DESC:FIELD OF INVENTION

A method and system for an electric cooking apparatus like induction cook top, radiation cook top or any such electronic cooking system, to count the whistles or similar sound coming from the pressure cooker or similar vessel, placed on the above said cooking apparatus for automated/regulated cooking.

BACKGROUND OF INVENTION

In the market, various types of safety devices and alerting devices are provided in pressure cooking utensils with the purpose of providing safety and convenience to the user. Typically a pressure whistle is provided in pressure cooker lid so that the steam produced during cooking provides a whistle sound during its release to alert the user. Hence in a pressure cooker, the whistling is indicative of the status of the cooking food. The domestic pressure cooker thereby needs to be in observation essentially to hear the sound of the whistling.

During the cooking process, the whistling unit typically generates a whistle sound and lifts the cooker weight. The audible whistling alerts the user about the internal temperature/pressure of the pressure cooker at that instant. The user may continue to cook until multiple whistling occurs. Thereafter the user switches off the gas source, or continue cooking on low heat by lowering the heat.

OBJECTS OF INVENTION

The first main object of the invention is to sense the whistle sound generated by the pressure cooker.

The second main object of the invention is to use the sensed whistle sound to trigger a control unit.

The third main object of the invention is to use the repeated triggering of control unit to associate with number of times the whistle sound is generated by the pressure cooker.

The fourth main object of the invention is to allow the user to engage herself/himself in another parallel work without worrying about the pressure cooker and the need to switch off the heat supply at right time to avoid accident and to achieve proper time/level of cooking of the food item.

The another object of the invention is to allow the user to set the required number of whistles and the control mode enabling the switch off of the heat source when the required number of whistles is reached.

The another object of the invention is to automate the switch off the heat source on the basis of whistle counter of a pressure cooker.

The another object of the invention is to automate the changeover of the heat source to a lower heat on the basis of the whistling counting of a pressure cooker, thereby enabling the food to continue to remain in warm state.

DESCRIPTION OF INVENTION

The present invention is a “Whistling Counter” integrated into an Electrical Heat Cooking Apparatus/Device (say) Induction Cook top, which works through a combination of Electric Circuitry, Algorithm and a controlling software. This invention enables the Electrical Heat Cooking Apparatus/Device to identify, record and monitor the number of whistles emitted by a Pressure Cooker (during cooking) while using the Cooking device, against a pre set number of whistles, so as to automatically switch off from the main cooking operation to keeping in warm mode, without the User actually being present till the completion of cooking.

The above novel idea of the invention is a combination of electrical circuitry and software algorithm illustrated in fig. 1 and fig. 2, which is integrated in the Electrical Heat Cooking Appratus/Device.

The acronym used are:
ICT = Induction Cook Top
HW = Implemented in hardware/electrical circuit
SW = Implemented in software algorithm

The invention is based on the above objects to provide an automatic, regulated, reliable cooking method and the system has been so designed to achieve this method of cooking which system is also economical to manufacture and is very reliable and a sturdy product.

The pressure cooker emits “whistles” when the pressure inside the cooker increases beyond the designed threshold limit due to steam formed inside the cooker as the food with cooking fluid is being cooked. The invention aims to detect and count the “whistles” emitted by the pressure cooker using the “sound waves” input available, so as to automatically regulate the cooking by adjusting the heat provided by the cooking apparatus/device to the Pressure Cooker. The “sound waves” allow high accuracy of detection and hence the system/method is simple yet very reliable.

In this method all it needs is the correct determination of “frequency” and “amplitude “of the whistle emitted by the pressure cooker, mounted on the cooking device, by filtering out any other sound generated by other cooking appliances around the Electrical Cooking Apparatus detecting this peak frequency of the whistle, counting these peaks of the whistles and regulating/lowering the heat to the pressure cooker after counting and recording the predetermined number of peaks/whistles.

The tracking of the whistle emitted by the pressure cooker may be monitored on two aspects: (1) Frequency of the sound wave and (2) Amplitude of sound wave.

However it is to be noted that due to the market demand and the generality of the product, pressure cookers from various manufacturers are as available for domestic use may emit sound with similar frequency. And the Amplitude varies with the distance of the cooker from the user.

However the invention does enable the Cooking Apparatus to distinguish the whistles emitted by Pressure Cooker from other different cooking vessels, like milk cooker, coffee filter, since frequency and amplitude will be different for different type of vessels.

The system to achieve the above objects includes a signaling means, a receiver means and a control means. The signaling means detects the frequency and amplitude, the receiver means may include microphones and controller corresponding triggers the control means to switch off/lower the heat from the heat source to pressure cooker.

Hence the method of controlling/automating the pressure cooking of food in a heated cooking vessel uses the steam whistle of the conventional pressure cooker and utilizing a microphone and an electronic control unit to regulate/switch off the heating element of the cooking apparatus/device. The invention with its elements are integrated into the cooking apparatus/device and the typically available prior art pressure cookers in the market may be used with this novel cooking apparatus/device.

In a typical application as per this invention, a pressure cooker may be placed on a electrical cooking apparatus equipped with the system or method. The pressure cooker or similar whistle emitting vessel used for cooking on the above referred electrical cooking apparatus, generates audible signals (generally referred as whistle) during various stages of cooking. Prior to commencement of cooking the user can preset the number of whistles or audible signals to be recorded/monitored by the Electrical cooking apparatus during the course of cooking, which will be emitted by the pressure cooker. This presetting of the number of whistles will depend on the nature of food item to be cooked in the Pressure Cooker.[Number of whistles preset for Rice, vegetables will be less than that required for cooking grams, non vegetarian food] . The above mentioned method or system will then count down the audio signals or whistles. Upon counting the number of whistles, or in other words upon the countdown reaching zero, the cooking apparatus can do one of the several actions, some of which are mentioned below. (1) The cooking apparatus can enter a special mode called ‘keep warm’ mode. In the keep warm mode, the cooking apparatus will be in an intermittent power mode and heat the vessel sufficient to keep the food warm. (2) The cooking apparatus also, upon counting down the whistles, can switch off the cooking apparatus to standby or power off mode of the cooking apparatus.

To achieve the objects, a combination of circuits is created within the cooking apparatus and is an integral part of the cooking apparatus. Further a typical ICT is a combination of hardware/electrical circuits that generate the necessary power supplies, energise the induction coil and hence compatible vessel and a controller IC, providing timing for various signals needed for the proper functioning of the ICT along with user controls and user interface among other things.

As per invention an additional circuit is implemented in the hardware and additional algorithm is added in the controller software to achieve the unique idea presented.

Typically in prior art, an user uses an induction compatible pressure cooker or similar vessel on the ICT and the ICT is turned on to start heating the vessel and hence the cooking of the food within the vessel. Usually the number of audible signals or whistles indicate the cooking stage. The user turns off the ICT based on the number of whistles or audible signals which the user has to count manually. This necessitates the user to be alert, count the whistles or audible signals accurately and also be present in front of the ICT to turn it off at the time the counts meet the user’s requirement. Any error in the counting by the user leads to under or over cooking or even a potentially dangerous situation of the pressure vessel getting dry heated etc. The number of whistles can vary depending on the food inside, quantity of food inside, amount of water used for cooking, etc. So this puts the user under pressure to keep count and not to be away from the area of cooking while being physically within the range of being able to hear the audible signal or whistle.

In the proposed scenario as per the invention, a special hardware/electrical circuit and software algorithm ensures that the user can perform an automatic and unattended operation of cooking with a pressure cooker like vessel. Once the user puts the pressure cooker or similar vessel on the ICT when the cooking starts the user, can ‘set’ the number of whistles or audible signals that the user wants to be counted after which the ICT to be turned off or put in a special mode like keep warm mode etc.

A pressure cooker or similar vessel generates an audible signal like a whistle. The electrical circuit within the ICT consisting of a microphone and added circuitry, picks up this audible signal, and subsequently conditions the audio signal further by frequency and amplitude filtering with a multi stage amplifier. This conditioned signal is used to generate a pulse and this pulse signal is now ready to be fed to the microcontroller. Only audible signals that are loud enough and passing through the signal conditioning will generate a pulse at the input of the microcontroller. The microcontroller upon getting a signal at its input pin counts this as a potential valid signal of an audible signal. The software algorithm running in the controller decides the validity of the whistle or audible signal by waiting for a certain time window to ascertain that it’s not a spurious signal.

Once the microcontroller gets the input signal the software running in the microcontroller will compare with the user set count for the audible signals or whistles. If the input number of signals have not reached the count set by the user, in other words, if the user set count is higher than the total number of audible signals counted by the controller, the ICT keeps functioning at the power level set by the user. Upon reaching the user set count the software will automatically switch off the ICT or enter in to a special mode like keep warm mode etc. A keep warm mode will make the ICT supply energy to the vessel being used intermittently. This will ensure the food is kept warm even after it is cooked without user intervention.

Advantages of the invention:

The advantages of the proposed novel idea are as follows;

1. User does not have to count the whistles or audible signals manually – hence no missed counting or errors possible
2. The user need not be present in the cooking area for the sake of counting
3. User can choose who many whistles or audible signals has to be counted by the ICT
4. User is not needed to perform any actions upon reaching the number of whistles
5. The ICT automatically performs the switching off action or a special action upon reaching the user set number of whistles or audible signals
6. Improved safety due to errors in counting and hence delayed switch off
7. Energy efficiency improvement as the ICT will be switched off precisely after the user set count
8. Helps users who are hard of hearing who are unable to hear the whistles also to operate the ICT and pressure cooker or similar in a safe and convenient manner

As such the invention has achieved the object of automated heat flow through a heat source on which a pressure cooker is placed for cooking. Fig. 1 is the block diagram of the system and method. The regulation of heating elements of heat source is as detailed above. During the cooking process, as illustrated in fig. 2, the whistle sound generated by pressure cooker is converted into electrical signals using condenser microphones. The converted electrical signal is amplified using an audio amplifier. Using a band-pass filter or any such other filtering means, only the predetermined whistle sound falling within selective frequency range will be sensed, avoiding all other sounds. The output of pass filter is converted into pulses using a pulse generator and pulse signal may be fed to a decimal up counter and the counter counts the number of whistle sounds on the basis of pulses fed into the counter. The output of the counter may be compared using a comparator with the predetermined number of whistles set by the user. The predetermined required number of whistles may be set using a typical set switch and a binary up counter. When the pre-set number of whistles and the actual number of whistles become equal, the output signal from the comparator switches off the power supply to all heating elements or switches off the power supply to some of the heating elements selectively. The output of the comparator is generally amplified using an amplifier and fed to any typical cut-off system. The cut-off means soon after receiving the comparator signal to stop/reduce the heat, disconnects all/some of the heating elements of the heat source to stop/reduce the heat. However if the comparator goes low, there is no signal to cut-off means and the power supply to heating elements of the heat sources is switched ON. Typically the cut-off means is disposed between the actual stove/burner and the actual power supply source.

In one of the embodiments the invention discloses a domestic cooking device with heating elements connected to heat/power source onto which a pressure cooking may be mounted for cooking, which device may be switched off/regulated on the basis of number of whistling sound signal of specific frequency range generated by the pressure cooker, a microphone to convert the said whistle signal to an electrical signal, a band pass filter means allowing only specific frequency range signal, an amplifier for amplifying the said signal, a decimal-up counter to count the number of whistles, a comparator to compare the number of whistles with preset number, a regulator means to regulate the power supply by cutting off power supply to some/all of the heating element.

In another embodiment of the invention discloses a method of pressure cooking food in a domestic cooking device using heating elements connected to heat/power source by regulating the heat/switching off the device on the basis of number of whistling sound signals of specific frequency range generated by the pressure cooker which cooking using a microphone to convert the said whistle signal to an electrical signal, using a band pass filter means for allowing only a specific frequency range signal, using an amplifier for amplifying the said signal, using a decimal-up counter to count the number of whistles, using a comparator to compare the number of whistles with the present number, using a regulator means to regulate the power supply by cutting off power supply to some/all of the heating elements.

It will be understand that each of the components/arrangements/method described above, in permutation and combination may find other useful applications in other types of cooking system and cooking method.

While there has been attempt to disclose the novel features of the invention, and are described and illustrated herein, the same is not intended to be limited to the details above, since it shall be understood that some of the modifications and substitutions in the forms and details of the device/method illustrated can be made by those skilled in the art without departing from the scope of the invention. All such variations and modifications are well within the scope of this invention.

All the variations and modifications obvious to the skilled person are well within the scope and spirit of the invention.
,CLAIMS:1. A domestic pressure cooking device operable with a heating means in association with heat / power input source means comprising a control means, the said control means including :-
a. a heat input means,
b. a selection means to select the number of desired whistle sound generated by the cooking device,
c. a converter means to convert whistle sound generated by pressure cooker during the process of cooking into electrical signal,
d. a counter means operably associated with converter means to count the number of generated whistle sounds,
e. a comparator means operably associated with selection means and comparator means to compare the selected desired number of whistles generation stored in selection means and actual generated whistles counted by counter means and generate an output when the two numbers match,
f. a cut off means operably associated with comparator means and power source input means to disconnect the power source from the cooking device on the basis of signal from the comparator means,
2. The domestic pressure cooking device as claimed in claim 1 wherein the said cut off means is arranged between the heat /power input source and the heating means.
3. The domestic pressure cooking device as claimed in claim 1 wherein the said convertor means includes condenser microphones for converting the whistle sound generated by the cooking device into electrical signals.
4. The domestic pressure cooking device as claimed in claim 1 & 3 wherein the converter means includes an audio amplifier means.
5. The domestic pressure cooking device as claimed in claim 1, 3 & 4 wherein the converter means includes a filtering means for detecting selective frequency range of whistle sounds generated by the cooking device.
6. The domestic pressure cooking device as claimed in claim 1, 3, 4 & 5 wherein the converter means includes a pulse generator means for converting the electrical signals into pulse signal adaptable for feeding into counter means.
7. The domestic pressure cooking device as claimed in claim 1, wherein the counter means may include a set switch and a binary-up counter.
8. The domestic pressure cooking device as claimed in claim 1, wherein the comparator means includes an amplifier means.