JP3760290B2 - Electromagnetic cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic cooker that is heated by electromagnetic induction.
[0002]
[Prior art]
Conventionally, in an electromagnetic cooker, an inverter circuit is driven by turning on a start key, and an electromagnetic coil starts heating. Then, the input current of the rectifying and smoothing circuit during heating and the collector voltage of the transistor of the inverter circuit are respectively measured to judge the characteristics of the pan, and the maximum output is controlled so that the transistor does not break down.
[0003]
[Problems to be solved by the invention]
In the above-described conventional electromagnetic cooker, the input current and the collector voltage change when there is a voltage fluctuation in the commercial power supply at the start of heating, so the characteristics of the pan may be erroneously determined. If the characteristics of the pan are wrong, the heat loss of the transistor increases, and this heat loss sometimes destroys the transistor.
[0004]
Further, when an overvoltage is detected during the start of heating, it returns to the initial state, so that it does not operate even when the start key is turned on, and this cause is unknown to the user. Further, since the microcomputer has a processing speed of several tens of ms, an overvoltage of several μs cannot be detected depending on the timing.
[0005]
Furthermore, when detecting the presence or absence of the pan, the inverter circuit is driven by a drive signal with an on-time of 500 ms and an off-time of 500 ms as one cycle. This cycle is the same as the human heart rate cycle. For this reason, an implantable cardiac pacemaker misunderstood as a human heart rate and sometimes malfunctioned.
[0006]
Also, when the output value of the heating coil was set by key operation, the corresponding indicator lamp was lit and informed by sound, but when the setting reached the upper limit or lower limit, the key was continuously turned on. But no sound was heard. In this case, especially for visually handicapped persons who rely on sound, if no sound is produced, it is determined that the device is out of order, which is not an appropriate display method.
[0007]
The present invention has been made to solve such a problem. Even if there is a voltage fluctuation in the commercial power supply, it can be judged without mistakes in the characteristics of the pan, and even if an overvoltage occurs, it can be reliably detected. It is an object of the present invention to provide an electromagnetic cooker that can set the output value of a heating coil accurately even for a visually impaired person without causing a malfunction of the pacemaker even if the person using the electromagnetic cooker is using it.
[0008]
[Means for Solving the Problems]
The electromagnetic cooker according to the present invention includes a rectifying / smoothing circuit for rectifying and smoothing a commercial power supply, an inverter circuit for applying an output voltage of the rectifying / smoothing circuit to a heating coil based on an input of a drive signal, and a start key being turned on. Measuring means for measuring the output voltage of the rectifying and smoothing circuit until the heating coil starts heating, measuring the input current of the rectifying and smoothing circuit after a predetermined time T1 has elapsed from the start of heating, and measuring the output voltage of the inverter circuit; determine whether the correct pot based on an output voltage of the input current and the inverter circuit of the measured rectifying and smoothing circuit at the measuring means is placed on the heating coil, it determines that the appropriate pot is placed The maximum output value of the heating coil is selected based on the input current and output voltage and the output voltage of the rectifying and smoothing circuit, and the selected maximum output value is arbitrarily set in advance. An output value selection means for an output value of the lower heating coil for its value by comparing a constant output value, and generates a drive signal based on the output value selected by the output value selecting unit inverter And signal control means to be input to the circuit .
[0009]
Further, the reference voltage set in advance is compared with the output voltage of the rectifying / smoothing circuit, and when the measured voltage is higher than the reference voltage, the input of the drive signal to the inverter circuit is interrupted, and the voltage fluctuation detection signal is A voltage fluctuation detection circuit for outputting to the signal control means is provided, and the signal control means stops the control of the drive signal when the voltage fluctuation detection signal is inputted and starts measuring the time, and the measurement time elapses a predetermined time T2. When the input of the voltage fluctuation detection signal is interrupted before the operation, the control stop of the drive signal is released, and when the predetermined time T2 elapses before the input of the voltage fluctuation detection signal is interrupted, the drive signal The control of is disabled.
[0010]
Further, the signal control means, when the heating coil and the start of heating, and generates a signal to a human on-off coil output at a cycle different from the cycle of the heart rate is inputted to the inverter circuit, the input of the signal of its When the input current of the rectifying / smoothing circuit exceeds a predetermined value, it is determined that the pan is placed, and a drive signal is generated based on the output value selected by the output value selection means , and the inverter circuit To input.
[0011]
Further, the present invention selects the output value of the heating coil every time the output setting key is turned on, determines whether the selected output value is the upper limit or the lower limit, and sets it when the output value is the upper limit or the lower limit. An output value determining means for outputting an invalid signal, and a lighting display according to the output value selected by the output value determining means, a preset sound being generated, and setting when the setting invalid signal is input And a display unit that issues an invalid alarm.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1. FIG.
FIG. 1 is a circuit diagram of an electromagnetic cooker showing a first embodiment of the present invention, FIG. 2 is a diagram for explaining setting of a maximum output of a heating coil in the first embodiment , and FIG. 3 is a first embodiment. flowchart illustrating the operation of the embodiment, FIG. 4 is a flow chart showing the operation when it detects an overvoltage.
[0013]
In FIG. 1, reference numeral 1 denotes a filter for removing harmonics, which is provided between a pair of capacitors C1 and C2 provided between lines of a commercial power source and the pair of capacitors C1 and C2, and is provided on each line of the commercial power source. The coil L1 is connected to each other. 2 is a full-wave rectifier circuit, 3 is a smoothing circuit composed of a choke coil L2 and a capacitor C3, and R1 and R2 are resistors for dividing the voltage of the rectified and smoothed commercial power supply. To enter. An inverter circuit 5 is a transistor Tr1 that is turned on / off based on an input of a drive signal (pulse), a diode D1 connected in parallel to the transistor Tr1, a resistor R3 and a zener diode connected between the base and the emitter, respectively. Dz.
[0014]
Tr2 is a transistor for controlling on / off of the drive signal based on an output signal (coil output) of the signal control unit 12 described later. The base is connected to the 5V power source via the resistor R5 and the signal control unit 12 has resistance. The collector is connected to the base side of the transistor Tr1 of the inverter circuit 5 via the resistor R4. Reference numeral 6 denotes a rectifier circuit that rectifies the detection current of the current detector CT, C4 is a smoothing capacitor that smoothes the rectified detection current, and this DC detection current is input to the measuring section 10 as a current CT1 via the limiting resistor R8. .
[0015]
Reference numeral 7 denotes a voltage fluctuation detection circuit, which is formed by connecting resistors R9 and R10 that divide a 5V power supply as a reference voltage, resistors R11 and R12 that divide the voltage of a rectified and smoothed commercial power supply, and inverting input terminals R11 and R12. The non-inverting input terminal is connected to the connection point of the resistors R9 and R10, the output terminal is connected to the base side of the transistor Tr1 of the inverter circuit 5 via the resistor R14 and the diode D2, and the limiting resistor R15. When the voltage V1 of the commercial power source divided by the resistors R11 and R12 is equal to or higher than the reference voltage, the comparator IC is connected to the signal control unit 12 via the resistor R12 and the capacitor C5 is connected in parallel to the resistor R12. The output (voltage fluctuation detection signal) is inverted to a low level to interrupt the input of the drive signal to the inverter circuit 5.
[0016]
R16 and R17 are resistors for dividing the collector voltage of the transistor Tr1 of the inverter circuit 5, and the divided voltage is input to the measuring unit 10 via the limiting resistor R18 as the collector voltage VCE. Reference numeral 8 denotes a buzzer circuit, a transistor Tr3 whose base is connected to the signal control unit 12 via a limiting resistor R20, a buzzer Bz whose one end is connected to the collector of the transistor Tr3, one end to the buzzer Bz, and the other end. Consists of resistors R19 connected to the 5V power supply of the voltage fluctuation detection circuit 7, respectively.
[0017]
Reference numeral 9 denotes a control unit, which is composed of, for example, a microcomputer, and measures the voltage VAC of the commercial power source divided by the resistors R1 and R2 from when a start key (not shown) is turned on until the heating coil 4 starts heating. Measure the current CT1 detected by the current detector CT after elapse of a predetermined time T1, for example, 500 ms from the start of heating, and measure the collector voltage VCE of the divided voltage of R16 and R17, and measure by the measurement unit 10 The maximum output value of the heating coil 4 is selected based on the voltage VAC, the current CT1 and the collector voltage VCE (see FIG. 2), and the selected maximum output value and the output value set manually in advance are selected. The drive value is controlled based on the output value selected by the output value selection unit 11 and the output value selection unit 11 in which the lower value compared with the output value of the heating coil 4 is compared. Out When the signal becomes low level, the control of the drive signal is temporarily stopped and the time measurement is started, and the output is inverted from the low level to the high level before a predetermined time T3, for example, 1 s elapses. The signal control unit 12 is configured to cancel the drive signal control stop and stop the drive signal control to initialize the drive signal when 1 s elapses before the output is inverted from the low level to the high level.
[0018]
When selecting the maximum output value, the output value selection unit 11 described above determines whether the measured collector voltage VCE is less than 400V or more than 400V, as shown in FIG. For example, when the collector voltage VCE is less than 400V, it is determined whether the current CT1 applies to any of the A, B, and C stages. When the collector voltage VCE is determined to be the B stage, the maximum output value is selected based on the voltage VAC. Then, the resulting output value is output to the signal control unit 12.
[0019]
When the collector voltage VCE and the current CT1 are both in the D stage, it is determined that an appropriate pan is not placed on the heating coil 4 and the “pan sign” is selected, and the heating stop signal is sent to the signal control unit. 12 and all the measured values are cleared. Then, the voltage VAC measured by the measuring unit 10 is input again, and then the collector voltage VCE and the current CT1 are input, and the maximum output value is selected. This operation is repeated every time the “hot pot sign” is selected. If the operation is continued for 1 minute or longer, that effect is displayed on the display (not shown) and the start key is turned off. To finish.
[0020]
The operation of the electromagnetic cooker configured as described above will be described based on the flowcharts of FIGS. 3 and 4. First, the operation at the time of setting the output value of the heating coil will be described based on the flowchart of FIG.
[0021]
When the start key is turned on (S1), the signal control unit 12 sets the coil output to a low level and inputs a drive signal to the inverter circuit 5, and the measurement unit 10 starts heating the heating coil 4 from the start key being turned on. Until then, the voltage VAC of the commercial power source divided by the resistors R1 and R2 is measured (S2), and the time measurement is started from the start of heating, and it is determined whether or not the time T1 (500 ms) has elapsed. (S3). On the other hand, when the heating coil starts heating, the signal control unit 12 inputs a drive signal having a pulse width of 15 μs to the inverter circuit 5 for 500 ms, and after that time has elapsed, interrupts the input of the drive signal for 500 ms. Repeatedly. When the measurement unit 10 confirms that the measurement time has passed 500 ms, it measures the current CT1 through the current detector CT (S4), and then measures the collector voltage VCE divided by the resistors R16 and R17. Hold (S5).
[0022]
When the voltage VAC, the current CT1, and the collector voltage VCE are measured, the output value selection unit 11 enters the maximum output value based on these measured values (S6). At this time, it is determined whether or not the “hot pot sign” has been selected (S7), and if “hot pot sign” is selected, it is determined whether or not 1 minute has elapsed since the start of heating (S13), and 1 minute has elapsed. If it is, the start key is turned off to end this operation (S16). If one minute has not elapsed, a heating stop signal is output to the signal controller 12, and the held voltage VAC, current CT1 and The collector voltage VCE is cleared (S14, S15). Then, the voltage VAC measured by the measuring unit 10 is input again (S2), and after the elapse of 500 ms, the collector voltage VCE and the current CT1 are input and the maximum output value is selected (S3 to S6).
[0023]
When an optimum maximum output value is selected while repeating this operation, the output value selection unit 11 compares the selected maximum output value with an output value set manually in advance (S8). When the maximum output value is lower, the value is set as the output value of the heating coil 4 (S9), and when the manually set output value is lower, the output value is set as the output value of the heating coil 4. The setting is made (S10), and the result is output to the signal control unit 12. The signal control unit 12 controls the drive signal via the transistor Tr2 so that the output value selected by the output value selection unit 11 is obtained (S11), and inputs the drive signal to the inverter circuit 5. At this time, the output value selection unit 11 determines whether or not the manual output value has been changed (S12), and if it has been changed, the process returns to step 8 to be compared with the maximum output value. Is not changed, the signal control unit 12 is notified accordingly.
[0024]
Next, the operation when the power supply voltage fluctuates during the heating control based on the selected output value will be described based on the flowchart of FIG.
During heating control (S21), the voltage fluctuation detection circuit 7 inputs the divided commercial power supply voltage V1 and compares it with the reference voltage (S22, S23). When the voltage V1 is 190 V or more, for example. Inverts the output level to a low level and blocks the input of the drive signal controlled by the signal control unit 12 to the inverter circuit 5 (S24). When the output of the voltage fluctuation detection circuit 7 is inverted to a low level, the signal control unit 12 inverts the level of the coil output to a high level to turn off the transistor Tr2 and temporarily stop the control of the drive signal. Time measurement is started (S25, S26). Then, it is determined whether or not the measurement time has passed 1 s (S27). When the measurement time has passed 1 s, the process proceeds to step 30, but when the measurement time has not passed 1 s, the output of the voltage fluctuation detection circuit 7 is high. It is determined whether or not the level has been reversed (S28). When the output is not inverted, the process returns to step 27 to confirm the passage of time again, but when it is confirmed that the output is inverted to the high level, the heating pause is canceled (S29). At this time, the voltage fluctuation detection circuit 7 detects the voltage V1 and enters a comparison with the reference voltage (S22).
[0025]
When it is confirmed in step 27 that the measurement time has elapsed for 1 s, the signal control unit 12 turns on the transistor Tr3 of the buzzer circuit 8 to sound the buzzer Bz (S30), and the heating control based on the selected output value. Stop, that is, invert the coil output to high level to turn off the drive signal (S31), and then return to the initial state and end (S32).
[0026]
In the first embodiment, the voltage VAC of the commercial power source is measured from when the start key is turned on until the heating coil 4 starts heating, and after the elapse of 500 ms from the start of heating, the current CT1 and the collector of the current detector CT are measured. The voltage VCE is measured, the maximum output value is selected based on these measured values, and the maximum output value is compared with the output value set manually in advance, and the lower value is determined for the heating coil 4. Since the output value is set, the characteristics of the pan can be specified without error even if a voltage fluctuation occurs in the commercial power supply. Moreover, since the specification of the pan characteristics is accurate, the transistor Tr1 can be prevented from being destroyed due to heat loss. There is an effect.
[0027]
When an overvoltage with a speed of several tens of μs occurs, the voltage fluctuation detection circuit 7 inverts the output to a low level to cut off the input of the drive signal to the inverter circuit 5, and the signal control unit 12 recognizes the output. When the heating is stopped at the same time when the coil output is set to the high level, the time is measured. If the output of the voltage fluctuation detecting circuit 7 is inverted to the high level before the time T2 elapses, the heating control is stopped. Since the heating control is returned to the initial state when the time T2 elapses before the output of the voltage fluctuation detection circuit 7 is reversed to the high level, the overvoltage of several tens of ms or more is conventionally used. There is an effect that it is impossible to deal with.
[0028]
Embodiment 2. FIG.
In the above embodiment, when the heating coil 4 starts heating, the drive signal time input to the inverter circuit 5 is set to 500 ms and the cut-off time is set to 500 ms. However, this is repeated, but the input time is set instead of the time. 2s, the shut-off time was 1s, yet good as repeated.
[0029]
FIG. 5 is a flowchart for explaining generation of a drive signal at the time of setting the output value of the heating coil. When the heating coil 4 starts heating after the start key is turned on, the signal control unit 12 converts the drive signal into an inverter for 2 s. The signal is input to the circuit 5, and after the elapse of time, it is cut off for 1 s, and this is repeated. This control of the drive signal is for determining whether or not the pan is placed on the heating coil 4. When the current CT1 of the current detector CT is 4A or more, it is determined that the pan is placed. Next, the operation will be described. When the heating coil 4 starts heating after the start key is turned on (S41), the signal control unit 12 sets the coil output level to low level to turn off the transistor Tr2 (S42), and inputs the drive signal to the inverter circuit 5 Let At this time, time measurement is started and it is determined whether or not the current CT1 of the current detector CT is 4A or more (S43, S44). If the detected current CT1 is less than 4 A, it is determined whether or not the measurement time has passed 2 s (S45). If the measurement time 2 s has passed, the process proceeds to step 46, but if 2s has not passed, the process proceeds to step 44. Returning, it is determined again whether or not the detected current CT1 is 4A or more. These steps 44 and 45 are repeated until the detected current CT1 becomes 4A or more, or until the measurement time 2s elapses.
[0030]
When the measurement time of 2 s has passed in step 45, the coil output is inverted from the low level to the high level to turn on the transistor Tr2 (S46), cut off the input of the drive signal to the inverter circuit 5 and stop the heating ( S47), the state is waited for 1 s (S48). When 1 s has passed, the process returns to step 42, the level of the coil output is inverted from the high level to the low level, and the time measurement is started (S43). By repeating this operation, the drive signal is input to the inverter circuit 5 every 2 seconds for 2 seconds. When the detected current CT1 becomes 4A or more by the input of the drive signal, the signal control unit 12 clears the measurement time (S49), and drives based on the output value of the heating coil selected by the output value selection unit 11 The control of the signal is started (S50), and this operation is finished.
[0031]
In the second embodiment, when the pan is detected after the start of heating, the drive signal is input to the inverter circuit 5 for 2 s, and then interrupted for 1 s, and this is repeated, so the implantable cardiac pacemaker is held. Even if a person using the electromagnetic cooker uses the pacemaker, the pacemaker does not malfunction.
[0032]
Embodiment 3. FIG.
FIG. 6 is a block diagram showing a third embodiment of the present invention, and FIG. 7 is a flowchart showing an operation in the third embodiment. In addition, the same code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment demonstrated in FIG. 1, and description is abbreviate | omitted.
[0033]
In the figure, 13 is a low output setting key, 14 is a high output setting key, 15 is an output value determination unit, which is provided in, for example, a microcomputer, and outputs the heating coil each time the setting keys 13 and 14 are turned on. A value is selected, and a message to that effect is output to the output value selection unit 11, and it is determined whether the selected output value is an upper limit or a lower limit. If the output value is an upper limit or a lower limit, a setting invalid signal is output.
[0034]
Reference numeral 16 denotes a display unit that lights the lighting unit 16a and generates a sound in accordance with the output value selected by the output value determination unit 15 . For example, a “beep” sound is generated for 0.2 s as the lighting part 16 a is lit in the “strong” direction, and a “buzzing” sound is generated during 0.2 s when the lighting part 16 a is lit in the “fire” direction. Is generated. In addition, when the “strong” lighting part 16a is lit by the input of the setting invalid signal, for example, a beep sound is generated for 0.5 s, and the “flashing” lighting part 16a is lit by the input of the setting invalid signal. Sometimes, for example, a "po" sound is generated for 0.5s.
[0035]
Next, the operation will be described based on the flowchart of FIG.
When the output setting key is turned on (S61), the output value determination unit 15 determines whether or not it is the high output setting key 14 (S62). When the high output setting key 14 is selected, it is determined whether or not the current setting is “strong” (S63). When the current setting is “strong”, a setting invalidation signal is output (S66). If not, a beep sound is generated on the display unit 16 for 0.2 s, and the lighting unit 16a is turned on by one step (S64, S65), and the process returns to step 61. When the current setting is “strong”, a setting invalid signal is output to the display unit 16 to generate a “pie” sound for 0.5 s (S66, S67), and the process returns to step 61.
[0036]
Further, when the output value determination unit 15 confirms that the low output setting key is turned on in step 62, the output value determination unit 15 determines whether or not the current setting is “fire” (S68), and when the current setting is not “fire”. During the 0.2 s, a “buzz” sound is generated on the display unit 16 and the lighting of the lighting unit 16a is lowered by one step (S69, S70), and the process returns to step 61. If the current setting is “fire”, a setting invalid signal is output to the display unit 16 to generate a “po” sound for 0.5 s (S71, S72), and the process returns to step 61.
[0037]
In the third embodiment, when the upper limit “strong” is selected by turning on the high output setting key, and conversely, when the lower limit “fire” is selected by turning on the low output setting key, different sounds are obtained. As a result of this, even visually impaired persons can recognize the invalidity of the setting.
[0038]
【The invention's effect】
As described above, according to the present invention, the output voltage of the rectifying / smoothing circuit is measured after the start key is turned on until the heating coil starts heating, and the input of the rectifying / smoothing circuit is input after a predetermined time T1 has elapsed from the start of heating. Measure the current and the output voltage of the inverter circuit, determine whether an appropriate pan is placed on the heating coil based on the measured input current of the rectifying and smoothing circuit and the output voltage of the inverter circuit, When it is determined that an appropriate pan is placed, the maximum output value of the heating coil is selected based on the input current and output voltage and the output voltage of the rectifying and smoothing circuit, and the selected maximum output value and the Since the output value of the heating coil is compared with the arbitrarily set output value, the output value of the heating coil can be specified. Because of the pan characteristics specified are accurate, there is an effect that it prevents the breakdown of the transistor of the inverter circuit due to heat loss.
[0039]
Further, when an overvoltage occurs, the voltage fluctuation detection circuit cuts off the input of the drive signal to the inverter circuit and outputs the voltage fluctuation detection signal to the signal control means. The signal control means receives the voltage fluctuation detection signal. When the control of the drive signal is stopped and the measurement of the time is started and the input of the voltage fluctuation detection signal is cut off before the measuring time T2 elapses, the control stop of the drive signal is canceled and the voltage fluctuation is detected. When the measurement time elapses before the signal input is cut off, the control of the drive signal is invalidated, so it can be reliably detected whether the overvoltage is tens of ms or several μs. to protect the inverter circuit, moreover there is an effect that the this is eliminated it does not work by turning on the start key when the overvoltage is applied.
[0040]
Further, when the heating coil starts heating, when the heating coil and the start of heating, and generates a signal to a human on-off coil output at a cycle different from the cycle of the heart rate is inputted to the inverter circuit, signal of its When the input current of the rectifying / smoothing circuit becomes equal to or greater than a predetermined value, it is determined that the pan is placed, and a drive signal based on the output value selected by the output value selecting means is generated. Since the inverter circuit is input, there is an effect that the pacemaker does not malfunction.
[0041]
Furthermore, since an invalid alarm is issued when the upper limit or lower limit of the output value is set by setting the heating power setting key, there is an effect that even visually impaired persons can identify the state.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of an electromagnetic cooker showing a first embodiment of the present invention.
FIG. 2 is a diagram for explaining setting of a maximum output of a heating coil in the first embodiment.
FIG. 3 is a flowchart showing the operation of the first embodiment.
FIG. 4 is a flowchart showing an operation when an overvoltage is detected.
FIG. 5 is a flowchart illustrating generation of a drive signal when setting an output value of a heating coil.
FIG. 6 is a block diagram showing a third embodiment of the present invention.
FIG. 7 is a flowchart showing an operation in the third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Filter, 2 full wave rectifier circuit, 3 smoothing circuit, 4 heating coil, 5 inverter circuit, 7 voltage fluctuation detection circuit, 8 buzzer circuit, 9 control part, 10 measurement part, 11 output value selection part, 12 signal control part.

Claims (4)

A rectifying / smoothing circuit for rectifying and smoothing a commercial power supply;
An inverter circuit for applying an output voltage of the rectifying and smoothing circuit to the heating coil based on an input of a drive signal;
The output voltage of the rectifying / smoothing circuit is measured after the start key is turned on until the heating coil starts heating, and the input current of the rectifying / smoothing circuit is measured after the elapse of a predetermined time T1 from the start of heating and the inverter circuit Measuring means for measuring the output voltage of
Determine whether based on the input current and output voltage of the inverter circuit of the rectifying and smoothing circuit which is measured by said measuring means suitable pan is placed on the heating coil, the appropriate pot is placed When it is determined that the maximum output value of the heating coil is selected based on the input current and output voltage and the output voltage of the rectifying and smoothing circuit, and the selected maximum output value and the output arbitrarily set in advance Output value selection means for comparing the value and setting the lower value as the output value of the heating coil;
Electromagnetic cooker, characterized in that a signal control means for input to the inverter circuit generates a drive signal based on the selected output value by the output value selecting means. The preset reference voltage and the output voltage of the rectifying / smoothing circuit are compared. When the measured voltage is higher than the reference voltage, the drive signal input to the inverter circuit is cut off, and the voltage fluctuation detection signal is controlled by the signal. A voltage fluctuation detection circuit for outputting to the means,
The signal control means stops the control of the drive signal when the voltage fluctuation detection signal is inputted and starts measuring the time, and the input of the voltage fluctuation detection signal is cut off before the measurement time T2 elapses. When the measurement time elapses a predetermined time T2 before the input of the voltage fluctuation detection signal is cut off, the drive signal control is invalidated. The electromagnetic cooker according to 1. Said signal control means, when the heating coil and the start of heating, and generates a signal for the human heart rate on-off coil output at a cycle different from the cycle of is inputted to the inverter circuit, the input of the signal of its When the input current of the rectifying / smoothing circuit exceeds a predetermined value, it is determined that a pan is placed, and a drive signal based on the output value selected by the output value selecting means is generated, The electromagnetic cooker according to claim 1, wherein the inverter circuit is input . Each time the output setting key is turned on, the output value of the heating coil is selected, and it is determined whether the selected output value is the upper limit or the lower limit. When the output value is the upper limit or the lower limit, an output that outputs a setting invalid signal is output. Value judging means;
A display unit that displays a light according to the output value selected by the output value determination unit, generates a preset sound, and issues a setting invalid alarm when the setting invalid signal is input; The electromagnetic cooker according to claim 1, 2, or 3.

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