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Claims  |
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What is claimed is:
1. A temperature setback controlling system suitable for use in a building
wherein a thermostat having a room temperature sensing element is employed
on a wall in a first room to sense room temperature for control of a
heating system effective in said first room to maintain a thermostat
selected ambient room temperature, wherein heating controls for said
system including a transformer having a secondary winding for providing
low voltage, 60 Hz power are located in a second room of said building,
and wherein a thermostat cable coupling said thermostat in said first room
to said heating controls in said second room is located at least partially
within interior walls of said building, said temperature setback
controlling system comprising
timed control means, adapted to be coupled to said transformer winding, for
modulating during selected time periods cycles of one polarity of said 60
Hz low voltage with a high frequency;
a resistive heater, adapted to be placed in proximity to said room
temperature sensing element; and
detector means, adapted to be coupled to said thermostat cable in said
first room, for detecting said high frequency modulation during cycles of
said one polarity and coupled to said resistive heater for providing
current flow thereto in response to such detected modulation, whereby the
ambient temperature in said first room tends to be maintained at a
predetermined temperature setback during said selected time periods.
2. The temperature setback controlling system as recited in claim 1 wherein
said timed control means comprises
a switch;
an electrical timer coupled to said switch so that said switch is closed
during selected time periods and is opened during non-selected time
periods;
an electronic oscillator circuit;
unilateral conducting means; and
means coupling said switch, said oscillator circuit, and said unilateral
conducting means in a serial circuit whereby said serial circuit is
adapted to be coupled to said transformer secondary winding.
3. The temperature setback controlling system as recited in claim 2 wherein
said electronic oscillator circuit comprises
a multivibrator having an output terminal; and
an amplifier having an input terminal coupled to said output terminal.
4. The temperature setback controlling system as recited in claim 2 wherein
said detector means comprises
a manual switch having a pair of terminals, one terminal of said manual
switch being adapted to be coupled to said thermostat cable, the other
terminal being coupled to a first junction point;
a silicon controlled rectifier having an anode, a cathode, and a gate
electrode, said cathode being adapted to be coupled to said thermostat
cable;
a serially connected resistor and a light emitting diode serially coupling
said first junction point to said anode, said diode being oriented so that
its direction of conductivity is in the same direction as said rectifier;
a capacitor coupled across said anode and said gate electrode;
a second resistor coupled across said cathode and said gate electrode;
a variable potentiometer coupling a second junction point to said anode of
said silicon controlled rectifier; and
means for coupling said junction points to said resistive heater.
5. The temperature setback controlling system as recited in claim 1 wherein
said detector means comprises
a manual switch having a pair of terminals, one terminal of said manual
switch being adapted to be coupled to said thermostat cable, the other
terminal being coupled to a first junction point;
a silicon controlled rectifier having an anode, a cathode, and a gate
electrode, said cathode being adapted to be coupled to said thermostat
cable;
a serially connected resistor and a light emitting diode serially coupling
said first junction point to said anode, said diode being oriented so that
its direction of conductivity is in the same direction as said rectifier;
a capacitor coupled across said anode and said gate electrode;
a second resistor coupled across said cathode and said gate electrode;
a variable potentiometer coupling a second junction point to said anode of
said silicon controlled rectifier; and
means for coupling said junction points to said resistive heater.
6. A temperature setback controlling system suitable for use in a building
wherein a thermostat having a room temperature sensing element is employed
on a wall in a first room to sense room temperature for control of a
heating system effective in said first room to maintain a thermostat
selected ambient room temperature, wherein heating controls for said
heating system including a transformer having a secondary winding for
providing low voltage, 60 Hz, power are located in a second room of said
building, and wherein a thermostat cable coupling said thermostat in said
first room to said heating controls in said second room is located at
least partially within interior walls of said building, said temperature
setback controlling system comprising
timed control means, adapted to be coupled to said transformer winding, for
modulating during one set of selected time periods cycles of positive
polarity of said 60 Hz low voltage with a high frequency, and for
modulating during a second set of selected time periods cycles of negative
polarity of said 60 Hz low voltage with a high frequency;
a first resistive heater and a second resistive heater, each adapted to be
placed in proximity to said room temperature sensing element; and
detector means, adapted to be coupled to said thermostat cable in said
first room, for detecting said high frequency modulatings and coupled to
said resistive heaters for providing current flow to said first heater in
response to detected modulation during cycles of said positive polarity
and for providing current flow to said second heater in response to
detected modulation during cycles of said negative polarity, whereby the
ambient temperature in said first room tends to be maintained at a first
predetermined temperature setback during said one set of selected time
periods and at a second predetermined temperature setback during said
second set of selected time periods, and, whereby, during those intervals
when said one set and said second set of time periods overlap, the ambient
room temperature in said first room tends to be maintained at a third
predetermined temperature setback.
7. The temperature setback controlling system as recited in claim 6 wherein
said timed control means comprises
a first switch;
a second switch;
electrical timing means coupled to said switches so that said first switch
is closed during said one set of selected time periods and is otherwise
normally opened, and so that said second switch is closed during said
second set of selected time periods and is otherwise normally opened;
a first electronic oscillator circuit;
first unilateral conducting means;
a second electronic oscillator circuit;
second unilateral conducting means;
means coupling said first switch, said first oscillator circuit, and said
first unilateral conducting means in a first serial circuit;
means coupling said second switch, said second oscillator circuit, and said
second unilateral conducting means in a second serial circuit; and
means for coupling said serial circuits in an opposing shunt relation
whereby the resulting shunt circuit is adapted to be coupled to said
transformer secondary winding.
8. The temperature setback controlling system as recited in claim 7 wherein
at least one of said electronic oscillator circuits comprises
a multivibrator having an output terminal; and
an amplifier having an input terminal coupled to said output terminal.
9. The temperature setback controlling system as recited in claim 7 wherein
said detector means comprises
a first silicon controlled rectifier having an anode, a cathode, and a gate
electrode;
a second silicon controlled rectifier having an anode, a cathode, and a
gate electrode;
a first serially connected resistor and a first light emitting diode
serially coupled to said anode of said first silicon controlled rectifier;
a second serially connected resistor and a second light emitting diode
serially coupled to said anode of said second silicon controlled
rectifier;
a first capacitor coupled across said first anode and said first gate
electrode;
a second capacitor coupled across second anode and said second gate
electrode;
a third resistor coupled across said first cathode and said first gate
electrode;
a fourth resistor coupled across said second cathode and said second gate
electrode;
a first variable potentiometer having a first terminal, and having a second
terminal coupled to said first anode;
a second variable potentiometer having a first terminal, and having a
second terminal coupled to said second anode;
means for coupling said first terminal of said first potentiometer, and
said second cathode, to said first resistive heater;
means for coupling said first terminal of said second potentiometer, and
said first cathode, to said second resistive heater;
a pair of leads adapted to be coupled to said thermostat cable;
means for coupling said first resistor and said second cathode to a first
of said leads;
means for coupling said second resistor and said first cathode to a second
of said leads; and
a manual switch in circuit with one of said leads.
10. The temperature setback controlling system as recited in claim 6
wherein said detector means comprises
a first silicon controlled rectifier having an anode, a cathode, and a gate
electrode;
a second silicon controlled rectifier having an anode, a cathode, and a
gate electrode;
a first serially connected resistor and a first light emitting diode
serially coupled to said anode of said first silicon controlled rectifier;
a second serially connected resistor and a second light emitting diode
serially coupled to said anode of said second silicon controlled
rectifier;
a first capacitor coupled across said first anode and said first gate
electrode;
a second capacitor coupled across second anode and said second gate
electrode;
a third resistor coupled across said first cathode and said first gate
electrode;
a fourth resistor coupled across said second cathode and said second gate
electrode;
a first variable potentiometer having a first terminal, and having a second
terminal coupled to said first anode;
a second variable potentiometer having a first terminal, and having a
second terminal coupled to said second anode;
means for coupling said first terminal of said first potentiometer, and
said second cathode, to said first resistive heater;
means for coupling said first terminal of said second potentiometer, and
said first cathode, to said second resistive heater;
a pair of leads adapted to be coupled to said thermostat cable;
means for coupling said first resistor and said second cathode to a first
of said leads;
means for coupling said second resistor and said first cathode to a second
of said leads; and
a manual switch in circuit with one of said leads.
11. A temperature setback controlling system suitable for use in a building
wherein a thermostat having a room temperature sensing element is employed
on a wall in a first room to sense room temperature for control of a
heating system effective in said first room to maintain a thermostat
selected ambient room temperature in said first room, wherein another
thermostat having a room temperature sensing element is employed on a wall
in a second room to sense room temperature for control of said heating
system effective in said second room to maintain a thermostat selected
ambient room temperature in said second room, wherein heating controls for
said heating system including a transformer having a secondary winding for
providing low voltage, 60 Hz, power are located in a third room of said
building, and wherein thermostat cables coupling said thermostats to said
heating controls are located at least partially within interior walls of
said building, said temperature setback controlling system comprising
timed control means, adapted to be coupled to said transformer winding, for
modulating during selected time periods cycles of one polarity of said 60
Hz low voltage with a high frequency;
a first resistive heater, adapted to be placed in proximity to said first
room, room temperature sensing element;
a second resistive heater, adapted to be placed in proximity to said second
room, room temperature sensing element;
first detector means, adapted to be coupled to said thermostat cable in
said first room, for detecting said high frequency modulation during
cycles of said one polarity and coupled to said first resistive heater for
providing current flow thereto in response to such detected modulation,
whereby the ambient temperature in said first room tends to be maintained
at a predetermined temperature setback during said selected time periods;
and
second detector means, adapted to be coupled to said thermostat cable in
said second room, for detecting said high frequency modulation during
cycles of said one polarity and coupled to said second resistive heater
for providing current flow thereto in response to such detected
modulation, whereby the ambient temperature in said second room tends to
be maintained at a predetermined temperature setback during said selected
time periods.
12. The temperature setback controlling system as recited in claim 11
wherein said timed control means comprises
a switch;
an electrical timer coupled to said switch so that said switch is closed
during said selected time periods and is opened during non-selected time
periods;
an electronic oscillator circuit;
unilateral conducting means; and
means coupling said switch, said oscillator circuit, and said unilateral
conducting means in a serial circuit whereby said serial circuit is
adapted to be coupled to said transformer secondary winding.
13. The temperature setback controlling system as recited in claim 12
wherein said electronic oscillator circuit comprises
a multivibrator having an output terminal; and
an amplifier having an input terminal coupled to said output terminal.
14. The temperature setback controlling system as recited in claim 12
wherein one of said detector means comprises
a manual switch having a pair of terminals, one terminal of said manual
switch being adapted to be coupled to said thermostat cable, the other
terminal being coupled to a first junction point;
a silicon controlled rectifier having an anode, a cathode, and a gate
electrode, said cathode being adapted to be coupled to said thermostat
cable;
a serially connected resistor and a light emitting diode serially coupling
said first junction point to said anode, said diode being poled so that
its direction of conductivity is in the same direction as said rectifier;
a capacitor coupled across said anode and said gate electrode;
a second resistor coupled across said cathode and said gate electrode;
a variable potentiometer coupling a second junction point to said anode of
said silicon controlled rectifier; and
means for coupling said junction points to said resistive heater.
15. The temperature setback controlling system as recited in claim 11
wherein one of said detector means commprises
a manual switch having a pair of terminals, one terminal of said manual
switch being adapted to be coupled to said thermostat cable, the other
terminal being coupled to a first junction point;
a silicon controlled rectifier having an anode, a cathode, and a gate
electrode, said cathode being adapted to be coupled to said thermostat
cable;
a serially connected resistor and a light emitting diode serially coupling
said first junction point to said anode, said diode being poled so that
its direction of conductivity is in the same direction as said rectifier;
a capacitor coupled across said anode and said gate electrode;
a second resistor coupled across said cathode and said gate electrode;
a variable potentiometer coupling a second junction point to said anode of
said silicon controlled rectifier; and
means for coupling said junction points to said resistive heater.
16. A temperature setback controlling system suitable for use in a building
wherein a thermostat having a room temperature sensing element is employed
on a wall in a first room to sense room temperature for control of a
heating system effective in said first room to maintain a thermostat
selected ambient room temperature in said first room, wherein another
thermostat having a room temperature sensing element is employed on a wall
in a second room to sense room temperature for control of said heating
system effective in said second room to maintain a thermostat selected
ambient room temperature in said second room, wherein heating controls for
said heating system including a transformer having a secondary winding for
providing low voltage 60 Hz power are located in a third room of said
building, and wherein thermostat cables coupling said thermostats to said
heating controls are located at least partially within interior walls of
said building, said temperature setback controlling system comprising
timed control means, adapted to be coupled to said transformer winding, for
modulating during one set of selected time periods cycles of positive
polarity of said 60 Hz low voltage with a high frequency, and for
modulating during a second set of selected time periods cycles of negative
polarity of said 60 Hz low voltage with a high frequency;
a first resistive heater, adapted to be placed in proximity to said first
room, room temperature sensing element;
a second resistive heater, adapted to be placed in proximity to said second
room, room temperature sensing element;
first detector means, adapted to be coupled to said thermostat cable in
said first room, for detecting said high frequency modulation during
cycles of said positive polarity and coupled to said first resistive
heater for providing current flow thereto in response to such detected
modulation, whereby the ambient temperature in said first room tends to be
maintained at a predetermined temperature setback during said one set of
selected time periods; and
second detector means, adapted to be coupled to said thermostat cable in
said second room, for detecting said high frequency modulation during
cycles of said negative polarity and coupled to said second resistive
heater for providing current flow thereto in response to such detected
modulation, whereby the ambient temperature in said second room tends to
be maintained at a predetermined temperature setback during said second
set of selected time periods.
17. The temperature setback controlling system as recited in claim 16
wherein said timed control means comprises
a first switch;
a second switch;
electrical timing means coupled to said switches so that said first switch
is closed during said one set of selected time periods and is otherwise
normally opened, and so that said second switch is closed during said
second set of selected time periods and is otherwise normally opened;
a first electronic oscillator circuit;
first unilateral conducting means;
a second electronic oscillator circuit;
second unilateral conducting means;
means coupling said first switch, said first oscillator circuit, and said
first unilateral conducting means in a first serial circuit;
means coupling said second switch, and second oscillator circuit, and said
second unilateral conducting means in a second serial circuit; and
means for coupling said serial circuits in an opposing shunt relation
whereby the resulting shunt circuit is adapted to be coupled to said
transformer secondary winding.
18. The temperature setback controlling system as recited in claim 17
wherein at least one of said electronic oscillator circuits comprises
a multivibrator having an output terminal; and
an amplifier having an input terminal coupled to said output terminal.
19. In combination,
a resistive heater, adapted to be placed in proximity to a room temperature
sensing element of a thermostat employed in a wall of a room; and
detector means, adapted to be coupled to a thermostat cable which engages
with said thermostat, for detecting high frequency modulation during
cycles of one polarity on said cable, and coupled to said resistive heater
for providing current flow thereto in response to such detected
modulation;
whereby the ambient room temperature in said room tends to be maintained at
a predetermined temperature setback during time periods of such detected
modulation.
20. A method of temperature setback control suitable for use in a building
wherein a thermostat having a room temperature sensing element is employed
on a wall in a first room to sense room temperature for control of a
heating system effective in said first room to maintain a thermostat
selected ambient room temperature, wherein heating controls for said
system including a transformer having a secondary winding for providing
low voltage, 60 Hz, power are located in a second room of said building,
and wherein a thermostat cable coupling said thermostat in said first room
to said heating controls in said second room is located at least partially
within interior walls of said building, said method comprising
modulating cycles of one polarity of said low 60 Hz voltage with a high
frequency during selected time periods;
detecting, at said thermostat cable in said first room, said high frequency
modulation; and
applying heat to said room temperature sensing element in response to such
detected modulation.
21. A method of temperature setback control suitable for use in a building
wherein a thermostat having a room temperature sensing element is employed
on a wall in a first room to sense room temperature for control of a
heating system effective in said first room to maintain a thermostat
selected ambient room temperature in said first room, wherein another
thermostat having a room temperature sensing element is employed on a wall
in a second room to sense room temperature for control of said heating
system effective in said second room to maintain a thermostat selected
ambient room temperature in said second room, wherein heating controls for
said heating system including a transformer having a secondary winding for
providing low voltage 60 Hz power are located in a third room of said
building, and wherein thermostat cables coupling said thermostats to said
heating controls are located at least partially within interior walls of
said building, said method comprising
modulating cycles of positive polarity of said low 60 Hz voltage with a
high frequency during one set of selected time periods, and modulating
cycles of negative polarity of said low 60 Hz voltage with a high
frequency during a second set of selected time periods;
detecting, at said thermostat cable in said first room, said modulation
during cycles of said positive polarity;
applying heat to said first room, room temperature sensing element in
response to such detected modulation;
detecting, at said thermostat cable in said second room, said modulation
during cycles of said negative polarity; and
applying heat to said second room, room temperature sensing elements in
response to such detected modulation during cycles of said negative
polarity. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an automatic temperature setback system for
controlling a heating unit. Accordingly, the general objects of this
invention are to provide new and improved devices and methods of such
character.
2. Description of the Prior Art
In accordance with a preliminary novelty search performed on behalf of the
applicant, the following U.S. patents were deemed to be of possible
interest:
U.S. Pat. No.
Patentee Issue Date
______________________________________
2,632,086 Hagen March 17, 1953
2,642,228 Machlet June 16, 1953
2,842,345 Brown July 8, 1958
2,984,729 Hykes et al May 16, 1961
3,231,719 DeViney et al Jan. 25, 1966
3,240,916 Bray et al March 15, 1966
3,243,609 Kompelien March 29, 1966
3,283,179 Carlisle et al
Nov. 1, 1966
3,305,766 Gambill Feb. 21, 1967
3,326,275 Ray June 20, 1967
3,334,244 Hanchett Aug. 1, 1967
3,335,263 Jewell et al Aug. 8, 1967
3,341,769 Grant Sept. 12, 1967
3,356,784 Bertioli et al
March 5, 1967
3,371,191 Seney Feb. 27, 1968
3,401,880 Verden Sept. 17, 1968
3,419,214 Evalds Dec. 31, 1968
3,421,691 Forbes Jan. 14, 1969
3,544,766 Muskovac Dec. 1, 1970
3,584,988 Hirsbrunner et al
June 15, 1971
3,588,448 Ziver June 28, 1971
3,600,118 Hirsbrunner Aug. 17, 1971
3,670,960 Chambers June 20, 1972
3,749,884 Detmann et al July 31, 1973
3,767,936 Sweger Oct. 23, 1973
3,834,618 Buckwalter Sept. 10, 1974
______________________________________
The foregoing patents are cited to aid the Patent and Trademark Office in
the examination of this invention, such art being that known to the
applicant, and for the following reasons:
Hagen, U.S. Pat. No. 2,632,086, discloses an oscillator used in the control
of a heating element, such as an electric blanket.
Machlet, U.S. Pat. No. 2,642,228, discloses an apparatus which can respond
to heat and uses an oscillator and carrier wave control. The circuit
diagram of FIG. 4 of Machlet includes an oscillator-thermostatic element
which, via a transformer, is puggable into a conventional power line of a
home. A remote unit located near the burner, as also pluggable into the
power line, acts as a carrier wave amplifier and detector for closing
relay contacts for providing electrical power to the burner when the
oscillator-thermostatic element combination is operative. Machlet terms
such apparatus as a "wired radio" control of an oil burner.
Brown, U.S. Pat. No. 2,842,345, utilizes gas discharge tubes in a
controller to control the heating of a resistor.
Hykes et al., U.S. Pat. No. 2,984,729, discloses a multivibrator used in a
heating control for an oven.
DeViney et al., U.S. Pat. No. 3,231,719, discloses a multivibrator and a
controlled rectifier firing to control a heating resistor.
Bray et al., U.S. Pat. No. 3,240,916, and Sweger, U.S. Pat. No. 3,767,936,
show anticipator circuits with a silicon controlled rectifier (SCR)
controlling the heating of a load.
Gambill, U.S. Pat. No. 3,305,766, is included as of interest for the
plurality of SCRs, shown in his FIG. 6, utilized in a full wave voltage
control system for heating loads.
Jewell et al., U.S. Pat. No. 3,335,263, discloses temperature control
equipment with an astable multivibrator circuit which is used for
controlling the temperature of a furnace.
Grant, U.S. Pat. No. 3,341,769, discloses circuitry for use in temperature
sensitive systems including an oscillator with pulsing to an SCR and
modulating alternating current. By making one or more of the resistances
of a Wheatstone bridge, shown in Grant, temperature sensitive, as for
example in thermometric systems, the power delivered may be made
proportional to the temperature in the ambient environment to which the
temperature sensitive resistor is exposed.
Bertioli et al., U.S. Pat. No. 3,356,784, discloses temperature control
circuitry with circuitry including multivibrators to controlled
rectifiers.
Seney, U.S. Pat. No. 3,371,191, discloses heater control through modulation
and amplification to a thyratron tube.
Verden, U.S. Pat. No. 3,401,880, and Forbes, U.S. Pat. No. 3,421,691,
disclose a SCR which fires with current to a heat accumulator which
affects a thermostat.
Evalds, U.S. Pat. No. 3,419,214, shown SCR and bridge circuitry in
temperature regulating apparatus.
Muskovac, U.S. Pat. No. 3,544,766, discloses a firing circuit for
proportionally controlling energy to a load from an alternating source.
The circuit includes a thyristor in series connection with the load and
source, a gate circuit, and connection to the gate of the thyristor and
the source for generating an application of trigger pulses to the gate.
The gate circuit has a sensor branch which includes a conditioning
responsive impedance. The sensor branch controls the application of the
trigger pulses with respect to the conductive half cycles of the source in
response to the condition and initiates thyristor conductions in response
thereto. The sensor branch is cycled to provide timed proportional control
of the thyristor. In one embodiment of Muskavac, cycling means is included
within the sensor branch and impresses a cyclic voltage variation on the
impedance. In another of his embodiments, an auxiliary load produces the
condition aspired with the main load and is closely coupled to the
condition responsive impedance so as to cause a secondary firing cycle
imposed upon a primary cycle resulting from the impedance response to
average environmental conditions.
Chambers, U.S. Pat. No. 3,670,960, is of interest for its showing of
pulsing and use of SCRs in heating control.
Buckwalter, U.S. Pat. No. 3,834,618, discloses a separate unit thermostat
the regular heater control with a timer which allows heat from a heat
source to affect a thermostat under which it is placed to obtain a
temperature setback level for a predetermined time.
The remaining cited patents, set forth above, all show some circuit
similarities to applicant's disclosure and, therefore, are included as of
interest. However, such patents are considered not to be anticipatory, in
the slightest, whether considered by themselves or in any combination
thereof.
The most pertinent of the foregoing cited patents, with respect to the
instant invention, is the patent to Buckwalter, U.S. Pat. No. 3,834,618.
Applicant's device operates differently and has a different principle than
Buckwalter, though one of the goals of both Buckwalter and the applicant
are common, namely to conserve energy during the nighttime. The comments
made by Buckwalter in certain portions of his specification are pertinent
to applicant's invention, and hence several paragraphs following
hereinbelow which were applicable to Buckwalter are also applicable to
this instant invention:
Both inventions, in part, relate to apparatus for automatically setting
back the temperature of a room controlled by a conventional heating system
during selectable time periods.
As background of the invention, Buckwalter stated, and it is equally
applicable here, that:
"Conventionally one may manually set a thermostat back to a lower night
time temperature for comfort or fuel economy. This manual setback method
has a disadvantge in that the temperature in the morning is too cold for
comfort. Devices for automatically varying the temperature of a room
during night time hours have been widely employed and described in the art
and provide the comfort of a warm-up before arising. Typically, a timer is
employed to determine when a temperature setback condition is to become
effective. An early U.S. Pat. No. describing a timer in use with a
thermostat controlled heating system is the patent to Otis U.S. Pat. No.
1,207,618. A night and day time temperature regulating system is described
in the U.S. Pat. Nos. 1,876,636 and 1,931,464 to Dicke. The U.S. Pat. No.
1,876,636 described a heat source which simulates a change in temperature
of a room by applying heat to a thermostat. The heat source thus causes
the thermostat to register a higher room temperature than actually exists
and thus inhibits the heating system operative in the room from being
energized as long as the heat source is on. In response to this
simulation, the thermostat de-energizes the heating system operative in
the room to obtain, for example, a cooler night time room temperature with
a corresponding saving in fuel. The system described in the Dicke patents
requires substantial wiring to install with electrical connections to the
heating system to bring the clock operated temperature setback mechanism
into operation. Such structural changes may be convenient to install
during the building of a house but require extensive work to install with
existing heating systems.
"In the German patent publication Auslegeschrift No. 1,248,261 applied for
in 1964 and laid open for inspection Aug. 24, 1967, a glow lamp is
employed adjacent to a temperature sensor to simulate a higher temperature
when a timer enables electrical power to be applied to the glow lamp.
Energization of the glow lamp provides a high temperature simulation,
which causes closure of a heating fluid control valve connected in series
with a radiator. The timer controlled heating system described in the
German patent prevents any heat from reaching the radiator during the time
the timer energizes the glow lamp. Thus the room temperature slowly
descends to whichever external temperature may exist until the timer
disables the glow lamp to enable resumption temperature the heating
system.
"Other recent patents relating to temperature setback devices are in U.S.
Pat. No. 3,386,496 to O'Connor, and to Schuller U.S. Pat. No. 3,525,222.
In the Schuller patent a temperature regulator for an electric
refrigerator is described wherein a heat source simulates a requirement
for refrigeration in excess of what is actually necessary in order to
maintain the refrigerator temperature sufficiently below the dew point.
U.S. Pat. No. 3,251,549 to Hewitt, Jr. et al., relates to an illuminated
thermostat for use with a domestic heat control system.
"A significant disadvantage and inconvenience of temperature setback
devices described in these various patents involves the extensive
structural changes needed to install a temperature setback device in
existing domestic heating systems. The installation commonly requires the
addition of wires which are routed inside walls and floors to connect to
furnace controls. These modifications tend to increase the cost of a night
time temperature setback device with an expensive charge for installation.
As a result, the extensive use of temperature setback devices has been
less attractive to the home owner. Yet a widespread use of night time
temperature setback devices would be of significant advantage in any age
where energy conservation is beneficial to the public and is a publicly
recognized and supported policy."
In essence, Buckwalter, U.S. Pat. No. 3,834,618, utilizes a temperature
setback control including a housing which may be utilized with existing
heating systems by mounting the housing with this control within an
airflow influencing distance from a conventional room thermostat which
controls the heating system. The Buckwalter housing produces a convection
flow of heated air during a setback time period to obtain a temperature
setback level in the room heating zone or building in which the thermostat
is located. A temperature sensor (actually another thermostat) regulates
the operation of the control to maintain the room at the setback
temperature level determined by the value set on the separate thermostat.
A housing to enable the influencing of the thermostat with the convection
flow of heated air is described by Buckwalter.
SUMMARY OF THE INVENTION
In a temperature setback control in accordance with the invention,
automatic temperature setback is provided in a convenient manner with
existing heating systems without requiring any wire modifications or
domestic structural changes.
A temperature setback controlled module in accordance with the invention is
mounted adjacent a conventional heating system thermostat, such as
employed in homes, apartments, offices, public accommodations, and the
like. The module is controlled via existing thermostat wiring from the
heating system by a modulated controlled signal on a low voltage 60 cycle
carrier. Two connections are made to existing thermostat heat connections
and a supplemental heater is positioned adjacent the bi-metallic element
inside the thermostat.
It is an object of this invention to provide novel methods and apparatus
for saving on heating system operating costs by automatically setting back
the temperature set points on an existing thermostat or thermostats in a
given heating system, whereby a saving in energy or fuel can by realized
by reducing the operating temperature during a heating season.
Another object of this invention is to provide novel means and methods for
automatically, consistently and accurately and conveniently setting back
an existing thermostat.
Still another object of this invention is to provide new and improved means
and methods for performing such setback without the need for the unsightly
addition of wires to an existing thermostat.
Yet another object of this invention is to provide a new and improved
temperature setback system which requires only one timer control unit for
a heating system.
In accordance with one embodiment of this invention, a temperature setback
controlling system is suitable for use in a building wherein a thermostat
having a room temperature sensing element is employed on a wall in a first
room to sense room temperature for control of a heating system effective
in the first room to maintain a thermostat selected ambient room
temperature, wherein heating controls for the heating system including a
transformer having a secondary winding for providing low voltage 60 Hz
power are located in a second room of the building, and wherein a
thermostat cable coupling the thermostat in the first room to the heating
controls in the second room is located at least partially within interior
walls of the building. The temperature setback controlling system includes
timed control means which are adapted to be coupled to the transformer
winding for modulating during selected time periods cycles of one polarity
of the 60 Hz low voltage with a high frequency. Detector means, adapted to
be coupled to the thermostat cable in the first room for detecting the
high frequency modulation during cycles of the one polarity, are coupled
to a resistive heater for providing current flow thereto in response to
such detected modulation. The resistive heater is adapted to be placed in
proximity to the room temperature sensing element of the thermostat. Thus,
the ambient temperature in the first room tends to be maintained at a
predetermined temperature setback during the selected time periods. In
accordance with certain features of the invention, the timed control means
includes an electrical timer coupled to a switch so that the switch is
closed during selected time periods and is opened during non-selected time
periods. The timed control means further includes the switch, an
electronic oscillator circuit, and a unilateral conducting means coupled
together in a serial circuit, which serial circuit is adapted to be
coupled to the transformer secondary winding. In accordance with still
other features of the invention, the electronic oscillator circuit
includes an amplifier having its input terminal coupled to the output
terminal of a multivibrator. In accordance with yet other features of the
invention, the detector means includes a manual switch having one terminal
being adapted to be coupled to the thermostat cable, and another terminal
being coupled to a first junction point. A silicon controlled rectifier
(SCR) has its cathode adapted to be coupled to the thermostat cable. The
first junction point, a resistor and a light emitting diode are serially
coupled to the anode of the SCR. The diode is so oriented that its
direction of conductivity is in the same direction as the rectifier. A
capacitor is coupled across the anode and the gate electrode of the SCR. A
second resistor is coupled across the cathode and the gate electrode of
the SCR. Further, a variable potentiometer couples a second junction point
to the anode of the SCR and means are provided for coupling the junction
points to the resistive heater.
In accordance with still another embodiment of the invention, a temperature
setback controlling system is suitable for use in building wherein a
thermostat having a room temperature sensing element is employed on a wall
in a first room to sense room temperature for control of a heating system
effective in the first room to maintain a thermostat selected ambient room
temperature, wherein heating controls for the heating system including a
transformer having a secondary winding for providing low voltage 60 Hz
power are located in a second room of the building, and wherein a
thermostat cable coupling the thermostat in the first room to the heating
controls in the second room is located at least partially within interior
walls of the building. The temperature setback controlling system includes
timed control means which are adapted to be coupled to the transformer
winding. Such time control means modulates during one set of elected time
periods cycles of positive polarity of the 60 Hz low voltage with a high
frequency and modulates during a second set of selected timed periods
cycles of negative polarity of the 60 cycle low voltage with a high
frequency. Two resistive heaters are adapted to be placed in proximity to
the room temperature sensing element. Detector means, adapted to be
coupled to the thermostat cable in the first room for detecting high
frequency modulations, are coupled to the resistive heaters for providing
current flow to one heater in response to detected modulating during
cycles of positive polarity and for providing current flow to the other
heater in response to detected modulation during cycles of negative
polarity. Thus, the ambient temperature in the first room tends to be
maintained at a | | |
