OBJECT OF THE INVENTION
[0001] The present invention belongs to the sector of electrical appliances and cooking
apparatus, and more specifically to control and regulation systems of ovens and glass
ceramic hobs.
[0002] The main object of the present invention is a control system, especially applicable
in homes, which enables obtaining a simultaneous and combined control of the power
consumed in an oven and a glass ceramic hob, in order so that the contract demand
limit is not exceeded, avoiding tripping in the electrical installation and achieving
a reduction in the users' electricity bill.
BACKGROUND OF THE INVENTION
[0003] At present, it is known that in some countries there are electricity limitations
in buildings, homes, etc., as they work with old distribution networks where the wiring
and transformation centres on which said buildings depend have expansion limits, whether
due to questions of size of the electricity network or due to the degree of investment
involved in the change. On the other hand, there are other countries wherein the power
limits of newly-built buildings are imposed by the law or the country's energy resources.
[0004] The order of electrical power installed currently in 60 cm embedded oven (volume
of 54 litres approx.) and four-ring glass ceramic hob units is in the order of 7 -
8 kW. The use of oven and hob at the same time entails an excessive load, both for
the home's individual electrical installation and for the rest of the building (apartment
block, or buildings with several storeys).
[0005] When due to user requirements both apparatus, oven and hob, are made to work simultaneously,
the current in amperes consumed by the hob and oven unit, the joint power whereof
is, for example, 7 kW at 210 V is of 31.8 A. A 20 A power control switch (PCS), typical
in kitchens to supply the oven and hob unit, enables the passage of said 31.8 A (1.5
In) during a few seconds. The immediate result is that the overload protections (power
switches of the kitchen circuit or the general home circuit) trip and disconnect the
electric circuit, causing a power cut in the home or the disconnection of the oven
and the hob, with the consequent loss of the programmed values for power, functions
(grill, cooking, rotisserie, toaster, etc.), times and other parameters such as weight
and temperature, assigned to the oven and hob.
[0006] Therefore, the technical problem posed here is to avoid the sudden drops and disconnections
caused in domestic cookers as a consequence of having exceeded the contract demand
limit for the oven and glass ceramic hob unit, when both apparatus are connected at
the same time. These disconnections in the power supply entail a loss of power, temperature
or time values programmed in each of the apparatus, which leads to a lack of control
in the food cooking process, with the subsequent "doubtful" result of the products
finally obtained, not to mention the trouble caused to the user of having to go to
the home's main switchboard for their reconnection.
DESCRIPTION OF THE INVENTION
[0007] The present invention resolves the aforementioned drawbacks, providing a combined
control system of the electricity consumed in an oven and a glass ceramic hob, especially
applicable in homes and hotel and catering premises, said control system being based
on the combined action of both apparatus, oven and glass ceramic hob, so that their
switching on is performed in a totally synchronized form, avoiding at all times exceeding
the contract demand limit, and with this, avoiding the power cuts or disconnections
that cause the loss of previously programmed values in both apparatus.
[0008] More specifically, the control system described here is applicable to the unit formed
by a domestic oven and a glass ceramic hob. Said oven is equipped with first means
of regulation for the programming of different cooking parameters, such as power,
function, temperature or time. Said oven may be basic, with switch to select the cooking
mode (rotisserie, toaster, grill, etc.) and a thermostat; or it may be an electronic
oven with user interface, digital displays, LCD screens, touch command input, etc.
[0009] For its part, the glass ceramic hob is provided with rings or electric heat points
and second means of regulation of the energy consumed in each one of its rings. Said
means of regulation of the hob basically comprises control relays connected to each
one of the rings, a user interface provided with "touch control" key commands, and
"display" digital indicators to observe the power level applied in each one of the
rings.
[0010] The control system object of the invention fundamentally stands out as it comprises
a first control unit of the oven, connected to said first means of regulation, and
a second control unit of the hob connected to each one of the rings, both control
units being associated through a communication module, which may be by cable or wireless
via radiofrequency RF, so that the switching on of the oven and the hob is performed
in a synchronized and controlled manner, avoiding at all times exceeding a contract
demand limit when both apparatus are simultaneously connected.
[0011] More in particular, the control unit of the oven has hardware / software means that
makes it possible to know the quantity of power selected in the oven, and in accordance
with this value sends an electric signal to the hob control unit, which has a microprocessor
which manages and processes the information received, said microprocessor being connected
to each one of the control relays of the rings or heat points of the hob, so that
this microprocessor regulates and finally reprograms the manner of working of each
one of said rings, reducing or increasing their power without ever exceeding a threshold
value of power previously assigned to the oven and hob unit.
[0012] Likewise, it has been provided that the microprocessor of the hob control unit is
adapted to maintain the last power indication selected by the user, so that if they
want to increase the power level in one of the rings, the power of the remaining rings
in operation will suitably lower theirs.
[0013] Furthermore, it has been provided that said microprocessor of the hob control unit
incorporates a safety algorithm so that, both apparatus, oven and hob, being operational,
if the oven stops being used and is switched off, the power values of each one of
the hob rings is maintained, i.e. they do not raise their power level, thus avoiding
possible risks of excessive heating of the food which is being cooked.
[0014] In accordance with another preferred embodiment, the microprocessor of the hob control
unit further comprises a time control algorithm which makes it possible to know the
working and rest times of the oven, said rest times of the oven being used by the
hob to optimise the food heating process, reducing the time used for it.
[0015] Therefore, through the control system object of the invention it is possible to obtain
a combined action of the unit formed by oven and glass ceramic hob, so that its switching
on is performed in synchronized manner, making it possible to avoid tripping in homes
and domestic cookers as a consequence of exceeding the contract demand limit when
both apparatus are simultaneously connected, with the advantages entailed by all of
this both for the user and the quality of food cooked, and for the electrical installation,
since it would not suffer unforeseen drops or surges in current which would also affect
the quality of the electrical system.
DESCRIPTION OF THE DRAWINGS
[0016] To complement the description being made and in order to aid towards a better understanding
of the characteristics of the invention, in accordance with a preferred example of
practical embodiment thereof, a set of drawings is attached as an integral part of
said description wherein, with illustrative and non-limiting character, the following
has been represented:
Figure 1. - Shows a schematic view of the control system of the invention applied
to an oven and hob unit.
PREFERRED EMBODIMENT OF THE INVENTION
[0017] An example of preferred embodiment of the combined power control system (1) object
of the invention is described below, without this entailing any limitation in the
scope of protection thereof.
[0018] In accordance with the present embodiment, there is a domestic oven (10) which allows
a maximum power consumption of 2.3 kW, and a glass ceramic hob (20) provided with
four electric rings (21), which switched on at maximum power have a consumption of
5.2 kW. Through the control system (1) described here, it is possible to obtain the
synchronized action of the oven (10) and the hob (20) never exceeding the value of
5.2 kW, which could lead to a tripping of the electricity supply, switching off both
apparatus, oven (10) and hob (20), and in consequence losing all the values previously
programmed in them, such as power, time, cooking function, temperature, etc.
[0019] As observed in figure 1, the control system (1) is applied to a basic domestic oven
(10) provided with first means of regulation (11) such as switches (12) and thermostat
(13), whereby it is possible to program different cooking parameters (rotisserie,
toaster, grill, etc.).
[0020] For its part, the glass ceramic hob (20) comprises four rings (21) and second means
of regulation (22) of the energy consumed in each one of said rings (21), and which
in the present embodiment comprises four control relays (23) connected to each one
of the four rings (21), a user interface provided with "touch control" type keys and
"display" digital indicators (24) of seven segments that sallow the user to observe
the power level applied in each of the rings (21), from "0" (ring switched off) to
"9" (ring at maximum heating power).
[0021] More in particular, the control system (1) of the invention stands out as it comprises
a first control unit (15) of the oven (20), and a second control unit (25) of the
hob (20), both associated through a communication module (30) in this case by cable,
so that the switching on of the oven (10) and the hob (20) are performed in synchronized
manner, avoiding exceeding the contract demand limit.
[0022] The first control unit (15) has hardware / software means (16) that makes it possible
to know the power level selected by the user in the oven (10), and in accordance with
this value said first control unit (15) sends an electric signal to the second control
unit (25), which has a microprocessor (26) which processes said electric signal and
manages the information received, said microprocessor (26) being connected to each
one of the control relays (23) of the rings (21) of the hob (20), said microprocessor
(26) regulating and reprogramming the manner of working of each one of the rings (21),
reducing or increasing their power without exceeding the power threshold assigned
to the oven (10) and hob (20) unit.
[0023] In this way, if we are initially cooking with the four rings (21) of the hob (20)
at maximum power, 5.2 kW, i.e. all rings (21) with power level "9", said number being
represented in the digital indicators (24), and later the user switches on the oven
(10) at maximum power, 2.3 kW, then, the microprocessor (26) of the second control
unit (25) orders through the control relays (23) an instantaneous reduction in the
power of the four rings (21), so that they lower their consumption to power level
"7", said change of numbering also appearing in the digital indicators (24).
[0024] On the other hand, once the four rings (21) of the hob (20) have reduced their value
of power consumed to "7", if the user wants to raise the power in one of said rings
(21), for example, by raising it to "9", the microprocessor (26) of the second control
unit (25) makes it possible to maintain this power level in said ring (21) in exchange
for reducing power in the remaining three rings (21), for example lowering to "5".
[0025] Furthermore, if the user later decides to switch off the oven (10), with the four
rings (21) of the hob operating with reduced power values, for example, at level "5",
it has then been provided that the microprocessor (26) has a safety algorithm, so
that the second control unit (25) sends an order to the control relays (23) so that
they continue maintaining their reduced values, and do not rise, which would be a
danger both to the user and for the food being cooked, avoiding them from burning.
[0026] On the other hand, it has been provided that said microprocessor (26) of the second
control unit (25) of the hob (20) also has a time control algorithm, whereby it is
possible to know the working and rest times of the oven (10), so that the times wherein
the oven (10) stops functioning, generally 50 % of the total use time, are made use
of by the hob (20) to reduce the food heating time. Preferably, this operating mode
is selected by the user through the user interface provided in the hob (20).
[0027] Finally, in accordance with another preferred embodiment, not represented, the communication
module between the first control unit (15) and the second control unit (25) is wireless,
both apparatus, oven (10) and hob (20) being communicated by radiofrequency RF. This
second option is especially applicable in restaurants and hotel and catering premises
where the oven (10) may be located a certain distance with respect to the hob (20).