U.S. patent number RE35,220 [Application Number 08/088,758] was granted by the patent office on 1996-04-30 for two terminal controller.
This patent grant is currently assigned to Beacon Light Products, Inc.. Invention is credited to Samuel A. Johnson.
United States Patent |
RE35,220 |
Johnson |
April 30, 1996 |
Two terminal controller
Abstract
A two-terminal, alternating current power control device
connected in an electrical path between a load and a remote switch,
comprising a current switching device, a controlling device and a
direct current power supply device. The current switching device
provides a low impedance electrical path in response to the
application of triggering signals thereto, and provides a high
impedance electrical path in the absence of the triggering signals.
A control circuit is provided for applying triggering signals to
the current switching device as the proper time in the AC cycle,
and is responsive to a momentary interruption in the applied AC
voltage so as to effect change in the power intensity or timed
duration of power delivered to the load. A remote switch in the
electrical path can be the source of a momentary power
interruption. The entire power control device can be constructed to
directly attach to the electrical screw shell base of a gas
discharge lamp, so the lamp and power control device can be mounted
into the normal accommodating electrical fixture without the need
for an intermediary fixture or additional electrical wiring.
Inventors: |
Johnson; Samuel A. (Eagel,
ID) |
Assignee: |
Beacon Light Products, Inc.
(Meridian, ID)
|
Family
ID: |
46248810 |
Appl.
No.: |
08/088,758 |
Filed: |
July 8, 1993 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
198282 |
May 25, 1988 |
|
|
|
Reissue of: |
345214 |
Apr 28, 1989 |
05030890 |
Jul 9, 1991 |
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Current U.S.
Class: |
315/208; 315/297;
323/325; 323/238 |
Current CPC
Class: |
H02M
5/2576 (20130101); H02M 5/2573 (20130101); H05B
39/02 (20130101); H05B 47/16 (20200101); H05B
39/04 (20130101); H05B 39/08 (20130101); H05B
47/185 (20200101); Y02B 20/42 (20130101); Y02B
20/40 (20130101) |
Current International
Class: |
H05B
37/02 (20060101); H05B 39/00 (20060101); H05B
39/04 (20060101); H02M 5/02 (20060101); H05B
39/08 (20060101); H02M 5/257 (20060101); H05B
39/02 (20060101); H04B 041/14 () |
Field of
Search: |
;315/208,360,362,293,297,DIG.5,DIG.7,307,2R
;323/321,322,324,325,238,239,241 ;307/141 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Neyzari; Ali
Attorney, Agent or Firm: Ley; John R.
Parent Case Text
.Iadd.This application is a reissue of Ser. No. 07/845,214, filed
Apr. 28, 1989, now U.S. Pat. No. 5,030,890, which is a
continuation-in-part of Ser. No. 07/198,282, filed May 25, 1988,
now abandoned. .Iaddend.
Claims
I claim:
1. A two-terminal power control device normally in an off condition
until activated by switch means .Iadd.to conduct power from an AC
power source to a power load, .Iaddend.said device comprising:
a. input and output terminals .[.adjacent an.]. .Iadd.adapted to be
connected to the .Iaddend.AC power source and .[.a.]. .Iadd.the
.Iaddend.power load, respectively;
b. .[.A.]. .Iadd.a .Iaddend.bi-directional dual silicon controlled
rectifier responsive to low voltage current pulses, said rectifier
in series with and between the input and output terminals;
c. micro-processor control circuit means in series with and
providing triggering signals to the rectifier, and responsive to
momentary power interruptions in the form of operator-controlled
.[.activation.]. .Iadd.activations .Iaddend.of the switch
means;
d. DC power supply means connected across the rectifier to provide
power to the control circuit means when the rectifier is in a state
of high or low impedance .[.and.]. in .[.absence.]. .Iadd.the
presence .Iaddend.of AC potential across the rectifier;
e. memory data retention means coupled to control circuit means to
retain .[.recently.]. stored data during periods of power removal
from said AC power source,
f. .Iadd.the .Iaddend.input and output terminals on opposed upper
and lower surfaces of a package, said package having dimensions
.[.such that it is.]. .Iadd.to allow it to be .Iaddend.retained
between an Edison-style lamp screw shell housing and an
incandescent bulb inserted therein, and
g. said power control device being provided with a timer responsive
to momentary power interruptions.
2. The device as recited in claim 1, wherein the load comprises an
incandescent bulb activated by the switch means.
3. The device as recited in claim 1, wherein the microprocessor
control circuit means delays the activation of the rectifier until
after a zero crossing of an AC waveform impressed across the input
and output terminals.
4. The device as recited in claim 1, wherein the microprocessor
.Iadd.control circuit means is .Iaddend.programmed to provide a
predetermined level of power to the load depending upon the number
of on-off .[.cycles.]. .Iadd.activations .Iaddend.of the switch
means.
5. A method of providing .Iadd.power from an AC power source to
.Iaddend.an electrical load .[.responsive.]. .Iadd.in response
.Iaddend.to momentary power interruptions .Iadd.resulting from
activations of switch means connected to the AC power source,
.Iaddend.comprising the steps of:
a. programming a micro-processor .[.controlled.]. .Iadd.control
.Iaddend.circuit means to be responsive to momentary power
interruptions initiated by an operator and .Iadd.applied to the
micro-processor control circuit means at an input terminal and an
output terminal to which the microprocessor control circuit means
is connected; .Iaddend.
a. connecting a bi-directional dual silicon controlled rectifier in
series with and between .[.a pair of.]. .Iadd..Iaddend.input and
output terminals and interconnecting the input and output terminals
in series with .[.an.]. .Iadd.the .Iaddend.AC power source and the
electrical load .Iadd.and connecting the micro-processor control
circuit means for controlling the conduction of the rectifier;
.Iaddend.
c. interrupting the AC power .[.supply.]. .Iadd.source .Iaddend.to
the microprocessor .Iadd.control circuit means .Iaddend.such that
responsive thereto the micro-processor .[.provides.]. .Iadd.control
circuit means controls the delivery of .Iaddend.power to the
.[.a.]. .Iadd.the .Iaddend.load in a predetermined manner,
d. packaging said micro-processor control circuit means, said
rectifier and said input and output terminals in a .[.and.].
.Iadd.adapted for .Iaddend.inserting said package between an
Edison-style lamp screw shell housing and an incandescent bulb
inserted therein, and
e. providing a timer in said package .Iadd.connected to the
micro-processor control circuit means which is .Iaddend.responsive
to momentary power interruptions.
6. The method as recited in claim 5, further comprising
interrupting the AC power source .[.supply.]. .Iadd.source
.Iaddend.in order to .Iadd.cause the micro-processor control
circuit means to control the rectifier to .Iaddend.provide a
predetermined level of power to the load depending upon the number
of on-off activations .[.cycles.]. .Iadd.activations .Iaddend.of
the switch means.
7. The method as recited in claim 5, further comprising
interrupting the AC power .[.supply.]. .Iadd.source .Iaddend.in
order to .Iadd.cause the micro-processor control circuit means to
control the rectifier to .Iaddend.provide power to the load a
predetermined period of time after said .Iadd.last
.Iaddend.interruption.
8. A method for controlling .Iadd.one of .Iaddend.either the
conduction time, duty cycle or .[.of.]. .Iadd.or
.Iaddend.illumination intensity of a lamp which comprises the steps
of:
a. providing in memory certain data values corresponding to the
timing or sequence at which power interruptions to said memory may
occur,
b. creating timed or sequenced power interruptions to said memory
and thereby
c. selecting a particular data value for storage in said memory
which is operable to control either said conduction time, said duty
cycle or said illumination intensity of said lamp, and
d. controlling said conduction time, duty cycle, or illumination
intensity of said lamp by connecting an AC triggerable switch to
said lamp and controlling its conductive state by the application
thereto of .Iadd.a signal corresponding to .Iaddend.said particular
data value selected for storage in said memory.
9. Circuitry for controlling the current level, duty cycle and
conduction time for current supplied to a selected load including,
in combination:
a. an AC controlled switch connected to a load,
b. data storage and conversion means connected to a gate or control
electrode of said AC controlled switch and responsive to manually
controlled power interruptions which are made at a predetermined
time and sequence with respect to the present current level, duty
cycle or current conduction time at said load for in turn changing
said current level, duty cycle or conduction time to another and
different current level, duty cycle or conduction time, and
c. said AC controlled switch is a Triac which is connectable
between one side of said load and one side of an AC supply voltage,
said AC supply voltage being further connected through a manually
operated and controlled switch to another side of said load, and
said data storage and conversion means including a micro-processor
connected to a DC voltage supply and further connected across input
and output terminals of said Triac and to a gate or control
electrode thereof, said micro-processor being operative to store
new data values therein in response to the manual switching action
of said manually operated switch in a controlled sequence to
thereby change the phase angle and conduction time of said
semiconductor Triac and thereby in turn control and change the
level of current, the duty cycle, or the conduction time of current
conducted through said load. .Iadd.10. A method as defined in claim
8 further comprising steps of:
correlating the durations and seguences of the power interruptions
with preprogrammed information within the memory to select said
data value, and
using the selected data value to modify the conductive state of the
switch to control the conduction time, duty cycle, or illumination
intensity of said lamp. .Iaddend. .Iadd.11. A method as defined in
claim 10 further comprising the steps of:
g. supplying a termination control signal to terminate the
conduction of power through the switch in response one power
interruption of a predetermined maximum duration, and
h. supplying a conduction control signal to initiate the conduction
of power through the switch in response an application of power
across the switch and the connected lamp after a power interruption
of greater than
the predetermined maximum duration. .Iaddend. .Iadd.12. A method as
defined in claim 11 further comprising the steps of:
i. modifying the conduction control signal to modify the conductive
state of the switch in response to a predetermined number of
relatively shorter power interruptions which correlate to a data
value corresponding to a modified conduction control signal,
and
j. restricting each of the relatively shorter power interruptions
to a predetermined duration less than the predetermined maximum
duration and greater than any power interruption occurring during a
zero crossing of an AC power wave form applied across the
connection of said switch and said lamp. .Iaddend. .Iadd.13. A
method as defined in claim 12 further comprising the step of:
k. modifying the conduction control signal in response to a
sequence of a plurality of relatively shorter power interruptions
which defines a pattern. .Iaddend. .Iadd.14. A method as defined in
claim 13 further comprising the step of:
l. supplying a plurality of different conduction control signals
in
response to a plurality of of different patterns. .Iaddend.
.Iadd.15. A method as defined in claim 12 further comprising the
step of:
k. maintaining the preprogrammed information in the memory during
power interruptions at least as long as the predetermined maximum
duration. .Iaddend. .Iadd.16. A method as defined in claim 15
further comprising the step of:
l. energizing the memory with power derived from an AC power source
from which said switch conducts power to said lamp. .Iaddend.
.Iadd.17. A two-terminal power control device normally activated by
switch means to conduct power from an AC power source to a load,
comprising:
input and output terminals adapted to be connected to the AC power
source and the load, respectively;
a controllable conductivity device responsive to control signals
and connected in series with and between the input and output
terminals, the controllable conductivity device varying the
impedance thereof and the conduction of power therethrough in
response to the control signals;
a controller connected in series with and operative for supplying
control signals to the switch in response to momentary power
interruptions resulting from activations of the switch means;
a DC power supply connected across the conductivity device to
provide power to the controller when the conductivity device is in
a state of high or low impedance in the presence of AC potential
across the switch;
a logic circuit memory of the controller to retain preprogrammed
data during periods of power termination from the AC power source
and the DC power supply,
a package having the input and output terminals connected thereto
on opposed ends of the package, the package having dimensions to
allow it to be retained between an Edison-style lamp screw shell
housing and an incandescent bulb inserted therein, and
a timer of the controller responsive to momentary power
interruptions,
the controller correlating the momentary power interruptions to
the
preprogrammed data to derive the control signals. .Iaddend.
.Iadd.18. A device as defined in claim 17, wherein the load
comprises an incandescent bulb energized from the AC power source
by conduction of the controllable conductivity device. .Iaddend.
.Iadd.19. A device as defined in claim 17, wherein the controller
delays the application of the control signal to initiate conduction
of the conductivity device until a predetermined time after a zero
crossing of an AC waveform impressed across the input and
output terminals. .Iaddend. .Iadd.20. A device as defined in claim
17, wherein the controller supplies different control signals to
achieve different levels of conductivity of the controllable
conductivity device to apply corresponding different predetermined
levels of power to the load depending upon the number of
activations of the switch means which create the power
interruptions. .Iaddend. .Iadd.21. A method of controllably
delivering power from an AC power source to an electrical load in
response to momentary power interruptions resulting from
activations of switch means connected to the AC power source,
comprising the steps of:
connecting a controllable conductivity device in series with and
between an input terminal and an output terminal;
interconnecting the input and output terminals in series with the
AC power source and the load;
controlling conduction of the controllable conductivity device to
control the power applied from the AC power source to the load;
connecting a controller between the input and output terminals;
preprogramming instructions in a data retention element. of the
controller to recognize and respond to predetermined momentary
power interruptions at the input and output terminals;
connecting to the controller a timer which is responsive to the
predetermined momentary power interruptions;
activating the switch means to create predetermined power
interruptions at the input and output terminals;
correlating the predetermined power interruptions created by
activating the switch means with the preprogrammed
instructions;
controlling the conduction of the controllable conductivity device
in a predetermined manner related to the correlation between the
predetermined momentary power interruptions and the preprogrammed
instructions to control the delivery of power to the load in a
predetermined manner; and
packaging the controllable conductivity device, the controller
including the data retention element and the timer, and the input
and output
terminals in a package. .Iaddend. .Iadd.22. A method as defined in
claim 21, further comprising the step of:
sizing the package for insertion between an Edison-style lamp screw
shell housing and an incandescent bulb inserted therein. .Iaddend.
.Iadd.23. A method as defined in claim 21, further comprising the
step of:
interrupting the AC power source by a predetermined number of
on-off activations of the switch means to cause the controller to
control the conductivity device to conduct a predetermined level of
power to the load depending upon the number of on-off activations
of the switch means.
.Iaddend. .Iadd.24. A method as defined in claim 21, further
comprising the step of:
interrupting the AC power source by a predetermined characteristic
of on-off activations of the switch means to cause the controller
to control the conductivity device to conduct power to the load a
predetermined period of time after the last interruption. .Iaddend.
.Iadd.25. A method for controlling either the conduction time, duty
cycle or illumination intensity of a load, comprising the steps
of:
selectively creating a plurality of different predetermined timed
or sequenced power interruptions which relate to controlling one of
either the conduction time, duty cycle or illumination intensity of
a load;
preprogramming in a data retention logic element a plurality of
predetermined data values each of which relates to a different one
of the predetermined power interruptions;
applying the predetermined power interruptions to the data
retention element;
comparing the predetermined power interruptions applied to the data
retention element with the data values programmed in the data
retention element;
selecting from the comparison a particular data value to control
said load; and
controlling said load by connecting a controllable conductivity
device to said load and by controlling a conductive state of the
conductivity device by applying to the conductivity device a
control signal corresponding to
the particular data value selected. .Iaddend. .Iadd.26. A method as
defined in claim 25 further comprising the steps of:
correlating the durations and sequences of the power interruptions
with preprogrammed data values within the data retention logic
element to select the particular data value; and
modifying the conductive state of the conductivity device by
selecting a new particular data value after a previous particular
data value has been selected. .Iaddend. .Iadd.27. A method for
controlling one of either the conduction time, duty cycle or
illumination intensity of a load, comprising the steps of:
preprogramming in a data retention logic element certain data
values corresponding to the timing or sequence at which power
interruptions to the data retention element may occur;
creating predetermined timed or sequenced power interruptions to
the data retention element;
correlating the predetermined power interruptions created with the
data values and thereby
selecting a particular data value to control one of either said
conduction time, said duty cycle or said illumination intensity of
said load;
controlling the one of said conduction time, duty cycle, or
illumination intensity of said load by connecting a controllable
conductivity device to said load and by controlling a conductive
state of the conductivity device by applying to the conductivity
device a control signal corresponding to the particular data value
selected; p1 terminating the conductive state of the conductivity
device in response to one power interruption of a predetermined
maximum duration; and
initiating the conductive state of the conductivity device in
response an application of power across the conductivity device and
the connected load after a power interruption of greater than the
predetermined maximum
duration. .Iaddend. .Iadd.28. A method as defined in claim 27
further comprising the steps of:
modifying the conductive state of the conductivity device in
response to a predetermined sequence of relatively shorter power
interruptions which define a pattern; and
restricting each of the relatively shorter power interruption to a
predetermined duration less than the predetermined maximum duration
and greater than any power interruption occurring during a zero
crossing of an AC power wave form applied across the input and
output terminals.
.Iaddend. .Iadd.29. A method as defined in claim 28 further
comprising the step of:
modifying the conductive state of the conductivity device in
response to a different pattern of relatively shorter power
interruptions after the creation of a previous pattern. .Iaddend.
.Iadd.30. A method as defined in claim 29 further comprising the
step of:
changing the conductive state of the conductivity device in
response to each of a plurality of different patterns of relatively
shorter power interruptions. .Iaddend. .Iadd.31. A method as
defined in claim 28 further comprising the step of:
maintaining the preprogrammed data values in the data retention
element during power interruptions at least as long as the
predetermined maximum duration. .Iaddend. .Iadd.32. A method as
defined in claim 31 further comprising the step of:
energizing the data retention element with power derived from an AC
power source from which the conductivity device conducts power to
said load.
.Iaddend. .Iadd.33. Circuitry for controlling the current level,
duty cycle and conduction time of current supplied from a power
source to a load comprising, in combination:
a controllable conductivity device adapted to connected in a series
combination of the load, the power source, and a power switch to
conduct current from the power source to the load when the power
switch is closed and the controllable conductivity device is
conductive, the controllable conductivity device having a control
terminal upon which to apply a control signal for controlling the
conductivity of the controllable conductivity device; and
a controller connected to the controllable conductivity device and
responsive to a predetermined pattern of power interruptions of
predetermined time and sequence created by manual activations of
the power switch, the controller supplying a control signal to the
control terminal for controlling the conductivity of the
controllable conductivity device to establish the current level,
duty cycle or conduction time in relation to the predetermined
pattern of power interruptions;
the controller including a data storage logic element, a processing
logic element, and a DC power supply to which the data storage and
processing logic elements are connected, the processing element
connected to the control terminal of the controllable conductivity
device, the data storage element operatively retaining data values
therein and storing information therein in response to the manual
activations of the power switch which create the pattern of power
interruptions, the processing element operatively supplying a
control signal to the control terminal of the controllable
conductivity device to thereby change the conductivity of the
controllable conductivity device to control and change the level of
current, the duty cycle, or the conduction time of current
conducted through the load, the processing element deriving the
control signal by correlating the predetermined pattern of power
interruptions with the data values stored in the data retention
element. .Iaddend. .Iadd.34. A power control device for selectively
controlling the application of electrical power to a load from an
AC power source in response to power interruptions of predetermined
durations from the power source, comprising:
two power terminals to connect said power control device in series
with the AC power source and at which power interruptions
occur;
a controllable conductivity device connected between the two power
terminals to selectively conduct power from the AC power source
between the two terminals during the application of power from the
AC power source, the controllable conductivity device including a
control terminal to which to apply a control signal, the control
signal varying the conduction of the controllable conductivity
device in relation to the control signal and the electrical power
from the AC power source; and
a controller connected to the two power terminals and to the
control terminal of the controllable conductivity device, the
controller including logic elements which are operative to
recognize a predetermined pattern of power interruptions of
predetermined durations and sequences from the AC power source and
to correlate the recognized pattern of power interruptions with
preprogrammed information of the logic elements, the controller
employing the correlated preprogrammed information to supply
control signals to the control terminal of the controllable
conductivity device;
the controller supplying a termination control signal to terminate
the conduction of power through the controllable conductivity
device in response a power interruption of a predetermined maximum
duration;
the controller supplying a conduction control signal to initiate
the conduction of power through the controllable conductivity
device between the power terminals in response an application of
power to the power terminals after a power interruption of greater
than the predetermined maximum duration; and
the controller modifying the conduction control signal to modify
the amount of power conducted through the controllable conductivity
device in response a predetermined pattern of a number of
relatively shorter power interruptions, each relatively shorter
power interruption having a predetermined duration less than the
predetermined maximum duration and greater than any power
interruption resulting from the zero crossing the
AC power source. .Iaddend. .Iadd.35. A power control device as
defined in claim 34 wherein:
the predetermined pattern of the predetermined number of relatively
shorter power interruptions to which the controller responds to
modify the conduction control signal is a plurality of relatively
shorter power interruptions. .Iaddend. .Iadd.36. A power control
device as defined in claim 35 wherein:
the predetermined pattern of the plurality of relatively shorter
power interruptions modify the conduction control signal to
selectively vary the intensity of power supplied by the
controllable conductivity device to the load. .Iaddend. .Iadd.37. A
power control device as defined in claim 35 wherein:
the predetermined pattern of the plurality of relatively shorter
power interruptions modify the conduction control signal to
selectively vary the time during which the conduction control
signal is applied to the controllable conductivity device to vary
the application of power to the load in a corresponding manner.
.Iaddend. .Iadd.38. A power control device as defined in claim 35
wherein:
he predetermined pattern of the plurality of relatively shorter
power interruptions modify the conduction control signal to
selectively vary the time at which the conduction control signal is
applied to the controllable conductivity device to apply power to
the load in a corresponding manner. .Iaddend. .Iadd.39. A power
control device as defined in claim 35 wherein:
the predetermined pattern of the plurality of relatively shorter
power interruptions modify the conduction control signal to
selectively vary the intensity of power supplied by the
controllable conductivity device to the load and the time during
which the conduction control signal is applied to the controllable
conductivity device. .Iaddend. .Iadd.40. A power control device as
defined in claim 35 wherein:
the logic elements of the controller are further operative to
recognize the predetermined pattern of the plurality of relatively
shorter power interruptions after a power interruption of greater
than the predetermined maximum duration. .Iaddend. .Iadd.41. A
power control device as defined in claim 40 wherein:
the logic elements of the controller are further operative to
recognize a plurality of different predetermined patterns of the
relatively shorter power interruptions and are further operative to
modify the conduction signal in a different manner in relation to
each different pattern. .Iaddend. .Iadd.42. A power control device
as defined in claim 41 wherein:
the logic elements of the controller are digital logic elements.
.Iaddend. .Iadd.43. A power control device as defined in claim 34
wherein:
the logic elements of the controller are further operative to
recognize zero crossings of the AC power at the power terminals and
are operative in response to the zero crossings recognized to
modify the conduction control
signal in response and relative to a zero crossing. .Iaddend.
.Iadd.44. A power control device as defined in claim 34
wherein:
the controller further comprises a DC power supply connected to the
power terminals and operative to derive DC power from the AC power
present between the terminals;
the controller further operative to modify the conduction control
signal to develop a potential between the power terminals for use
by the DC power supply. .Iaddend. .Iadd.45. A power control device
as defined in claim 44 wherein:
the logic elements of the controller are energized by DC power
supplied from the DC power supply; and
the DC power supply further includes a DC power storage element for
retaining DC power during the relatively shorter power
interruptions and during zero crossings of the AC wave form at the
power terminals. .Iaddend. .Iadd.46. A power control device as
defined in claim 45 wherein:
the logic elements of the controller are further operative to
recognize zero crossings of the AC power at the power terminals and
are operative in response to the zero crossings recognized to
modify the conduction control
signal in response and relative to a zero crossing. .Iaddend.
.Iadd.47. A power control device as defined in claim 46
wherein:
the controller and the power switch are formed on a single
integrated circuit. .Iaddend. .Iadd.48. A power control device as
defined in claim 47 wherein:
the single integrated circuit and the power terminals are combined
in a package in which the power terminals are on opposite ends of
the package. .Iaddend. .Iadd.49. A power control device as defined
in claim 48 wherein:
the package is of a size to be received between the screw housing
of an incandescent bulb and a receptacle into which the screw
housing is inserted. .Iaddend. .Iadd.50. A power control device as
defined in claim 47 wherein:
the controller comprises digital circuit elements. .Iaddend.
.Iadd.51. A power control device as defined in claim 50
wherein:
the controller comprises one of a micro-processor or a
micro-controller. .Iaddend. .Iadd.52. A power control device as
defined in claim 47 wherein:
the load is a lighting device. .Iaddend. .Iadd.53. A power control
device as defined in claim 52 wherein:
the lighting device is one of a gas filled discharge bulb or a
incandescent bulb. .Iaddend. .Iadd.54. A power control device as
defined in claim 47 wherein:
the load is one of a heating load or a motor load. .Iaddend.
.Iadd.55. A power control device as defined in claim 34
wherein:
the controllable conductivity device is a controllable switch.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to AC power control devices, and more
particularly, to two terminal incandescent lamp controllers.
The single pole, single throw (SPST) fast acting electrical
lighting switch has been the primary device for the control of
alternating current to Edison and fluorescent lighting fixtures for
over a century. It is simple in operating concept, and has evolved
into a highly reliable and inexpensive means of lighting control.
It's obvious limitation is the purely binary nature of it's control
of current. It is either fully on or fully off, except during those
initial microseconds prior to closure or following opening.
Depending on the inductive or capacitive nature of the applied
load, arcing and mechanical damage to the current carrying contacts
may occur, thus reducing the long term reliability of the switch.
Additionally, as most electrical loads exhibit initially lower
impedances when first turned on, the initial in-rush currents to
both the switch and the electrical load can be many times higher
than the steady state, normal operating currents. This current
in-rush phenomena is damaging safety limits of the wiring network
and the protective circuit breakers or fuses. Thus, these elements
must be greatly over-designed to survive the initial current
in-rush conditions.
The past two decades have seen the development of solid state
dimmers and mechanical and electronic timer switches intended to
directly replace the SPST lighting control switch for commercial
and residential control of the Edison gas discharge lamps. Such
devices tend to be larger in size than the SPST lighting switch
they are intended to replace, and require the homeowner to perform
a lengthy procedure to disconnect the power to the effected
lighting circuit, remove the previous switch, and install the new
device. To many homeowners possessing a healthy fear of
electricity, this installation procedure appears dangerous, and
thus they would not purchase or install such a device. The primary
failure mode of such devices is during the initial turn-on phase,
when the in-rush currents of gas discharge lamps can be 16 to 20
times that of the steady state current. As a result, such devices
must have very heavy duty current switching elements to withstand
this initial electrical stress, which adds significantly to the
cost and complexity of the controlling device.
Still other devices exist which act as intermediary fixtures
between the incandescent bulb to be controlled and the original
receiving fixtures. These devices are usually used to turn on the
lamp at the advent of nightfall, or upon sensation of sound or
motion. Such devices, while very useful, can only be used in a
limited number of fixtures since they add considerable length to
the overall bulb to fixture dimensions. Such devices also tend to
be unreliable due to the large current in-rushes through the power
switching device at initial turn-on.
SUMMARY OF THE INVENTION
The general object of this invention is to provide a new and
improved AC power control device which does not require a lengthy
installation procedure, which can be fitted onto any standard
incandescent bulb, and which does not require the above-mentioned
oversized current switching devices with their attendant costs and
circuit complexities.
Another object of the present invention to provide a solid state
power control device which when connected in an electrical path
between an alternating current voltage source and a load element,
will be responsive to a remotely induced momentary power
interruption, so as to cause a change in the intensity or duration
of power delivered to the load.
A further object of this invention is to increase the useful life
of electric gas filled discharge lamps by slowly applying power to
a load at initial voltage application by closure of a remotely
located mechanical or solid state switch.
A feature of this invention is the capability of being so
constructed to directly attach to the electrical screw shell of a
gas discharge lamp, whereby so little space is consumed by the
device that the lamp can be safely mounted in it's receiving
fixture. This feature permits the use of existing switches,
fixtures, and wiring by the user to achieve a variety of lighting
conditions simply by installing this device.
The above objects, features and attendant advantages of this
invention may be accomplished by the provision of a current
switching means being connected in an electrical path between a
load and an AC voltage source. The application of AC voltage is
controlled by a remote switch. A control circuit means is connected
to the triggering port of the current switching means so as to
cause the current switching means to change from a high impedance
state to a low impedance state, thus turning on the electrical
load. This control circuit means can also be responsive to a
momentary power interruption caused by opening, then closing, the
remote switch. This even can cause the control circuit means to
substantially modify the power delivered to the load, either by a
change in the intensity or the timed duration of the power
delivered to the load.
By using miniaturized assembly and packaging techniques, such a
power control device can be fitted between the existing center
terminals of an incandescent bulb base and the mating terminals of
the screw shell receptacle, without significantly reducing the
number of engaging threads needed to safely mechanically retain the
bulb in it's retaining fixture.
These and other objects and features of this invention will become
more readily apparent from the following description of the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the power control device of this
invention;
FIG. 2 is a diagram illustrating the applied voltages across the
various electrical terminals of the power control device of FIG.
1;
FIG. .[.3.]. .Iadd.3A-3B .Iaddend.is a diagram illustrating the
effects of AC phase control on power delivered to an incandescent
load under the varying conduction angles illustrated by FIG.
3B;
FIG. 4 is a schematic diagram of control circuitry used in the
controller of FIG. 1;
FIG. 5 is a diagram illustrating the current in-rush of a typical
incandescent bulb as a function of time after turn-on; and
FIG. 6 shows the assembly of the present invention when used with
an Edison gas discharge lamp.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 shows a power controller 10 made
in accordance with the present invention. The power controller
comprises two .Iadd.power .Iaddend.terminals 4 and 5, which are
connected in a series with a load 15, a main remote power switch
16, and an AC source 17.
FIG. 1 depicts a .Iadd.controllable conductivity or impedance
device or switch such as a .Iaddend.triac semi-conductor switch 1
in series with .[.triac.]. .Iadd.the power .Iaddend.terminals 4 and
5. A triac is a bidirectional dual silicon controlled rectifier
(SCR) which can conduct current in both directions only upon the
application of a short low voltage current pulse applied to the
gate terminal 6 at the proper time in the AC cycle. The triac will
then latch into conduction for the remainder of the positive or
negative going AC cycle until the impressed voltage across
terminals 4 and 5 is at or near zero, at which time the triac
returns to its normally high impedance state until again
triggered.
Also included within power controller 10 as shown in FIG. 1 is a
direct current power supply means 2, which has two terminals 2a and
2b connected in shunt with the triac 1, whereby the voltage across
the said triac when it is in normally high impedance state is
reduced in magnitude by any number of well-known means, and is
rectified and filtered to become a steady source of direct current
at a third terminal 2c.
Also comprising power controller 10 as shown in FIG. 1 is a
micro-processor control circuit 3, being powered by DC source 2 and
having voltage sensing terminal 3a to detect the AC zero crossing
across terminals 4 and 5 when said triac 1 is in a nonconduction
state. Also, a trigger terminal 3b connected directly to triac gate
trigger la triggers said triac into conduction at the proper time
in the AC waveform. The micro-processor control circuit can be any
combination of generally known computer devices, memories,
input/output devices, etc. Such control circuit has a property to
retain data recently stored in the memory elements even during
relatively long periods of power interruption, such interruption
caused by the .[.intentionaly.]. .Iadd.intentional .Iaddend.opening
of the remote switch, or by an unanticipated power failure. In the
present embodiment the device is a single chip 4-bit
micro-controller being readily commercially available having
internal random access memory (RAM), read only memory (ROM), and
Input/Output (I/O) drivers. The many possible operating modes of
the complete power controller 10 and the controller responses to
momentary interruptions in the applied AC voltage are determined by
the computer program resident in internal ROM.
As an illustrative example, the power controller 10 of FIG. 1 can
be a means of modulating the power intensity delivered to a
heating, lighting or motor load. After initially closing remote
switch 16, the power to the load will be maintained at some initial
value determined by the period of time the triac remains in a high
impedance state following a zero crossing, and prior to the
micro-processor control circuit issuing a command to fire the triac
into a conducting state. By programming the microprocessor control
circuit to sense a power interruption caused by the rapid opening
and closing of remote switch 16, the power delivered to the load
can be varied. By modifying when the triac is triggered into
conduction after zero voltage crossing of the applied AC waveform
across triac terminals 4 and 5, various preprogrammed values can be
selected. .[.Successive.]. .Iadd.A pattern of sequence of
successive .Iaddend.short power interruptions can modify firing of
the triac to create an entire range of power intensity values
delivered to the load. For example, a single on-off sequence of
switch 16 can be programmed to supply full power to load 15; two
on-off sequences might produce 60% power, and three such sequences
might supply 40% power.
In another embodiment, the apparatus of the present invention can
be used as a delay timer, as for household lighting. The power
controller 10, when connected to an existing load and remote switch
of FIG. 1, can be programmed to turn on or turn off a load after a
specific time interval following the closure of remote switch 16.
Variable timed interval duration can be selected by a user such
that the period of delay can be selected depending upon how many
on-off cycles of switch 16 the user initiates.
.[.As.]. .Iadd.In .Iaddend.yet another embodiment, the power
controller 10 can provide be programmed to provide a "soft-start"
to a load at initial remote switch 16 closure. By initially
delaying the firing of the triac well beyond the zero crossing of
the AC waveform impressed across the triac terminal 4 and 5, the
initial power surge can be dampened and load life increased. Rather
than using phase control as in commercially available solid state
dimmer switches designed for use with incandescent lighting
circuits, the power controller 10 controls the rate of power
increase to full power after initial turn on according to the
particular program instructions resident in ROM.
Operation of the power controller 10 of FIG. 1 above can be best
understood by referring to FIG. 2, which depicts voltage waveforms
A, B, C and D with respect to time. Assuming the AC source of FIG.
1 is 115 volts RMS, 60 hertz, the peak voltage excursions of the
sinusoidal waveform approach +/-187 volts with a period of
approximately 16.66 milliseconds. Curve A represents the voltage
impressed across the load terminals of FIG. 1; curve B represents
the voltage across terminals 4 and 5 of controller 10; curve C is
the output of the DC power supply means of controller 10, and curve
D is the pulse generated by the microprocessor control circuit
which is applied to the gate of triac 1 to trigger the triac into
conduction.
Following a very long period with switch 16 "open", upon closure of
remote switch 16, at time t=0 of FIG. 2, an AC waveform will be
impressed across the triac terminals 4 and 5 (curve B) as long as
the triac remains in the high impedance, untriggered state. During
this first AC cycle, DC power supply 2 will rectify and reduce in
magnitude the applied waveform across terminals 2a and 2b so that a
filtered, low ripple DC voltage appears at terminal 2c, as
illustrated by curve C of FIG. 2. This voltage, present at the
micro-processor power terminal, will then enable the
micro-processor to begin executing a unique program or programs
resident in the read-only-memory (ROM) or in the form of
preprogrammed digital logic. Based on the particular function
desired, the micro-processor control circuit may then trigger the
triac into conduction at certain desired time delays following the
sensed zero crossing at terminal 3a. As illustrated for AC cycles
1-7, of curve D, the soft-start feature can be implemented at
initial device turn-on whereby in each successive AC cycle,
increasing amounts of power are delivered to the load by simply
decreasing the amount of delay between the time the zero crossing
occurs as shown in curve B and the time the triac is caused to
fire.
In order to maintain the DC power supply at some desired voltage
level, it is necessary to fire the triac a minimum of a 5-30
electrical degrees after the zero crossing (curve B). This ensures
that the power supply 2 can absorb enough electrical charge from
the potential across terminals 4 and 5 of the triac to provide
adequate stored charge to operate the micro-processor control
circuit during the remaining electrical cycle that the triac is in
a conducting state and thus has little potential developed across
terminals 4 and 5. FIG. .[.3.]. .Iadd.3A .Iaddend.illustrates the
effect of full wave phase control, whereby it can be seen that with
a 20 electrical degree triggering phase angle, the power delivered
to the load will be about 99% of that delivered by a full
electrical waveform. To achieve other desired power intensities
delivered to the load, it is simply necessary to delay the firing
angle of the triac by an appropriate number of electrical
degrees.
FIG. 4 is a detailed schematic of one preferred embodiment of the
present invention. Triac 1 is connected between terminals 4 and 5
of the power controller 10, and serves as the high current power
control switch. The DC power supply includes resistors 23 and 27,
diode 24, zener diode 25, and capacitors 26 and 28. Resistor 23
limits the current delivered to the zener diode 25, and serves as a
voltage divider with zener 25. Diode 24 prevents current leakage
from the power supply when terminal 4 is negative with respect to
terminal 5. During the time diode 24 is conducting current, current
will flow into capacitor 26 until the voltage across this capacitor
equals the zener breakover voltage of zener diode 25. The zener is
necessary to limit the voltage impressed across the capacitor 26 to
prevent capacitor failure. At the breakover voltage, the zener then
shunts any additional current to ground until the triac either
triggers into a low impedance state or the voltage polarity across
triac terminals 4 and 5 reverses. It is during these times when
there is no charging potential across the triac that capacitor 26
serves as a charge reservoir to capacitor 28 additionally serves as
a first order filter to substantially smooth the ripple and create
more of a true direct current than what would normally be available
if capacitor 26 were solely used to filter the pulsating DC.
Microprocessor control circuit 3 is a very low power CMOS device
which has all necessary memory, input/output, and computing
functions on a single silicon chip. Resistor/capacitor pair 32, 33
form the RC oscillator timebase for the control circuit 3, and can
be a crystal or other form of periodic oscillation device. Resistor
29 limits the current from the voltage divider shunt path across
triac terminals 4 and 5 to the lower level logic input 3a of
control circuit 3 to sense the moment the AC zero crossing occurs
across the triac terminals 4 and 5. PNP transistor 30 and base
resistor 31 amplify a 10 micro-second triac trigger pulse from the
control circuit and apply the needed gate drive pulse to the triac
gate to cause the triac to switch from a high to a low impedance
state. The triac then remains on until the triac current crosses
zero, at which time the triac commutes to a high impedance state.
At the next positive half-cycle, the DC power supply circuit is
allowed to regain lost charge before the triac is again ready for
firing.
FIG. 5 illustrates the typical initial current surge of a gas
filled incandescent lamp which is not provided with the soft-start
feature of the present invention. This initial current surge of 16
to 20 times the steady state current is responsible for a majority
of the triac failures in existing lighting control devices, and
also is the primary reason for lamp filament failure at initial
turn-on. The present invention can be programmed so that at initial
power turn-on, the power intensity delivered to the load is
modulated for an initial very low power level necessary to prewarm
the filament, to gradually increasing power over a number of
electrical cycles to near 100% of full power if desired. FIG. 2,
(curve B) cycles 1-7 illustrate this feature. Using the soft-start
power modulation of the present invention, incandescent bulb life
has been increased by a factor of five, while average bulb power as
maintained at near 100% after initially soft-starting.
FIG. 6 illustrates a preferred packaging arrangement for the
two-terminal power controller as described above when used as an
individual incandescent light bulb controller for Edison base style
lamps. By employing current manufacturing technologies such as
surface mounting of components and chip on board die attach
techniques, it is possible to package all the components for the
inventive power controller into a thin disc less than three
millimeters thick and less than 23 millimeters in diameter.
Terminals 4 and 5 of the triac power switching device are
positioned centrally on the opposing planar faces of a disc 40,
this disc being attached by adhesive foamed tape 41 to the base of
the lamp screw shell housing 42. Negligible space between the bulb
center contact 44 and the fixture center contact 45 of FIG. 6 is
consumed. By mounting the present invention as illustrated in FIG.
6, all existing wiring, switches, and fixtures can remain intact,
and no modification of the electrical circuit is required by the
installer. The invention is susceptible to use in many different
and useful lighting control functions, including, but not limited
to: soft-starting the filament power for increased bulb life; lamp
dimming to predefined or selected intensity levels by the
controller responsive to short power interruptions; and allowing
predefined or selected time intervals to elapse after initial power
application whereby the lighting load is either turned on or off in
a singly or multiply occurring sequence at single or repeated
intervals of time.
Thus, there has been described a two-terminal power control device
which may greatly expand the usefulness of a great variety of
alternating current circuits, especially in the area of lighting
control, where new useful functions can be added to existing
circuits without the need for wiring modifications, with the added
benefit of significantly increasing bulb life.
While a preferred embodiment of the invention has been disclosed,
various modes of carrying out the principles disclosed herein are
contemplated as being within the scope of the following claims.
Therefore, it is understood that the scope of the invention is not
to be limited except as otherwise set forth in the claims.
* * * * *