KR100314443B1 - Motion monitoring circuit and method of multiple heaters - Google Patents

Abstract

A plurality of heater operation monitoring circuit and method according to the present invention is to monitor the presence or absence of normal operation of each heater when using a plurality of heaters as a heating means of the microwave oven. Therefore, a current transformer is connected to a common load line to which all heaters are connected, and a plurality of heaters are sequentially operated to detect a voltage level induced on the secondary side of the current transformer. In addition, the detected voltage value is compared with the reference voltage, and the heater that does not operate normally is displayed and checked on the display unit, and the cooking time is compensated for when a specific heater does not operate when cooking is performed. .

Description

Motion monitoring circuit and method of multiple heaters

The present invention relates to an apparatus for monitoring the operation of a plurality of heaters, and more particularly to an operation monitoring circuit and method of a plurality of heaters that can prevent cooking performance degradation due to any heater failure.

Conventional microwave ovens use a plurality of heaters (eg halogen lamps) as a heating source. Such an embodiment is shown in FIG.

As shown in the prior art, a microwave oven includes a plurality of heaters HT1 to HTn connected in parallel to a power supply stage, and each of the plurality of heaters HT1 to HTn controls the current path of the heater. The relays RY1 to RYn are connected in series. The on / off control of the relays RY1 to RYn is controlled by the control unit 10.

Operation of the plurality of heaters HT1 to HTn by the above configuration is performed as follows.

First, when a user selects a desired dish by using a key input unit (not shown), the controller 10 recognizes which dish the user selects. The relay of the heater to be driven according to the cooking type selected by the user is turned on. In this case, the relay controlled by the controller 10 may be one or a plurality may be simultaneously controlled. That is, a relay connected to a heater required according to the selected cooking type is operated.

As such, when a specific relay is turned on under the control of the controller 10, heat is generated while the heater connected in series with the turned on relay is driven, and cooking is performed by the generated heat.

When the operation of the heater is started as described above, the operation of the heater is then controlled by controlling the on / off of the relay according to the sensed temperature of the temperature sensor during the set cooking time according to the selected cooking.

However, in the conventional multiple heater control circuits, it is not possible to detect the failure of the heater in a short time. In particular, there was no way to monitor which of the heaters failed. Thus, when a specific heater is broken, but it is not detected, the cooking time cannot be compensated for the cooking in progress, resulting in a significant decrease in cooking performance.

Accordingly, an object of the present invention is to provide an operation monitoring circuit and a method of a plurality of heaters for monitoring the normal operation of the plurality of heaters.

Another object of the present invention is to provide an operation monitoring circuit and a method of a plurality of heaters that can indicate this in case of any failure of the plurality of heaters.

Another object of the present invention is to provide an operation monitoring circuit and method for a plurality of heaters that can compensate for cooking time for a failed heater.

1 is a configuration diagram showing a conventional heater control circuit,

2 is an operation monitoring circuit diagram of a plurality of heaters according to a first embodiment of the present invention;

3 is an operation monitoring circuit diagram of a plurality of heaters according to a second embodiment of the present invention;

4 is a detailed configuration diagram of the current transformer shown in FIG.

FIG. 5 is a block diagram showing a detailed configuration of a control unit shown in FIG. 2;

6 is an output waveform diagram for relay operation;

7 is a flowchart illustrating a monitoring operation of a plurality of heaters according to the present invention.

Explanation of symbols on the main parts of the drawings

HT1 'to HTn', HT1 "to HTn": heaters RY1 'to RYn', RY1 "to RYn": relay

30,40: Current transformer 50,60: Control unit

51: microcontroller 52: power supply

53: temperature sensor unit 54: CT circuit unit

55: display unit 56: data input unit

57: other circuit unit 58: relay control unit

Operation monitoring circuit of a plurality of heaters according to the present invention for achieving the above object, a plurality of heaters as a heating source; Voltage detecting means connected to a common load line connected to the plurality of heaters; And control means for determining whether the heater is in normal operation based on the detected voltage value of the voltage detecting means.

Operation monitoring method for a plurality of heaters according to the present invention for achieving the above object, the step of operating a plurality of heaters in sequence; Detecting a voltage value for the return current of the heater in operation; Comparing the detected voltage value with a normal operation discrimination voltage of a heater; And determining whether the heater is operating normally based on the compared value.

The present invention is characterized in that in a microwave oven using a plurality of heaters as a heating source, it is possible to easily detect any heater which is not operated among a plurality of heaters in a short time.

In addition, the present invention is characterized in that in a microwave oven using a plurality of heaters as a heating source, it is possible to detect any heater that has failed, and to indicate which heater has failed.

The present invention is capable of compensating for cooking time for a failed heater when any heater failure is detected among a plurality of heaters during cooking or at the beginning of cooking.

Therefore, the present invention makes it possible to easily detect the failure of the heater among a plurality of heaters in a short time and to display it, thereby enabling the failure diagnosis of the heater. At the same time, there is an effect that can maintain the cooking performance in the optimal state by compensating for the cooking time for the failed heater.

Hereinafter, an operation monitoring circuit and a method of a plurality of heaters according to the present invention will be described in detail with reference to the accompanying drawings.

2 is an operation monitoring circuit diagram of a plurality of heaters according to a first embodiment of the present invention.

In the operation monitoring circuit of a plurality of heaters of the present invention, as shown, a plurality of heaters HT1 'to HTn' are connected in parallel to a power input terminal, and each of the plurality of heaters HT1 'to HTn' is connected to each other. Relays RY1 'to RYn' connected in series are configured. Relays RY1 'to RYn' connected in series to the heaters are elements for controlling current paths of the respective heaters.

That is, according to the on / off control operation of the plurality of relays RU1 'to RYn', a current path of the heater connected to the relay is formed, and power is supplied to the heater, thereby driving the heater.

The primary side of the current transformer 30 is connected between the power input terminal and the plurality of relays RY1 'to RYn' connected in parallel. The control unit 50 is connected to the secondary side of the current transformer 30. The connection configuration of the current transformer 30 and the controller 50 is shown in detail in FIG. 4.

Accordingly, the controller 50 detects a voltage value differentiated and induced on the secondary side of the current transformer 30 by a return current applied according to an arbitrary heater driving operation. The controller 50 is configured to control the on / off operation of the plurality of relays RY1 'to RYn'. That is, the controller 50 selects a heater to be driven according to the type of cooking selected by the user, and controls an operation of the heater by driving a relay connected in series with the heater.

Therefore, after controlling the operation of the heater through the relay, the controller 50 determines whether the heater is normally operated by detecting the voltage value induced on the secondary side of the current transformer 30.

That is, the voltage value induced on the secondary side of the current transformer 30 when the first heater HT1 'is driven, and the current transformer 30 when the first and second heaters HT1' are driven. Since the voltage value induced on the secondary side is different, it is possible to detect the presence or absence of any normal operation of the heater by detecting the voltage value induced on the secondary side of the current transformer 30.

Next will be described the operation of the operation monitoring circuit and method of a plurality of heaters according to the present invention having the above configuration.

7 is a flowchart illustrating a process of monitoring operations of a plurality of heaters according to the present invention.

Referring to FIGS. 2 and 7, the operation of the check function for detecting the normal operation of the heater will be described.

When the controller 50 checks whether the heater is normally operated, the controller 50 determines the normal operation of the heater by checking the voltage level applied to the secondary side of the current transformer 30 while sequentially operating the plurality of heaters.

That is, the controller 50 outputs a control signal for turning on the first relay RY1 'to operate the first heater HT1' as shown in FIG. 6 (step 100 of FIG. 7). .

Then, the current path of the first heater HT1 'is formed by the ON operation of the first relay RY1', and power is supplied to the first heater. Then, the driving of the first heater is started. On the other hand, the controller 50 determines whether a predetermined time t1 has elapsed before the first heater HT1 'normally drives after outputting a control signal for turning on the first relay RY1'. (Step 102). As shown in FIG. 6, the time t1 is a time from the output of the first relay driving signal to the detection of a voltage value from the secondary side of the current transformer 30.

When the predetermined time according to step 102 has elapsed, the controller 50 detects a voltage value induced on the secondary side of the current transformer 30. The detected voltage value V1 is compared with the preset reference voltage x1 (step 104). The reference voltage (x1) is a voltage for monitoring whether the normal operation of the first heater (HT1 ') is performed, which is induced on the secondary side of the current transformer (30) when the first heater is performed normally. The value is preset based on the voltage level.

In step 104, the first heater HT1 ′ is compared when the detected voltage value V1 is large by comparing the voltage value V1 induced on the secondary side of the current transformer 30 with the reference voltage x1. It is determined that the operation is normal (step 106).

However, when the voltage value V1 induced on the secondary side of the current transformer 30 is smaller than the reference voltage x1 in step 104, the first heater HT1 ′ is determined to be a failure and the first heater ( HT1 ') is displayed (step 108).

Next, the control unit 50 outputs a signal for turning on the second relay RY2 ', as shown in FIG. 6, to determine whether the second heater HT2' is normally operated (110). step).

In operation 110, the second relay RY2 ′ is turned on and a current path of the second heater HT2 ′ is formed. Then, while the power is supplied to the second heater, the second heater is driven. On the other hand, the controller 50 determines whether the time t2 at which the second heater HT2 'can be normally driven has elapsed after the second relay RY2' is turned on in operation 110 (step Step 112).

If a predetermined time t2 has elapsed in step 112, the voltage induced on the secondary side of the current transformer 30 is detected. It is determined whether the detected voltage V2 is greater than the reference voltage x2 (step 114). The reference voltage x2 is a voltage for monitoring whether the first heater HT1 'and the second heater HT2' are normally operated, and the first heater and the second heater are normally operated. At this time, the predetermined value is obtained based on the voltage level induced on the secondary side of the current transformer 30.

When the voltage V2 detected in the step 114 is greater than the reference voltage x2, the second heater HT2 'determines that the normal operation is performed (step 118).

However, when the voltage detected in the step 114 is less than the reference voltage, it is determined that the second heater is not performing a normal operation (step 116).

As such, the controller 50 determines whether the heater is normally operated by turning on the relay, detecting the secondary voltage of the current transformer 30, and comparing the detected voltage with a reference voltage. Repeat the discrimination process sequentially.

After the process of determining whether the last heater HTn 'is normally operated (steps 120 to 128) is performed, a heater on which the normal operation is not performed is displayed on the display unit (step 130).

If there is a heater that is displayed in step 130, that is, when there is a heater that does not perform a normal operation (step 132), it is displayed so that the user knows that there is a broken heater, and at the same time check the failed heater Perform step 134.

The above process is to determine whether the plurality of heaters are all operating normally or not. When a failed heater is detected, this is checked to prevent deterioration of cooking performance due to the failed heater.

That is, the plurality of heater checks according to the first embodiment of the present invention are sequentially performed from the first heater HT1 'to the last heater HTn'. Therefore, the reference voltage x1 for determining whether the first heater HT1 'is normally operated is set based on the voltage induced on the secondary side of the current transformer 30 during the normal operation of the first heater HT1'. Value. In addition, the reference voltage x2 for determining whether the second heater HT2 'is normally operated is induced on the secondary side of the current transformer 30 during the normal operation of the first heater HT1' and the second heater HT2 '. It becomes a value set based on the voltage to become. Further, the reference voltage xn is a value set based on the voltage induced on the secondary side of the current transformer 30 in the normal operation of all the heaters.

However, as another embodiment of the present invention, in performing the determination of whether the heater is operating normally, using a method of detecting the secondary voltage of the current transformer 30 by selectively operating only one heater among a plurality of heaters. It is possible. In this case, the reference value for determining whether the heater is in normal operation should be set based on the voltage value induced in the secondary side of the current transformer in the normal operation of the heater.

Next, an operation process according to a process of detecting a failure of the heater and compensating for cooking time while performing cooking by driving the heater will be described.

FIG. 5 is a block diagram showing a detailed configuration of the control unit 50 shown in FIG. 2.

The control unit 50 of the present invention includes a controller power supply unit 52 for generating a rated power supply from a power source applied from a power input terminal and supplying the power to the microcontroller 51, and a temperature sensor unit installed at one side of the cavity to detect temperature ( 53) and a data input unit 56 for inputting information according to the type of cooking to be cooked, that is, cooking time, cooking temperature, type of cooking, and the like.

In addition, the controller 50 of the present invention uses the display device unit 55 for displaying the display information of the corresponding dish from the input information of the data input unit 56, and the plurality of relays RY1 'to RYn'. And a relay control unit 58 for generating a signal to control, and a CT circuit unit 54 for detecting the secondary current of the current transformer 30.

Therefore, the microcontroller 51 included in the controller 50 of the present invention controls the on / off operation of the relay connected in series with the heater to be driven through the relay controller 58. The microcontroller 51 determines whether the heater is operating normally by the current value detected through the CT control unit 54 when the heater is driven. In addition, the microcontroller 51 controls the cooking to be advanced by the temperature detected from the temperature sensor unit 53 and displays the display information of the display device unit 55 based on the input signal of the data input unit 56. Outputs

Reference numeral 57 includes various other circuit parts that operate under the control of the microcontroller 51.

Operation monitoring and cooking time compensation of a plurality of heaters of the present invention made as described above is made of the following process.

For example, fault detection of the heater may be detected irrespective of cooking progress, or may be detected before cooking starts and while cooking is in progress.

If the heater check is detected according to FIG. 7 before or during cooking or when a failed heater is detected, the failed heater is displayed on the display unit 50 to recognize the failed heater and perform the next operation. It is possible to properly compensate for the cooking time in the cooking operation.

In addition, failure monitoring of the heater during cooking is performed as follows. First, the microcontroller 51 recognizes which dish the user has selected based on the information input from the data input unit 56. When the recognized cooking type is a dish to be driven by the heater, the heater to be driven is selected according to the cooking type, and the relay connected in series with the heater is turned on. The on operation of the relay is performed by the relay controller 58 under the control of the microcontroller 51.

If the dish selected by the user needs to drive the first heater HT1 'and the second heater HT2', the relay controller 58 drives the first and second relays RY1 'and RY2'. A signal is applied to turn on the first and second relays. Then, while power is supplied to the first and second heaters HT1 ′ and HT2 ′ connected to the first and second relays, the first and second heaters are driven.

When the first and second heaters HT1 'and HT2' are formed, the microcontroller 51 detects the secondary voltage of the current transformer 30, and the detected voltage is a reference voltage (the first and second heaters The microcontroller 51 detects an abnormality of the operated first heater and / or the second heater when it is detected to be smaller than a predetermined value based on a voltage to be induced on the secondary side of the current transformer. will be.

The microcontroller 51 continuously monitors whether there is an abnormality of the first and second heaters from the detected voltage of the CT circuit unit 54 even while the cooking selected by the user is controlled by the sensed temperature of the temperature sensor unit 53. Done.

When the abnormality of the heater is detected by the monitoring operation, the microcontroller 51 displays the failed heater on the display unit 55 and adjusts the operating time of the heater that is normally driven to compensate for the entire cooking time. It is possible to give (step 134).

Therefore, when the heaters to be driven according to the cooking type are classified, the microcontroller 51 sets the current transformer secondary voltage level for monitoring whether the heater is normally operated in the cooking type. And it becomes possible to monitor the operation | movement of a heater, changing a reference voltage suitably according to the heater which wants to operate.

Next, FIG. 3 is a block diagram showing an operation monitoring circuit of a plurality of heaters according to a second embodiment of the present invention. That is, if the circuit configuration shown in Fig. 2 is a single-phase two-wire system, the circuit configuration shown in Fig. 3 is a circuit configuration by a single-phase three-wire system.

That is, in the circuit shown in FIG. 3, power is input through three terminals, heaters HT1 ″ and HT2 ′ are connected in parallel between the first and second power input terminals, and a heater ( HT3 ', HT4') are connected in parallel, and the current transformer 40 is connected to the second power input terminal so as to be connected in parallel with all the heaters, that is, the current transformer according to the operation of each of the plurality of heaters. The voltage value induced on the secondary side of 40 is changed.

A relay for controlling the current passage of each heater is connected in series with each heater, and the on / off control of the relay is performed by the controller 60.

That is, the plurality of heater operation monitoring circuits according to the second embodiment of the present invention is configured to detect the voltage level of the current transformer by connecting the current transformer to a common load line connected to all heaters.

As described above, when the plurality of heaters are used as the heating means of the microwave oven, it is possible to easily determine which of the heaters does not operate normally among the plurality of heaters. In addition, in order to minimize the inconvenience of the user due to the deterioration of cooking performance due to the failure of the heater, there is an effect that can maintain the cooking performance to the maximum by compensating for the cooking time for the failed heater.

Claims (3)

A plurality of heaters as heating sources; A current transformer connected to a common load line connected to the plurality of heaters; And a control means for determining whether the heater is normally operated based on the detected voltage value of the current transformer. Sequentially operating a plurality of heaters; Detecting a voltage value for the return current of the heater in operation; Comparing the detected voltage value with a normal operation discrimination voltage of a heater; The operation monitoring method of a plurality of heaters comprising the step of determining whether or not the normal operation of the heater based on the compared value. The method of claim 2, When it is determined that the specific heater operation is abnormal, the operation monitoring method of a plurality of heaters further comprises a cooking time compensation step for compensating the operation time of the other heaters driven together.