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Description  |
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TECHNICAL FIELD
The subject matter of the invention is a microprocessor controlled timer,
which is continously programmed in real time by actuation of a manual
power switch (stand-by mode) and which on request can replace the function
of the manual power switch (simulation mode).
RELATED APPLICATION
This application is a continuation of the Swiss Application No. 5 141/83-3,
filed Sept. 22, 1983 and entitled "Relais /e/ lectrique /a/ s/e/ quence
temporelle cyclique autoprogrammable".
BACKGROUND AND SUMMARY OF INVENTION
The present invention relates to power switches with built-in programmable
timers of the type which has its most important commercial application as
a control for energizing and de-energizing of electrical appliances used
in homes and offices, which emit acoustic or luminous energy, thus
simulating the presence of persons, when these are in fact absent. A
deterrent effect is thus achieved on intruders, although certain aspects
of the invention have a more general application. In such a commercial
application, the present invention will form an electric power switch, of
the type to be connected in series with a power cord of the appliance and
incorporated in the housing of the appliance itself or in its miniaturized
version just connected as a mobile switch at the two ends of the power
cord carrying the power from the plug to the appliance.
The utilization of mechanical and electromechanical timers for similar
purposes is known since long time. These devices have small dimensions and
are easily programmed by users without any technical knowledge. Their main
drawback lies in the limited amount of on/off sequences which can be
programmed during a cycle, which usually covers a time period of a day or
a multiple thereof. So it is difficult to have more than 100 on/off
sequences per cycle, and the minimum delay between two adjacent sequences
is also limited by the precision, with which mechanical markers can be
machined and visually seen as distinct. A further drawback of these type
of timers lies in their limited lifelength, due to wear of mobile
mechanical parts.
Consequently in the last ten years novel fully electronic means of enacting
the timer function have been devised, allowing for a very large number of
on/off sequences per cycle and remotely controlling a large number of
appliances with different of/off sequences for each appliance. In their
known form, these devices consist of a central control console, with a
built in microprocessor timer and a input keyboard, and of a certain
number of peripheral remotely controlled switches, which control
energization of the appliances. Unfortunately these devices are not easily
programmed by unskilled persons and even the skilled ones need often a
well written manual, their installation costs are quite high and they take
up a sizable volume.
The object of the present invention is to realize an electric power switch
with built-in electronic timer, whose use is straightforward when the user
wants it to act as a simulator during his absence, whose dimensions are
compatible with the space available in appliances, and having an extremly
high number of on/off sequences during any given cycle. Furthermore the
lifelength of the electric power switch according to the invention is not
limited by wear of mechanical rotating or moving parts and the
installation on existing appliances or other electrical apparatus can be
handled by any person familiar with electrical power connection practice.
A further object of this invention is to provide an electric power switch,
which can even compensate for inadvertent oblivion by the user, when
leaving without requesting the electric power switch to enter into the
simulation mode, which is appropriate during his absence.
To achieve these aims, the electric power switch according to the invention
is housed in a container B (FIG. 1), having suitable input and output
connections for the power cord and being activated by the user thru manual
pression on a suitable knob, toggle or button I, which is well visible for
the user. A further smaller commutator S, placed on the side or the
underside of the container, having at least a stable position for the
"stand-by" mode of operation and another stable position for the
"simulation" mode of operation, is operated by the user, when he is either
leaving or coming back from a prolonged absence from the room, where the
electrical apparatus is installed, which is energized by the electric
power switch according to this invention. Thus the operation of this
switch is so simple, that even illiterate users can learn and retain its
operating procedure. In a refined version of the electric power switch
according to the invention, the commutator S has a third intermediate
stable position "fail safe stand-by", whereby if the user does not
activate the main manual toggle I within a certain period of time since
the last manual operation of I, the electric power switch automatically
and without any action from the outside goes over to the "simulation" mode
and stays in that mode until the manual toggle I is operated again.
In accordance with another feature of the present invention, any
dysfunction of the electric power switch which is detected by a special
self-check program stored in a suitable memory of the microprocessor gives
rise to a coded alarm signal in the form of a characteristic train of very
frequent on/off sequences of the power energizing the appliance, thus
alerting the user that something is wrong.
Since the use of electronic memories in the timer portion of the electric
power switch allows the storing of a very large number of on/off sequences
during one cycle, the preferred cycle duration is of one week or a
multiple thereof. This has the advantage that the changing pattern of
on/off sequences during workdays and weekends is simulated properly when
the electric power switch is in the "simulation" mode. In accordance with
another feature of the present invention, the microprocessor checks at
regular intervals the content of each day section of the stored program of
on/off sequences and in case it finds a one day section which is empty
(e.g. has not a predetermined minimum amount of on/off sequences), it
replaces said one day section with another which is available in the
stored program, having a large number of on/off sequences.
This last feature of the invention is particularly useful when installing
the electric power switch for the first time, since then, if no particular
provisions have been taken, the stored program controlling the timer
portion of the electric power switch is completely empty, e.g. all the one
day portions of it are empty. After a one day period of use of the
electric power switch in the "stand-by" mode, all the empty one-day
sections of the stored program will then automatically be filled with the
pattern of on/off sequences of the first day, allowing the user to set the
electric power switch into the "simulation" mode even though said switch
was not in use in the "stand-by" mode for the full length of a recording
cycle. Accordingly no special initialization of the timer has to be
performed upon the first time of use, which again is very useful and
acceptable for technically unskilled users, the only requirement being to
use the electric power switch in the "stand-by" mode at least for one day.
Since power failures of short duration (less than 5 minutes) are quite
frequent, the critical parts of the timer portion of the electric power
switch are protected against loss of power by voltage supplied by a small
rechargeable battery or a litium battery, which is provided in the low
voltage supply part of the electric power switch. In particular the
electronic memory holding the stored program of on/off sequences and the
clock are fed by the emergency battery in case of power failure. If the
voltage of the emergency battery falls below a certain proper value, the
microprocessor, according to another feature of the present invention,
detects it and signals it to the user by generating a train of frequent
on/off sequences of the power energizing the appliance. This allows the
user of either changing the emergency battery or waiting until the battery
has been recharged, before setting the electric power switch into the
"simulation" mode.
According to another feature of the present invention, in case that the
electric power switch has been disconnected from the power outlet for a
very long period of time, the appliance it controls not being used or
having been inadvertently disconnected by children or other unaware
people, the electric power needed to keep the clock and the memory with
the stored on/off sequences going is supplied under the day by a
photovoltaic cell which charges the emergency battery with the current
generated by conversion of daylight, so as to compensate also for the loss
of charge of the battery during the night period. A preferred version of
such a photovoltaic cell is an amorphous silicon solar cell, which is
mounted on the same side of the container B where also the main toggle I
is located, so as to get maximum light exposure during the day.
When in the same building more than one electric power switch according to
the present invention are installed, it might be useful to control from a
central point the setting of said switches into the "simulation" mode or
back into the "stand-by" mode. To achieve this and according to another
feature of the present invention, the microprocessor is provided with a
special decoder circuit, which decodes high frequency signals which are
sent along the power lines from a suitable central unit which is operated
by the user when leaving or coming back from a prolonged absence. So when
a coded high frequency signal is sent along the power lines, each electric
power switch goes simultaneously into the "simulation" mode, but each of
said switch has a different program of on/off sequences, which simulate
e.g. the activity of a person moving from one room to the other.
Furthermore and according to another feature of the present invention, the
electric power switches are provided with a coded high frequency signal
emitting circuit, which sends alarms signal into the power line, in case
that the manual toggle I is activated when the electric power switches are
operating in the "simulation" mode. Since by definition during the
"simulation" mode nobody should be in the building, if there is a charge
of the status of any of the toggles I an intruder has penetrated into the
building: in this case the coded high frequency signals emitted by the
corresponding electric power switch are received and decoded by the
central unit, which can then take proper action, e.g. alerting the police
over the phone line or energizing an acoustic alarm horn.
In the case where high security is required, the electric power switch is
provided according to another feature of the present invention with a
voice recognition electronic device, which is speaker dependent and
connected to a small microphone, mounted on a suitable face of the
container B, so as to be exposed optimally to the mouth of the user, who
is entitled to operate it. At the time of first installation of the said
switch, the authorized user can teach the voice recognition device by
spelling e.g. the works "stand-by" and "simulation" when the commutator S
is in the corresponding position and having a special auxiliary button for
the "teach" function depressed with his hand. After that, the access to
the commutator S is rendered difficult to unauthorized persons, by sealing
it e.g. with a lid or any other physical means hampering access and the
electric power switch is incorporated into the electrical apparatus which
it controls, having only the side with the toggle I and the microphone
exposed to the outside. With this particular set-up only the authorized
user is able to commute the electric power switch from the "stand-by"
into the "simulation" mode and vice versa.
Furthermore it might be useful for the user to have a feed-back, that the
electric power switch is properly operating in the "simulation" mode, when
the order to do it is either entered by action on the commutator S or by
other previously described means. According to another feature of the
invention, such an immediate feed-back signal is generated by having after
a short delay upon the change of mode a predetermined sequence of few
on/off or off/on switches of the power, which end after 10 to 30 seconds,
signalling to the user that the microprocessor is working properly. In
opposition to this and as already said before, if there is some
dysfunction of the electric power switch, the sequences of on/off power
switches keep steadily going for as long as the user is taking appropriate
action to eliminate said dysfunction.
A further check that the electric power switch according to the present
invention is in the "simulation" mode can be achieved by disabling the
toggle I in the "simulation" mode, that is either disconnecting from the
power the input of the manual switch operated by the toggle I or by
suppressing any action that the toggle operated switch might have on the
operation of the microprocessor. This feature of the present invention is
especially useful in buildings, where security guards performs regular
tours, checking the status of electrical apparatus: when operating the
toggle I they notice no change in the energized status of the apparatus,
they have the proof that the electrical power switch is in the
"simulation" mode.
When the appliance or apparatus which is controlled by the electric power
switch needs a variable power input according to the user's wishes, it
might be useful, according to another feature of the present invention, to
incorporate the power regulating means into the electric power switch in
such a way, that the microprocessor is storing the on/off sequences and
the level of power allowed during the "on" state into said memory during
the "stand-by" mode and replays then during the "simulation" mode both the
on/off sequences and the level of electric power allowed, as they were
stored during the immediately preceding cycle in the "stand-by" mode. The
same considerations apply to appliances or apparatus which need for their
operation DC voltage supply, in which case the AC/DC converter may be
incorporated into the electric power switch, having the added benefit that
DC power can be directly supplied to the electronic control timer, if
provisions are made in order to have an output of the AC/DC converter with
the suitable DC voltage (in most cases 5 V).
The above and other advantages and features of the invention will become
apparent upon making reference to the specification to follow, the claims
and the drawings.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an electric power switch, connected between
the ends of the electric power carrying cord, which supplies power to the
appliance or apparatus which is turned on or off by manual operation of a
toggle mounted in the housing of the electric power switch, as long as the
commutator on the side of the housing is set in the "stand-by" position.
If said commutator is set in the "simulation" position, the electric power
switch is then operated automatically by the built-in electronic control
timer, housed in said housing and protected from external influences,
which might impair its correct operation.
FIG. 1a is a perspective view of an electric power switch and its remote
manual operated toggle or button, which is connected to the electric power
switch by additional wirings incorporated into the special portion of the
power cord between the electric power switch and the remote toggle or
button. The normal power cord is connected at one end at the appropriate
side of the electric power switch and at the other end at the appropriate
side of the remote toggle's or button's housing.
FIG. 1b is a perspective view of an electric power switch and its remote
manual operated toggle or button together with the remote
stand-by/simulation commutator, both of which are connected to the
electric power switch by suitable wirings in a special cord, whereas the
ends of the electric power cord are directly connected at the appropriate
sides of the electric power switch.
FIG. 2 is a box diagram of the basic control elements of the electronic
control timer and of the power switching means according to an embodiment
of the present invention, where said power switching means have an air gap
when in the "off" state and where both the toggle or button and the
stand-by/simulation commutator are mounted in the same housing as the
electric power switch.
FIG. 3 is a box diagram of the basic control elements of the electronic
control timer and of the power switching means according to another
embodiment of the present invention, where the toggle or button as well as
the stand-by/simulation commutator are housed in an auxiliary housing, as
apparent from FIG. 1b, and where said power switching means are of the
solid-state type, like ignition controlled rectifiers and the like.
DESCRIPTION OF FIRST EXEMPLARY FORM OF THE INVENTION
Referring now to FIG. 1, FIG. 1a and FIG. 1b, there is shown an electric
power switch housed in a housing B, connected between the ends of power
carrying cord V (plug side) and W (appliance input). The manually operated
toggle or button I is housed in B, as depicted on FIG. 1 or in a remote
auxiliary housing Ba connected to the power cord as depicted in FIG. 1a,
or finally in an auxiliary remote housing Bb together with the
stand-by/simulation commutator S, as depicted in FIG. 1b.
The stand-by/simulation commutator S is housed in B, as depicted in FIG. 1
and FIG. 1a, in such a way that it is accessible to manual operation from
the user, when the housing B is mounted or incorporated in an appliance or
apparatus, which is controlled by the electric power switch. In the case
that this shall not be possible for practical reasons, the commutator S is
then incorporated into the auxiliary remote housing Bb, as earlier
mentioned and as depicted in FIG. 1b.
The commutator S has in the present example two distinct positions
"stand-by" and "simulation", which are visually indicated by appropriates
signs on the housings B or Bb, so that the user can check in which mode of
operation the electric power switch is set. If more modes of operations
are available, like the e.g. "remote control" mode, then the commutator S
shall have additional stable and visually indicated positions, so as to
indicate to the user, in which mode the electric power switch is
operating.
In each of the examples of FIGS. 1,1a and 1b, use of the electric power
switch according to the present invention is straightforward: as long as
the commutator S is in the "stand-by" position, the turning on and off of
the appliance or apparatus controlled by it is performed by the user by
manual operation of toggle or button I, as it is widely used in common
electric power switches. When the user wants to operate the electric power
switch during his absence, he just has to set the commutator S in the
"simulation" position before leaving. From that moment on, the built-in
electronic timer will take over the operation of the electric power switch
according to the schedule of on/off switching sequences which has been
stored in the immediately preceding cycle during the "stand-by" mode of
operation. To get back to the "stand-by" mode of operation, the user has
only to set the commutator S in the "stand-by" position again. Similar
considerations apply, if the commutator S has more than two stable
positions, since they are visually apparent and indicated to the user.
DESCRIPTION OF THE MAIN ELEMENTS OF THE ELECTRIC POWER SWITCH
Coming now to FIG. 2, there is shown two AC power lines V1 and V2 on the
input side of the electric power switch housed in B, which are connected
to the DC low voltage power supply Y, to the terminals of an
electromechanical relay C and of a contactor mechanically operated by the
toggle or button I. At the output side there are two AC power lines W1 and
W2, connected at the corresponding terminals of the relay C and of the
contactor mechanically operated by I as well as to connected to a voltage
sensing detector D, which transforms the AC voltage into a suitable DC low
voltage signal compatible with the input levels of the microprocessor P.
These power lines W1 and W2 bring the power to the appliance or apparatus
A. If, A needs a 3-phase power feed, the electromechanical relay C and the
contactor mechanically operated by I are changed accordingly, whereas the
low voltage power supply Y and the detector D can be fed by only two
phases, or by a phase and the common.
The low voltage DC power supply Y has a rechargeable battery or a lithium
battery or other suitable DC electric power storage means, which allow it
to feed appropriate electric DC power to the clock H and the memory M of
the electronic control timer, in case that a power failure on the lines V1
and V2 occurs. The microprocessor P, which manages all the functions of
the electronic control timer, is connected to the detector D and to an
output interface unit T, which commands the relay C. The three elements
P,D and T are fed by low voltage DC power from a separate line of Y, which
is not protected against mains power failure on the lines V1 and V2.
The microprocessor P is further connected to the clock H, from where it
gets the appropriate timing signals, and to the memory M, in which are
stored the sequences of on/off power switchings detected and stored during
one cycle in the "stand-by" mode and continously refreshed as long as the
electric power switch stays in the "stand-by" mode, said sequences being
entered into the memory M by the microprocessor P according to
corresponding input signals coming from detector D concerning presence or
absence of AC voltage on the lines W1 and W2. The contact of commutator S
is also connected to P in such a way that e.g. when said contact is on the
"0" digital voltage level, the microprocessor P is forced to operate in
the "stand-by" mode, whereas if said contact is on the "1" digital voltage
level, P is forced to operate in the "simulation" mode.
The operating software which is necessary to operate the microprocessor P
according to the present invention is stored in ROM or EPROM memories,
which are incorporated in the same chip as the microprocessor P. When P is
forced to operate in the "simulation" mode by having the contact of
commutator S on the "1" digital voltage level, the microprocessor P reads
the content of memory M, which in this case is no longer refreshed by the
output of detector D, and transforms said content into timed commands,
which over the output of the output interface unit T are causing relay C
to turn on and off the electric power on lines W1 and W2 according to the
schedule stored in M and within the timing precision of the minimum
sampling time of the microprocessor P. This action goes on continously, in
the sense that when the content of one cycle has been read, the
microprocessor P starts reading at the beginning of the cycle again and
indefinitely, unless the commutator S is brought back by the user in the
"stand-by" position.
If a short power failure occurs on lines V1 and V2, the clock H and the
content of memory M are thereby not concerned, being fed automatically by
the rechargeable batteries of Y, so that when the mains power comes back,
P picks up the content of M at the correct location as instructed by the
timing signals of H and continues playing back the on/off switching
sequences on C, as if there was no mains failure at all.
As an illustration of this first example, an electric power switch has been
built, having as microprocessor P a 8-bit integrated circuit of the 8751
Intel type, as memory M a 16 kbits integrated circuit of the HM6116LP
Hitachi type and as a timing unit for the clock H incorporated into the
8751 type processor a 12 Mhz quartz resonator. The cycle time was one week
and the processor 8751 did sample every minute the output of detector D,
transferring it into the memory HM6116LP during the "stand-by" mode. In
this particular case only 60.times.24.times.7=10,080 bits of the memory
HM6116LP were needed in order to fully cover storage of a whole recoding
cycle of 168 hours.
It is now apparent to persons skilled in the field of electronic controls
using microprocessors, that further features of the present invention and
following can be implemented by adding suitable inputs to the
microprocessor P, by connecting it with other suitable electronic units,
by introducing more complex instructions in the operating software which
runs the microprocessor P or by a combination of all these said means.
Referring to FIG. 3, whereby the contactor mechanically operated by the
toggle or button I is spacially separated from housing B, it is apparent
to persons skilled in electricity that the wirings connecting the
auxiliary housing Ba or Bb to housing B of FIG. 1a or FIG. 1b includes the
lines V1,V2,W1,W2 in both cases, with the addition of three wirings
(contact input to P,"0" and "1" digital voltage levels) to the terminals
of commutator S in the FIG. 1b.
DESCRIPTION OF A SECOND EXEMPLARY FORM OF INVENTION
From the user's standpoint, all what was said in the foregoing description
of first exemplary form of the invention still applies. Referring now to
the FIG. 3, there is shown a housing B, containing the earlier described
building elements Y,H,M,P and T, with the exception of relay C and of
detector D, no longer needed, and with the addition of suitable ignition
controlled silicon rectifiers or power transistors X, acting as power
switching means. In a separate auxiliary housing Bb there are contacts
connecting suitable inputs of P to the "0" or "1" digital voltage level,
the first of said contacts being activated by the toggle I, the other ones
being activated by commutator S in such a way, that the three commands
"stand-by", "fail-safe stand-by" and "simulation" are univocally
transmitted to P when commutator S is in the corresponding position.
As long as S is in the "stand-by" position, changes of status level of the
contact operated by the toggle I are stored by P into the memory M and at
the same time they enable or disable through the output interface unit T
the ignition of X, thus effectively turning on or off the power on lines
W1 and W2, as requested by manual operation of toggle I. If the commutator
S is positioned on "simulation", the input coming from the contact
operated by I is disabled and P starts reading the content of M and
accordingly enabling or disabling thru T the ignition of X, thus replaying
the sequences of on/off power switchings commanded by operation of I
during the cycle immediately preceding the transition from "stand-by" to
the "simulation" mode.
If the commutator S is positioned as to force P into the "fail-safe
stand-by" mode, as long as the changes of status of the contact operated
by I follow each other within a predermined lapse of time, they are stored
into M and at the same time they enable or disable through T the ignition
of X, as it always is in the "stand-by" mode. Once the toggle I is not
operated for a lapse of time longer than said predetermined lapse (e.g.
one day), the microprocessor P automatically goes over into the
"simulation" mode, but the input of the contact operated by I is not
disabled, allowing the microprocessor P to revert to the "stand-by" mode
as soon as I is operated again.
As an illustration of this second exemplary form of the invention, an
electric power switch was built having as P an integrated circuit of the
40C49 type, as memory M an integrated circuit of the HM6116LP type backed
by auxiliary integrated circuits 74C373 and 27C16 and as power switching
means X a triac of the 2N6073A type. Said illustration was fitted into a
housing B with dimensions less than 10.times.5.times.2 cm., including
rechargeable batteries of the NiCd type for a nominal voltage of 5 volts
DC. It is now apparent to persons skilled in the field of electronic
controls using microprocessors, that further features of the present
invention and following can be implemented by adding suitable inputs to P,
by connecting to P suitable signal processing units, such as high
frequency signal receiver or emitter and the like, by introducing more
complex instructions sets in the operating software of P, such as routines
for periodically checking the content of 24-hours segments of M and for
replacing empty segments with other available segments having more than
predetermined number of on/off sequences, or such as routines for
commanding coded on/off sequences of power switchings on the lines W1,W2
by acting on ignition of X, if specific information about the status of
the electric power switch or of its elements and detected by suitable
means affecting P, has to be indicated to the user.
Furthermore a solar cell fed electronic unit can be connected to Y in order
to keep its rechargeable batteries at operating voltage, taking into
account that said batteries have to continously feed DC power to the clock
H and to the memory M also during nighttime, in case of prolonged
disconnection of the power on lines V1,V2. By adding a voltage sensing
electronic unit into Y, which sends appropriate alarm signals to P if the
batteries voltage is lower than a predetermined limit, a routine of the
operating software of P is activated, whereby P commands coded sequences
of on/off switchings to X, thus signalling to the user that batteries have
to be replaced or checked.
It is also apparent to skilled persons, that if power switching means are
required, which in the "off" state have an open air gap, the solid state
switches in X are replaced by an electromechanical relay, which is
controlled by a suitable output interface unit in T.
The practical applications of the electric power switch according to the
present invention are of different nature and can be found in fields as
diverse as medical patient care, biology, intelligence and military,
feeding of animals, security of goods and persons and the like, where
operation of electrical apparatus should continue if the user consciously
or unconsciously is prevented to directly and manually operate said toggle
or button.
A preferred application of the electric power switch according to the
present invention is the control of illumination sources in houses and
offices, like electrical lamps or motor-driven window-shutters and the
like.
By now it should be apparent that the present invention allows to build
extremly user friendly and ever-ready electric power switches, which do
not require any special programming of on/off schedule by the user other
that the regular use of the electric power switch in the "stand-by" mode
for at least a short period of its chosen cycle time, which if necessary
can be extended to encompass the change of seasons over a whole year (52
weeks), if a memory M of sufficient capacity (e.g. 64 kbits or 256 kbits
RAM's) is used.
It should be understood that numerous modifications may be made with
reference to the exemplary forms of the invention as described in this
patent application, without deviating from the broader aspects of the
present invention.
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