pulses, then this can significantly affect the
behaviour of the light bulb. With the selection of the appropriate parameters,
for lighting for direct human observation, the percentage of radiation given
out
as visible light can be enhanced considerably. In effect, this enables a light
bulb to be run at a lower nominal power rating, while producing the same
amount of visible light. This in turn means that less power is wasted as heat,
so the light bulb runs cooler.
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In accordance with another aspect of this invention, the present
inventor has realized is that both for charging and discharging a battery,
conventional techniques lead to much wastage of energy. Conventionally, as
noted above, both for charging and discharging, current is drawn off
essentially as a constant DC current. For practical applications, discharging
will often result in a varying or intermittent current; but the essentially DC
nature of the discharge certainly does not amount to a pulsed discharge as
taught by the present invention and as detailed below).
What the present inventor has realized is that, for both charging and
discharging, one can identify an apparent resonant effect. At the atomic
level,
it is believed that charging and discharging essentially requires ionization
(or
the reverse) of individual atoms or molecules. If such ionization is effected
by
application of a constant DC potential, often ionization is effected at a less
than optimum quantum state, thus requiring excess energy and wastage of
energy. On the other hand, if ionization is, in effect, synchronized with an
optimum quantum state of the particular atom or molecule, then less energy
is required.
At a macroscopic level, the inventor has discovered that this appears
as a resonant effect. Thus, for charging, the inventor has discovered that if
the
series or train of pulses is applied during the charging process, then much
more efficient charging can be obtained. In effect, between each pulse, the
battery or cell is permitted to relax, and when the next pulse is applied,
atoms
or molecules are in an optimum state for receiving a charge. It is possible to
devise an optimum wave form, to increase or to optimize the power or energy
output of primary and secondary batteries and energy input to secondary
batteries. This is achieved by developing an algorithm relating the power
or energy obtained from (or delivered to) the battery to key parameters of the
pulse train, namely, voltage, frequency and pulse width. Then, one or more,
and optionally two or more of these parameters (voltage, frequency and pulse
width) are optimized for a particular load, to improve the performance of the
battery during charging or discharging.
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It will be appreciated that apparatus embodying this mode are also
within the scope of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other advantages of the instant invention will be more fully
and particularly understood in connection with the following description of
the
preferred embodiments of the invention in which:
Figure 1 (a) - (d) are prior art electrical signals and Figure 1 (e) is an
electrical signal according to the instant invention;
Figure 2 is a schematic view of an internal combustion engine in
accordance with the present invention.
Figure 3 is a schematic view of an apparatus and an electric motor in
accordance with the present invention;
Figure 4 is a circuit schematic which may be used with the apparatus of
Figure 3;
Figure 5 is a cross-section of a vacuum cleaner including the motor
control circuit of Figure 4;
Figure 6 is an alternate schematic view of an apparatus and an electric
motor in accordance with the present invention;
Figure 7 is an alternate schematic view of an apparatus and an light
bulb in accordance with the present invention;
Figure 8 is an alternate schematic view of an apparatus for discharging
a battery in accordance with the present invention;
Figure 9 is an alternate schematic view of an apparatus for charging a
battery in accordance with the present invention;
Figure 10 is a graph of electrical power versus flow for a motor
receiving a pulsed signal according to the instant invention;
Figure 11 is a graph of power versus flow for a second motor receiving
a pulsed signal according to the instant invention;
Figures 12(a) - (c) are a graph of voltage versus time and a graph of
current versus time for a pulse train signal provided to a motor;
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Figure 13 is a representation of a pulsed signal provided to a light bulb
in accordance to the instant invention; and,
Figure 14 is a graph showing the voltage and current for an alternate
pulsed signal provided a light bulb.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In one aspect, the invention relates to fluid mechanical systems. Fluid
mechanical systems include those systems which use an impact member to
transmit motive power between the impact member and the fluid. The impact
member may be designed for transmitting motive power from the impact
member to the fluid whereby the movement of the impact member causes the
fluid to move. Examples of such systems are fans, pumps, turbines. These
devices have impact members (eg. fan blades, propellers, turbine foils and
the like) which interact with the fluid to produce movement of the fluid. The
impact member may alternately be designed for receiving motive power from
the fluid and transmitting the motive power to, eg., a drive rod on which the
impact member is mounted whereby the movement of the fluid causes the
impact member to move. Examples of such systems are electrical generators
and a steam powered engine wherein a fluid is expanded through a turbine. In
each case, the impact member, hereinafter referred to as a "vane" deflects the
fluid (a gas or a liquid) to move the fluid downstream (eg. a pump) or
deflection of the fluid provides motive power (such as in the case of a
propeller) to a vehicle or the tike to produce mechanical power (such as
rotational power provided by a drive rod wherein the drive rod is rotated by
rotation of the impact member) or electrical power (such as in the case of an
electric generator).
By way of example, as gas passes over a fan blade, a Prandtl layer
forms along the fan blade. As a fan blade rotates, a thicker boundary layer
will
be developed. At some point, the layer of fluid travelling along with the
blade
will be of a sufficient thickness such that all or a portion of the boundary
layer
will separate from the blade. When this occurs, turbulence or vortical flow
will
occur. Without being limited by theory, it is believed that as a fan blade
rotates
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either the Prandtl layer is thickening and then thinning when a portion of it
breaks off, or, alternately, that a plurality of layers are forming on top of
the
Prandtl layer and that these outer layers break off periodically at a certain
thickness. In eifiher case, when a portion of the layer travelling with the
blade
breaks off, this disrupts the Prandtl layer. The existence of the Prandtl
layer is
required to assist a fan blade in transmitting motive force to the fluid or
receiving motive force from the fluid. Therefore preventing degradation of the
Prandtl layer (e.g. the collapse of the Prandtl layer due to the sudden
thickening of the boundary layer or the delamination of all or a portion of
the
Prandtl layer) increases the efficiency of a fan blade.
In accordance to the instant invention, power is delivered to the fan
blade so as to prevent the Prandtl layer from collapsing or delaminating. By
maintaining an effective Prandtl layer on a blade for a greater period of
time,
more of the energy which is input into the system to cause the fan blade to
rotate will be transmitted to the fluid passing over the blade. Accordingly,
the
pulse train is modulated to vary the acceleration (which may be a negative
acceleration, i.e. a deceleration) of the impact member to reduce degradation
of a Prandtl layer which forms on the impact member as the fluid travels over
the impact member.
Conventionally, the cyclical thickening of the boundary layer on the fan
blade occurs since the power is supplied uniformly to the fan blade (i.e. a
fan
blade rotates at essentially a constant rpm). In accordance with the instant
invention, the fan blade is decelerated (eg. the rate of rotation is reduced)
prior to the Prandtl layer collapsing or delaminating. The sequential
acceleration and deceleration of a fan blade causes a variation in the speed
(i.e. rpm) of a fan blade that results in the Prandtl layer being more stable
on
the fan blade and therefore the fan blade transmits motive power to the fluid
for a greater period of time during which the fan blade is rotating. In the
case
of an electrically operated fan blade, the blade may be accelerated and
decelerated by sending a pulsed electrical signal to the motor or by not
sending a signal to the motor (eg. sending a DC signal to the motor and
intermittently discontinuing the DC signal whereby the motor is sequentially
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accelerated and decelerated) or by attenuating an AC signal. The pulsed
signal is determined so as to provide the requisite acceleration or
deceleration
for the fan blade. The exact pulsing of the signal which is required for a fan
blade will vary depending upon the actual configuration of the fan blade and
the motor.
This invention has particular applicability to vacuum cleaners. As such,
a motor for a vacuum cleaner is attached to a fan, for drawing air through the
vacuum cleaner, so as to produce the desired vacuum effect. What the
inventor has realized is that if the signal supplied to the motor is
configured so
as to cause deceleration just prior to collapse or delamination of the Prandtl
layer, and to accelerate shortly thereafter so as to rethicken or reestablish
the
Prandtl layer and prevent it from completely collapsing. Thus the Prandtl
layer
is reduced of thinned down as opposed to collapsing or delaminating. Further,
the acceleration results in the Prandtl layer being built up faster. in
effect, this
reduces the vortex energy thrown off from the blade, and hence significantly
reduces energy losses. Accordingly, the algorithm for the pulse train for a
vacuum cleaner should be developed, with this in mind. This is done simply
by running a series of tests or experiments on a complete vacuum cleaner,
which will allow for any effects which will alter the power consumption of the
motor.
It will similarly be appreciated that the same effect may be obtained in
non-electrical (i.e. mechanical systems). Once again, the mechanical system
(e.g. an internal combustion engine) will be operated such that, eg., the
shaft
on which an impact member, eg. a piston, is mounted does not rotate at a
constant rate but is accelerated and decelerated in a similar manner as an
electrically operated fan blade for a vacuum cleaner so as to prevent the
collapse or delamination of the Prandtl layer. More preferably, the impact
member is operated so as to maintain the Prandtl layer between
predetermined minimum and maximum thicknesses so that the effectiveness
of the impact member in transmitting motor force to a fluid is maintained at a
relatively constant level, but the angular velocity of the impact member is
not
held constant.
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Therefore, in one aspect of the invention, there is provided a method of
moving a fluid using a impact member, the method comprises providing power
to rotate the impact member and form a Prandtl layer of fluid on the impact
member as the impact member moves and, varying the rate of rotation of the
impact member to reduce the degradation of the Prandfil layer as the fluid
travels over the impact member. The impact member may comprise the
power transfer member of a fluid pump and the method further comprises
driving the impact member to cause the fluid to flow.
Therefore, in another aspect of the invention, there is provided a
method of generating power from a fluid using a impact member comprises
providing fluid to rotate the impact member and form a Prandtl layer of fluid
on
the impact member as the impact member moves, the impact member being
drivingly connected to an apparatus for producing power in response to the
rotation of the impact member and, varying the rate of rotation of the impact
member to reduce the degradation of the Prandtl layer as the fluid travels
over
the impact member. The apparatus may comprise an electrical generator and
the method further comprises driving the generator to produce electrical
current. Alternately, the apparatus may comprise drive rod and the method
further comprises driving the drive rod to obtain mechanical power.
Referring to Figure 2, a mechanical system for providing a pulsed
system according to the instant invention is shown. In accordance with this
system, an internal combustion engine comprises at least one and preferably
a plurality of pistons 180. Just one such piston is shown in Figure 2 and it
is
received in the bore 184 of a cylinder 182. A drive rod 186 is pivotally
attached to piston 182. Drive rod 186 has a distal end 188 which may be
drivingly connected to a crank shaft or other power transfer coupling known in
the art of internal combustion engines. Cylinder 182 is provided with first
and
second fuel dispensers 190 and 192, eg. fuel injectors. Each fuel dispenser is
in fluid communication with a source of fuel, such as by means of a fuel line
194 which feeds individual fuel feed lines 196. A fuel ignition system, such
as
spark plug 198 is also provided. An electronic ignition system 200 is provided
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to control fuel dispenser 190, spark plug 198 and fuel dispenser 192 by
means of wires 202, 204 and 206 respectively.
First and second fuel dispensers 190 and 192 provide different aliquots
of fuel to cylinder 182. For example, first fuel dispenser 190 may be designed
to provide one microliter of fuel to the cylinder whereas second fuel
dispenser
192 may be designed to provide two microliters of fuel to cylinder 182.
Moreover; the amount of fuel dispensed or injected or by each dispenser 190,
192 is preferably variable provided that differing amounts may be sequentially
introduced into bore 184 so as to provide differing levels of power as
described herein. Further, a single dispenser or injector may be used for each
cylinder 182 provided it is capable of providing differing quantities of fuel
to
bore 184. Electronic ignition system 200 may sequentially actuate one or the
other, or both, fuel dispensers by means of wires 202 and 206. Spark plug
198 will cause ignition of the fuel in cylinder 182. By varying the amount of
fuel which is ignited in cylinder 182, the amount of acceleration exerted on
piston 182 by the ignition of the fuel is varied so as to provide the
requisite
pulsed acceleration to any member drivenly connected to drive rod 186. Thus,
for example, drive rod 186 may be drivenly connected, by any means known
in the art, to an impact member. Accordingly, the modulation of the fuel flow
rate to the internal combustion engine and/or the spark temperature may be
utilized to accelerate and decelerate the impact member so as to prevent, or
at least reduce, the collapse or delamination of the Prandtl layer on the
impact
member. In particular, a reduced amount of fuel and/or a lesser spark would
decelerate the crank shaft while extra fuel and/or a higher spark temperature
would accelerate the crank shaft.
It will also be appreciated that the same operational mode may be
utilized with impact members which interact with a fluid so as to cause the
fluid to do work. Examples of these include turbine and windmills which are
used to generate electricity. As a fluid (e.g. air or steam) passes over a
foil or
turbine, a Prandtl layer is built up which cyclically thickens and thins. By
interacting with, e.g., the shaft on which the turbine is mounted so as to
cause
the turbine to accelerate and decelerate under the influence of the fluid leg.
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using a solenoid to drive a brake member to periodically contact the shaft to
slow the shaft or a clutch to selectively change the load on the shaft), the
thickness of the boundary layer on the turbine may be controlled so as to
prevent degradation of the Prandtl layer. In this way, a greater amount of
power may be transmitted by the turbine from the fluid to a system (eg. an
electrical generator or to a drive rod on which an impact member is attached
so as to provide rotational mechanical power). It will be appreciated that, by
accelerating and decelerating the turbine, the drive rod on which the impact
member is mounted will provide non-uniform rotational power. This non-
uniform rotational power may be converted to linear power or, alternately, to
electrical current by means of an electrical generator. The electrical signal
produced by the generator may accordingly be a pulsed signal which is the
digital equivalent of the non-uniform rotational power fed to the generator.
Such a signal may be provided to a load. Preferably, if the mechanical power
is used to drive an electric generator and the pulsed signal produced by the
generator would not cause the load to perform work in an energy efficient
manner, the signal may be further attenuated so as to alter the pulse train
produced by the generator to one which is appropriate for the load to which
the generator is supplying power. In a similar manner, the non-uniform
mechanical power provided by the drive rod may also be attenuated to
provide continuous power or an alternate pulsed power which is appropriate
for the system to which the drive rod provides power.
Alternately, the desired acceleration and deceleration of the impact
member can be achieved by applying a pulse train signal to an
electromagnetic clutch which couples a prime mover to the impact member. If
the impact member is a fan blade or the like, then the prime mover is the
shaft
which is drivingly connected to the fan blade. If the impact member is a
turbine for generating electricity, then the prime mover is the drive rod
which
is drivenly connected to the turbine. In the case of an electromagnetic
clutch,
the series of electrical pulses cause differential slip to occur in the clutch
thereby accelerating and decelerating the impact member. A further
alternative method produces the desired acceleration and deceleration of the
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impact member by applying a pulse train of hydraulic pressure pulses to a
hydraulic mechanical clutch which couples a prime mover to the impact
member. In the case of an hydraulic mechanical clutch, the series of pressure
pulses cause differential slip to occur in the clutch thereby accelerating and
decelerating the impact member.
in one embodiment, the electrical signal is used to power a tan blade,
such as may be used in a vacuum cleaner. Figure 3 shows a voltage source
10, which can provide either AC or DC power, and connected to an electronic
control unit 12 by connections or wires 13, 14. The electronic control unit 12
in
turn is connected to the actual electric motor 15, by means of wires 16 and
17.
The electronic control unit 12 receives either an AC or DC power
supply signal over the wires 13, 14. This is modified or conditioned by
modulating the signal with a pulse train. The unit 12 effectively modifies one
or more of the characteristics of the pulses, namely pulse width, voltage and
frequency. This is done by modulating at least one, and possibly two or three
of these characteristics. Thus, the unit 12 could modify: the pulse width and
voltage of the signal; the frequency and voltage of the signal; the frequency
and pulse width of the signal; or the frequency, pulse width and voltage
together. Whichever characteristic is not modulated, is set at a fixed value.
For a given motor in a given system, the actual pulse train which is
used will vary. A series of tests or experiments may be easily carried out to
establish the characteristics that give optimum performance.
In order to optimize the performance of a given motor for a given load,
a series of variables are sequentially altered and the power consumed is
measured. For example, initially, the normal running voltage for the motor is
applied and the frequency is increased in 10% increments. At each frequency
increment, the pulse width of the signal is reduced until either the power
consumed decreases by, eg., 25% or the motor r.p.m. is altered by more than
20%. This procedure is repeated for selected voltages, preferably 250% of the
normal running voltage down to 20% of the normal running voltage such as by
10% decrements. When a voltage greater than the internal operating voltage
CA 02420497 2003-02-28
18
is applied, the energy delivered in the pulses is kept to a level below the
level
at which degradation of the insulation by heat, or other physical damage will
occur by reducing the duration (time) associated with the pulses. This data is
then topographically mapped and an algorithm to optimize the motor is
selected so as to reduce the power consumed by modulating the applied
voltage, applied frequency and pulse width of the signal.
The pulse train comprises a set cycle of pulses, for example, a plurality
of pulses that rnay be of the order of 10 pulses or more longer. Pulses within
the cycle can vary, in terms of their pulse width and pulse height. This cycle
is
repeated continuously, to generate the pulse train.
Figure 4 shows a motor control circuit which may be used in a vacuum
cleaner in accordance with the instant invention. Figure 5 exemplifies a
vacuum cleaner including the circuit: As shown in Figure 5, an upright vacuum
cleaner 70 has vacuum cleaner head 72 and main casing 74. Cleaning head
72 has rear wheels 76 and front wheels 78 to enable movement of cleaning
head 72 across a surface. Cleaning head 72 is provided with a rotatably
mounted brush 80 which is positioned above air inlet 82. Cleaning head 72
has an air outlet 84 positioned at the end of air flow path 86. Rotatable
valve
88 is provided in the cleaning head 72 so as to isolate the filtration means
in
main casing 72 from air flow path 86 when the vacuum cleaner is in the
upright position shown in Figure 5.
Main casing 74 contains the filtration means which preferably
comprises cyclone housing 90 defining cyclone chamber 92. Cyclone
chamber 92 is provided with an air inlet 94 which is in air flow communication
with air outlet 84 by means of air flow path 100. Vacuum cleaner 70 may also
be adapted for above floor cleaning such as by means of hose 102 which is
releasably connectable to main casing 74.
Motor 98 is positioned above and downstream from air outlet 96. Outlet
108 from vacuum cleaner 70 is provided downstream from motor 98.
Additional filtration means may be provided, if desired, in one or both of
chambers 104 and 106. Handle 110 is provided so as to enable the vacuum
cleaner to be pushed by a user.
CA 02420497 2003-02-28
19
It will be appreciated by those skilled in the art that the motor control
circuit of the instant application may be utilized with any vacuum cleaner,
such
as with a vacuum cleaner using any filtration means known in the art, as well
as any type of vacuum cleaner, e.g. upright, canister, back-pack and central
vacuum systems. According to one aspect of the instant invention, the motor
control circuit may be utilized with a vacuum cleaner which is to be plugged
into a standard electrical outlet in a house. In such a case, the power
control
system is designed to reduce the power required by the motor. Alternately,
the power control system may also be used with a vacuum cleaner which is
powered by rechargeable batteries. Preferably, in such a case, the power
control system also controls the charging and discharging the batteries.
Referring to Figure 4, power control circuit 112 comprises a motor
controller as well as a battery charger. Battery 114 supplies 50% the power
for motor 98 as DC current. The other half of the power is supplied to the
motor through an inverter (namely field effect transistor 120 and transformer
122). This has the advantage that half the power is transmitted as DC (which
has nominal circuit losses) and half is transmitted through the inverter
(which
may have an efficiency of eg: about 85%) for an overall efficiency of about
92.5%. It is recognized that by increasing the power channelled through the
inverter, the flow rate of the mechanical system can be controlled. However,
increasing the power channelled through the inverter increases the heat
losses through the circuit and mitigates a portion of the energy saving
realized
in the fluid mechanical portion of the system. It will be appreciated the
battery
114 may supply all of the power to motor 98 through the inverter circuit
resulting in about a 7.5% reduction in the power savings. The instant design
also advantageously allows multiple power levels to be supplied to motor 98.
The vacuum cleaner is operated by a user turning the vacuum cleaner
on by an onloff switch 118, which may be any switch known in the art. When
vacuum cleaner 70 is turned on, micro controller 116 receives a signal from
switch 118 and in turn starts to oscillate field effect transistor 120 at a
high
frequency (e.g. about 60 KHz). Gircuit 112 is provided with transformer 122
having primary and secondary coils 124 and 126. The high frequency
CA 02420497 2003-02-28
oscillation produced by field effect transistor 120 causes primary coils 124
to
induce a high voltage in secondary coils 126. The high voltage induced in
second coil 126 is switched on and off by field efFect transistor 128 at a
much
lower frequency (e.g. 9 Hz) as controlled by micro controller 116 by means of
wire 152. The high voltage induced in second coil 126 may also be supplied to
diode multiplier 172 which to provide current to, eg. an electrostatic
generator
in vacuum cleaner 70.
Field effect transistor 128 is connected to motor 98 via wire 130, switch
132 and wire 134. Accordingly, the pulse train developed by field effect
transistor 128 is supplied to motor 9$ so as to cause sub-rotational
accelerations as described herein whereby the efficiency of the power transfer
from motor 98 to the fluid stream passing through vacuum cleaner 70 is
improved.
In a cyclonic vacuum cleaner, the impulses are preferably 1/81
seconds long having a voltage (amplitude) six times greater than the DC
voltage supplied by battery 114 to motor 98 by means of wires 136, 138. The
frequency of the pulses produced by field effect transition 128 is preferably
6-
20 Hz for a cyclonic vacuum cleaner using a series universal motor wound to
produce the desired flow rate when 50 volts AC is applied with 200 watts
available. It will be appreciated that the pulse which is provided to motor 98
may be varied by changing the frequency of field effect transistor 128.
In accordance with another aspect of this invention, circuit 112 may
include a microswitch 140 which is activated when vacuum cleaner 70 is
placed in the upright position shown in Figure 4 (i.e. axis A of main casing
74
is essentially perpendicular to the surface being cleaned). Microswitch 140
may be of any known in the art which will provide a signal to microcontroller
116 depending upon the position of upper casing 74.
Microswitch 140 causes a signal to be sent to microcontroller 116 by
means of wire 142. This causes microcontroller 116 to terminate the
oscillation of field effect transistors 120 and 128 thereby reducing the power
consumption and airflow through motor and fan blade assembly 98.
CA 02420497 2003-02-28
21
Typically, a user may leave a vacuum cleaner running when in the
upright position when attending to other tasks associated with vacuuming
such as to move furniture or other objects which may be in the way. When
microswitch 140 is actuated, moving the vacuum cleaner into a standby
mode, the power consumed by motor and fan blade assembly 98 is reduced
thereby permitting a user to move furniture, answer the telephone or the like
while reducing the power consumption of motor and fan blade assembly 98.
Microswitch 140 maybe utilized to switch a vacuum cleaner operating from a
standard electrical outlet to a standby mode. This may be advantageous to
decrease the noise produced by vacuum cleaner 70 when it is not being used.
However, use of the standby mode is particular advantageous in a battery
powered vacuum cleaner.
Optionally, hose 102 is detachable from main casing 74 so as to
enable above the floor cleaning, e.g. hose 102 may have a rigid wand 114
slidably received therein for receiving a crevice cleaning tool or other
attachment. In such a case, circuit 112 preferably also includes microswitch
146 for switching motor and fan blade assembly 98 to a high flow mode. The
higher flow is desirable for enhanced cleaning using accessory tools.
Alternately, as the use of a hose causes additional pressure losses,
increasing the power provided to motor and fan blade assembly 98 may result
in the same flow rate when hose 102 is used. Microswitch 146 may be
provided in the receptacle in which hose 102 is received and actuated when
hose 102 is released from the receptacle (in the direction of arrow B).
Microswitch 146 may be a pressure actuated switch (i.e. the switch may have
a button which is pressed inwardly). When hose 102 is released, the button
extends outwardly thereby sending a signal to microcontroller 116 by means
of wire 148. In response to this signal, microcontroller 116 sends a signal to
field effect transistors 120 and 128 by means of wires 150 and 152
respectively. This causes field effect transistor 120 to oscillate at a high
frequency (e.g. 60 KHz or greater) and cause field effect transistor 128 to
oscillate at a higher frequency than before (e.g. 11-15 Hz) with pulses of,
e.g.
1/81 to 1160 of a second for a typical cyclonic vacuum cleaner as described
CA 02420497 2003-02-28
22
above. The longer pulse width and/or greater frequency of pulses delivered to
motor and fan blade assembly 98 produces a higher flow of air through
vacuum cleaner 70 then when the vacuum cleaner is drawing dirt laden air
through inlet 82.
In accordance with another aspect of the instant invention,
microcontroller 116 also includes a circuit for determining a level of charge
remaining in battery 114. To this end, microcontroller 116 sends a signal to
field effect transistor 120 which causes field effect transistor to switch on
for a
short period (e.g. approximately 0.1-0.2 seconds). This produces an impulse
equivalent to DC. As the frequency of this impulse is very low, transformer
122 effectively becomes a low resistance short circuit across battery 114
thereby causing a current surge through low value resistor 154 which is series
with transformer 122.
The voltage drop across low value resistor 154 caused by the current
surge is conducted to (e.g.) the analog to digital port of microcontroller 116
by
means of wires 156 and 158. While the voltage which is supplied by battery
114 may be relatively constant over a substantial portion of the operating
life
of a battery (e.g. 75% or more), it has surprisingly been determined that the
rate of rise of current in response to a momentary short circuit does not
remain constant. In particular, as the capacity of the battery is reduced
(i.e.
charge is withdrawn from the battery), the ability of battery 114 to supply a
current surge is also reduced. Therefore, it is possible to determine the
capacity remaining in the battery by occasionally producing a short circuit
across battery 114 and monitoring the rate of rise of the current in response
to
the short circuit. For a NiMH sub C battery pack comprising two sets of
twelve sintered cells connected in parallel, the dildt varies from 300 AIS to
120 AIS from 90% capacity to 20% capacity while the voltage output is
essentially constant. Thus, by knowing the di/dt relationship for a battery
over
the capacity for a battery, microcontroller 116 may provide a signal
indicating
the amount of capacity remaining in the battery or, if the battery is being
charged, the degree to which the battery has been charged.
CA 02420497 2003-02-28
23
The same method may be utilized during the recharging of the battery
to determine the charge state of the battery. Typically, the charge state of
the
battery is determined using the -OV. When a battery is in the -~V range, it is
already overcharged. Rechargeable batteries are subject to degradation if
their temperature increases too much, which occurs when they are
overcharged. Therefore, it is advantageous to determine the charged state of
a battery prior to the battery becoming overcharged. Accordingly, during the
recharging of a battery, microcontroller 116 may cause field effect
transformer
120 to occasionally emit a low frequency pulse thereby producing a current
surge which may be measured by the voltage drop across low value resistor
154.
Preferably, microcontroller 116 includes means for opening the circuit
to thereby shut off motor and fan blade assembly 98 when battery 114 is at a
sufficiently low charge level. Accordingly, circuit 112 may shut down the
power drawn from battery 114 by opening relay 160 which opens the circuit to
motor and fan blade assembly 98 and by terminating the signals which are
send to field effect transistors 120 and 128.
It will be appreciated that battery 114 may be charged by removing
battery 114 from vacuum cleaner 70 and placing it in a suitable charging unit.
Preferably, battery 114 is charged in situ. To this end, vacuum cleaner 70 may
include a plug 162 which is suitable for being received in a standard
electrical
outlet. Plug 162 is connected to circuit 112 by means of cord 164. When plug
162 is withdrawn from receptacle 166 (which may be provided at any desired
position in vacuum cleaner 70), mechanical lever 168 trips switch 132 so as to
disconnecf motor and fan blade assembly 98 from the current. In this way,
motor and fan blade assembly 98 will still receive current from wires 136 and
138 thereby causing motor and fan blade assembly 98 to operate at low
power during the recharging operation: The operation of motor and fan blade
assembly 98 at low voltage DC during the recharging operation causes motor
and fan blade assembly 98 to operate at a low speed so that air may be
drawn across battery 114 and over; e.g., heat sink 170 which is thermally
connected to battery 114 so as to cool battery 114 while it is being charged.
CA 02420497 2003-02-28
24
Optionally, switch 132 may be arranged to disconnect wire 136 from motor
and fan blade assembly 98 so that motor and fan blade assembly 98 will not
operate during the charging mode or to close another circuit to operate a
cooling motor and fan assembly provided in air flow communication with
battery 114 to reduce the sensible temperature of battery 114 during charging.
When plug 162 is removed from receptacle 166, a signal is sent to
microcontroller 116 such that when plug 162 is plugged into a standard power
outlet, field effect transistor 128 is operated at, e.g. 60 KHz by
microcontroller
116 while field effect transistor 120 provides low frequency pulses (eg. 10
Hz)
to charge battery 114. The frequency of operation of field effect transistor
128
can be raised or lowered to vary the output voltage used to charge battery
114.
The power control system may be designed to automatically optimize
the power consumption of a system. Referring to Figure 6, the system of
Figure 3 has added thereto a feedback system. In this embodiment, electronic
control unit 12 is connected by wire 16 directly to a motor 15, and by wires
17
and 18 and an inductor 19, in series, to the motor 15.
A second inductor 20 is provided, inductively coupled to the inductor
19, and connected to a second electronic control unit 21 by wires 22 and 23.
The second electronic control unit 21 receives power through wires 30 and
31, connected to the first electronic control unit 12. Additionally, the
second
electronic control unit 21 provides control information, detailed below, to
the
first electronic control unit 12 through the wires 30, 31.
To monitor the motor speed, a magnet 24 is mounted on the rotating
shaft 25 of the motor, and is magnetically coupled to an inductor 26. The
inductor 26 is connected by wires 27 and 28 to the second electronic control
unit 21. Thus, rotation of the shaft 25 and the magnet 24 generate a pulse
train from the inductor 26, which is detected by the second electronic control
unit 21, and the frequency of this pulse train is proportional to the speed of
the
motor 15.
A control input far the electronic control unit 21 is indicated
schematically at 29. Although shown as a single lead, it will be understood
CA 02420497 2003-02-28
that this could comprise a multiple lead input. It enables input of desired or
intended characteristics for the motor behaviour, for example, speed and
power supplied to the motor.
In use, the second electronic control unit 21 receives signals indicative
of motor speed and current supplied to the motor. The control unit 21 is also
pre-loaded with an algorithm relating motor performance to the three main
parameters of a pulse train, namely frequency, pulse width and pulse height
(or voltage). In dependence on this algorithm, sensed motor conditions or load
and the input at 29, the electronic control unit 21 sends control signals to
the
first electronic control unit 12, to cause the control unit 12 to deliver a
pulse
train to the motor 15, which pulse train will give the desired motor
performance.
In accordance with another aspect of the instant invention, the power
control system is used in the management of power which is provided to a
radiation emitting device such as an incandescent light bulb, a fluorescent
light bulb and a sodium lamp. In all light emitting devices, electrical energy
is
input into the system to produce electrons having a higher electrical charge.
These electrons are dynamically unstable and return to their natural orbital
state. When this occurs, photons are emitted which result in the production of
light. When energy is provided as a continuous signal to electrons, the
electrons are raised to numerous quantum states. When the electrons release
the additional energy imparted to them, they return to their natural orbital
state
and emit radiation. As the electrons are changing quantum states at
essentially the same time, and as the release of energy from different
quantum states produces a different wavelengths of radiation, the electrons,
and accordingly the light emitting member, will emit a broad spectrum of
radiation. An example of this are light bulbs which provide light not only in
the
visible spectrum but, in addition, light bulbs also emit radiation in other
parts
of the radiation spectrum including ultraviolet and infrared. In particular,
the
radiation emitting member (e.g. a filament in the case of an electric light
bulb
or the gas in the case of a fluorescent light or electrodes in the case of
sodium
CA 02420497 2003-02-28
26
lamps) will emit a broad spectrum of light when a continuous symmetrical
signal (eg. AC current) is provided to the radiation emitting member.
In typical lighting applications, the provision of visible light is all that
is
required. However, the radiation which is emitted by an electron when it
changes from one quantum state to another varies depending upon the
beginning and end quantum state. Therefore, by controlling the quantum
states to which the electrons ire raised when excited, the radiation which is
produced when an electron reverts to its normal quantum state may be
controlled so as to provide radiation in only a desired portion of the
spectrum
(eg. visible light in the case of light bulbs).
Accordingly, in accordance with the instant invention, the power control
system provides electricity to the radiation emitting member so as to excite
electrons to only specific quantum states. In standard' lighting applications,
the
electric current to fhe light emitting member preferably would be attenuated
so
as to produce only or at least more visible light. However, it will be
appreciated that in some applications it may be desirable to produce more
and preferably only infrared light, x-rays or another spectrum of radiation.
A power control system for use with, eg., an incandescent light bulb is
shown in Figure 7. Commonly, for domestic and industrial applications,
voltage source 10 may be an alternating current source, for example a 120 V,
60 Hz supply as used throughout North America. However, it is equally
applicable to a DC source. Electronic control unit 12 is connected to an
incandescent light bulb 22, by wires 16 and 17. The lighfi bulb 22 is shown
schematically, and it will be understood by those skilled in the art that,
commonly, the wires 16 and 17 will be connected to a fixed, light fixture,
providing a socket into which the light bulb 22 is itself mounted.
Therefore, in one aspect of the invention, there is provided a method
for operating a radiation emitting device having a radiation emitting member
in
a plurality of bands when a uniform electrical signal is provided to the
radiation emitting member wherein the method comprises providing a power
supply to produce a signal to excite selected quantum states within the
radiation emitting member to preferentially produce radiation is a selected
CA 02420497 2003-02-28
27
spectrum and, supplying the signal to the radiation emitting device to supply
power to the radiation emitting member. The radiation emitting member may
comprises an incandescent light bulb, a fluorescent light bulb or a sodium
lamp and the radiation emitting member comprises a filament, gas in the
fluorescent light bulb and electrodes respectively.
In accordance with another aspect of the instant invention, the power
control system is used in the management of power for charging secondary
(i.e. rechargeable) batteries as well as discharging of secondary and primary
(eg. alkaline) batteries. Generally, batteries provide current, or are
charged,
by causing a chemical reaction to occur within the battery: For example, when
a battery is used to produce power, a chemical reaction occurs within the
battery which causes a flow of electrons between the electrodes in the battery
so as to produce an electrical current. Conversely, when a battery is being
charged, electrons are input into the battery to cause a chemical reaction to
be reversed thereby effectively storing the electrons for later use.
it will be appreciated that the chemical reaction which occurs when a
battery is charged or discharged is not a single reaction. In particular, a
plurality of sequential steps occur whereby the charge storing compounds
(reactants) react to produce electrons and unstable products. These products
become reactants in subsequent reactions which occur to produce stable
products. Each of these reactions proceeds at a different rate. The exact
reaction which will occur as well as the rates of reactions vary depending on
the type of battery which is being used (e.g. an alkaline battery, a lithium
battery or a nickel metal hydride battery).
The reactions which occur when a battery is being discharged produce
electrons having different potentials. The electrons which have a higher
potential will result in the production of more electrical power from the
power.
However, if these higher potential electrons are utilized to complete
reactions
which may be completed by electrons having a lower potential, then the extra
pofential will result in the production of work which manifests itself as
heat.
Currently, the standard approach is to discharge a battery by drawing a
constant flow of electrons from the battery. The disadvantage of this approach
CA 02420497 2003-02-28
28
is that the different reactions which occur when a battery is being discharged
compete for electrons since each reaction wants to go to completion. Thus,
electrons having a higher potential will be used to complete reactions which
would go to completion by utilizing lower potential electrons.
In accordance to the instant invention, power is withdrawn from a
battery in a discontinuous manner so that the reactions are allowed to
proceed more toward completion. In this way, a greater percentage of the
higher potential electrons may be withdrawn from the battery and applied to a
load so as to perform work. Further, this reduces the heating of batteries
which results in the degradation of secondary batteries. By modulating the
electron flow from a battery to preferentially use higher potential electrons
to
provide power to an external load, the actual amount of power which may be
withdrawn from a battery may be substantially increased above a
manufacturer's specification. For example, by using the power control system
of the instant invention, a sintered NiMH D cell battery which is designed by
a
manufacturer to provide 1.2 volts continuously for 6.5 amp hours may be used
to provide 1.2 volts for 7.7 amp hours when pulse train discharging is used.
Therefore, in accordance with this invention, a method for discharging
a battery comprises modulating the electron flow from the battery to
preferentially use higher potential electrons to provide energy to an external
load.
Figure 8 shows an apparatus in accordance with the present invention
for discharging a battery. Battery holder or connector 32 is shown connected
to a pair of batteries or cells 34. It will be understood that, in known
manner,
either a single battery could be provided or two or more batteries could be
provided, connected either in parallel or in series. Additionally, as already
noted, the batteries could be either primary cells or secondary cells.
The battery connector 32 is connected by wires 36 to an electronic
control unit 38. This electronic control unit 38 imparts a pulsed wave form to
the current drawn from the batteries 34. The electronic control unit 38 itself
takes power necessary for its operation from the batteries 34, but the
additional toad is minimal, and much less than any power saving achieved.
CA 02420497 2003-02-28
29
Figure 8 also shows a second electronic control unit 40 connected by
wires 42 to the first electronic control unit 38. This unit is intended, in
this
particular embodiment, to further attenuate the signal, to make it suitable
for
the desired load. For some applications, this second electronic control unit
40
could be omitted. The load for this embodiment is an electric motor, indicated
at 44 and connected by wires 46 to the second electronic control unit 40.
Conventionally, the motor 44 would simply draw a relatively constant
current from the batteries 34. In the present invention, the control unit 38
serves to modulate this current drain to give a pulsed wave form. When
pulses are provided, it is believed that a relaxation period following each
pulse
ensures that during each pulse all or most of the charge is drawn at an
optimal state. This reduces the losses and leads to more efficient recovery of
energy stored in the battery or cell.
Conversely, it will be appreciated that the time required to recharge a
battery may be substantially reduced by using the power control system of the
instant invention. By modulating the electron flow to a battery so as to
preferentially use lower potential electrons in those: reactions requiring
only
lower potential electrons, the amount of energy which is required to charge a
battery is reduced and this consequently decreases the amount of time which
is required to recharge the battery. The electron flow which is provided to a
battery contains electrons at various power levels. When a battery is being
recharged, by driving the reactions in reverse and allowing them to proceed
more to completion, fewer high potential electrons are required to be input
into
a system so as to recharge the battery to its desired charge state. Allowing
the reaction to proceed more to completion, in either direction, decreases the
competition for the higher potential electrons. Currently, batteries may be
recharged at a rate of up to about C/1 without unduly degrading the battery.
At
higher rates, excessive heating occurs which will degrade the battery. By
using the power control system of the instant invention, a battery may be
recharged at, for example CI0.25 (ie. for a battery which may be discharged in
one hour, the battery may be recharged in 15 minutes).
CA 02420497 2003-02-28
Therefore, in accordance with this invention, a method for charging a
rechargeable battery comprises providing an electrical signal to reverse
chemical reactions which occur during the discharge of the battery wherein
different chemical reactions can utilize electrons having differing potentials
and modulating the signal to preferentially use electrons having a higher
potential to reverse chemical reactions requiring higher potential electrons.
Figure 9 shows an apparatus in accordance with the present invention
for charging a battery. The apparatus includes a basic transformer and
rectifier unit 50, as is common for any secondary battery charger. The
transformer and rectifier 50 is connected to a plug 52, shown schematically,
by leads or wires 54. The plug 52, in known manner is adapted for connection
to a standard alternating current supply. The unit 50 then transforms the
alternating supply to a suitable potential and rectifies this potential to
provide
a DC output.
Leads 56 connect the DC output signal from the transformer and
rectifier 50 to an electronic control unit 58 which is adapted to modulate the
DC signal with a pulse train.
The electronic control unit 58 is connected by leads 60 to a charger
unit 62. As for conventional chargers, the charger unit 62 is adapted to
receive at least one secondary cell, and preferably adapted to receive a
plurality of such secondary cells as indicated at 34.
The electronic control unit 58, as mentioned, is adapted to modulate
the DC signal received through the wires or leads 56 with a pulse train. This
pulse train essentially comprises a sequence of a large number of pulses,
each of which can have differing characteristics, in terms of pulse widths and
pulse height or voltage amplitude. At least one, and preferably two, of these
parameters (pulse width, frequency and voltage) can be selected and then
modified to give the best result. The complete cycle of pulses is continuously
repeated, so as to provide a continuous pulse train.
Example 1
CA 02420497 2003-02-28
31
!n order to demonstrate the power efficiency available using the power
control system of the instant invention, a Panasonic motor model number
SDS-251FF was connected downstream from a cyclone bin similar to that
shown in Figure 5. The air flow rate through the cyclone bin was determined
by measuring the pressure drop across the cyclone bin using a manometer. In
order to provide a reading of the pressure drop, two picot tubes were inserted
into the air flow path, one upstream of the cyclone bin and the other
downstream of the cyclone bin. The pitot tubes provided minimal interaction
with the air flow through the air flow conduit. The current and voltage drawn
by the motor were measured using a Tektronix A622 ACIDC Current Probe
with a frequency response of DC to 100kHz for up to 100A peak current and a
Tektronix P5200 High Voltage Differential Probe. The power was calculated
by the equation Pelec.inst(t)= i(t).v(t). The results are shown in Figure 10.
In
this Figure; the line designated as "A2" provides the electrical power
required
by the motor at different flow rates when operated on conventional 60 Hz DC
power. The line designated "A" is the electrical power required to obtain the
same flow rates using the power control system of the instant invention. The
signal which is fed to the motor is shown in Figure 12(a). As shown in Figure
12(a), the pulse train had a frequency of 12.5Hz (i.e. each cycle or pulse
train
had a duration of 80 milliseconds) with 10 pulses per cycle. The strongest
pulse (pulse C) had a peak voltage of aboufi 120 volts. The peak pulse was
sandwiched between two strong pulses (pulses B) which had a peak voltage
of about 60 volts. The remaining pulses (pulses A) had a peak voltage of
about 20 volts. Two other signals on which the motor was operated are shown
in Figures 12(b) and (c). The signal shown in Figure 12(b) had a peak voltage
for pulse A of 106 volts. The pulse train had a frequency of 13 Hz. The signal
shown in Figure 12(c) had a peak voltage for pulse A of 90 volts. The pulse
train had a frequency of 9 Hz.
A second test was conducted utilizing a custom wound 50 volt test
motor which was obtained from Amatek (model number E-11459-2D). The
results are set out in Figure 11. Once again, line "A2" is used to designate
the
power required when the motor was operated on conventional 60 Hz DC
CA 02420497 2003-02-28
32
power and line "A" is used for the line representing the power required when
the motor was operated using the power control system of the instant
invention. In this case, the signal fed to the motor was similar to that fed
to the
Panasonic motor.
Example 2
This Example demonstrates the use of a pulsed train signal with a light
bulb. As shown in Figure 13, a pulse train wherein each period contained five
pulses was fed to a light bulb.
Within the period or cycle 220, there are five pulses, indicated at 221,
222, 223, 224, and 225. The pulses are spaced by intervals indicated as ~,~,
~.2, ~.3, a,4, ~s. The specific values for these pulses in this example are:
Duration of Pulse
Pulse No. Voltage Pulse Interval
(Pulse Widthj
21 50 10 ~,~=10
22 55 7 ~,2=12
23 60 12 ~~ ~3=g
24 57 9 ~,4=10
25 4g 9 ~,5=12
As indicated at the right hand side, at 221', the next period has the
same sequence of pulses.
As this table shows; within the period 220, all the parameters of the
pulses, namely frequency (i.e. inverse of the pulse interval), pulse width or
duration, and pulse height (voltage) are varied. This gives a distinct pulse
profile for the period, and this is repeated in following periods. In general,
depending on the particular application, it may not be necessary to vary all
three parameters, and it may be sufficient to vary just two of them, or even
just one of them, with the others) being kept constant. Additionally, it will
be
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understood that the absolute magnitude of each of these parameters can vary
greatly depending upon the actual application.
It is believed that by selection of suitable parameters, a resonance
effect is achieved, causing the filament to provide a significantly larger
proportion of the radiation in the visible region. This enables, for example,
a
normally 40-watt bulb to be driven with significantly less than 40 watts of
power, and yet stilt produce the same amount of visible light.
Figure 14 shows a print out of a pulsed signal which was used for a
fluorescent light bulb. As can be seen from Figure 14, the voltage which was
applied to the light bulb was relatively constant. However, the current
fluctuated substantially and comprised a signal having 10 pulses per period.
Each cycle or period was 119 second and the frequency was 9 Hz. A light
meter was used to measure the visible light emitted by the light bulb when the
light bulb was operated on a standard AC signal and when the light bulb was
operated on the signal of Figure 14. When the signal of Figure 14 was used,
the light bulb emitted the same amount of visible light but consumed 18% less
power.
Example 3
A pulsed signal comprising ten pulses per period was provided to a
secondary battery for recharging the battery. The pulse train was similar to
that shown in Figure 12. In this case, peak voltage "C" was 21 volts, pulse B
was 16.5 volts and the remaining pulses (pulses A) had a peak voltage of
14.5 volts. The duration of each pulse was 0.1 seconds. As a result of this
pulse train, sub-C batteries were charged at a rate of C/0.5 (i.e. they were
charged in 30 minutes) without causing any heat damage to the batteries.
