Liquid presence determination and identification in beverage machine

Abstract

Methods and systems for employing a sensor to detect whether a liquid is present in a beverage machine or to identify a liquid in a beverage machine. A sensor may have a controller to apply alternating current (AC) excitation pulses to one of two probes disposed in the beverage machine. The sensor may also have a detector to obtain one or more voltage measurements used to determine a presence of liquid or identify a type of liquid.

Description

LIQUID PRESENCE DETERMINATION AND IDENTIFICATION IN BEVERAGE MACHINERELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C.§ 119(e) of U.S. Provisional Application Serial No. 63 / 627,994, filed February 1, 2024, which is incorporated herein by reference in its entirety.FIELD

[0002] This disclosure relates to beverage machines, such as coffee brewers that use a liquid to form the beverage.BACKGROUND

[0003] Beverage machines frequently employ a temperature sensor to detect a temperature of water or other liquid, e.g., to help ensure that the liquid is suitably heated, cooled or otherwise at a desired temperature for beverage formation. As an example, some coffee brewers use a temperature sensor positioned to contact liquid in a heater tank to detect the temperature of liquid in the tank and to control a heater accordingly.SUMMARY

[0004] According to one aspect, a beverage machine is provided. The beverage machine may include probes disposed in the beverage machine and a controller to apply an excitation signal to at least one of the probes. The excitation signal is a periodic signal including a rising edge and a falling edge. The controller may apply one or more cycles of the excitation signal to the at least one of the probes. A detector determines a presence of liquid between the probes based on a single voltage measurement obtained prior to a settling time of the excitation signal following the rising edge or the falling edge of one cycle of the one or more cycles of the excitation signal in air.

[0005] According to another aspect, a beverage machine is provided. The beverage machine may include probes disposed in the beverage machine and a controller to apply an excitation signal to at least one of the probes. The excitation signal is a periodic signal including a rising edge and a falling edge. The controller may apply one or more cycles of the excitation signal to the at least one of the probes. A detector identifies a type of liquid between the probes based on a plurality of voltage measurements obtained at different time delays following initiation of one of the one or more cycles of the excitation signal.

[0006] These and other aspects of the disclosure will be apparent from the following description and claims. It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments when considered in conjunction with the accompanying figures.BRIEF DESCRIPTION OF DRAWINGS

[0007] In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0008] FIG. 1 is a perspective view of a beverage machine in an illustrative embodiment;

[0009] FIG. 2 is schematic diagram of selected components of the beverage machine in an illustrative embodiment;

[0010] FIG. 3 is a circuit diagram of an exemplary sensor arrangement that can be employed in a beverage machine;

[0011] FIG. 4 is a circuit diagram of another exemplary sensor arrangement that can be employed in a beverage machine;

[0012] FIG. 5 is a circuit diagram of another exemplary sensor arrangement that can be employed in a beverage machine; and

[0013] FIG. 6 illustrates voltage waveforms associated with air and different exemplary liquids that may be used in the detection of liquid presence or liquid type according to some embodiments.DETAILED DESCRIPTION

[0014] It should be understood that aspects of the disclosure are described herein with reference to certain illustrative embodiments and the figures. The illustrative embodiments described herein are not necessarily intended to show all aspects of the disclosure, but rather are used to describe a few illustrative embodiments. Thus, aspects of the disclosure are not intended to be construed narrowly in view of the illustrative embodiments. In addition, aspects of the disclosure may be used alone or in any suitable combination with other aspects of the disclosure.

[0015] Generally speaking, a beverage machine may be used to form any suitable beverage, such as tea, coffee, other infusion-type beverages, beverages formed from a liquid or powdered concentrate, soups, juices or other beverages made from dried materials, carbonated or uncarbonated beverages. The beverage machine can form such beverages using a base liquid,such as water (e.g., demineralized water, tap water, bottled water), stored in a liquid supply tank. A beverage machine can be capable of forming a variety of beverages, each requiring a different amount or type of the base liquid. Thus, it may be desirable for a beverage machine to include features that allow the beverage machine to detect one or more physical characteristics of the liquid, e.g., detect a liquid level in the liquid supply tank, detect that liquid is available for use and / or is being provided to the machine components, detect a type of the liquid, detect a temperature of the liquid, etc. As discussed in more detail below, in some embodiments, a beverage machine can include a sensor that detects a presence of liquid using a single measurement and / or detects a type of the liquid using two or more measurements.

[0016] FIG. 1 shows a perspective view of a beverage machine 100 that incorporates features of this disclosure. In this illustrative embodiment, the machine 100 is arranged to form coffee or tea beverages. As is known in the art, a beverage cartridge 1 may be provided to the system 100 and used to form a beverage that is deposited into a user’s cup or other suitable container 2. The cartridge 1 may be manually or automatically placed in a brew chamber of a beverage dispensing station 15 that in some embodiments includes a cartridge holder 3 and cover 4 of the beverage machine 100. For example, the holder 3 may be or include a circular, cup-shaped or otherwise suitably shaped opening in which the cartridge 1 may be placed. With a cartridge 1 placed in the cartridge holder 3, a handle 5 may be moved by hand (e.g., downwardly) so as to move the cover 4 to a closed position (as shown in FIG. 1). In the closed position, the cover 4 at least partially covers the cartridge 1, which is at least partially enclosed in a space in which the cartridge 1 is used to make a beverage. For example, with the cartridge 1 held by the cartridge holder 3 in the closed position, water or other liquid may be provided to the cartridge 1 (e.g., by injecting the liquid into the cartridge interior) to form a beverage that exits the cartridge 1 and is provided to a cup 2 or other container. Of course, aspects of the disclosure may be employed with any suitably arranged system 100, including drip-type coffee brewers, carbonated beverage machines, and other systems that deliver water or other liquid to form a beverage. Thus, a cartridge 1 need not necessarily be used, but instead the beverage dispensing station 15 can accept loose coffee grounds or other beverage material to make a beverage. Also, the dispensing station 15 need not necessarily include a cartridge holder 3 and a cover 4. For example, dispensing station 15 can include a filter basket that is accessible to provide beverage material (such as loose coffee grounds), and the filter basket itself may be movable, e.g., by sliding engagement with the beverage machine housing 10, and a cover 4 may be fixed in place. In other embodiments, the dispensing station 15 need not be user accessible but, instead, beverage material may be automatically provided to, and removed from, the dispensing station 15.Moreover, the system 100 need not have a brew chamber but, instead, other types of dispensing stations, e.g., that dispense hot and / or cold water (whether still or carbonated) at an outlet such as a dispensing nozzle without mixing with any beverage ingredient. Accordingly, a wide variety of different types and configurations for a dispensing station may be employed with aspects of this disclosure.

[0017] In some embodiments, the beverage machine 100 uses liquid, such as water, that is provided by a liquid supply 6 to form a beverage. In some embodiments, the liquid supply 6 can include a tank 61 arranged to hold water or other liquid. The tank 61 can be removably supported on a base 62, which fluidly couples to a port on a bottom of the tank 61 to receive and deliver liquid to other components of the machine 100, such as the dispensing station 15. The floor 60 of the tank 61 is indicated above the base 62 in FIG. 2. A removable tank 61 can be convenient for a user because the user can remove the tank 61 from the base 62, e.g., by grasping a handle on the tank 61, for filling and then replace the tank 61 on the base 62. This is just one example, however, and a machine 100 can receive and / or store liquid in other ways. For example, the machine 100 can have a connection to a mains water supply (e.g., so-called “city water” or a line that delivers water under pressure to the machine 100), can have an internal or non-removable liquid supply tank or reservoir, or other suitable arrangement.

[0018] In some embodiments, the machine 100 has one or more sensor components, and some of those components may detect characteristics of liquid in the liquid supply 6. As an example, the machine 100 can include a sensor component that contacts liquid in the liquid supply 6 to detect a presence or absence of liquid (e.g., to indicate a low water level in the tank 61), a type of the liquid, a temperature of water received from the tank 61, and / or other physical characteristics of the liquid. Such sensor components can be part of a sensor circuit that is electrically powered and used by a machine controller to detect the physical characteristics of the liquid and control the machine 100 accordingly. As an example, a controller can use a low water signal from a sensor circuit to provide an indication to a user that water needs to be added to the tank 61 and / or use a temperature signal from a sensor circuit to control a heater or other liquid conditioner (such as a chiller, carbonator, etc.).

[0019] In some embodiments, for example, the beverage machine 100 can have a sensor component arranged to detect physical characteristics of the liquid in a supply line, such as the presence or absence of the liquid and / or a temperature of the liquid.

[0020] FIG. 2 shows a schematic diagram of selected beverage machine 100 components in one embodiment that employs a sensor 9 that includes sensor components 91, 92 arranged to detect at least one physical characteristic of liquid in the liquid supply 6. In one example, the sensorcomponent 91 may include a conductive component arranged to contact liquid in the supply line 63 and may also include a temperature component arranged to detect a temperature of liquid in a supply line 63. Thus, in some arrangements, the sensor component 91 can include a first conductive probe having an electrically conductive portion in contact with the liquid to detect a first physical characteristic of the liquid (e.g., to detect a presence and absence of the liquid), and a temperature probe that is electrically insulated from the liquid and arranged to detect a second physical characteristic of the liquid (e.g., the temperature probe such as a thermistor arranged to detect temperature of the liquid). The first conductive probe of the sensor component 91 may work in conjunction with the sensor component 92, which may include a second conductive probe, as discussed. The sensor component 92 may, additionally or alternately to the sensor component 91, also include a temperature probe.

[0021] In some embodiments, the supply line 63 is fluidly coupled to the tank 61 (e.g., via a port at a bottom of the tank 61) and arranged to deliver liquid to a pump 12. The pump 12 can have an inlet fluidly coupled to the supply line 63 to receive liquid from the tank 61, and can deliver the liquid via an outlet to a heater 13 (or other liquid conditioner such as a chiller, carbonator, etc. that is fluidly coupled to the pump outlet), which heats (cools, carbonates, etc.) the liquid that is subsequently delivered to the dispensing station 15. In FIG. 2, the sensor component 91 is shown between the tank 61 and the pump 12, but the sensor (or other additional sensors) can be located in other places, such as between the pump 12 and heater 13, for example. The second sensor component 92 is shown upstream of the heater 13, but may also be located in other places. The sensor components 91, 92 may be located anywhere along the liquid supply conduit (between the tank 61 and dispensing station 15).

[0022] In some embodiments, the sensor components 91, 92 and specifically, the first conductive probe and the second conductive probe can detect the presence or absence of liquid in the supply line 63 and / or a type of the liquid, as detailed with reference to FIGs. 3-6. If the sensor component 91 and / or the sensor component 92 includes a temperature probe or a pressure sensor, detecting the presence of liquid may provide an indication that another physical characteristic detected by the sensor component 91, 92 (such as a temperature or pressure) is associated with the liquid rather than some other item. This can be useful, for example, where the sensor 9 is located in a part of the liquid supply 6 where liquid is not always present, and / or where the sensor 9 detects another characteristic, such as temperature, that is used to control operation of a pump 12 and / or heater 13. In addition, the presence / absence of liquid determined and signaled by the sensor 9 can provide an indication that the tank 61 is disconnected from the machine 100, has an exhausted liquid supply and / or that a liquid level in the tank 61 is below athreshold level. In the arrangement of FIG. 2, the supply line 63 is fluidly coupled to the bottom of the tank 61 and extends upwardly, e.g., above a maximum liquid level ML of the tank 61.

[0023] Since the sensor components 91, 92 are arranged in the supply line 63 and the path from the heater 13 to the dispensing station 15, this can allow the sensor 9 to detect whether liquid is present at least between the sensor components 91, 92.

[0024] In some cases, the sensor 9 can detect whether a liquid level LL of liquid in the supply line 63 is above or below a location of the sensor component 91 along the supply line 63. This can allow a determination of whether a liquid level LL in the tank 61 is below a threshold level, such as a minimum level required to dispense a beverage. In some embodiments, the supply line 63 can include a vent 64 arranged to vent the supply line 63 to atmospheric or other ambient pressure, e.g., the vent 64 can include an electrically-operated valve that a controller 16 can open to expose the supply line 63 to ambient pressure. In some cases, the vent 64 can be positioned above the maximum liquid level ML and / or above a position of the sensor component 91. Venting of the supply line 63 can allow the liquid level in the supply line 63 to correspond to, or be the same as, the liquid level LL in the tank 61. Thus, if the supply line 63 is vented and the sensor 9 detects the presence of liquid, the controller 16 can determine that the liquid level LL in the tank 61 is above the position or height of the sensor component 91 (e.g., above a threshold level), and if the sensor 9 does not detect the presence of liquid (i.e., detects the absence of liquid), the controller 16 can determine that the liquid level LL in the tank 61 is below the position or height of the sensor component 91 or that the tank 61 is disconnected from the supply line 63. In some embodiments, the beverage machine need not include a valve for the vent 64. For example, the vent 64 can have a permanently open orifice or other opening of suitable size to always vent the supply line 63 to atmosphere. The vent 64 opening sized can be arranged relative to the pump capacity such that the pump can deliver liquid for beverage formation even though air may be drawn into the vent 64.

[0025] In some embodiments, the pump 12 is located at or above the maximum liquid level ML of the tank 61 or at least downstream of the location of the sensor component 91 along the supply line 63. This arrangement can allow a determination whether liquid is being supplied to the pump 12 or not and can be useful to determine whether the tank 61 is disconnected from the machine 100 and / or a liquid supply in the tank 61 has been exhausted. For example, if the tank 61 is removed from the base 62 or runs out of liquid during operation of the pump 12 in drawing liquid from the tank 61, air will be drawn into the supply line 63 rather than liquid. When air reaches the sensor component 91, the sensor 9 can detect the absence of liquid and thus that the tank 61 has been removed or the liquid supply exhausted.

[0026] As will be understood from the above, the sensor components 91, 92 of the sensor 9 can be positioned in a liquid supply 6 in a location where liquid may not always be present between the first and second conductive probes, e.g., whether upstream or downstream of the pump 12 and / or in other locations. Thus, where the sensor 9 can detect the presence / absence of liquid and any other characteristics of the liquid such as temperature or pressure, the sensor 9 can provide the controller 16 with information regarding not only whether liquid is present or absent, but also whether the other detected characteristic is properly associated with the liquid or not. For example, if no liquid is detected by the sensor 9, then a detected temperature by the sensor component 91 may not be of the liquid, but rather of the supply line 63, air or other item. The controller 16 can use signals from the sensor 9 regarding detected characteristics to control at least a portion of the beverage machine. As an example, the controller 16 may normally use liquid temperature sensed by the sensor component 91 to control a heater 13, such as an inline heater or flash heater. Such inline heaters may heat liquid relatively rapidly as the liquid passes through the heater 13, and so the incoming temperature of liquid can be useful to control a heating rate, output power or other characteristics of the heater 13 and / or to control a flow rate of liquid delivered by the pump 12 to the heater 13. As an example, colder incoming water may require use of a higher heating rate or power and / or a lower liquid flow rate than warmer incoming water.

[0027] Where the sensor component 91 is positioned upstream of the heater 13, the controller 16 can determine whether a sensed temperature is indicative of liquid delivered to the heater 13 or not, and this information can be used to control the heater 13, the pump 12 and / or other components. For example, in some embodiments, the controller 16 can be arranged to control the vent 64 and pump 12 to deliver air to the heater 13 so that the air can be heated and delivered to dispensing station 15 (e.g., to pre-heat the station 15 prior to dispensing a hot beverage. This can be done by opening the vent 64 and operating the pump 12 so only air is pumped to the heater 13 and dispensing station 15.). Heating air may require a lower heating rate or output power than heating water and so the controller 16 may control the heater accordingly.

[0028] Subsequently, the controller 16 can control the vent 64 and pump 12 to deliver liquid from the tank 61 to the heater 13 for heating and delivery to the dispensing station 15 (e.g., by closing the vent 64 and operating the pump 12 to draw liquid from the tank 61 and deliver the liquid to the heater 13). The sensor component 91, if positioned between the vent 64 and the pump 12 or between the pump 12 and heater 13 in alternate embodiments, can be used to detect temperature of air or water, as well as to determine, in conjunction with sensor component 92, whether and when liquid is being delivered to the heater 13.

[0029] The controller 16 can control various components of the beverage machine 100 in different ways based on signals from the sensor 9 regarding detected physical characteristics. In some embodiments, the controller 16 can provide an indication to the user to add liquid to the tank 61 as well as shut down or reduce a heating rate of the heater 13 if the sensor 9 detects the absence of liquid. The sensor 9 can also provide an indication that the tank 61 is removed from the machine 100 if the sensor 9 detects the absence of liquid while the pump 12 is drawing water from the tank 61. That is, if the tank 61 is removed as the pump 12 is pulling liquid from the supply line 63, liquid will no longer be provided to the inlet side of the supply line 63 and the pump 12 will empty the supply line 63. Once liquid is drawn past the sensor component 91, the sensor component 91 will no longer detect liquid, indicating that the tank 61 has been removed. In this case, the controller 16 can provide an indication to the user to replace the tank 61, stop pump and heater operation, etc.

[0030] In some embodiments, such as those detailed with reference to FIGs. 3-5, the sensor 9 can include circuit elements and be electrically powered by a non-isolated power supply 7 that receives input electrical power via a mains power connection 8 (such as a plug arranged to connect with a wall outlet or other power source) and conditions the input power to provide output power to the sensor 9. The input electrical power to the power supply 7 can be arranged in various ways, but in general will be at a higher voltage than that used by the sensor 9 and other components of the machine 100. As an example, the input electrical power can be about 120 Volts AC as provided within some residences. The non-isolated power supply 7 can be arranged to reduce the voltage of the input electrical power, e.g., to 120 Volts AC, and to convert the input electrical power to direct current, e.g., 120 Volt AC can be converted to 12 Volt DC.

[0031] The non-isolated power supply 7 can use a plurality of impedances (e.g., resistors) to reduce the voltage of the input electrical power, and a voltage converter to convert the 120 Volt AC to 12 Volt DC. The non-isolated power supply 7 can also include a voltage regulator or other component to reduce the voltage of the converted DC power, e.g., to reduce the 12 Volt DC to 3.3 Volts DC. The 3.3 Volt DC output electrical power can be used to power the sensor circuit 9 as well as other components of the machine 100, such as parts of the controller 16. Similarly, the 12 Volt DC power can be used to power other components, such as the pump 12 and / or parts of the controller 16. In some cases, some components such as the heater 13 can be powered by unmodified input power, e.g., the input electrical power can be selectively directly connected to the heater 13 using relay switches or other components controlled by the controller 16. These are only illustrative embodiments, however, and the non-isolated power supply 7 canbe arranged to produce other voltage levels using any suitable components. Regardless, the nonisolated power supply 7 employs a common ground or circuit neutral for input and output power. Note as well that the machine 100 can employ other types of power supplies than a nonisolated power supply, such as isolated power supplies, to power beverage machine components including the sensor 9.

[0032] FIG. 3 is a circuit diagram of an exemplary sensor 9 that can be employed in the FIG. 2 arrangement and others. The metallic probes of the sensor components 91, 92 are shown with a simplified electric model of water as an exemplary medium between them. When the medium is water, as in the exemplary illustration for an exemplary sensor 9, the capacitance (C_Medium) may be 2.1 nanofarad (nf) and the resistance (R_Medium) may be 1800 kilo-ohm (K). Each of the values varies with the medium, and resistance may vary with ionic content and probe design. Prior approaches to detecting whether liquid is present in a beverage machine rely on the conductivity (resistance) of water (e.g., by using direct current (DC) excitation). However, the inventor has appreciated that these approaches are sensitive to the ionic content of water. That is, conductivity of water can vary widely based on ionic content and impurities in water such that threshold values used to detect the presence of water with a given ionic content may not apply to water with a different ionic content, for example. Thus, demineralized water may be difficult to detect with prior approaches. According to the approach described with reference to the exemplary embodiments illustrated in FIGs. 3-6, both the conductivity and capacitance of a medium are used to detect the presence of a liquid and, additionally, the type of the liquid may be determined.

[0033] This may be reflected in the use of alternating current (AC) or pulsating DC excitation and in one or more measurements of voltage resulting from each excitation pulse cycle, as detailed. While an AC changes direction such that the resulting voltage (referred to as AC excitation for explanatory purposes) spans between positive and negative values (e.g., between +120 Volts and -120 Volts for an average of 0 Volts over a cycle), a pulsating DC refers to switching DC voltage on and off such that the DC current oscillates in amplitude over a cycle (i.e., pulsating DC is also periodic). Because DC does not change direction like AC, the average voltage resulting from pulsating DC (referred to as pulsating excitation for explanatory purposes) is a non-zero value. For example, an exemplary pulsating excitation voltage may be a 3.0 Volt square wave that is 3.0 Volts for 50 percent of the time such that the average voltage over a pulsating DC cycle is 1.5 Volts.

[0034] As noted, one or more voltage measurements may be taken within one pulsating excitation cycle. For example, a voltage measurement, at analog-to-digital converter (ADC)330, may be obtained only once per excitation pulse cycle to determine a presence of liquid. Specifically, a voltage measurement may be obtained within a specific duration following a start of an excitation cycle (within DI in FIG. 6) or within a specific duration following the end of an excitation cycle (within D2 in FIG. 6). As further discussed with reference to FIG. 6, the durations DI and D2 may end before a settling time of the excitation pulse in air following the rising edge and the falling edge, respectively. Settling time in a given medium (e.g., air) after a rising edge refers to the delay following the time that an excitation pulse is applied (i.e., turned on) when the excitation pulse has reached and remains at the excitation value (within a specified error band) in the medium. Similarly, settling time in the medium after a falling edge refers to the delay following the time that an excitation pulse is ended (i.e., turned off) before the excitation pulse reaches zero in the medium. Settling time in a given medium in which the sensor component 91 to which the excitation pulse is applied is disposed is based on the dielectric constant of the medium. Depending on the dielectric constant of a medium and the duration of the excitation pulse, the settling time may not be reached before the end of one excitation cycle. For example, the dielectric constant of air is approximately 80 times less than the dielectric constant of water. As such, settling time of the excitation pulse is faster when the sensor component 91 is disposed in air rather than water (i.e., when the supply line 63 has no liquid in it). By measuring voltage at the sensor component 91 before the settling time for the excitation pulse in water (or liquid, more generally), the presence of only air (i.e., absence of a liquid) in the supply line 63 may be determined. More generally, voltage may be measured at the sensor component 91 at a specified time following a rising or falling edge of the excitation signal. In general, the specified time may be before the settling time of the excitation signal in air.

[0035] As further discussed with reference to FIG. 6, the single voltage measurement may be sufficient to determine whether a liquid is present or there is only air in the supply line 63. Alternately, a voltage measurement may be obtained at two or more time delays following the start of the excitation cycle to determine a type of liquid. As also discussed with reference to FIG. 6, two or more voltage measurements may be compared against known voltage values for a set of liquids to identify the liquid in the supply line 63.

[0036] The optional shunt resistor (R_shunt) 310 may be included to limit the voltage at the analog-to-digital converter (ADC) input (ADC_in) 320. The ADC input 320 is to an ADC 330 that provides a digital signal for processing at the controller 16, as further discussed. One of the first or second conductive probes of the sensor components 91, 92 may be provided with an AC excitation via the general input / output (GPIO) pin 340. The power supply 7 may be used toobtain a voltage at voltage excitation pin (V_pin) 350 that is output as an excitation pulse at the GPIO pin 340. The resistor (R_series) 360 may be a current limiting resistor in series with the voltage pin 350 and may have a value that is chosen based on the ADC 330. One or both of the capacitors (C_seriesP, C_seriesN) 370P, 370N may be arranged, as shown, to limit the input to the ADC input 320 for safety. That is, regardless of the capacitance value of the medium, the input to the ADC 330 is limited by the value of the capacitor(s) 370P, 370N. The value of the capacitors 370P, 370N may be on the order of 100 nF, for example. In terms of excitation, rather than detection, the capacitors 370P, 370N may convert a pulsating excitation at V_pin 350 (i.e., a voltage resulting from pulsating DC) to AC excitation at the first and second conductive probes of the sensor components 91, 92. Each of the optional connectors 380 facilitates connection and disconnection between the sensor components 91, 92 and the detection portion including the excitation source (350).

[0037] The sensor 9 may operate based on control and determination by the controller 16. The controller 16 may control application of the excitation pulses to the conductive probe of the sensor component 91, according to the exemplary arrangement shown in FIG. 3. Voltage values between the sensor components 91, 92 resulting from the excitation pulses may be measured at the ADC 330 and may be used to determine a presence of liquid (i.e., the medium being other than air) or a type of liquid. Specifically, as shown in FIG. 3, voltage is measured using the same conductive probe (sensor component 91) that received the excitation pulse. Further, as shown, the detector of the sensor 9 is configured such that the voltage measured at the ADC 330 is a filtered version of the voltage signal between the sensor components 91, 92 determined by the capacitor 370P and resistor 310.

[0038] As noted, for each applied excitation pulse, one or more voltage values may be measured. That is, one or more measurements may be obtained at the ADC 330 between excitation pulses. A single voltage measurement may be compared with a threshold value or range to determine a presence of liquid (e.g., a voltage measurement resulting from an excitation pulse at the conductive probe of the sensor component 91 may have to be below a threshold value or between minimum and maximum threshold values in order for the controller 16 to indicate a presence of liquid). Two or more voltage measurements may be compared with known voltage values for specific liquids to identify a type of liquid in the supply line 63.

[0039] Alternately, a status at the GPIO pin 340 may be used to detect a presence of liquid or identify a liquid. That is, the ADC 330 may not be included in the sensor 9. Instead, the controller 16 may obtain the status at the GPIO pin 340 (e.g., via a universal asynchronous receiver transmitter (UART) coupled to the GPIO pin 340). The status at the GPIO pin 340indicates the excitation signal voltage value followed by a voltage value between the sensor components 91, 92. The GPIO pin 340 may be regarded as an ADC with only two levels. This is because any voltage at the GPIO pin 340 (resulting from the excitation pulses) that is below a first threshold value (e.g., 1.6 V) will result in a LO status at the GPIO pin 340, and any voltage at the GPIO pin 340 that is above a second threshold value (e.g., 2.2 V) will result in a HI status at the GPIO pin 340. A voltage value between the first and second threshold values will still result in a HI or LO status at the GPIO pin 340. Thus, to avoid such an ambiguous result, the excitation cycle may be chosen to minimize a duration for which the excitation signal voltage is between the first and second threshold values compared with the duration for which the excitation signal voltage is below the first threshold value or above the second threshold value. The detection of liquid presence or identification of a liquid based on the status at the GPIO pin 340 is further discussed with reference to FIG. 6.

[0040] FIG. 4 is a circuit diagram of another embodiment of an exemplary sensor 9 that can be employed in the FIG. 2 arrangement and others. The exemplary circuit arrangement of FIG. 4 is a simplified version of the circuit arrangement shown in FIG. 3. As discussed with reference to FIG. 3, an excitation pulse (e.g., pulsating excitation) is generated at voltage excitation pin (V_Pin) 450 and provided as excitation pulses at pin 460. Thus, the HI or LO status at this pin 460 may be used rather than the ADC 420 in alternate embodiments. Unlike in the exemplary embodiment of FIG. 3, the simplified embodiment of FIG. 4 is shown without the capacitors 370P, 370N or other components to convert pulsating excitation to AC excitation at the conductive probes of the sensor components 91, 92. Thus, the average current at the conductive probes of the sensor components 91, 92 is not zero in the exemplary embodiment of FIG. 4 (as it is when AC excitation is applied as in the exemplary embodiment of FIG. 3) but may be lower than the average current that results from prior approaches using (non-pulsating) DC excitation.

[0041] The resistor (Rseries) 470 may be a current limiting resistor in series with the excitation pin 450 and may have a value that is chosen based on the ADC 420. The optional connectors 480 facilitate connection and disconnection between the conductive probes of the sensor components 91, 92 and the detection portion including the excitation source (450). For each excitation pulse that is provided to the conductive probe of the sensor component 91, voltage between the conductive probes of the sensor components 91, 92, represented at ADC input (ADC_pin) 410 is measured by the ADC 420 and used by the controller 16 to determine whether the medium between the sensor components 91, 92 is a liquid (i.e., not air).

[0042] Specifically, as is the case for the detector shown in FIG. 3, the configuration of the voltage detection portion of the sensor 9 of FIG. 4 is as a voltage divider. Thus, for each cycleof excitation pulse, multiple voltage measurements are obtained at the ADC 420, and each voltage measurement is a fraction of the voltage between the sensor components 91, 92 that is based on values of the ADC resistor (R_adc) 430 and the ADC capacitor (c_adc) 440. As noted for the embodiment of FIG. 3, the controller 16 may obtain a single voltage measurement to detect a presence of liquid or may obtain two or more voltage measurements to determine a type of liquid in the supply line 63.

[0043] FIG. 5 is a circuit diagram of another embodiment of an exemplary sensor 9 that can be employed in the FIG. 2 arrangement and others. Like the sensor configurations shown in FIGs.3 and 4, the exemplary configuration of the sensor 9 shown in FIG. 5 includes optional connectors 580 that facilitate connection and disconnection between the sensor components 91, 92 and the detection portion. In the case of the exemplary sensor 9 of FIG. 5, the detection portion includes a transformer that provides galvanic isolation between the primary coil 520 and secondary coil 530. An optional shunt resistor (R_shunt) 510 is shown, as in the embodiment of FIG. 3. This shunt resistor 510 may limit the voltage on the primary side and, thus, on the secondary side, which affects the voltage at the ADC input (ADC_in) 560 provided to the ADC 570.

[0044] As is the case for the embodiments shown in FIGs. 3 and 4, the voltage measured at the ADC 570 represents voltage between the conductive probes of the sensor components 91, 92 and is based on excitation pulses provided from voltage excitation pin (V_Pin) 550 through the resistor (R_series) 540 that is in series and that may be a current limiting resistor. Like the exemplary embodiment shown in FIG. 3, the exemplary embodiment of FIG. 5 involves the application of AC excitation at the conductive probes of the sensor components 91, 92. The conversion of pulsating excitation at V_Pin 550 to AC excitation is based on mutual inductances LI at the primary coil 520 and secondary coil 530, as indicated, that serve a similar function in the conversion as the capacitors 370P, 370N in the exemplary embodiment of FIG. 3. As previously noted, one or multiple voltage measurements may be obtained based on each excitation pulse to detect a presence of liquid or identify a type of liquid between the sensor components 91, 92 in the supply line 63.

[0045] FIG. 6 illustrates voltage waveforms 610, 620, 630, 640 associated with air and different liquids that may be used in the detection of liquid presence or liquid type according to some embodiments. Time is indicated along the horizontal axis, and voltage is indicated along the vertical axis. The voltage waveforms 610, 620, 630, 640 are respectively associated with air, tap water, alkaline water, and distilled water, and different patterns are used to indicate each of the voltage waveforms 610, 620, 630, 640. A start and end of an exemplary excitation cycle aremarked on the axis indicating time. The voltage waveforms 610, 620, 630, 640 illustrate the voltage values resulting from application of the excitation signal when air, tap water, alkaline water, and distilled water are present between the sensor components 91, 92 in the supply line 63, respectively. A settling time SI in air following the start of the excitation pulse is indicated. This may be the time following the start of the excitation cycle (i.e., delay) at which the value of the voltage waveform 610 reaches 90 percent (%) of the maximum voltage of the excitation pulse. A settling time S2 in air following the end of the excitation pulse is also indicated. This may be the time following the end of the excitation cycle (i.e., delay) at which the value of the voltage waveform 610 reaches 10 % of the maximum voltage of the excitation pulse. Generally, settling times SI and S2 will be the same.

[0046] As shown, the voltage waveform 610 associated with air increases immediately following the start of the excitation cycle, as compared with the other voltage waveforms 620, 630, 640, and decreases immediately following the end of the excitation cycle, while other voltage waveforms 620, 630, 640 rise and fall more gradually. That is, the value of the voltage waveform 610 is clearly distinguishable from the values of the voltage waveforms 620, 630, 640 within the duration DI after the start of the excitation cycle or within the duration D2 after the end of the excitation cycle. Thus, a single voltage measurement taken within the duration DI or within the duration D2 may be used to determine the presence of a liquid in the supply line 63 (i.e., whether something other than air is between the sensor components 91, 92).

[0047] More particularly, as shown in FIG. 6, the duration DI (set of delays following the rising edge) may begin when the voltage waveform 610 value increases to a threshold value TH_h and may end before the settling time SI. During this duration DI, only the voltage waveform 610 has voltage values above the threshold value TH_h. Thus, the presence of air (i.e., absence of a liquid) may be detected if a single voltage measurement taken within the duration DI has a value at or above the threshold value TH_h. The duration D2 (set of delays following the falling edge) may begin when the voltage waveform value falls to a threshold value TH_1 and may end before the settling time S2. During this duration D2, only the voltage waveform 610 has voltage values below the threshold value Th_l. Thus, the presence of air (i.e., absence of a liquid) may be detected if a single voltage measurement taken within the duration D2 has a value at or below the threshold value TH_1. According to an exemplary embodiment, durations DI and D2 may be the same and may be based on the settling times SI and S2. In alternate embodiments, DI and D2 may be same or different percentages of a cycle time of the excitation cycle (i.e., of a duration between the start of the excitation cycle and the end of the excitation cycle, as labeled in FIG. 6).

[0048] Alternately, the excitation pulse voltage value may be selected such that only the voltage waveform 610 associated with air would result in a HI status at the GPIO pin 340 (or pin 460) immediately following the start of the excitation cycle or a LO status immediately following the end of the excitation cycle. In this case, without using ADC 330 (or 420), a HI status during duration DI or a LO status during duration D2 may indicate that air is present between the sensor components 91, 92 (i.e., there is no liquid in the supply line 63).

[0049] According to other embodiments, two or more voltage measurements obtained at different time delays following the start of the excitation cycle can be matched with voltage values of one of the voltage waveforms 610, 620, 630, 640 to identify whether air, tap water, alkaline water, or distilled water is present between the sensor components 91, 92 in the supply line 63. While the four voltage waveforms 610, 620, 630, 640 are discussed with reference to FIG. 6 for explanatory purposes, it should be clear that any number of known voltage waveforms may be used to identify any number of liquids according to the techniques detailed herein.

[0050] According to some embodiments, an ADC 330, 420, or 570 may be used to obtain two or more voltage measurements at corresponding two or more time delays following the start of the excitation cycle, and the controller 16 may compare the voltage measurements with voltage values of known waveforms (e.g., 610, 620, 630, 640 and any additional waveforms) at the same time delays. Based on a closest match identified by the comparison, the liquid (or air) in the supply line 63 may be identified.

[0051] In alternate embodiments, the status (HI or LO) at a GPIO pin 340 (or pin 460) may be used instead of voltage measurements at an ADC 330, 420, or 570. For example, 8 samples may be obtained at different time delays following the start of an excitation cycle and (e.g., with HI = 1 and LO = 0), a resulting byte may be compared with a byte associated with each known waveform (e.g., 610, 620, 630, 640 and any additional waveforms). For example, based on the first few time delays, the byte associated with air may be [01111111] or [11111111] because, as FIG. 6 indicates for voltage waveform 610, the voltage value increases almost immediately to a voltage that would result in a HI status (1) following the start of the excitation cycle.

[0052] To initiate a beverage cycle, a user may first insert a cartridge 1 into the dispensing station 15 and provide an indication (e.g., by pressing a button or other suitable step) to beverage machine 100 to prepare a beverage. At or before this time, the controller 16 can monitor the sensor 9 to assess whether liquid is present between the sensor components 91, 92. If the supply line 63 is provided with a controllable vent 64, the controller 16 can open the vent valve 64 to help ensure that the liquid level in the supply line 63 is equal to the liquid level in the tank 61. Ifno liquid is detected, the controller 16 can stop beverage formation and provide an indication to the user, e.g., via a user interface on the housing 10, that water or other liquid must be added and / or the tank 61 replaced. If liquid is detected or identified, the controller 16 can proceed with beverage formation, e.g., including closing the vent 64, operating the pump 12 to deliver liquid to the heater 13. A temperature of the incoming liquid (e.g., detected by a temperature probe at sensor component 91) can be used by the controller 16 to control the heater 13 and / or pump 12. As an example, a power output of the heater 13 and / or a flow rate of the pump 12 can be adjusted to compensate for different incoming liquid temperatures. During pump 12 operation, the controller 16 can monitor the sensor 9 for the absence of liquid. If an absence of liquid is detected, the controller 16 can stop pump operation, heating and / or other functions, e.g., because the tank 61 may have been removed and / or a liquid supply in the tank 61 exhausted. The controller 16 can provide an indication to a user via the user interface that the tank 61 should be replaced to begin or restart beverage dispensing.

[0053] As noted above, operation of the pump 12, heater 13 and other components of the machine 100 may be controlled by the controller 16, which may include a programmed processor and / or other data processing device along with suitable software or other operating instructions, one or more memories (including non-transient storage media that may store software and / or other operating instructions), temperature and liquid level sensors, pressure sensors, input / output interfaces (such as a user interface on the housing 10), communication buses or other links, a display, switches, relays, triacs, or other components necessary to perform desired input / output or other functions. A user interface may be arranged in any suitable way and include any suitable components to provide information to a user and / or receive information from a user, such as buttons, a touch screen, a voice command module (including a microphone to receive audio information from a user and suitable software to interpret the audio information as a voice command), a visual display, one or more indicator lights, a speaker, and so on.

[0054] While aspects of the disclosure may be used with any suitable cartridge, or no cartridge at all, some cartridges may include features that enhance the operation of a beverage machine 100. As is known in the art, the cartridge 1 may take any suitable form such as those commonly known as a sachet, pod, capsule, container, tablet, or other. For example, the cartridge 1 may include an impermeable outer covering within which is housed a beverage medium, such as roasted and ground coffee or other. The cartridge 1 may also include a filter so that a beverage formed by interaction of the liquid with the beverage medium passes through the filter before being dispensed into a container 2. As will be understood by those of skill in the art, cartridges in the form of a pod having opposed layers of permeable filter paper encapsulating a beveragematerial may use the outer portion of the cartridge 1 to filter the beverage formed. The cartridge 1 in this example may be used in a beverage machine to form any suitable beverage such as tea, coffee, other infusion-type beverages, beverages formed from a liquid or powdered concentrate, etc. Thus, the cartridge 1 may contain any suitable beverage material, e.g., ground coffee, tea leaves, dry herbal tea, powdered beverage concentrate, dried fruit extract or powder, powdered or liquid concentrated bouillon or other soup, powdered or liquid medicinal materials (such as powdered vitamins, drugs or other pharmaceuticals, nutriaceuticals, etc.), and / or other beveragemaking material (such as powdered milk or other creamers, sweeteners, thickeners, flavorings, and so on). In one illustrative embodiment, the cartridge 1 contains a beverage material that is configured for use with a machine that forms coffee and / or tea beverages, however, aspects of the disclosure are not limited in this respect.

[0055] In some embodiments, a cartridge may be provided in the form of a beverage tablet. In some embodiments, the beverage ingredients of the tablet have been compacted to form the tablet. The tablet may be able to hold its own shape, and thus may not require individual packaging to prevent dispersing of the beverage ingredients prior to use in forming a beverage. In some embodiments, the tablet may be coated. In some embodiments, the beverage tablet may directly contact a beverage machine without intervening packaging containing the beverage tablet. For example, in some embodiments, the coating of the beverage tablet, or the compacted ingredients (e.g. coffee grounds) of the tablet, may directly contact a beverage machine without intervening packaging.

[0056] Also, the disclosure may be embodied as a method, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.

[0057] As used herein, “beverage” refers to a liquid substance intended for drinking that is formed when a liquid interacts with a beverage material, or a liquid that is dispensed without interacting with a beverage material. Thus, beverage refers to a liquid that is ready for consumption, e.g., is dispensed into a cup and ready for drinking, as well as a liquid that will undergo other processes or treatments, such as filtering or the addition of flavorings, creamer, sweeteners, another beverage, etc., before being consumed.

[0058] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merelyas labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0059] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0060] Having thus described several aspects of at least one embodiment of this disclosure, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the disclosure. Accordingly, the foregoing description and drawings are by way of example only.

Claims

CLAIMS1. A beverage machine comprising: probes disposed in the beverage machine; a controller configured to apply an excitation signal to at least one of the probes, wherein the excitation signal is a periodic signal including a rising edge and a falling edge, and the controller is configured to apply one or more cycles of the excitation signal to the at least one of the probes; and a detector configured to determine a presence of liquid between the probes based on a single voltage measurement obtained prior to a settling time of the excitation signal following the rising edge or the falling edge of one cycle of the one or more cycles of the excitation signal in air.

2. The beverage machine according to claim 1, wherein the excitation signal is based on an alternating current (AC) or pulsating excitation.

3. The beverage machine according to claim 1, wherein the detector includes an analog- to-digital converter (ADC) arranged to measure the single voltage measurement.

4. The beverage machine according to claim 3, wherein the detector is configured to determine the presence of the liquid by comparing the single voltage measurement with a threshold voltage value.

5. The beverage machine according to claim 4, wherein the threshold voltage value is different based on whether the single voltage measurement is obtained following the rising edge or the falling edge.

6. The beverage machine according to claim 5, wherein the threshold voltage value based on the single voltage measurement being obtained following the rising edge is greater than the threshold voltage value based on the single voltage measurement being obtained following the falling edge.

7. The beverage machine according to claim 1, wherein the detector includes a general input / output pin (GPIO) arranged to provide a high or low signal as the single voltage measurement.

8. The beverage machine according to claim 7, wherein the detector is configured to determine the presence of the liquid based on whether the single voltage measurement is the high or low signal.

9. The beverage machine according to claim 8, wherein the detector is configured to determine the presence of the liquid based on the single voltage measurement being the low signal and being obtained prior to the settling time of the excitation signal following the rising edge and to determine that liquid is not present based on the single voltage measurement being the high signal.

10. The beverage machine according to claim 1, wherein the detector is configured to obtain the single voltage measurement within a duration that is ten percent of a duration of the one cycle of the one or more cycles of the excitation signal.

11. A beverage machine comprising: probes disposed in the beverage machine; a controller configured to apply an excitation signal to at least one of the probes, wherein the excitation signal is a periodic signal including a rising edge and a falling edge, and the controller is configured to apply one or more cycles of the excitation signal to the at least one of the probes; and a detector configured to identify a type of liquid between the probes based on a plurality of voltage measurements obtained at different time delays following initiation of one of the one or more cycles of the excitation signal.

12. The beverage machine according to claim 11, wherein the excitation signal is an alternating current (AC) or pulsating excitation.

13. The beverage machine according to claim 11, wherein the detector includes an analog-to-digital converter (ADC) arranged to measure the plurality of voltage measurements.

14. The beverage machine according to claim 13, wherein the detector is configured to identify the type of liquid by comparing the plurality of voltage measurements with different sets of known voltage measurements at the different time delays.

15. The beverage machine according to claim 14, wherein each of the different sets of known voltage measurements corresponds with air or a different type of liquid.

16. The beverage machine according to claim 11, wherein the detector includes a general purpose input / output (GPIO) pin arranged to provide a high or low signal as each of the plurality of voltage measurements.

17. The beverage machine according to claim 16, wherein the GPIO pin switches to a high signal when a voltage value at the GPIO pin exceeds a first threshold value and the GPIO pin switches to a low signal when the voltage value at the GPIO pin falls below a second threshold value.

18. The beverage machine according to claim 16, wherein the detector is configured to obtain a byte based on the high or low signal as each of the plurality of voltage measurements with each high signal being obtained as 1 and each low signal being obtained as 0.

19. The beverage machine according to claim 18, wherein the detector is configured to compare the byte with a set of known bytes.

20. The beverage machine according to claim 19, wherein the detector is configured to identify the type of liquid based on a result of comparing the byte with the set of known bytes, the set of known bytes corresponding with voltage measurements for air and one or more types of liquid.