Note: Descriptions are shown in the official language in which they were submitted.
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ASCENDING OR DESCENDING VOLUME CONTROL FOR
CLOCK RADIO
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates generally to a method and apparatus of
selectively controlling the volume of a clock or wake-up device such as a
clock
radio such that the radio gets louder and louder or more insistent over a
period of
time and in the go-to-sleep mode the radio gets softer and softer in volume
before
it turns off.
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2. DESCRIPTION OF RELATED ART INCLUDING INFORMATION
DISCLOSED UNDER 37 CFR 1.97 AND 1.98
Alarm clocks and/or clock radios have been around for many years, and have
probably become the preferred method of waking up in the morning when an
individual must be at a location at a particular time. Normally, clock radios
are a
desirable way of waking up in that the radio may be tuned to a music station
or
news and the user is not jarred out of a sound sleep but can awake slowly.
Unfortunately for many users, if the radio is tuned to a station playing soft
music
the person may often be lulled back to sleep by the music and not get up at
the
intended hour.
One attempt to solve this problem has been to provide a more strident buzzer
or alarm in confirmation with the radio to assure that the user is up and
awake. Of
course if the clock radio goes into the buzzer or alarm mode the advantage of
the
soothing wake-up of the clock or music is lost. Accordingly, it would be
desirable
to provide methods and apparatus for allowing a sound sleeper to wake up to
the
sound of music or news without the sudden jarnng effect of a buzzer or alarm.
It would also be desirable to provide such a wake-up system which although
while initially providing soft wake-up music, the music will become louder and
louder over time thereby waking up the sound sleeper while still avoiding the
jarring effect of the buzzer or alarm.
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SUMMARY OF THE INVENTION
The present invention solves the previously discussed problems and other
problems by providing methods and apparatus comprising a sound system which
has an output volume which varies over a selected period of time. There is
provided a first circuit for generating electrical signals which signals have
frequencies within the audio frequency band. A typical example of such
circuitry
could include a radio receiver, a CD player or any other music or pleasant
sound-
creating system as well as a buzzer or alarm system. A second circuit receives
the
electrical signal in the audio frequency band and then selectively amplifies
these
signals in response to a volume control signal. The volume control signal
increases or decreases as will be discussed in detail later over a selected
period of
time. There is also included third circuitry or circuitry for generating
clocking
signals and clock-based control signals. In a preferred embodiment, the third
circuitry will include a source of clock pulses provided to a microprocessor
designed to provide appropriate signals to a typical electrical clock so as to
provide
a representation of the actual time of day such as in a 12 hour AM-PM mode or
a
24 hour clock mode. In addition, according to the present invention, the
microprocessor will also provide clock-based control signals for turning the
clock
radio or other sound source on or off and, according to the teachings of this
invention, also provide a control signal for selectively decreasing or
increasing the
volume control signal over a selected period of time. A clock-based control
signal
for varying the volume output of the sound system is provided to a volume
control
circuitry which generates a volume control signal as a function of the clock-
based
control signal. In a preferred embodiment, the volume control circuitry
receives a
PWM (pulse width modulated) signal which has a duty cycle which can
selectively
increase or decrease over a period of time. The ever increasing (or
decreasing)
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pulse width of the PWM signal is used to vary the charge on a capacitor
connected
so as to control a transistor. For example, the charge on the capacitor may
control
the base input of a transistor such as for example an NPN transistor. Of
course,
other types of transistor and related circuitry could be used including FET's
(field
effect transistors). In one embodiment using the NPN transistor, the collector
of
the transistor is connected to the amplifying circuit and the emitter is
connected to
ground. Thus, when the capacitor is fully charged the transistor will be fully
on
such that all of the audio frequency range signals from the amplifying circuit
will
be effectively connected to ground. Thus, when the transistor is fully
conductive,
the volume will be at a minimum.
When the system of the present invention is to be used as a clock radio for
waking someone up, the system may further include switching circuitry which is
controlled by the microprocessor and which preferably, in addition to
providing
the varying output PWM signal, also switches either the radio receiver or the
amplifier from an off condition to on at a preselected time. At this point in
the
preferred embodiment, the duty cycle of the PWM signal will be at a maximum
and will begin to decrease such that the volume, which as was discussed above
is
initially "OFF", will slowly begin to increase to a maximum value over the
selected period of time.
It will also be appreciated of course that the typical clock radio can also be
used to provide music for a period of time to help soothe someone to sleep and
then to cut off automatically. Thus, according to another feature of the
present
invention, the microprocessor further provides a control signal for switching
one of
the amplifier or radio receivers "ON." Also, another pin on the chip is
provided
for using a duty cycle of the pulse width modulated signal which is at a
minimum
and then slowly increasing the pulse width and thereby decrease the volume
output
from the system over a period of time. An audio speaker such as is well-known
in
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the art, is connected to the amplifying circuit for receiving the electrical
signals
which, as have been discussed above vary from a maximum to a minimum or
alternately from a minimum to a maximum over a period of time such that the
radio or music gets softer and softer or louder and louder.
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BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will be more fully disclosed
when taken in conjunction with the following Detailed Description of the
Invention in which like numerals represent like elements and in which:
FIG. 1 shows a block diagram of a sound system incorporating the
teachings of the present invention;
FIG. 2 shows a specific embodiment of volume control circuitry for
varying the volume output of the system over a selected period of time; and
FIG. 3 illustrates a typical flow diagram of the functions of a clock
radio using the teachings of the present invention.
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DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. l, there is shown generally at 10 a sound system
incorporating the teachings of the present invention. As shown, there is a
power
supply 12 which typically provides low voltage DC power to the various
components of the circuitry. However, as shown, the power supply 12 typically
receives its power from normal house power (i.e., 1 IOVAC 60 cycle power).
Thus, it will be appreciated the power supply 12 will typically be a power
converter for converting the 110VAC power to the typical 1.5 to 15VDC power
used by electronic circuitry. According to the invention, there is also an
audio
signal source 16 which in most embodiments will include an AM/FM radio
receiver 18a. It will be appreciated, of course, that in other more
sophisticated
sound systems, any type of audio sounds may be included including a connection
for a CD player 18b, a record player 18d, a cassette player 18c or any other
sources
18e of music or other soothing sounds. In addition to audio signals
representing
music or other soothing sounds, the system may also include an audio signal
for
providing the sound of a buzzer or other alarm such as indicated at 20. Thus,
the
audio signals are provided from audio signal source 16 by connection line 22
to an
audio signal amplifier 24. The gain of the audio signal amplifier 24 as will
be
discussed hereinafter is determined by the control signal on line 26a from
volume
control circuitry 28. The amplified signal from audio signal amplifier 24 is
then
provided on line 30 to a speaker system which may include a single speaker
such
as indicated by speaker 32 or could include a very elaborate speaker system
(not
shown). Power may be supplied to both the audio signal source 16 and to the
audio signal amplifier 24 by power connection lines 34 and 36 respectively. It
will
be noted however, that in the embodiment shown the power is not provided
directly from power supply 12 through line 38 but goes through a switching
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circuitry 40. In addition, it can be seen that power supply 12 also provides
power
to third circuitry 42 by means of power line 44. The third circuit or control
circuitry 42 typically includes an oscillator 46 which provides clocking
pulses on
line 48 to microprocessor 50. Microprocessor 50 may be a dedicated type clock
integrated circuit which is commercially available. In addition, as shown,
microprocessor 50 also provides switching signals to the switching circuit 40
on
line 52. Also as shown, microprocessor 50 may also provide the signals for a
digital clock display as shown by display 54. Further, according to the
teachings
of the present invention, the third circuitry 42 will also provide a clock-
based
signal on line 56 to volume control circuitry 28. In a preferred embodiment,
the
clock-based control signal on line 56 will be a PWM (pulse with modulated)
signal
which has a duty cycle which decreases or increases depending upon whether the
volume output of the speaker system is to get louder and louder or softer and
softer.
There is also included in the embodiment shown a manual volume control
circuit 58 connected between audio signal amplifier 24 and automatic volume
control circuitry 28 by conductor lines 26a and 26b respectively. Manual
control
circuit 58 is used to set the radio to the desired level for normal listening.
Thus,
the maximum volume to be provided by the speaker system 32 can be set by
manual control volume 58.
Referring now to FIG. 2, there is shown a specific example of circuitry for
the automatic volume control 28. It will be appreciated that although the
embodiment shown and described in FIG. 2 is simple, inexperienced and
effective,
other volume control circuits would be acceptable. The specific example of
FIG. 2
is not intended to limit the scope of this invention except as is set forth in
the
claims. As shown in FIG. 2, manual volume control 58 is connected to a
transistor
60 through a capacitor 62. In a normal "ON" condition of the radio, the
transistor
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will be in non-conducting state. That is, when it is not in the sleep or wake-
up
modes, transistor 60 will be biased (volt bias for an NPN transistor) such
that it is
not conducting to ground 64. According to the circuitry of FIG. 2, a PWM
signal
is received on line 56 and provided through a resistor 66 and a capacitor 68.
Resistor 66 and capacitor 68 act as an RC circuit such that the voltage level
at node
70 is the same as the positive plate of capacitor 68 which is fully charged
when the
duty cycle of the PWM signal on line 56 is at a maximum. That is, the pulse
width
signal has a duration that allows for the maximum charge to be stored on
capacitor
68. The voltage at node 70 is provided to the base input 72 of transistor 60
through a current-limiting resistor 74. Thus, in the embodiment shown, when
the
PWM signal on line 56 has a maximum duty cycle and the node 70 is at its
highest
voltage level, the transistor 60 being an NPN transistor will be fully on and
fully
conductive. Thus, all of the amplified audio signals provided by the audio
signal
generator 16 will be effectively connected through capacitor 62, through
transistor
60, and then to ground 64. Thus, when the voltage at node 70 is at a maximum
and transistor 60 is fully on the volume is at a minimum.
Conversely, when the voltage at node 70 is at a minimum, the transistor 60
will be fully off or non-conductive such that the volume output by the speaker
system will then be whatever the volume setting is for the manual volume
control
circuitry 58.
Referring now to FIG. 3, there is shown a flow diagram of a clock radio used
with the sleep mode, the wake-up mode and the buzzer alarm all activated. As
shown in the first block 80, the clock is set such that the sleep mode is on
and the
wake-up time is set. By starting the sleep mode the radio will be on and the
PWM
signal on line 56 as shown in FIG. 2 will be at a minimum such that the
voltage
level at node 70 will be at a minimum which results in the transistor 60 being
in a
non-conductive stage. Thus, the music will be playing at a volume selected by
the
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manual control system 58. It will also be appreciated as indicated by arrow 82
all
of the blocks progress with time. That is, each block follows the next block
in a
time progression order. After the system has been set and the sleep mode
started,
over a selected period of time which may vary from any desired amount such as
S for example from 15 minutes to an hour, microprocessor SO will slowly
increase
the duty cycle of the PWM signal on line 56 from a zero value to the maximum
value over the selected time period as indicated by step 84. Thus, the voltage
level
on node 70 will slowly increase over this time period and will in turn slowly
change the conductive status of transistor 60 from a non-conductive to a fully-
10 conductive state. After the volume has been decreased to a minimum, and
according to a preferred embodiment, the amplifier 24 and/or receiver 16 may
be
placed in the "OFF" condition as indicated by box 86. At this point, the
system is
off and will remain off until the wake-up time as originally set arrives. That
is, the
clock function will continue to work but the radio portion and/or the sound
portion
is off. The waiting state is shown at step 88. At the appointed wake-up time,
the
sound system will be turned back on and the microprocessor will start sending
PWM signals having a maximum duty cycle out on line 56 to the volume control
circuitry 28, which results in minimum volume as indicated by step 90. Then,
as
shown in box 90, the duty cycle of the PWM signal will be slowly decreased
thereby lowering the voltage level at node 70 and slowly turning transistor 60
into
a less and less conductive state. Consequently, it will be appreciated from
the
above discussions that the volume will begin to increase and will continue to
increase until the maximum volume set by the manual volume control circuitry
58
is achieved as indicated at step 94. Thus, over a selected period of time such
as
from about 15 to 30 minutes the music volume will go from substantially zero
to
the maximum set volume. Also according to this invention, it will be possible
to
set the buzzer alarm such that if the buzzer is not turned off before the
radio has
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been on for a selected time or maximum volume reached, the loud and jarring
buzzer will sound as shown at step 96. Further, as is true in most presently
available clock radios, after another set period of time of the music playing
at the
volume set by the manual control such as for example for an hour to two hours,
the
system may be set to turn itself off as shown in step 98.
The corresponding structures, materials, acts, and equivalents of all means or
step plus function elements in the claims below are intended to include any
structure, material, or act for performing the function in combination with
other
claimed elements as specifically claimed.
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