JP2007012578A - Heater disconnection detecting device - Google Patents

Heater disconnection detecting device Download PDF

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JP2007012578A
JP2007012578A JP2005219555A JP2005219555A JP2007012578A JP 2007012578 A JP2007012578 A JP 2007012578A JP 2005219555 A JP2005219555 A JP 2005219555A JP 2005219555 A JP2005219555 A JP 2005219555A JP 2007012578 A JP2007012578 A JP 2007012578A
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heater
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voltage
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Kiyoteru Inaoka
精晃 稲岡
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Foresuto Kk
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a heater disconnection detecting device which can detect surely the disconnection of a heater out of a plurality of parallel heaters even in the case of an operation at a low voltage lower than a specified voltage of the heater and can be generally used for a variety of heaters. <P>SOLUTION: The heater disconnection detecting device is composed of an electric heater circuit connected with a transformer and a current detector. A voltage impressed on a heater is detected by a transformer and inputted as a heater voltage signal, and a voltage flowing in the heater is detected by the current detector and inputted as a heater current signal, and in the case a relation of the signals is deviated from a predetermined region, an alarm is outputted. The device is provided with a circuit holding a maximum value signal of the heater voltage signal and the heater current signal, and constructed so that an operation for resetting a circuit that holds a maximum value signal is repeated succeeding to the finish of the take-in processing of the maximum value signal by a singal processing part, and the determination of heater disconnection is made from a relation of the maximum value of the heater voltage signal and the maximum value of the heater current signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、電気ヒータを用いて加熱や保温するための電気炉や加熱処理装置のヒータの断線を検出し、警報を発するヒータ断線検出装置に関する。The present invention relates to a heater break detection device that detects a break in a heater of an electric furnace or heat treatment apparatus for heating or keeping warm using an electric heater and issues an alarm.

電気炉や加熱処理装置（以下、単に加熱装置と称する）は、半導体製造工程など、種々な生産工程で使用されている。これら、加熱装置に使用する電気ヒータ（以下、単にヒータと称する）は、運転効率を高めるために、急速加熱に対応する高容量のヒーターを使用して、定常運転では定格電圧より格段と低い電圧で運転する方法が一般化している。これらヒータの電力制御は、サイリスタによる位相制御電源が多く用いられる。Electric furnaces and heat treatment apparatuses (hereinafter simply referred to as heating apparatuses) are used in various production processes such as semiconductor manufacturing processes. These electric heaters (hereinafter simply referred to as “heaters”) used in the heating device use a high-capacity heater corresponding to rapid heating in order to increase the operation efficiency, and in the steady operation, the voltage is much lower than the rated voltage. The method of driving in is generalized. For power control of these heaters, a phase control power source using a thyristor is often used.

また、ヒータは複数を並列接続して構成していることが多く、１０本以上も並列接続されている場合も少なくない。
このような加熱装置の構成、運転状況において、使用ヒータのうち、一本のヒータが断線すると、加熱装置内の温度分布がみだれ、加工中の製品に不良が発生して多くの損害をもたらす。In many cases, a plurality of heaters are connected in parallel. In many cases, 10 or more heaters are connected in parallel.
In such a configuration and operating state of the heating device, if one of the heaters used is disconnected, the temperature distribution in the heating device is found, causing defects in the product being processed, causing a lot of damage.

使用しているヒーターが１本の場合は、ヒータが断線すると、電流が流れなくなるので検出も単純で高い検出精度を必要としない。
しかし、仮に１０本のヒータが並列接続されていて、１本のヒータが断線した場合、ヒータ電流の変化量は１０％しか生じない。このような場合の断線を誤動作なく信頼性高く確実に検出するには、少なくとも変化量の１／２以下、５％以内の検出感度と精度を有するヒータ断線検出装置でヒータを監視する必要がある。In the case of using one heater, since the current stops flowing when the heater is disconnected, the detection is simple and does not require high detection accuracy.
However, if 10 heaters are connected in parallel and one heater is disconnected, the amount of change in the heater current is only 10%. In order to reliably and reliably detect disconnection in such a case without malfunction, it is necessary to monitor the heater with a heater disconnection detection device having a detection sensitivity and accuracy of at least ½ or less of the change amount and within 5%. .

このようなヒータ断線検出装置にはヒータを運転中に、ヒータに印加する電圧とヒータに流れる電流を、ヒータ電圧信号とヒータ電流信号として入力して、それぞれの信号（交流）を整流した後、両者を比較処理、あるいは電圧÷電流などの計算処理を施し、これらの処理の結果、ヒータ断線と判定した場合、警報信号出力を行うリレーをを配置しているものがある。（例えば、特許文献１、特許文献２、特許文献３、参照）In such a heater breakage detection device, while operating the heater, the voltage applied to the heater and the current flowing through the heater are input as a heater voltage signal and a heater current signal, and each signal (AC) is rectified, Some of them are subjected to a comparison process or a calculation process such as voltage / current, and a relay is provided for outputting an alarm signal when it is determined that the heater is disconnected as a result of these processes. (For example, see Patent Document 1, Patent Document 2, and Patent Document 3)

従来のヒータ断線検出装置は、前記参照文献で示されたようにして、ヒータの断線検出を行い、監視をしている。
ヒータへ印加する電圧は、温度制御のために制御され、時々刻々と変化する交流電圧であり、ヒーター監視のために、取込まれるヒータ電圧信号とヒータ電流信号は整流して信号処理をしている。交流の電圧、電流は一般的には実効値で表現されるが、測定器などで、整流して入力される場合、その値は実効値ではなく、回路構成上本質的に平均値となる。前記いずれの参照文献においても、ヒータ電圧信号とヒータ電流信号は平均値で信号が処理される。
特開平０６−２９０８５４号公報（第４頁、図１） 特開平０４−２２３０８６（第３頁、図１） 特開平０３−５３４８４（第３頁、図１） The conventional heater disconnection detecting device detects and monitors the heater disconnection as shown in the above-mentioned reference.
The voltage applied to the heater is an AC voltage that is controlled for temperature control and changes from moment to moment. For heater monitoring, the heater voltage signal and heater current signal that are captured are rectified and processed. Yes. AC voltage and current are generally expressed as effective values, but when rectified and input by a measuring instrument or the like, the values are not effective values but are essentially average values in terms of circuit configuration. In any of the above references, the heater voltage signal and the heater current signal are processed with average values.
JP-A-06-290854 (page 4, FIG. 1) Japanese Patent Laid-Open No. 04-223086 (3rd page, FIG. 1) JP 03-53484 (3rd page, FIG. 1)

一般の測定器などの感度や精度は、定格入力（フルスケール）に対する値（％）で示されるが、ヒータ断線検出装置に要求される感度や精度は、本質的に現在の測定値に対する値（％）が要求される。The sensitivity and accuracy of general measuring instruments are indicated by the value (%) with respect to the rated input (full scale), but the sensitivity and accuracy required for the heater disconnection detector is essentially the value for the current measurement value ( %) Is required.

１０本の並列接続ヒータのうち、１本のヒータ断線を検出する場合、ヒータ断線検出装置は５％以内の検出感度と精度が必要と背景技術の項で述べたが、実際のヒータは定常運転では定格電圧より低い電圧で運転され、たとえば定格電圧の２０％程度で運転することもある。Of the 10 parallel connected heaters, when detecting one heater break, the heater break detection device requires detection sensitivity and accuracy within 5%. Is operated at a voltage lower than the rated voltage, and for example, it may be operated at about 20% of the rated voltage.

さらに汎用性を持つヒータ断線検出装置は、各種のヒータに対応することを求められ、装置の最大定格電流より小さい電流のヒータを監視することがある。たとえば定格電流１０Ａのヒータに対応するように製作されたヒータ断線検出装置で、定格電流２Ａのヒータを監視することもあり、この場合の電流入力は、ヒータ断線検出装置定格電流の２０％が最大入力電流となる。このような場合、ヒータ断線検出装置の電流入力は、２０％×２０％となり、定格電流の４％しか入力されないことになる。Furthermore, the heater disconnection detection device having versatility is required to cope with various heaters, and may monitor a heater having a current smaller than the maximum rated current of the device. For example, a heater disconnection detection device manufactured to support a heater with a rated current of 10A may monitor a heater with a rated current of 2A. In this case, the maximum current input is 20% of the rated current of the heater disconnection detection device. Input current. In such a case, the current input of the heater break detection device is 20% × 20%, and only 4% of the rated current is input.

さらに、不都合なことにこれらの値は、交流の実効値で示しているが、この種の装置で実際に扱われる信号は平均値で入力され、入力はさらに小さくなる。
ＡＣ１００Ｖの電圧を位相制御で実効値２０Ｖ（２０％）にすると、平均値は約７．５Ｖにしかならない。実効値１００Ｖのとき、平均値は約９０Ｖであるから７．５Ｖの場合、その割合は８．５％となる。Furthermore, these values are unfortunately shown as effective values of alternating current, but the signals actually handled by this type of device are input as average values, and the input is further reduced.
When the voltage of AC100V is set to an effective value of 20V (20%) by phase control, the average value is only about 7.5V. When the effective value is 100V, the average value is about 90V. Therefore, in the case of 7.5V, the ratio is 8.5%.

従って上記、実効値で計算して４％としたヒータ断線検出装置の電流入力は、実際には２０％×８．５％、即ち１．７％になってしまう。
この入力に対しても、検出感度と精度が５％以内の値でないと、ヒータの断線を検出できなかったり、誤警報を出力するなどの不具合を生じる。定格入力の１．７％の入力で、精度５％を保つことは、一般の測定器のように、定格入力に対する値に換算すると、精度０．０８５％となり、精密計器と同等以上の検出感度と精度が必要となり、製造現場などで使用する実用装置としての製作実現が困難である、との課題があった。
本発明は、このような課題を解決したヒータ断線検出装置を提供する。Therefore, the current input of the heater break detection device calculated as an effective value of 4% is actually 20% × 8.5%, that is, 1.7%.
Also for this input, if the detection sensitivity and accuracy are not values within 5%, problems such as failure to detect heater disconnection and output of false alarms occur. Maintaining an accuracy of 5% at an input of 1.7% of the rated input is 0.085% of accuracy when converted to a value for the rated input as in a general measuring instrument, and the detection sensitivity is equivalent to or better than that of a precision instrument. However, there is a problem that it is difficult to realize production as a practical device to be used at a manufacturing site.
The present invention provides a heater break detection device that solves such problems.

電気ヒータ回路に、変圧器と電流検出器を接続し、ヒータに印加される電圧を該変圧器で検出してヒータ電圧信号として入力し、ヒータに流れる電流を該電流検出器で検出してヒータ電流信号として入力して、両信号の関係が予め設定した範囲を外れた場合に、警報を出力するようにしたヒータ断線検出装置において、ヒータ電圧信号、およびヒータ電流信号の最大値信号を保持する回路を設け、信号処理部が該最大値信号の取込み処理を終了するに続き、最大値信号を保持する回路をリセットする動作を繰り返すように構成し、ヒータ電圧信号の最大値とヒータ電流信号の最大値の関係からヒータの状態を判別してヒータの断線判定行うことを特徴としたものである。A transformer and a current detector are connected to an electric heater circuit, a voltage applied to the heater is detected by the transformer and input as a heater voltage signal, and a current flowing through the heater is detected by the current detector. In the heater disconnection detection device that is input as a current signal and outputs an alarm when the relationship between the two signals is outside the preset range, the heater voltage signal and the maximum value signal of the heater current signal are held. A circuit is provided, and the signal processing unit is configured to repeat the operation of resetting the circuit that holds the maximum value signal after the maximum value signal capturing process is completed, and the maximum value of the heater voltage signal and the heater current signal It is characterized in that the heater state is determined by determining the state of the heater from the maximum value relationship.

このように構成した本発明によれば、サイリスタによる位相制御によってヒータの電圧、および電流の実効値が低くなったヒータ運転状態、たとえば実効電圧が２０％に低下した場合においても、ヒータ電圧の最大値は５６％までしか低下しない。同様に電流の最大値の低下も５６％である。
また、監視ヒータが装置定格電流の２０％のものであるとき、両者あわせた入力の低減率は、５６％×２０％≒１１．２％で、この入力において必要とされる検出感度と精度５％以内とされる値は、定格入力換算で０．５６％となる。この値は平均値入力で処理している従来装置の０．０８５％に比べ、実用装置の製作をはるかに容易にする。
以上は入力が小さい極端な例であるが、通常の使用においても、平均値入力処理より入力低減率が低いため、精度良くヒータの断線を検出することができる。
以上のように精度向上が図れるので、複数並列ヒータの、１本のヒータ断線を確実に検出することが可能で、また広範囲のヒータ電流に対応することが出来る効果がある。According to the present invention configured as described above, even if the heater operating state in which the effective value of the heater voltage and current is reduced by the phase control by the thyristor, for example, the effective voltage is reduced to 20%, the maximum heater voltage is reached. The value drops only to 56%. Similarly, the decrease in the maximum current value is 56%.
When the monitoring heater is 20% of the rated current of the apparatus, the reduction rate of the combined input is 56% × 20% ≈11.2%, and the detection sensitivity and accuracy required for this input are 5 The value within% is 0.56% in terms of rated input. This value makes the production of the practical device much easier compared to 0.085% of the conventional device that is processing with the average value input.
The above is an extreme example where the input is small, but even in normal use, since the input reduction rate is lower than the average value input process, the disconnection of the heater can be detected with high accuracy.
Since the accuracy can be improved as described above, it is possible to reliably detect one heater breakage of a plurality of parallel heaters and to cope with a wide range of heater currents.

ヒータに印加される電圧を、変圧器を介してヒータ電圧信号として入力、ヒータに流れる電流を、電流検出器を介してヒータ電流信号として入力して、この両信号をそれぞれ整流した後、信号の最大値を保持するようにして、信号処理部がこの最大値信号の取込み処理を終了すると、最大値信号のリセットを行い、信号処理部は、取込んだ最大ヒータ電圧信号と最大ヒータ電流信号を比較、あるいは計算処理を行って、ヒータ断線判定を行うようにする。The voltage applied to the heater is input as a heater voltage signal via a transformer, and the current flowing through the heater is input as a heater current signal via a current detector. When the maximum value is held and the signal processing unit finishes this maximum value signal capturing process, the maximum value signal is reset, and the signal processing unit outputs the captured maximum heater voltage signal and maximum heater current signal. Comparison or calculation processing is performed to determine heater breakage.

図１は本発明のヒータ断線検出装置の実施例１を示す回路構成図で、監視対象のヒータ５を備えた加熱装置１と、このヒータ５の断線を検出するように接続したヒータ断線検出部２を示している。
加熱装置１の交流電源３は、位相制御を行うサイリスタ電源４を介して、複数のヒータが並列接続されているヒータ５に接続され、ヒーター電力の制御を行って、加熱温度を制御している。
この加熱装置１のヒータ回路には、ヒータ断線検出部２がヒータ電流を入力するための電流検出器６が直列に接続され、またヒータ断線検出装置２がヒータ電圧を入力するための変圧器７が、ヒータに並列に接続されている。FIG. 1 is a circuit configuration diagram showing a heater break detection device according to a first embodiment of the present invention. A heater 1 having a heater 5 to be monitored and a heater break detection unit connected so as to detect the break of the heater 5 2 is shown.
The AC power source 3 of the heating device 1 is connected to a heater 5 in which a plurality of heaters are connected in parallel via a thyristor power source 4 that performs phase control, and controls the heater power to control the heating temperature. .
The heater circuit of the heating device 1 is connected in series with a current detector 6 for the heater break detector 2 to input a heater current, and a transformer 7 for the heater break detector 2 to input a heater voltage. Are connected in parallel to the heater.

ヒータ断線検出部２に入力された、ヒータ電流信号と、ヒータ電圧信号は、それぞれ整流回路８ａ、８ｂによって、全波整流波形、すなわち元の交流波形を０Ｖで折り返した波形の脈流に変換して、最大値信号を保持する回路９ａ、９ｂに入力する。
なお、整流後の信号は平滑しないで、最大値信号を保持する回路９ａ、９ｂに入力する。また図１では整流回路８ａ、８ｂは全波整流回路で示したが、この整流回路は半波整流回路でもよい。The heater current signal and the heater voltage signal input to the heater disconnection detection unit 2 are converted into a full-wave rectified waveform, that is, a pulsating current waveform obtained by folding the original AC waveform at 0 V, by the rectifier circuits 8a and 8b, respectively. Are input to the circuits 9a and 9b for holding the maximum value signal.
The rectified signal is not smoothed and is input to the circuits 9a and 9b that hold the maximum value signal. In FIG. 1, the rectifier circuits 8a and 8b are shown as full-wave rectifier circuits, but the rectifier circuits may be half-wave rectifier circuits.

最大値信号を保持する回路９ａ、９ｂは、いわゆるピークホールド回路と同等で、リセット信号が与えられるまで、入力した信号の最大値を保持する。
このようにして保持された、ヒータ電流信号とヒータ電圧信号の最大値は、信号処理部１２のＡＤＣ（アナログ／デジタル変換器）１３ａ、１３ｂに取込まれる。The circuits 9a and 9b that hold the maximum value signal are equivalent to a so-called peak hold circuit, and hold the maximum value of the input signal until a reset signal is given.
The maximum values of the heater current signal and heater voltage signal held in this way are taken into ADCs (Analog / Digital Converters) 13a and 13b of the signal processing unit 12.

信号処理部１２はヒータ電流信号とヒータ電圧信号の取込みを終了すると、デジタル出力１４ａ、１４ｂからリセット信号を出力して、最大値信号を保持する回路９ａ、９ｂで保持した最大値信号をリセットする。リセットはアナログＳＷ１０ａ、１０ｂをＯＮすることで行う。図１でこのアナログＳＷはＦＥＴを使用しているが、ＩＣ化したアナログＳＷを使用してもよい。When the signal processing unit 12 finishes taking in the heater current signal and the heater voltage signal, the signal processing unit 12 outputs a reset signal from the digital outputs 14a and 14b, and resets the maximum value signal held in the circuits 9a and 9b holding the maximum value signal. . The reset is performed by turning on the analog SWs 10a and 10b. In FIG. 1, this analog SW uses an FET, but an analog SW made into an IC may be used.

図２は、信号と処理タイミングを示した波形図で、図１交流電源３の波形２０は、図１サイリスタ電源４で位相制御され、例えば波形２１のような位相制御波形として、ヒータに印加される。
この電圧（または電流）の波形２１は、図１ヒータ断線検出部２に入力され、それぞれ整流して整流波形２２を得る。この整流波形２２は最大値信号を保持する回路で波形２３のように最大値が保持され、信号処理部１２に入力処理タイミング２４で取込まれる。その後リセット信号２５を出力して、最大値信号をリセットしている。FIG. 2 is a waveform diagram showing signals and processing timing. FIG. 1 shows a waveform 20 of the AC power supply 3 that is phase-controlled by the thyristor power supply 4 of FIG. The
The voltage (or current) waveform 21 is input to the heater break detection unit 2 in FIG. 1 and rectified to obtain a rectified waveform 22. The rectified waveform 22 is a circuit that holds the maximum value signal, and the maximum value is held like the waveform 23 and is taken into the signal processing unit 12 at the input processing timing 24. Thereafter, a reset signal 25 is output to reset the maximum value signal.

位相制御された交流電圧の、導通角と、実効値、平均値、最大値との関係は、位相制御の導通角０°〜１８０°をθ、元の交流電圧の最大値をＶｍ、平方根をＳＱＲとすると、
実効値は、Ｒ＝Ｖｍ×ＳＱＲ（（θ−ｓｉｎ２θ／２）／２π）
平均値は、Ａ＝Ｖｍ×（１−ｃｏｓθ）／π
位相制御された後の最大値Ｐは、Ｐ＝Ｖｍ×ｓｉｎθ
で示される。
ただし、最大値Ｐについては、導通角θが９０°以上の場合、９０°の値と同じ値となる。The relationship between the conduction angle of the phase-controlled AC voltage, the effective value, the average value, and the maximum value is as follows: θ is the conduction angle of phase control 0 ° to 180 °, Vm is the maximum value of the original AC voltage, and the square root is SQR,
The effective value is R = Vm × SQR ((θ−sin 2θ / 2) / 2π)
The average value is A = Vm × (1-cos θ) / π
The maximum value P after the phase control is P = Vm × sin θ
Indicated by
However, the maximum value P is the same as the value of 90 ° when the conduction angle θ is 90 ° or more.

図３は、これらの関係を示すグラフで、導通角１８０°のときの電圧を電圧比率１００％として、比較している。
実際の電圧は元の交流電圧値を１００Ｖ（実効値）とすると、１８０°で実効値１００Ｖ、最大値は約１４１Ｖ、平均値は約９０Ｖであるが、これらの値をそれぞれ１００％として図３で示している。FIG. 3 is a graph showing these relationships, and compares the voltages at a conduction angle of 180 ° with a voltage ratio of 100%.
Assuming that the original AC voltage value is 100V (effective value), the actual voltage is 100V effective value at 180 °, the maximum value is about 141V, and the average value is about 90V. Is shown.

導通角約３４°で、実効値が２０％（２０Ｖ）になったとき、最大値の電圧比率は約５６％であるのに対して、平均値の電圧比率は約８．５％に低下していることがわかり、発明が解決しようとする課題の項で説明した内容が明確になっている。
このグラフからも導通角の変化による最大値と平均値の低下率の違いが明白で、最大値処理によって装置の検出感度と精度がよくなることが判る。When the conduction angle is about 34 ° and the effective value is 20% (20V), the maximum voltage ratio is about 56%, while the average voltage ratio is reduced to about 8.5%. The contents explained in the section of the problem to be solved by the invention are clarified.
From this graph, it can be seen that the difference between the decrease rate of the maximum value and the average value due to the change of the conduction angle is obvious, and that the detection sensitivity and accuracy of the apparatus are improved by the maximum value processing.

再び説明を図１に戻し、このようにして検出したヒータ電流信号とヒータ電圧信号の最大値は、計算部１６で処理し、警報設定器１８で設定した値の範囲から外れた場合に、デジタル出力１７からヒータが断線した旨の信号を出力し、警報出力回路１９のリレーをＯＮして断線警報を出力する。Returning to FIG. 1 again, the maximum values of the heater current signal and the heater voltage signal detected in this way are processed by the calculation unit 16, and when the value is out of the range set by the alarm setting unit 18, A signal indicating that the heater is disconnected is output from the output 17, and the relay of the alarm output circuit 19 is turned ON to output a disconnection alarm.

計算部１６では、ヒータ抵抗＝ヒータ電圧信号÷ヒータ電流信号、
あるいは、ヒータ導電率＝ヒータ電流信号÷ヒータ電圧信号、としてヒータ固有の特性値を計算し、警報設定器１８の設定値を、デジタル入力１５を介して与えられた値と比較して、正常、異常の判定をおこなう。In the calculation unit 16, heater resistance = heater voltage signal ÷ heater current signal,
Alternatively, the characteristic value unique to the heater is calculated as heater conductivity = heater current signal ÷ heater voltage signal, and the set value of the alarm setting device 18 is compared with the value given via the digital input 15 to determine whether normal, Check for abnormalities.

例えば、正常時のヒータ電圧を１００Ｖ、ヒータ電流を１０Ａとしたとき、ヒータ導電率は０．１であるが、ヒータが１０本並列接続されていて、１本断線しヒータ電流を９Ａになると、ヒータ導電率は０．０９となる。
設定値の値を０．０９５としておき、ヒータ導電率がこの値以下になった場合にヒータ断線の警報を出力するようにしておけば、この例の場合、警報が出力される。
ヒータ電圧が位相制御されて低くなった場合でも、ヒータ導電率＝ヒータ電流信号÷ヒータ電圧信号は一定で、正常に検出される。
これは、ヒータ抵抗＝ヒータ電圧信号÷ヒータ電流信号としたときでも同様である。For example, when the normal heater voltage is 100 V and the heater current is 10 A, the heater conductivity is 0.1, but when 10 heaters are connected in parallel and one is disconnected and the heater current is 9 A, The heater conductivity is 0.09.
If the value of the set value is set to 0.095 and a heater break alarm is output when the heater conductivity falls below this value, an alarm is output in this example.
Even when the heater voltage is low due to phase control, the heater conductivity = heater current signal ÷ heater voltage signal is constant and detected normally.
This is the same even when heater resistance = heater voltage signal ÷ heater current signal.

このように本発明ヒータ断線検出装置を構成、実施することにより、平均値処理を行っていた従来のヒータ断線検出装置と異なり、最大値処理を行っていることで、検出感度と精度がすぐれたを装置を実現することができる。In this way, by configuring and implementing the heater disconnection detection device of the present invention, unlike the conventional heater disconnection detection device in which the average value processing was performed, the detection sensitivity and accuracy were improved by performing the maximum value processing. The device can be realized.

なお、これまでの説明はヒータの電力制御を位相制御として説明してが、電圧を１サイクル毎に制御するサイクル制御や、時分割制御の場合でも本発明のヒータ断線検出装置を使用することができる。
この場合、ヒータ電圧の実効値や平均値が低くなっても、本発明のヒータ断線検出装置では、電圧比率１００％のままで、電流がヒータの状態に応じた値として検出するので、精度低下をすることなくヒータの断線検出をおこなうことができる。In the above description, the heater power control is described as phase control. However, the heater disconnection detection device of the present invention can be used even in the case of cycle control for controlling the voltage for each cycle or time division control. it can.
In this case, even if the effective value or average value of the heater voltage is low, the heater disconnection detection device of the present invention detects the current as a value corresponding to the state of the heater while the voltage ratio remains at 100%, resulting in a decrease in accuracy. It is possible to detect disconnection of the heater without performing the above.

本発明のヒータ断線検出装置の実施例１を示す回路構成図The circuit block diagram which shows Example 1 of the heater disconnection detection apparatus of this invention 信号と処理タイミングを示した波形図Waveform diagram showing signal and processing timing 位相制御された交流電圧の、導通角と、実効値、平均値、最大値との関係を示すグラフGraph showing the relationship between conduction angle, effective value, average value and maximum value of phase-controlled AC voltage

符号の説明Explanation of symbols

１ 加熱装置
２ ヒータ断線検出部
３ 交流電源
４ サイリスタ電源
５ ヒータ
６ 電流検出器
７ 変圧器
８ａ、８ｂ 整流回路
９ａ、９ｂ 最大値信号を保持する回路
１０ａ、１０ｂ アナログＳＷ
１２ 信号処理部
１３ａ、１３ｂ ＡＤＣ
１４ａ、１４ｂ デジタル出力
１５ デジタル入力
１６ 計算部
１７ デジタル出力
１８ 警報設定器
１９ 警報出力回路DESCRIPTION OF SYMBOLS 1 Heating device 2 Heater disconnection detection part 3 AC power supply 4 Thyristor power supply 5 Heater 6 Current detector 7 Transformer 8a, 8b Rectifier circuit 9a, 9b Circuit 10a, 10b which hold | maintains a maximum value signal Analog SW
12 Signal processor 13a, 13b ADC
14a, 14b Digital output 15 Digital input 16 Calculation unit 17 Digital output 18 Alarm setter 19 Alarm output circuit

Claims (1)

電気ヒータ回路に、変圧器と電流検出器を接続し、ヒータに印加される電圧を該変圧器で検出してヒータ電圧信号として入力し、ヒータに流れる電流を該電流検出器で検出してヒータ電流信号として入力して、両信号の関係が予め設定した範囲を外れた場合に、警報を出力するようにしたヒータ断線検出装置において、ヒータ電圧信号、およびヒータ電流信号の最大値信号を保持する回路を設け、信号処理部が該最大値信号の取込み処理を終了するに続き、最大値信号を保持する回路をリセットする動作を繰り返すように構成し、ヒータ電圧信号の最大値とヒータ電流信号の最大値の関係からヒータの状態を判別してヒータの断線判定行うことを特徴としたヒータ断線検出装置。A transformer and a current detector are connected to an electric heater circuit, a voltage applied to the heater is detected by the transformer and input as a heater voltage signal, and a current flowing through the heater is detected by the current detector. In the heater disconnection detection device that is input as a current signal and outputs an alarm when the relationship between the two signals is outside the preset range, the heater voltage signal and the maximum value signal of the heater current signal are held. A circuit is provided, and the signal processing unit is configured to repeat the operation of resetting the circuit that holds the maximum value signal after the maximum value signal capturing process is completed, and the maximum value of the heater voltage signal and the heater current signal A heater break detection device, wherein a heater break is determined by determining a heater state from a maximum value relationship.
JP2005219555A 2005-07-01 2005-07-01 Heater disconnection detecting device Pending JP2007012578A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009070682A (en) * 2007-09-13 2009-04-02 Omron Corp Heater control device
US20100018957A1 (en) * 2006-12-19 2010-01-28 Siltech Limited Laser marking
KR20230030309A (en) * 2021-08-25 2023-03-06 지엔에스엠 주식회사 Control apparatus for freeze protection

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100018957A1 (en) * 2006-12-19 2010-01-28 Siltech Limited Laser marking
JP2009070682A (en) * 2007-09-13 2009-04-02 Omron Corp Heater control device
KR20230030309A (en) * 2021-08-25 2023-03-06 지엔에스엠 주식회사 Control apparatus for freeze protection
KR102531692B1 (en) 2021-08-25 2023-05-11 지엔에스엠 주식회사 Control apparatus for freeze protection

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