KR20230039354A - Method and apparatus for sensing dryness - Google Patents

Abstract

Disclosed are a dryness sensing apparatus comprising a first circuit outputting a first voltage based on a change in resistance between the first electrode and the second electrode due to contact of an object to be dried; a second circuit amplifying a difference between the first voltage and a predetermined offset voltage and outputting a second voltage; and a control unit measuring the first voltage and the second voltage to check the dryness level of the object to be dried, and an operating method of the dryness sensing apparatus. The dryness sensing apparatus can precisely check the dryness level of an object to be dried, thereby preventing overdrying or underdrying.

Description

Dryness sensing apparatus and method {Method and apparatus for sensing dryness}

The present disclosure relates to an apparatus and method for sensing the dryness level of a dry object.

Dryers can be used for handling washed or wet laundry. The dryer may dry laundry inside the drum by blowing hot air with low humidity as the drum rotates therein.

Dryers can be divided into exhaust type dryers and condensation type dryers according to a method of treating humid air discharged from a drum after drying clothes. In addition, the dryer may use a heat pump to reduce energy consumption by using heat energy discarded in the process of exhausting or condensing to heat air.

The dryer may be configured to detect the dryness of the laundry and set an operation time accordingly to dry the laundry.

However, when the dryer is operated for a set period of time while the drum rotates at a set rotation speed, even when the same type of laundry is loaded, a difference may occur in the drying state of the laundry depending on the amount of laundry or the degree of wetness of the laundry. Accordingly, a difference in time taken to perform drying to a level desired by the user may occur.

Accordingly, an operation of determining the degree of drying as drying progresses and resetting and displaying the drying time accordingly may be performed. In order to perform such an operation, a dryness sensor may be disposed inside the dryer to determine the dryness level of the laundry, and it is necessary to more accurately determine the dryness level of the laundry.

The disclosed embodiments are intended to disclose an electronic device and an operating method thereof. The technical problem to be achieved by the present embodiment is not limited to the technical problems described above, and other technical problems may be inferred from the following embodiments.

A dryness sensing device according to an embodiment of the present disclosure, comprising: a first circuit outputting a first voltage based on a change in resistance between a first electrode and a second electrode due to contact of a drying object; a second circuit amplifying a difference between the first voltage and a predetermined offset voltage and outputting a second voltage; and a control unit that measures the first voltage and the second voltage to determine a drying level of the object to be dried.

According to another embodiment, a dryness sensing method may include measuring a first voltage output based on a change in resistance between a first electrode and a second electrode due to contact of an object to be dried; checking a drying level of the object to be dried based on a first voltage measured for a first time; measuring a second voltage output by amplifying a difference between the first voltage and a predetermined offset voltage; and checking a drying level of the object to be dried based on a second voltage measured for a second time following the first time.

According to the present disclosure, the dryness detection device checks the dryness level of the object to be dried using the second voltage of the second circuit as well as the first voltage of the first circuit, so that the dryness level of the object to be dried can be more accurately checked. . Accordingly, the drying detection device can prevent overdrying or underdrying by increasing drying precision.

1 is a schematic view showing the appearance of an embodiment of a dryer.
Figure 2 is a schematic diagram showing the interior of the embodiment of Figure 1;
3 shows a dryness sensing device according to an exemplary embodiment.
4 shows a first circuit according to an embodiment.
5 and 6 show circuit diagrams according to the operation of the sensing unit.
7 shows a second circuit according to an embodiment.
8 shows an example of the first voltage and the second voltage measured by the controller.
9 is a diagram for explaining a method for detecting dryness according to an exemplary embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present invention without obscuring it by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In each figure, the same reference number is assigned to the same or corresponding component.

Advantages and features of the present disclosure, and methods for achieving them, will become clear with reference to embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, but the present disclosure is intended to complete the present disclosure and to those skilled in the art. It is provided to give a complete indication of the scope of the invention, and the disclosure is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

At this time, it will be understood that each block of the process flow chart diagrams and combinations of the flow chart diagrams can be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates means to perform functions. These computer program instructions may also be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular way, such that the computer usable or computer readable memory The instructions stored in are also capable of producing an article of manufacture containing instruction means that perform the functions described in the flowchart block(s). The computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to generate computer or other programmable data processing equipment. Instructions for performing processing equipment may also provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is possible for the functions mentioned in the blocks to occur out of order. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in reverse order depending on their function.

At this time, the term '~unit' used in this embodiment means software or a hardware component such as FPGA or ASIC, and '~unit' performs certain roles. However, '~ part' is not limited to software or hardware. '~bu' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Therefore, as an example, '~unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within components and '~units' may be combined into smaller numbers of components and '~units' or further separated into additional components and '~units'. In addition, components and '~units' may be implemented to play one or more CPUs in a device or a secure multimedia card.

Hereinafter, specific details for carrying out the present invention through an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a schematic view showing the appearance of an embodiment of a dryer.

Referring to FIG. 1 , the dryer 1 includes a main body 11 forming an exterior, and a drum 10 rotatably installed in the main body 11 and having a plurality of lifters protruding from the inner circumferential surface. An input port 14 is formed on the front of the main body 11 to put clothes, which are objects to be dried, into the main body.

The input port 14 is opened and closed by a door 13, and a control panel 12 having various operation buttons and a display device for operating the dryer 1 is disposed above the input port 14. A drawer 15 is provided on one side of the control panel 12, and a liquid to be sprayed onto the drum may be stored inside the drawer 15.

Figure 2 is a schematic diagram showing the interior of the embodiment of Figure 1;

A drum 10 is provided inside the body 11 so as to be rotatably installed so that an object to be dried can be dried therein, and the drum 10 is rotatably supported by supporters (not shown) at the front and rear. do.

The drum 10 is connected to the drive motor 20 provided at the lower part of the dryer through a power transmission belt 22 to receive rotational force. The drive motor 20 is provided with a pulley 21 on one side to which a power transmission belt 22 for driving the drum is connected.

A suction duct 50 is installed at the rear of the drum 10, and a heater 40 for heating intake air is installed in the suction duct 50. The heater 40 may use a method using high-temperature electrical resistance heat in order to increase the efficiency of space occupied in the dryer. The suction duct 50 is connected to the rear of the drum 10 and may have a discharge port 51 for discharging heated air to the drum 10 .

In addition, a filter for filtering out foreign substances such as lint contained in the air discharged from the drum 10 is installed on the lower front side of the drum 10, and an exhaust duct 60 for discharging the air after filtering the foreign substances from the drum installed The intake duct and exhaust duct are divided into intake and exhaust based on the drum. Here, although an embodiment of the circulation type dryer is shown in FIG. 2, the present disclosure is not limited thereto and may be applied to an exhaust type.

In the embodiment of the circulation type dryer as shown in FIG. 2, the intake duct 60 and the exhaust duct 50 are integrally connected to form one circulation passage. However, in the case of an exhaust type dryer embodiment (not shown), the suction duct and the exhaust duct are not connected.

A blowing fan 30 is installed in the exhaust duct 50 to suck air in the drum 10 and forcibly blow it. For example, in the case of the circulation type dryer of FIG. 2 , the exhaust duct 50 serves to guide air forcedly blown by the blowing fan 30 to the drum through the suction duct 60 . However, in the case of an exhaust type dryer, the exhaust duct serves to guide the air forcedly blown by the blowing fan 30 to the outside.

The blower fan 30 shown in this embodiment may be a pull-type blower fan that is present on a duct through which air is exhausted from the drum 10 and sucks air discharged from the drum toward the exhaust duct.

As described above, a pulley is provided on one side of the drive motor 20 to connect the power transmission belt 22 for driving the drum. Here, the other side of the drive motor 20 is used to drive the blowing fan 30. It is connected to the drive shaft of the blowing fan. Therefore, in the embodiment of FIG. 2, when the drive motor rotates, the drum and the blowing fan rotate simultaneously. A system that uses one motor to simultaneously drive the drum and the blowing fan is called a one-motor system. By the way, a separate drive motor for driving the blowing fan may be provided, but this is undesirable because the structure becomes complicated and the cost increases.

In addition, a dryness sensor 70 may be provided inside the drum to which the object to be dried may come into contact in order to precisely control the degree of dryness of the object to be dried accommodated inside the drum. The dryness detection sensor 70 may detect the degree of drying of the object to be dried by using impedance generated at both ends of the electrodes according to the moisture content of the object to be dried when both electrodes are simultaneously contacted with the object to be dried and output the result as a voltage signal. The degree of dryness may be divided into a number of levels (eg, Very Dry, More Dry, Normal, Less Dry, Damp Dry) according to the moisture content.

3 shows a dryness sensing device according to an exemplary embodiment.

The dryness detection device 300 may include a first circuit 310 , a second circuit 320 and a controller 330 . According to one example, the dryness detection device 300 may be included in the dryness detection sensor 220 of FIG. 2 . According to another example, some components of the dryness detection device 300 may be included in the dryness detection sensor 220 . For example, the first circuit 310 and the second circuit 320 of the dryness detection device 300 may be included in the dryness detection sensor 220 . In the dryness detection device 300 shown in FIG. 3, only components related to the present embodiment are shown. Accordingly, those skilled in the art can understand that other general-purpose components may be further included in addition to the components shown in FIG. 3 .

The first circuit 310 may output a first voltage based on a change in resistance between the first electrode E1 (electrode 1) and the second electrode E2 (electrode 2) due to the contact of the object to be dried. Specifically, the resistance value of both ends of the first and second electrodes E1 and E2 may change according to the amount and humidity of the object to be dried in contact with the first and second electrodes E1 and E2, and the first circuit ( 310) may output a first voltage in which the change in the resistance value is reflected.

4 shows a first circuit according to an embodiment.

The first circuit 400 includes a detection unit 110, an electrostatic protection unit 120, a power supply unit 130, a filter unit 140, an output unit 150, a voltage limiting unit 160, and a protection unit 170. ) may be included. In the first circuit 400 shown in FIG. 4, only components related to the present embodiment are shown. Accordingly, those skilled in the art can understand that other general-purpose components may be further included in addition to the components shown in FIG. 4 . The first circuit 400 may be an example of the first circuit 310 of FIG. 3 .

The sensing unit 110 may include first and second electrodes E1 and E2, and the first and second electrodes E1 and E2 are in contact with the first and second electrodes E1 and E2 according to the amount and humidity of the drying object. A resistance value across the second electrodes E1 and E2 may change. That is, the resistance value of the sensing resistor Rs, which is an equivalent model of resistance across the first and second electrodes E1 and E2, may change.

5 and 6 show circuit diagrams according to the operation of the sensing unit.

When the object to be dried does not contact the first and second electrodes E1 and E2 or the object to be dried in contact with the first and second electrodes E1 and E2 is completely dried, as shown in FIG. 5, the sensing resistance (Rs ) can be infinite. Accordingly, both ends of the first and second electrodes E1 and E2 may operate like an open circuit.

In a state in which humidity of the object to be dried in contact with the first and second electrodes E1 and E2 exists to some extent, the value of the sensing resistance Rs may change as shown in FIG. 6 . Therefore, the value of the sensing resistance Rs changes according to the humidity of the object to be dried, and accordingly, the sensing voltage applied to the filter unit 140, that is, the voltage on the first node N1 may vary.

Referring back to FIG. 4 , the static electricity protection unit 120 may include first and second static electricity prevention circuits 121 and 122 . The first antistatic circuit 121 may be connected between the ground and the second node, and the second antistatic circuit 122 may be connected between the first node N1 and the second node N2. The first anti-static circuit 121 may include a first capacitor C1 and a second diac 1 connected in parallel to each other and connected between the first and second nodes N1 and N2, and The anti-static circuit 122 may include a second capacitor C2 and a second diac 2 connected in parallel to each other and connected between the second node N2 and the ground. The static electricity protection unit 120 may reduce noise introduced into the static electricity protection unit 120 .

The power supply unit 130 includes a first operational amplifier OP1 capable of outputting a first output voltage Vo1 as a power supply voltage and first and second resistors R1 and R2 connected to the first operational amplifier OP1. can include Here, the first operational amplifier OP1 and the first and second resistors R1 and R2 may be connected to each other so as to operate as a non-inverting amplifier. Specifically, the first power supply (Vs1) is supplied to the non-inverting terminal (+) of the first operational amplifier (OP1), and the first resistor (R1) is connected between the inverting terminal (-) of the first operational amplifier (OP1) and the ground. , and a second resistor R2 may be connected between the inverting terminal (-) of the first operational amplifier OP1 and the output terminal. The first operational amplifier OP1 may be driven by the first positive supply voltage Vcc1+ and the first negative supply voltage Vcc1-. For example, the first negative supply voltage Vcc1- may be 0V, and the first operational amplifier OP1 may be driven as a single-power operational amplifier.

The first output voltage Vo1 of the first operational amplifier OP1 may satisfy Equation 1 below.

[Equation 1]

In Equation 1, when the values of the first and second resistors R1 and R2 are the same, the first output voltage Vo1 of the first operational amplifier OP1 may be twice the first power supply Vs1. Accordingly, the power supply 130 may output the first output voltage Vo1 corresponding to twice the first power source Vs1 as the power voltage.

The filter unit 140 may include first and second filter units 141 and 142 . The first filter unit 141 includes a first filter resistor Rf1 connected between the first node N1 and the third node N3 and a filter capacitor Cf connected between the third node N3 and the ground. The second filter unit 142 may include a second filter resistor Rf2 connected between the output terminal of the first operational amplifier OP1 and the third node N3 and a filter capacitor Cf. there is. The first and second filter units 141 and 142 may have a structure in which a filter capacitor Cf is shared.

The filter unit 140 not only can perform a low frequency pass filter (LPF) function to remove high-frequency noise from the input signals, but also the first and second filter units 141 and 142, respectively. Response characteristics of signals according to the first and second time constants tau1 and tau2 may be determined. Specifically, when the sensing voltage on the first node N1 and the first output voltage Vo1 of the first operational amplifier OP1 pass through the filter unit 140, the first and second filter units 141 and 142 respectively Depending on the first and second time constants tau1 and tau2, the degree of exponential increase of the voltage of the third node N3 may vary, and the cutoff frequency fc may vary as a low pass filter.

The first time constant tau1 of the first filter unit 141 is defined as the product of the first filter resistance Rf1 and the filter capacitor Cf, and the second time constant tau2 of the second filter unit 142 may be defined as a product of the second filter resistance R2 and the filter capacitor Cf, and the first and second time constants tau1 and tau2 may be adjusted in consideration of the dryness resolution.

The output unit 150 may receive and output the sensing voltage on the first node N1 that has passed through the filter unit 140 from the third node N3. The output unit 150 may include a second operational amplifier (OP2), the inverting terminal (-) and the output terminal of the second operational amplifier (OP2) are connected to each other to perform a voltage follower function, The inverting terminal (+) is connected to the third node N3 so that the voltage on the third node N3 can be output as the second output voltage Vo2 through the output terminal. The second operational amplifier OP2 may be driven by the second positive supply voltage Vcc2+ and the second negative supply voltage Vcc2-. The second negative power supply Vcc2- may be 0V, and the second operational amplifier OP2 may be driven as a single-power operational amplifier.

Since the sensing unit 110 measures a large resistance component of hundreds of kohms or more, it is necessary to use an operational amplifier having an input impedance close to infinity. In this case, cost can be reduced by configuring the second operational amplifier OP2 as a single-power operational amplifier. In addition, the power supply unit 130 can supply a separate voltage source lower than the supply power of the second operational amplifier OP2, and the first operational amplifier OP1 of the power supply unit 130 is also configured as a single power operational amplifier. Additional cost savings may be possible.

The voltage limiting unit 160 includes a first clamping diode DL1 having a cathode electrode connected to the output terminal of the first operational amplifier OP1 and an anode electrode connected to the third node N3, and a third node N3. It may include a second clamping diode DL2 having a cathode electrode connected to and an anode electrode connected to ground.

The voltage limiting unit 160 may make the voltage on the third node N3 satisfy Equation 2 below.

[Equation 2]

That is, the voltage limiting unit 160 determines that the voltage V _N3 on the third node N3 corresponds to the first output voltage Vo1 of the first operational amplifier OP1 and the threshold voltage Vth of the first clamping diode DL1. ) can be made to exceed the sum of At this time, the first output voltage Vo1 is adjusted so that the voltage on the third node N3 does not exceed the second positive supply voltage Vcc2+ in consideration of the second positive supply voltage Vcc2+ of the second operational amplifier OP2. can

The protection unit 170 may include first and second output resistors Ro1 and Ro2, and the first output resistor Ro1 is between the output terminal of the second operational amplifier OP2 and the fourth node N4. , and the second output resistor Ro2 may be connected between the fourth node N4 and the ground. The protection unit 170 controls the second output voltage Vo2 of the output unit 150 to reduce the signal-to-noise ratio and allow a voltage below the measurement limit of the control unit 330 to be input to the control unit 330. The voltage may be divided through the first and second output resistors Ro1 and Ro2 and output to the fourth node N4. Accordingly, the first circuit 400 can output the first voltage through the fourth node N4, and the controller 330 can measure the first voltage output from the fourth node N4. According to another embodiment, the first circuit 400 may include a measurement unit capable of measuring the first voltage output through the fourth node N4, and the first voltage value measured by the measurement unit is determined by the control unit. It can be passed to (330).

The first circuit 400 may further include an output capacitor Co connected between the fourth node N4 and the ground, and the output capacitor Co functions as a filter together with the output unit 150 to remove noise. can do. The first circuit 400 may further include an output diode Do having a cathode electrode connected between the second power source Vs2 and the fourth node N4. The output diode Do makes the voltage on the fourth node N4 satisfy Equation 3 below so that the voltage V _N4 on the fourth node N4 due to noise is prevented from becoming higher than the measurement limit of the control unit 330 can do.

[Equation 3]

In Equation 3, Vth means the threshold voltage of the output diode Do.

In FIG. 4 , the second power source Vs2 may have the same voltage value as the first power source Vs1 , and the voltage values of the first and second power sources Vs1 and Vs2 are determined according to the measurement limit value of the measuring unit 200 . It may be set to the same value as the voltage value, and the voltage value of the positive supply power supply (Vcc1+, Vcc2+) of each of the first and second operational amplifiers (OP1, OP2) is the voltage of the first and second power supply (Vs1, Vs2). value can be higher than For example, in FIG. 4 , the voltage values of the positive power supplies Vcc1+ and Vcc2+ may be 13V, respectively, and the voltage values of the negative power supplies Vcc1- and Vcc2- may be 0V, respectively, and the power supply unit 130 Each of the first and second resistors R1 and R2 of ) may be 4.7k ohm, the first capacitor C1 and the second capacitor C2 of the static electricity protection unit 120 may be 0.01uF, and the filter unit The filter capacitor Cf of 140 may be 0.01 uF, the first filter resistance Rf1 and the second filter resistance Rf2 of the filter unit 140 may be 510 k ohm and 100 k ohm, respectively, and the protection unit ( 170), the first and second output resistors Ro1 and Ro2 may be 4.7k ohm and 3.9k ohm, respectively, the output capacitor Co may be 0.01uF, and the first and second power supplies Vs1 and Vs2 The voltage values of may be 5V, respectively.

Referring back to FIG. 3 , the second circuit 320 may output a second voltage by amplifying a difference between the first voltage output by the first circuit 310 and the preset offset voltage. For example, the second circuit 320 may be a differential amplifier.

7 shows a second circuit according to an embodiment.

The second circuit 700 may be an example of the second circuit 320 of FIG. 3 .

The second circuit 700 may output the second voltage Vout by amplifying the difference between the first voltage V2 output by the first circuit 310 and the preset offset voltage V1. Specifically, the second circuit 700 may amplify the difference between the first voltage V2 and the offset voltage V1 according to the ratio of the resistance R2 and the resistance R1. The offset voltage V1 may be generated using a voltage source in the first circuit 310 . For example, the offset voltage V1 may be generated through an output voltage of the power supply unit 130 of FIG. 4 and an operational amplifier. In this case, the first circuit 310 and the second circuit 320 may be implemented through a 4-channel operational amplifier.

For example, in FIG. 7 , resistor R1 and resistor R3 may be 10k ohm, resistor R2 and resistor R4 may be 40k ohm, and offset voltage V1 may be 3.5V.

Referring back to FIG. 3 , the controller 330 measures the first voltage output by the first circuit 310 and the second voltage output by the second circuit 320 to check the drying level of the object to be dried. there is. Specifically, the controller 330 may check the resistance value of the object to be dried through the measured voltage value of the first voltage or the second voltage, and check the drying level of the object to be dried through the checked resistance value.

The controller 330 may check the drying level of the object to be dried by measuring the first voltage for a first time, and check the drying level of the object by measuring the second voltage for a second time following the first time. Here, the controller 330 may distinguish a first time from a second time by comparing a preset voltage value with a measured value of the first voltage. In other words, the control unit 330 checks the drying level of the object to be dried by measuring the first voltage for the first time, and then, after the first voltage reaches the preset voltage value, the control unit 330 applies the second voltage to the object to be dried for a second time. You can check the drying level of

The controller 330 may measure the first voltage to determine at least one drying level among the plurality of drying levels, and measure the second voltage to determine a drying level other than at least one drying level among the plurality of drying levels. there is. For example, when a plurality of drying levels are divided into 5 levels (Very Dry, More Dry, Normal, Less Dry, Damp Dry), a first voltage is applied for the Damp Dry level, Less Dry level, and Normal level. The drying level of the object to be dried may be confirmed by measuring, and the drying level of the object to be dried may be checked by measuring the second voltage for the remaining More Dry and Very Dry levels.

Therefore, the dryness detection device 300 uses the first voltage of the first circuit 310 as well as the second voltage of the second circuit 320 to check the dryness level of the object to be dried, so that the dryness level of the object to be dried is more precise. You can check the drying level. In addition, since the drying level of the object to be dried is more precisely checked, the dryness detection device 300 can improve prevention of overdrying or underdrying, and thus the sensitivity of the output value of the dryness detection sensor at the end of drying can be improved. Specifically, since the voltage variation of the first voltage output from the first circuit 310 gradually decreases while the object to be dried in a moist state is being dried in a dryer, the dryness detection device 300 determines the dry level through the first voltage. After a certain point in time, the drying level of the object to be dried is checked through the second voltage having a relatively large voltage change, so that more precise drying level can be checked.

According to an embodiment, the dryness detection device 300 may further include a third circuit (not shown) as well as the first circuit 310 and the second circuit 320 . Specifically, the third circuit may output a third voltage by amplifying the difference between the first voltage output from the first circuit 310 and the preset offset voltage, and the controller 330 may output the first voltage and the second voltage. In addition, the drying level of the object to be dried may be confirmed by measuring the third voltage. For example, the third circuit may amplify the difference between the first voltage and the offset voltage to a higher level than the second circuit. Specifically, the control unit 330 checks the drying level of the object to be dried through a first voltage for a first time, checks the drying level of the object to be dried through a second voltage for a second time following the first time, and During the third time following 2 hours, the drying level of the object to be dried may be checked through the third voltage. Accordingly, the dryness detection device 300 may more accurately check the dryness level of the object to be dried using the first to third voltages.

8 shows an example of the first voltage and the second voltage measured by the controller.

The controller 330 may measure the first voltage output from the first circuit 310 as shown in the graph 810 shown in FIG. 8, and as shown in the graph 820 shown in FIG. 8, the second circuit 320 ) It is possible to measure the second voltage output from. Specifically, the controller 330 may measure the first voltage or the second voltage to check the resistance value of the object to be dried corresponding to the measured voltage value, and check the drying level of the object to be dried through the resistance value of the object to be dried. there is.

For example, while an object to be dried in a wet state is being dried in a dryer, the measured first voltage value gradually increases, but the amount of change in the first voltage may gradually decrease. Also, since the second voltage is a voltage obtained by amplifying a difference between the first voltage and the offset voltage, the amount of change in the second voltage may be relatively large compared to the amount of change in the reduced first voltage. Therefore, in order to more accurately check the resistance of the object to be dried, the control unit 330 checks the resistance of the object to be dried through the first voltage value, and when the first voltage value reaches a specific voltage (eg, around 4V), After that, the resistance of the object to be dried may be checked through the second voltage value.

9 is a diagram for explaining a method for detecting dryness according to an exemplary embodiment.

The method shown in FIG. 9 may be performed by each component of the dryness detection device 300 of FIG. 3, and duplicate descriptions will be omitted.

In step S910, the dryness detection device 300 may measure the output first voltage based on a change in resistance between the first electrode and the second electrode due to the contact of the object to be dried.

In step S920, the dryness detection device 300 may check the dryness level of the object to be dried based on the first voltage measured for the first time. The dryness detection device 300 may check the dryness level of the object to be dried using the first voltage in order to check at least one dryness level among a plurality of preset dryness levels.

In step S930, the dryness detection device 300 may measure a second voltage output by amplifying a difference between the first voltage and the preset offset voltage. The dryness detection device 300 may check whether the first voltage value measured in S910 has reached a preset voltage value, and if the check result has reached it, measure the second voltage.

In step S940, the dryness detection device 300 may check the dryness level of the object to be dried based on the second voltage measured for a second time following the first time.

The dryness detection device 300 may check the dryness level of the object to be dried using the second voltage in order to check a dryness level other than at least one dryness level checked in S920 among a plurality of preset dryness levels.

The device according to the present embodiments described above includes a processor, a memory for storing and executing program data, a permanent storage unit such as a disk drive, a communication port for communicating with an external device, a touch panel, a key, a button, and the like. The same user interface device and the like may be included. Methods implemented as software modules or algorithms may be stored on a computer-readable recording medium as computer-readable codes or program instructions executable on the processor. Here, the computer-readable recording medium includes magnetic storage media (e.g., read-only memory (ROM), random-access memory (RAM), floppy disk, hard disk, etc.) and optical reading media (e.g., CD-ROM) ), and DVD (Digital Versatile Disc). A computer-readable recording medium may be distributed among computer systems connected through a network, and computer-readable codes may be stored and executed in a distributed manner. The medium may be readable by a computer, stored in a memory, and executed by a processor.

On the other hand, preferred embodiments of the present invention have been disclosed in the present specification and drawings, and although specific terms have been used, they are only used in a general sense to easily explain the technical content of the present invention and help understanding of the present invention. It is not intended to limit the scope of the invention. It is obvious to those skilled in the art that other modified examples based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein.

Claims (11)

As a dryness detection device,
a first circuit outputting a first voltage based on a change in resistance between the first electrode and the second electrode due to the contact of the object to be dried;
a second circuit amplifying a difference between the first voltage and a predetermined offset voltage and outputting a second voltage; and
and a controller configured to measure the first voltage and the second voltage to determine a dryness level of the object to be dried. According to claim 1,
The control unit,
Drying detection for determining the dryness level of the object to be dried by measuring the first voltage for a first time, and checking the dryness level of the object to be dried by measuring the second voltage for a second time following the first time Device. According to claim 1,
The control unit,
The dryness detection device for distinguishing the first time from the second time by comparing a preset voltage value with a measured first voltage value. According to claim 1,
The control unit,
In order to check at least one drying level among a plurality of preset drying levels, the drying level of the object to be dried is checked using the first voltage, and the drying level other than the at least one drying level among the plurality of preset drying levels is checked. The dryness detection device for checking the dryness level of the object to be dried using the second voltage to check the dryness level. According to claim 1,
In the second circuit,
and a differential amplifier outputting the second voltage proportional to a difference between the first voltage and the offset voltage. According to claim 1,
In the first circuit,
the first electrode connected to a first node;
the second electrode connected to a second node;
a non-inverting amplifier that amplifies the first power supply voltage and outputs a first output voltage;
A first filter resistor connected between the first node and a third node, a filter capacitor connected between the third node and ground, and a second filter resistor connected between an output terminal of the non-inverting amplifier and the third node. a filter unit to;
a voltage follower outputting the voltage on the third node as a second output voltage;
a protection unit including a first output resistor connected between the output terminal of the voltage follower and a fourth node, and a second output resistor connected between the fourth node and a ground;
an output diode having a cathode terminal connected to a second power supply voltage and an anode terminal connected to the fourth node; and
An output capacitor connected between the fourth node and ground;
The first voltage is a voltage on the fourth node. According to claim 6,
In the first circuit,
Static electricity including a first capacitor and a first diac connected in parallel between the first node and the second node, and a second capacitor and a second diac connected in parallel between the second node and a ground. Dryness sensing device further comprising a protection unit. According to claim 6,
A first diode having a cathode terminal connected to the output terminal of the non-inverting amplifier and an anode terminal connected to the third node, and a second diode having a cathode terminal connected to the third node and an anode terminal connected to the second node Further comprising a voltage limiting unit comprising a dryness sensing device. As a dry detection method,
measuring a first voltage output based on a change in resistance between the first electrode and the second electrode due to contact with the object to be dried;
checking a drying level of the object to be dried based on a first voltage measured for a first time;
measuring a second voltage output by amplifying a difference between the first voltage and a predetermined offset voltage; and
and checking a dryness level of the object to be dried based on a second voltage measured for a second time following the first time. According to claim 9,
The step of measuring the second voltage,
checking whether the first voltage value has reached a preset voltage value; and
and measuring the second voltage when the check result is reached. According to claim 9,
Checking the drying level of the object to be dried based on the first voltage measured for the first time,
Checking a drying level of the object to be dried using the first voltage to check at least one drying level among a plurality of preset drying levels;
Checking the drying level of the object to be dried based on the second voltage measured for the second time,
and checking a dryness level of the object to be dried using the second voltage to determine a dryness level other than the at least one dryness level among the plurality of predetermined dryness levels.

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