EP0371295B1 - Radiant heating element - Google Patents

Radiant heating element Download PDF

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Publication number
EP0371295B1
EP0371295B1 EP89120765A EP89120765A EP0371295B1 EP 0371295 B1 EP0371295 B1 EP 0371295B1 EP 89120765 A EP89120765 A EP 89120765A EP 89120765 A EP89120765 A EP 89120765A EP 0371295 B1 EP0371295 B1 EP 0371295B1
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EP
European Patent Office
Prior art keywords
damping
light
radiator
radiant element
switching device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP89120765A
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German (de)
French (fr)
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EP0371295A2 (en
EP0371295A3 (en
Inventor
Gerhard Goessler
Eugen Wilde
Rolf Seeburger
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EGO Elektro Geratebau GmbH
Original Assignee
EGO Elektro Gerate Blanc und Fischer GmbH
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Publication of EP0371295A3 publication Critical patent/EP0371295A3/en
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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/20Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00Ohmic-resistance heating
    • H05B3/68Heating arrangements specially adapted for cooking plates or analogous hot-plates
    • H05B3/72Plates of sheet metal
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00Ohmic-resistance heating
    • H05B3/68Heating arrangements specially adapted for cooking plates or analogous hot-plates
    • H05B3/74Non-metallic plates, e.g. vitroceramic, ceramic or glassceramic hobs, also including power or control circuits

Definitions

  • the invention relates to a radiant heater, in particular for glass ceramic hot plates, with an electric light emitter and at least one series resistor.
  • Radiant heaters of this type have become known, for example, from EP-A-176 027.
  • the light heater is an electrical heating resistor that is heated to a much higher temperature (above 1500 K and preferably above 2000 K) than the usual heating resistor coils that work at a temperature below 1500 K and are referred to below as dark lamps even though they also work in the field of red heat.
  • the light emitters are usually encapsulated in a protective gas atmosphere, for example in quartz glass bulbs or tubes and partially provided with means to counteract the evaporation of the material or to reverse it, for example by a halogen filling.
  • EP-A 176 027 therefore provides a series connection of a series resistor in the form of a dark radiator in front of the light radiator, which dampens the inrush current and supplements the power emitted by the light radiator during operation as a dark radiator.
  • the total installed power can also be divided between the light emitter and the dark emitter, which is particularly advantageous in the case of the arrangement of the light emitter in straight rods, which was customary hitherto, for filling the entire heated zone.
  • a radiant heater which contains a damping switching device.
  • two light emitters are provided, each of which has a separate series resistor and are connected in parallel with one another.
  • one of the two light emitters is only switched on by a delay circuit with a certain delay, so that the inrush current is reduced even further, apart from by the separate series resistors.
  • the object of the invention is to provide a radiant heater with a plurality of light emitters and a damping switching device which ensures a permissible inrush current for all light emitters with little effort in terms of resistance.
  • the damping switching device preferably switches on the series resistor during the heating phase of each of the light emitters and advantageously switches it off again automatically after the light emitter that has just been switched on is heated up. It can work depending on the voltage drop on the light source, which is due to the positive temperature coefficient after it warms up.
  • a threshold switching device which responds to the voltage drop can be provided here. This can consist of a relay, but is preferably designed as an electronic circuit that triggers when a certain voltage value is reached and causes a series resistor to be switched off.
  • the reactivation ie the signal which triggers the reactivation of the series resistor, can be triggered by completely switching off the voltage, for example by a special isolating switch.
  • the damping device can also consist of a delay circuit, i.e. a timer, because usually the heating phase of a radiant heater is quite short and is on the order of 1 to 2 seconds.
  • the series resistor can be a separate damping resistor, which is therefore switched off during further operation.
  • the resistor is not exposed to permanent loads, it can be subjected to quite a high load and can therefore be small and simple.
  • it should preferably be arranged in the region of the radiant heater so that the heat generated by it can be dissipated well on the one hand and can be used on the other.
  • the invention leads to a reduction in the inrush current to a permissible value in all types of radiant heaters which contain several light emitters, which without the measures of the invention can in some cases be ten times higher than the working current and also because of its short-term nature and its sudden occurrence would otherwise lead to impermissible network loads.
  • the radiation helper body is controlled or regulated by a clocking, for example by a regulator or switch operating in power cycles of different relative duty cycles.
  • FIGS. 1 to 7 are intended to support the invention realized in FIG. 8.
  • Fig. 1 shows a plan view of a radiant heater 11, which has a bowl-shaped insulation 12 in a sheet metal shell.
  • the edge 13 of this insulation is intended to be pressed onto the underside of a glass ceramic hotplate, so that the radiant heater 11 forms a circular heating zone on this glass ceramic plate.
  • a light radiator 15 is arranged, which has the shape of a circular tube comprising almost 360 °, the two ends of which are guided parallel to each other to the outside.
  • This tube which is made of quartz or quartz glass, is sealed at both ends 16 and provided with electrical connections 17, several times with one, not shown, lying in the tube supported heating coil are connected, which consists of tungsten or another highly heat-resistant electrical resistance material.
  • the light emitter can also be polygonal or have other shapes. In the example shown, it runs around the outer circumference of the heating zone and thus creates a circular area inside, which is partially covered with a dark radiator 18. As described in EP-A 176 027, to which reference is made here, this can consist of wire coils made of conventional resistance material, which are laid on the bottom of the insulation 12 by means of conventional fastening means in zigzag or spiral form.
  • Both radiant heaters 15 and 18 are arranged at a distance from the glass ceramic plate and the light radiator 15, possibly supported by it, is also at a distance from the insulation 12.
  • a rod-shaped temperature sensor 19 of a temperature limiter 20 runs diametrically over the entire heating zone 14.
  • a damping resistor 21 arranged in the area of the heating zone 14 is indicated in the schematic plan view according to FIG. 1.
  • This can be a resistor similar to a dark radiator 18, but with a higher load. With a relatively high resistance value in length, diameter and arrangement, it can therefore be dimensioned such that it would assume a temperature which was not itself beneficial to it in continuous operation.
  • the damping resistance can also be part of the heating or in the form of a conventional resistance heating element of the radiator.
  • damping resistors which have a different configuration are also suitable, for example band resistors, sheet resistors or the like.
  • damping resistor 21 assign a thermal mass to which it is connected in a heat-conducting manner and which derives the warming that occurs only intermittently on it and thus makes it more uniform.
  • An arrangement of a damping resistor outside the radiant heater is also possible.
  • FIG. 2 shows a circuit of the radiant heater according to FIG. 1.
  • the light radiator 15 is connected in series with the dark radiator 18 and this is additionally preceded by the damping resistor 21.
  • the voltage present on both sides of the light radiator 15 is monitored by a damping switching device 22, which is symbolized in the example shown as a voltage relay coil 23 with a switching contact 24 actuated thereby.
  • the damping device thus consists of the damping resistor 21 and the damping switching device 22.
  • the switching contact 24 can bridge the damping resistor 21 when it is closed.
  • the switching contact of the temperature limiter 20 and a clocking power control unit 27 are switched into one of the power supply lines 25, 26.
  • This is of the type as it is usually referred to as an "energy regulator” and has a switch contact 28 which is actuated in a continuously adjustable manner by a bimetal 29.
  • the bimetal is heated by a control heater 30 which is connected in parallel to the radiant heater.
  • the power control contact 28 is closed, as is the contact of the temperature limiter 20, while the contact 24 is open, because for the time being the voltage difference on both sides of the light radiator is small, since its internal resistance due to the cold filament is still very low.
  • the two upstream resistors 18 and 21 cause the inrush current in spite of the low resistance in the light emitter 15 remains limited to a permissible value.
  • the resistance increases by about a power of ten (usually 10 to 12 times), so that the voltage drop caused by it also increases and the damping switching device is effective is, for example, the relay coil 23 attracts and thereby closes the contact 24.
  • the arrangement works loss-free, since all the heat in the area of the radiant heater is released, and the damping is so short and so short that it hardly affects the effectiveness of the light radiator, which is designed to heat up quickly and emit radiant heat falls.
  • a mathematical example illustrates this: It is assumed that a radiant heater with a total output of 2200 W has a light source of 1100 W and a dark radiator of the same power, each based on the operating state.
  • the operating current at 220 V is 10 A and the resistance of the radiators is 11 ohms each, ie 22 ohms in series. While the temperature coefficient of resistance in the dark radiator is relatively low and is neglected for the purpose of this calculation, the high resistance temperature coefficient of the light radiator causes the resistance in the cold state to drop to a tenth to a twelfth, so that if one takes an average of 1 / 11, the cold resistance of the light radiator is only 1 ohm is.
  • FIG. 3 shows a circuit in which a light emitter 15 is connected in parallel with a dark emitter 18.
  • the light and dark emitters would each have a resistance of 44 ohms in the operating state, which would drop to 4 ohms in the cold state, so that the light emitter in the cold state has a current of 55 A equal to approx would draw 12 kW. Together with the dark radiator, this would be 13 kW, which would be highly inadmissible.
  • a damping resistance of, for example, 40 ohms would limit the total power to 10 A equal to 2200 W and would create approximately the same heating conditions as described with reference to FIG. 2.
  • the damping resistor 21 is therefore connected in series with the light emitter in the strand containing the light emitter, while the dark emitter is parallel to this strand.
  • the damping resistor 21 is in turn bridged by a damping switching device 22.
  • the use of a parallel connection of light and dark radiators can be advantageous because the resistance of the heating coil in the light radiator can be higher, which can lead to advantages in the production of the light radiator due to a thinner filament. The same applies to the dark radiator.
  • the response time until the full luminous intensity of the light source is reached can also be reduced.
  • a dot-and-dash circuit 31 is indicated, which can be used instead of the switching device 23 which responds to voltage on the light emitter and which closes the switching contact 24 which is open when the current is switched off only after a set time.
  • the usual heating time of up to approx. 2 seconds for the light emitter could be selected as such a time.
  • Such a delay switching device could be an electronic or thermal delay switch of a known type.
  • FIG. 4 shows a plan view of a two-circuit radiant heater which, with the structure similar to that of FIG. 1, has an inner heating zone 14a and an outer heating zone 14b which are delimited from one another by an intermediate edge 13a.
  • each heating zone there is a light radiator 15a, 15b and a dark radiator 18a, 18b.
  • the outer light emitter can be designed such that its ends 16 lie on both sides of the ends 16 of the inner light emitter 15a and the dark emitter 18b can be in the form of a possibly at the exits the light emitter has an interrupted circular ring.
  • the damping resistor 21 can be arranged at any point, in the example in the central heating zone 14a.
  • the circuit according to FIG. 5 shows that the series circuit of light emitter 15a and dark emitter 18a belonging to the central heating zone 14a is provided without a damping resistor, while the damping resistor 21 is assigned to the heating zone T4b and the heating resistor combination 15b, 18b is connected in series.
  • a damping device 22 of the type already described above switches the damping resistor 21 off by short-circuiting after the heating phase of the light radiator 15b.
  • the regulation or switching can be the same as that described with reference to FIG. 2.
  • an additional switch (not shown) is provided with which the inner heating zone, which is always in operation when the radiant heater is switched on, can be connected to the outer heating zone 14b as required.
  • the inner heating zone usually has a lower power, so that the damping through the series connection of the dark radiator 18a may be sufficient here, while the outer heating zone has a higher power and accordingly the damping resistance ensures a sufficiently low inrush current.
  • Fig. 6 shows a circuit of a two-circuit radiator body, in which only the inner heating zone 14a is assigned a dark radiator 18a in series with the light radiator 15a, while the outer heating zone 14b contains only one light radiator 15b, to which, however, a damping resistor 21, which is switched in the manner described, is assigned.
  • Fig. 7 shows an arrangement of the same type, but in which there is no separate damping resistor, but the dark radiator 18c of the inner heating zone 14a is connected upstream of the two bright radiators 15a and 15b when switched on.
  • An electronic damping circuit is indicated here as the damping circuit, which is preferred over a relay with a voltage coil because any fluttering phenomena in the switching range can be avoided with a correspondingly stable threshold value circuit.
  • Such electronic circuits are generally known. They can be designed in such a way that after a single response (exceeding the voltage threshold value) the device is only switched off again after the entire line has been disconnected from the power supply. This can be done with an additional switch, as shown in Fig. 8 with the reference numeral 35a. The function of this additional switch could also be taken over by the contact of the power control unit.
  • An electronic threshold value switching device 22 can also respond to criteria other than the voltage difference on the light radiator or the time.
  • the damping switching device belongs to the individual radiant heater, it is preferably arranged (except for the damping resistance) outside the radiant heater, for example at its outer or other locations on the cooking appliance.
  • the damping switching device is actuated 22 a contact 24 which is designed as a changeover contact and at the same time interrupts the line branch of the outer heating zone 14b when it switches the light radiator 15b on in the manner described in the line branch of the inner heating zone 14a.
  • FIG. 8 shows an embodiment in which there is only one damping resistor 21 in the case of two light emitters 15a, 15b, which is connected upstream of the two light emitters and can be bridged by a device 22 such as that described with reference to FIG. 7.
  • the power control takes place in turn with a clocking power control device 27, which, as already mentioned, can additionally actuate a contact 35a, which briefly de-energizes the entire circuit when the external heating circuit is switched on and thereby reactivates the threshold switch contained in the damping switching device. This shutdown could also be done by the manual switch 35.
  • the outer heating zone is switched on as required via the switch 33.
  • the electronic switching device 22 is thereby also effective when the light emitter 15b is connected to the light emitter 15a already in operation, so that the damping resistor 21 is then briefly switched on again. It is also advantageous that the damping device somewhat alleviates the optical effect of the light emitter, in particular also in clocked regulation.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Resistance Heating (AREA)
  • Electric Stoves And Ranges (AREA)
  • Control Of Resistance Heating (AREA)
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Abstract

A radiant element (11) contains a light radiator, e.g. a substantially circular halogen tubular lamp (15) and a dark radiator (18) in the form of standard open, electric radiant heating coils. For damping or attenuating the high starting or transient current of the light radiator (15), a damping resistor (21) is connected in series therewith, namely during the warming-up phase of the light radiator (15). Following the rise of the resistance of the light radiator due to its heating or after a certain time lapse, a damping switching device (22) disables the series resistor by shorting across it.

Description

Die Erfindung bezieht sich auf einen Strahlungs-Heizkörper, insbesondere für Glaskeramik-Kochplatten, mit einem elektrischen Hellstrahler und wenigstens einem Vorwiderstand.The invention relates to a radiant heater, in particular for glass ceramic hot plates, with an electric light emitter and at least one series resistor.

Derartige Strahlungs-Heizkörper sind beispielsweise aus der EP-A-176 027 bekanntgeworden. Bei dem Hellstrahler handelt es sich um einen elektrischen Heizwiderstand, der auf eine wesentlich höhere Temperatur (oberhalb 1500 K und vorzugsweise über 2000 K) aufgeheizt wird, als die normalerweise üblichen Heizwiderstandswendeln, die bei einer Temperatur unter 1500 K arbeiten und im folgenden als Dunkelstrahler bezeichnet werden, obwohl sie ebenfalls im Bereich der Rotglut arbeiten. Die Hellstrahler sind meist in einer Schutzgasatmosphäre gekapselt, beispielsweise in Quarzglaskolben oder -röhren und teilweise mit Mitteln versehen, um der Materialverdampfung entgegenzuwirken oder diese wieder rückgängig zu machen, z.B. durch eine Halogenfüllung.Radiant heaters of this type have become known, for example, from EP-A-176 027. The light heater is an electrical heating resistor that is heated to a much higher temperature (above 1500 K and preferably above 2000 K) than the usual heating resistor coils that work at a temperature below 1500 K and are referred to below as dark lamps even though they also work in the field of red heat. The light emitters are usually encapsulated in a protective gas atmosphere, for example in quartz glass bulbs or tubes and partially provided with means to counteract the evaporation of the material or to reverse it, for example by a halogen filling.

Ein Problem bei diesen Hellstrahlern ist ihr großer positiver Temperaturkoeffizient des Widerstandes, der zu außerordentlich hohen und teilweise unzulässigen Einschaltströmen führt, würde man sie allein betreiben. In der EP-A 176 027 ist daher eine Serien-Vorschaltung eines als Dunkelstrahler ausgebildeten Vorwiderstandes vor den Hellstrahler vorgesehen, der den Einschaltstrom dämpft und im Betrieb als Dunkelstrahler die vom Hellstrahler abgegebene Leistung ergänzt. Auf diese Weise kann auch die gesamte installierte Leistung auf den Hellstrahler und den Dunkelstrahler aufgeteilt werden, was insbesondere bei der bisher üblichen Anordnung des Hellstrahlers in geraden Stäben zur Ausfüllung der gesamten beheizten Zone vorteilhaft ist.One problem with these light sources is their large positive temperature coefficient of resistance, which leads to extremely high and sometimes impermissible inrush currents if they were operated alone. EP-A 176 027 therefore provides a series connection of a series resistor in the form of a dark radiator in front of the light radiator, which dampens the inrush current and supplements the power emitted by the light radiator during operation as a dark radiator. In this way, the total installed power can also be divided between the light emitter and the dark emitter, which is particularly advantageous in the case of the arrangement of the light emitter in straight rods, which was customary hitherto, for filling the entire heated zone.

Bei sehr hohen Leistungen des Hellstrahlers wird dies trotzdem problematisch, weil der Einschaltstrom dann trotz des Vorwiderstandes zu hoch wird und damit das Netz unzulässig belastet.This becomes problematic at very high powers of the light emitter because the inrush current then becomes too high despite the series resistor and thus impermissibly loads the network.

Aus der EP-A-235 895 ist ein Strahlungs-Heizkörper bekanntgeworden, der eine Dämpfungsschalteinrichtung enthält. Meist sind dort mehrere Hellstrahler parallel zueinander geschaltet und werden auch stets gleichzeitig betrieben. Bei einer Ausführung (Fig. 4) sind zwei Hellstrahler vorgesehen, die jeweils einen gesonderten Vorwiderstand aufweisen und zueinander parallelgeschaltet sind. Der eine der beiden Hellstrahler wird jedoch durch eine Verzögerungsschaltung erst mit einer gewissen Verzögerung zugeschaltet, so daß der Einschaltstrom außer durch die gesonderten Vorwiderstände noch weiter reduziert wird.From EP-A-235 895 a radiant heater has become known which contains a damping switching device. Usually there are several light emitters connected in parallel to each other and are always operated simultaneously. In one embodiment (FIG. 4), two light emitters are provided, each of which has a separate series resistor and are connected in parallel with one another. However, one of the two light emitters is only switched on by a delay circuit with a certain delay, so that the inrush current is reduced even further, apart from by the separate series resistors.

Aufgabe der Erfindung ist es, einen Strahlungs-Heizkörper mit mehreren Hellstrahlern und einer Dämpfungsschalteinrichtung zu schaffen, der für einen zulässigen Einschaltstrom für alle Hellstrahler mit geringem Aufwand an Widerständen sorgt.The object of the invention is to provide a radiant heater with a plurality of light emitters and a damping switching device which ensures a permissible inrush current for all light emitters with little effort in terms of resistance.

Diese Aufgabe wird erfindungsgemäß durch den Anspruch 1 gelöst.This object is achieved by claim 1.

Die Dämpfungsschalteinrichtung schaltet vorzugsweise den Vorwiderstand während der Anheizphase jedes der Hellstrahler zu und vorteilhaft nach Erwärmung des gerade eingeschalteten Hellstrahlers selbsttätig wieder aus. Sie kann in Abhängigkeit vom Spannungsabfall am Hellstrahler arbeiten, der ja aufgrund des positiven Temperaturkoeffizienten nach dessen Erwärmung zunimmt. Hier kann eine auf den Spannungsabfall ansprechende Schwellwert-Schalteinrichtung vorgesehen sein. Diese kann aus einem Relais bestehen, ist jedoch vorzugsweise als elektronische Schaltung ausgebildet, die beim Erreichen eines bestimmten Spannungswertes auslöst und die Abschaltung eines Vorwiderstandes bewirkt. Um auf jeden Fall durch Spannungsänderungen bewirkte unbeabsichtigte Schaltvorgänge zu vermeiden, kann die Wieder-Aktivierung, d.h. das das Wiedereinschalten des Vorwiderstandes auslösende Signal, durch das komplette Abschalten der Spannung ausgelöst sein, beispielsweise durch einen besonderen Trennschalter.The damping switching device preferably switches on the series resistor during the heating phase of each of the light emitters and advantageously switches it off again automatically after the light emitter that has just been switched on is heated up. It can work depending on the voltage drop on the light source, which is due to the positive temperature coefficient after it warms up. A threshold switching device which responds to the voltage drop can be provided here. This can consist of a relay, but is preferably designed as an electronic circuit that triggers when a certain voltage value is reached and causes a series resistor to be switched off. In order to avoid unintentional switching processes caused by voltage changes in any case, the reactivation, ie the signal which triggers the reactivation of the series resistor, can be triggered by completely switching off the voltage, for example by a special isolating switch.

Die Dämpfungseinrichtung kann jedoch auch aus einer Verzögerungsschaltung, d.h. einem Zeitglied bestehen, weil üblicherweise die Anheizphase eines Strahlheizkörpers recht kurz ist und in der Größenordnung von 1 bis 2 Sekunden liegt.However, the damping device can also consist of a delay circuit, i.e. a timer, because usually the heating phase of a radiant heater is quite short and is on the order of 1 to 2 seconds.

Der Vorwiderstand kann ein gesonderter Dämpfungswiderstand sein, der also während des weiteren Betriebes abgeschaltet ist. Dadurch kann der Widerstand, weil er keinen Dauerbelastungen ausgesetzt ist, recht hoch belastet und damit klein und einfach ausgeführt sein. Er sollte aber vorzugsweise im Bereich des Strahlheizkörpers angeordnet sein, um die von ihm erzeugte Wärme einerseits gut abführen zu können und andererseits nutzbringend mit zu verwenden.The series resistor can be a separate damping resistor, which is therefore switched off during further operation. As a result, because the resistor is not exposed to permanent loads, it can be subjected to quite a high load and can therefore be small and simple. However, it should preferably be arranged in the region of the radiant heater so that the heat generated by it can be dissipated well on the one hand and can be used on the other.

Insbesondere bei Zweikreis-Strahlheizkörpern, d.h. Strahlheizkörpern, die mehrere, einzeln schaltbare Heizzonen aufweisen, beispielsweise zwei zueinander konzentrische Heizzonen, ist es auch möglich, die normalerweise als Dauerbeheizung vorgesehenen Dunkelstrahler als Vorwiderstände über die Dämpfungseinrichtung den Hellstrahlern vorzuschalten. Die Dunkelstrahler könnten jeweils einem anderen Hellstrahler vorgeschaltet werden als sie es in ihrer Arbeitsschaltung sind oder sie könnten auch in anderen Kombinationen geschaltet werden. So könnten beispielsweise die Vorwiderstände beider Heizzonen einem einzelnen Hellstrahler in Reihe zueinander vorgeschaltet werden oder der Dunkelstrahler der einen Heizzone dem Hellstrahler der anderen.In particular in the case of dual-circuit radiant heaters, that is to say radiant heaters which have a plurality of individually switchable heating zones, for example two heating zones which are concentric with one another, it is also possible to connect the dark radiators normally provided as permanent heating as series resistors to the bright radiators via the damping device. The dark emitters could each be connected upstream of a different light emitter than they are in their working circuit or they could also be in other combinations be switched. For example, the series resistors of both heating zones could be connected upstream of a single light emitter in series, or the dark emitter of one heating zone could be connected to the light emitter of the other.

Es ist zu erkennen, daß die Erfindung bei allen Arten von Strahlungs-Heizkörpern, die mehrere Hellstrahler beinhalten, zu einer Herabsetzung des Einschaltstromes auf einen zulässigen Wert führt, der ohne die Maßnahmen der Erfindung teilweise um eine Zehnerpotenz Uber dem Arbeitsstrom liegen kann und auch wegen seiner Kurzzeitigkeit und seinem stoßartigen Auftreten anderenfalls unzulässige Netzbelastungen herbeiführen würde. Das gilt insbesondere, wenn die Steuerung oder Regelung des Strahlungs-Helzkörpers durch eine Taktung erfolgt, beispielsweise durch einen in Leistungstakten von unterschiedlicher relativer Einschaltdauer arbeitenden Regler oder Schalter.It can be seen that the invention leads to a reduction in the inrush current to a permissible value in all types of radiant heaters which contain several light emitters, which without the measures of the invention can in some cases be ten times higher than the working current and also because of its short-term nature and its sudden occurrence would otherwise lead to impermissible network loads. This applies in particular if the radiation helper body is controlled or regulated by a clocking, for example by a regulator or switch operating in power cycles of different relative duty cycles.

Diese und weitere Merkmale von bevorzugten Weiterbildungen der Erfindung gehen außer aus den Ansprüchen auch aus der Beschreibung und den Zeichnungen hervor, wobei die einzelnen Merkmale jeweils für sich allein oder zu mehreren in Form von Unterkombinationen bei einer Ausführungsform der Erfindung und auf anderen Gebieten verwirklicht sein und vorteilhafte sowie für sich schutzfähige Ausführungen darstellen können. Ein Ausführungsbeispiel der Erfindung ist in den Zeichnungen dargestellt und wird im folgenden näher erläutert. In den Zeichnungen zeigen:

Fig. 1
die schematische Draufsicht auf einen Strahlungs-Heizkörper mit einem Hellstrahler und einem Dunkelstrahler,
Fig. 2 und 3
Schaltbilder für einen derartigen Strahiheiz-körper,
Fig. 4
die schematische Draufsicht auf einen Strahlheizkörper mit zwei Hellstrahler- und zwei Dunkelstrahler-Zonen,
Fig. 5
eine Schaltung für einen derartigen Zweikreis-Strahlheizkörper,
Fig. 6
eine Schaltung eines Zweikreis-Strahlheizkörpers mit nur einem Vorwiderstand und einem besonderen Dämpfungswiderstand,
Fig. 7
eine Schaltung eines derartigen Heizkörpers ohne besonderen Dämpfungswiderstand, und
Fig. 8
eine Schaltung eines Strahlheizkörpers nach der Erfindung mit zwei Hellstrahlern ohne permanente Dunkelstrahler.
These and further features of preferred developments of the invention are evident from the claims and also from the description and the drawings, the individual features being implemented individually or in groups in the form of sub-combinations in one embodiment of the invention and in other areas, and can represent advantageous and protectable versions. An embodiment of the invention is shown in the drawings and is explained in more detail below. The drawings show:
Fig. 1
the schematic plan view of a radiant heater with a light radiator and a dark radiator,
2 and 3
Circuit diagrams for such a radiant heater,
Fig. 4
the schematic plan view of a radiant heater with two light emitter and two dark emitter zones,
Fig. 5
a circuit for such a two-circuit radiant heater,
Fig. 6
a circuit of a two-circuit radiant heater with only one series resistor and a special damping resistor,
Fig. 7
a circuit of such a radiator without special damping resistance, and
Fig. 8
a circuit of a radiant heater according to the invention with two light emitters without permanent dark emitters.

Die in den Fig.1 bis 7 gezeigten Beispiele sollen die in Fig.8 verwirklichte Erfindung unterstützend erläutern.The examples shown in FIGS. 1 to 7 are intended to support the invention realized in FIG. 8.

Fig. 1 zeigt in Draufsicht einen Strahlheizkörper 11, der in einer Blechschale eine schüsselförmige Isolierung 12 aufweist. Der Rand 13 dieser Isolierung ist dazu bestimmt, an die Unterseite einer Glaskeramik-Kochplatte angedrückt zu werden, so daß der Strahlheizkörper 11 eine kreisförmige Heizzone auf dieser Glaskeramikplatte ausbildet.Fig. 1 shows a plan view of a radiant heater 11, which has a bowl-shaped insulation 12 in a sheet metal shell. The edge 13 of this insulation is intended to be pressed onto the underside of a glass ceramic hotplate, so that the radiant heater 11 forms a circular heating zone on this glass ceramic plate.

In der Heizzone 14, die den innerhalb des Randes 13 liegenden kreisförmigen Raum einnimmt, ist ein Hellstrahler 15 angeordnet, der die Form eines nahezu 360° umfassenden kreisförmigen Rohres hat, dessen beide Enden parallel zueinander nach außen geführt sind. Dieses aus Quarz oder Quarzglas bestehende Rohr ist an seinen beiden Enden 16 zugeschmolzen und mit elektrischen Anschlüssen 17 versehen, die mit einer nicht dargestellten, in dem Rohr liegenden, mehrfach abgestützten Heizwendel verbunden sind, die aus Wolfram oder einem anderen hochwärmebeständigen elektrischen Widerstandsmaterial besteht. Der Hellstrahler kann auch mehreckig sein oder andere Formen haben. Im dargestellten Beispiel läuft er im Bereich des Außenumfanges der Heizzone um und schafft so in seinem Inneren einen kreisförmigen Bereich, der teilweise mit einem Dunkelstrahler 18 belegt ist. Dieser kann, wie in der EP-A 176 027, auf die hier Bezug genommen wird, beschriebenen Weise aus Drahtwendeln aus üblichem Widerstandsmaterial bestehen, die auf dem Boden der Isolierung 12 durch ebenfalls übliche Befestigungsmittel in Zickzack- oder Spiralform verlegt sind.In the heating zone 14, which occupies the circular space lying within the edge 13, a light radiator 15 is arranged, which has the shape of a circular tube comprising almost 360 °, the two ends of which are guided parallel to each other to the outside. This tube, which is made of quartz or quartz glass, is sealed at both ends 16 and provided with electrical connections 17, several times with one, not shown, lying in the tube supported heating coil are connected, which consists of tungsten or another highly heat-resistant electrical resistance material. The light emitter can also be polygonal or have other shapes. In the example shown, it runs around the outer circumference of the heating zone and thus creates a circular area inside, which is partially covered with a dark radiator 18. As described in EP-A 176 027, to which reference is made here, this can consist of wire coils made of conventional resistance material, which are laid on the bottom of the insulation 12 by means of conventional fastening means in zigzag or spiral form.

Der Hellstrahler 15 ragt mit seinen Enden 16 durch den Rand 13 hindurch nach außen und ist dort mit elektrischen Anschlüssen 17 versehen. Beide Strahlheizkörper 15 und 18 sind in Abstand von der Glaskeramikplatte angeordnet und der Hellstrahler 15, ggf. von dieser abgestützt, auch in Abstand von der Isolierung 12.The ends of the light radiator 15 protrude outwards through the edge 13 and are provided with electrical connections 17 there. Both radiant heaters 15 and 18 are arranged at a distance from the glass ceramic plate and the light radiator 15, possibly supported by it, is also at a distance from the insulation 12.

Diametral über die gesamte Heizzone 14 verläuft ein stabförmiger Temperaturfühler 19 eines Temperaturbegrenzers 20.A rod-shaped temperature sensor 19 of a temperature limiter 20 runs diametrically over the entire heating zone 14.

In der schematischen Draufsicht nach Fig. 1 ist ein im Bereich der Heizzone 14 angeordneter Dämpfungswiderstand 21 angedeutet. Es kann sich dabei um einen Widerstand ähnlich einem Dunkelstrahler 18 handeln, der jedoch höher belastet ist. Er kann also bei relativ hohem Widerstandswert in Länge, Durchmesser und Anordnung so bemessen sein, daß er im Dauerbetrieb eine ihm an sich nicht zuträgliche Temperatur annehmen würde. Der Dämpfungswiderstand kann auch Teil der Beheizung bzw. in Form eines konventionellen Widerstands- heizelementes des Strahlkörpers sein. Es sind jedoch auch Dämpfungswiderstände geeignet, die eine andere Konfiguration haben, beispielsweise Band-, Schichtwiderstände oder dergleichen. Es ist auch möglich, dem Dämpfungswiderstand 21 eine thermische Masse zuzuordnen, mit der er wärmeleitend verbunden ist und die die ja an ihm nur stoßweise auftretende Erwärmung ableitet und somit vergleichmäßigt. So ist auch eine Anordnung eines Dämpfungswiderstandes außerhalb des Strahlheizkörpers möglich.A damping resistor 21 arranged in the area of the heating zone 14 is indicated in the schematic plan view according to FIG. 1. This can be a resistor similar to a dark radiator 18, but with a higher load. With a relatively high resistance value in length, diameter and arrangement, it can therefore be dimensioned such that it would assume a temperature which was not itself beneficial to it in continuous operation. The damping resistance can also be part of the heating or in the form of a conventional resistance heating element of the radiator. However, damping resistors which have a different configuration are also suitable, for example band resistors, sheet resistors or the like. It is also possible to use the damping resistor 21 assign a thermal mass to which it is connected in a heat-conducting manner and which derives the warming that occurs only intermittently on it and thus makes it more uniform. An arrangement of a damping resistor outside the radiant heater is also possible.

Fig. 2 zeigt eine Schaltung des Strahlheizkörpers nach Fig. 1. Der Hellstrahler 15 ist mit dem Dunkelstrahler 18 ständig in Reihe geschaltet und diesem ist zusätzlich noch der Dämpfungswiderstand 21 vorgeschaltet. Die an beiden Seiten des Hellstrahlers 15 anliegende Spannung wird von einer Dämpfungsschalteinrichtung 22 überwacht, die im dargestellten Beispiel als eine Spannungs-Relaisspule 23 mit einem davon betätigten Schaltkontakt 24 symbolisiert ist. Die Dämpfungseinrichtung besteht also im dargestellten Beispiel aus dem Dämpfungswiderstand 21 und der Dämpfungsschalteinrichtung 22. Der Schaltkontakt 24 kann den Dämpfungswiderstand 21 überbrücken, wenn er geschlossen ist.FIG. 2 shows a circuit of the radiant heater according to FIG. 1. The light radiator 15 is connected in series with the dark radiator 18 and this is additionally preceded by the damping resistor 21. The voltage present on both sides of the light radiator 15 is monitored by a damping switching device 22, which is symbolized in the example shown as a voltage relay coil 23 with a switching contact 24 actuated thereby. In the example shown, the damping device thus consists of the damping resistor 21 and the damping switching device 22. The switching contact 24 can bridge the damping resistor 21 when it is closed.

In eine der Netzzuleitungen 25, 26 ist der Schaltkontakt des Temperaturbegrenzers 20 und ein taktendes Leistungssteuergerät 27 eingeschaltet. Dies ist von der Art, wie es üblicherweise als "Energieregler" bezeichnet wird und besitzt einen Schaltkontakt 28, der in stufenlos einstellbarer Weise von einem Bimetall 29 betätigt wird. Das Bimetall ist von einer Steuerbeheizung 30 beheizt, die parallel zum Strahlheizkörper angeschlossen ist.The switching contact of the temperature limiter 20 and a clocking power control unit 27 are switched into one of the power supply lines 25, 26. This is of the type as it is usually referred to as an "energy regulator" and has a switch contact 28 which is actuated in a continuously adjustable manner by a bimetal 29. The bimetal is heated by a control heater 30 which is connected in parallel to the radiant heater.

Nach Einschalten des Strahlheizkörpers ist der Leistungssteuerkontakt 28 ebenso geschlossen wie der Kontakt des Temperaturbegrenzers 20, während der Kontakt 24 offen ist, weil vorläufig die Spannungsdifferenz auf beiden Seiten des Hellstrahlers gering ist, da sein innerer Widerstand wegen des kalten Glühfadens noch sehr gering ist. Die beiden vorgeschalteten Widerstände 18 und 21 bewirken jedoch, daß der Einschaltstrom trotz des geringen Widerstandes im Hellstrahler 15 auf einen zulässigen Wert begrenzt bleibt. Nach Erwärmung des Hellstrahlers 15, was normalerweise innerhalb von ca. 2 Sekunden geschieht, steigt sein Widerstand ca. um eine Zehnerpotenz (normalerweise auf das 10- bis 12-fache) an, so daß der von ihm bewirkte Spannungsabfall ebenfalls ansteigt und die Dämpfungsschalteinrichtung wirksam wird, z.B. die Relaisspule 23 anzieht und dadurch den Kontakt 24 schließt. Damit ist der Dämpfungswiderstand 21 überbrückt und es sind lediglich Hell- und Dunkelstrahler 15, 18 in Reihe eingeschaltet. Wenn durch Erwärmung des Bimetalls 29 der Leistungskontakt 28 öffnet, wird die ganze Anordnung stromlos und damit sinkt auch die Spannung an der Schalteinrichtung 22 auf Null, so daß der Kontakt 24 wieder öffnet. Dieses Spiel wiederholt sich bei jedem Takten des Leistungssteuergerätes 27 und des Temperaturreglers 20.After switching on the radiant heater, the power control contact 28 is closed, as is the contact of the temperature limiter 20, while the contact 24 is open, because for the time being the voltage difference on both sides of the light radiator is small, since its internal resistance due to the cold filament is still very low. However, the two upstream resistors 18 and 21 cause the inrush current in spite of the low resistance in the light emitter 15 remains limited to a permissible value. After heating the light radiator 15, which usually happens within about 2 seconds, its resistance increases by about a power of ten (usually 10 to 12 times), so that the voltage drop caused by it also increases and the damping switching device is effective is, for example, the relay coil 23 attracts and thereby closes the contact 24. This dampens the damping resistor 21 and only light and dark radiators 15, 18 are switched on in series. When the power contact 28 opens due to the heating of the bimetal 29, the entire arrangement is de-energized and thus the voltage at the switching device 22 also drops to zero, so that the contact 24 opens again. This game is repeated every time the power control unit 27 and the temperature controller 20 are cycled.

Die Anordnung arbeitet verlustfrei, da die gesamte Wärme im Bereich des Strahlheizkörpers frei wird, und die Dämpfung ist so kurzzeitig und gering, daß sie auch für die Wirksamkeit des Hellstrahlers, der ja dazu bestimmt ist, sich schnell aufzuheizen und Strahlungswärme abzugeben, kaum ins Gewicht fällt.The arrangement works loss-free, since all the heat in the area of the radiant heater is released, and the damping is so short and so short that it hardly affects the effectiveness of the light radiator, which is designed to heat up quickly and emit radiant heat falls.

Ein rechnerisches Beispiel verdeutlicht das: Es sei angenommen, daß in einem Strahlungs-Heizkörper von 2200 W Gesamtleistung ein Hellstrahler von 1100 W und ein Dunkelstrahler der gleichen Leistung, jeweils bezogen auf den Betriebszustand, installiert sei. Der Betriebsstrom beträgt dann bei 220 V 10 A und der Widerstand der Strahler je 11 Ohm, d.h. 22 Ohm in Serie. Während der Temperaturkoeffizient des Widerstandes bei dem Dunkelstrahler relativ gering ist und für den Zweck dieser Rechnung vernachlässigt wird, bewirkt der hohe Widerstands-Temperaturkoeffizient des Hellstrahlers einen Abfall des Widerstandes im kalten Zustand auf ein Zehntel bis Zwölftel, so daß, wenn man einen Mittelwert von 1/11 nimmt, der Kalt-Widerstand des Hellstrahlers nur 1 Ohm beträgt. Bei Einschaltung des Hell- und Dunkelstrahlers ohne Dämpfungswiderstand wäre der Gesamtwiderstand 12 Ohm entsprechend einem Einschaltstrom von 18,3 A Einschaltstrom (= 4 kW). Auch als kurzzeitiger Spitzenstrom, der darüber hinaus noch, wenn auch in abgeschwächter Form, bei jedem Regeltakt wieder auftritt, wäre dies unzulässig, vor allem, wenn man bedenkt, daß oft in einem Herd mehrere derartige Strahlheizkörper enthalten sind, deren Einschaltströme unter Umständen auch zusammentreffen können.A mathematical example illustrates this: It is assumed that a radiant heater with a total output of 2200 W has a light source of 1100 W and a dark radiator of the same power, each based on the operating state. The operating current at 220 V is 10 A and the resistance of the radiators is 11 ohms each, ie 22 ohms in series. While the temperature coefficient of resistance in the dark radiator is relatively low and is neglected for the purpose of this calculation, the high resistance temperature coefficient of the light radiator causes the resistance in the cold state to drop to a tenth to a twelfth, so that if one takes an average of 1 / 11, the cold resistance of the light radiator is only 1 ohm is. If the light and dark radiators were switched on without damping resistance, the total resistance would be 12 ohms, corresponding to an inrush current of 18.3 A inrush current (= 4 kW). Even as a brief peak current, which also occurs again, albeit in a weakened form, with every control cycle, this would be inadmissible, especially when you consider that there are often several such radiant heaters in a stove, the inrush currents of which may also coincide can.

Bei der Vorschaltung eines Dämpfungswiderstandes 21 von 10 Ohm erhöht sich der Widerstand der Reihenschaltung 15, 18, 21 auf 22 Ohm, was einem Einschaltstrom von 10 A gleich 2200 W entspricht, also nicht höher als der Betriebsstrom ist. Im kalten Zustand nimmt der Hellstrahler anfänglich nur 100 W auf, während der Dunkelstrahler 1100 W und der Dämpfungswiderstand kurzfristig 1000 W aufnimmt. Nach Bruchteilen von Sekunden hat sich diese Verteilung schon geändert und durch das Ansteigen des Widerstandes im Hellstrahlungsheizkörper haben sich die Leistungen der drei Widerstände in kürzester Zeit stabilisiert. Man sieht daran, daß die Aufheizzeit nicht wesentlich beeinträchtigt wird.When a damping resistor 21 of 10 ohms is connected upstream, the resistance of the series circuit 15, 18, 21 increases to 22 ohms, which corresponds to an inrush current of 10 A equal to 2200 W, that is to say not higher than the operating current. In the cold state, the light radiator initially only consumes 100 W, while the dark radiator 1100 W and the damping resistor temporarily absorbs 1000 W. After a fraction of a second this distribution has already changed and as the resistance in the radiant heater rises, the power of the three resistors has stabilized in a very short time. This shows that the heating-up time is not significantly affected.

Fig. 3 zeigt eine Schaltung, bei der ein Hellstrahler 15 einem Dunkelstrahler 18 parallelgeschaltet ist. In diesem Falle würden bei dem obengenannten Beispiel der Leistungsverteilung Hell- und Dunkelstrahler im Betriebszustand jeweils ein Widerstand von 44 Ohm haben, der im kalten Zustand beim Hellstrahler auf 4 Ohm fallen würde, so daß der Hellstrahler im kalten Zustand einen Strom von 55 A gleich ca. 12 kW ziehen würde. Zusammen mit dem Dunkelstrahler wären dies 13 kW, was hochgradig unzulässig wäre. Ein Dämpfungswiderstand von beispielsweise 40 Ohm würde die Gesamtleistung auf 10 A gleich 2200 W begrenzen und etwa die gleichen Aufheizungsverhältnisse schaffen, wie anhand von Fig. 2 beschrieben.3 shows a circuit in which a light emitter 15 is connected in parallel with a dark emitter 18. In this case, in the above example of the power distribution, the light and dark emitters would each have a resistance of 44 ohms in the operating state, which would drop to 4 ohms in the cold state, so that the light emitter in the cold state has a current of 55 A equal to approx Would draw 12 kW. Together with the dark radiator, this would be 13 kW, which would be highly inadmissible. A damping resistance of, for example, 40 ohms would limit the total power to 10 A equal to 2200 W and would create approximately the same heating conditions as described with reference to FIG. 2.

Bei Fig. 3 ist also in dem den Hellstrahler enthaltenden Strang der Dämpfungswiderstand 21 mit dem Hellstrahler in Reihe geschaltet, während der Dunkelstrahler zu diesem Strang parallel liegt. Der Dämpfungswiderstand 21 wird wiederum von einer Dämpfungsschalteinrichtung 22 überbrückt.In FIG. 3, the damping resistor 21 is therefore connected in series with the light emitter in the strand containing the light emitter, while the dark emitter is parallel to this strand. The damping resistor 21 is in turn bridged by a damping switching device 22.

Die Verwendung einer Parallel-Schaltung von Hell- und Dunkelstrahler kann vorteilhaft sein, weil dadurch der Widerstand der Heizwendel im Hellstrahler höher sein kann, was wegen eines dünneren Glühdrahtes zu Vorteilen in der Produktion des Hellstrahlers führen kann. Gleiches gilt auch für den Dunkelstrahler. Auch die Ansprechzeit bis zur Erreichung der vollen Leuchtintensität des Hellstrahlers kann dadurch verringert werden.The use of a parallel connection of light and dark radiators can be advantageous because the resistance of the heating coil in the light radiator can be higher, which can lead to advantages in the production of the light radiator due to a thinner filament. The same applies to the dark radiator. The response time until the full luminous intensity of the light source is reached can also be reduced.

Es ist strichpunktiert eine Verzögerungsschaltung 31 angedeutet, die statt der auf Spannung am Hellstrahler anprechenden Schalteinrichtung 23 verwendet werden kann und den beim Ausschalten des Stromes geöffneten Schaltkontakt 24 erst nach einer eingestellten Zeit wieder schließt. Als eine solche Zeit könnte die übliche Aufheizzeit von bis ca. 2 Sekunden für den Hellstrahler gewählt werden. Eine solche Verzögerungsschalteinrichtung könnte ein elektronischer oder thermischer Verzögerungsschalter bekannter Bauart sein.A dot-and-dash circuit 31 is indicated, which can be used instead of the switching device 23 which responds to voltage on the light emitter and which closes the switching contact 24 which is open when the current is switched off only after a set time. The usual heating time of up to approx. 2 seconds for the light emitter could be selected as such a time. Such a delay switching device could be an electronic or thermal delay switch of a known type.

Fig. 4 zeigt eine Draufsicht auf einen Zweikreis-Strahlheizkörper, der bei im übrigen ähnlichem Aufbau wie Fig. 1, eine innere Heizzone 14a und eine äußere Heizzone 14b aufweist, die durch einen Zwischenrand 13a voneinander abgegrenzt sind. In jeder Heizzone liegt ein Hellstrahler 15a, 15b und ein Dunkelstrahler 18a, 18b. Der äußere Hellstrahler kann so ausgebildet sein, das seine Enden 16 zu beiden Seiten der Enden 16 des inneren Hellstrahlers 15a liegen und der Dunkelstrahler 18b kann die Form eines ggf. an den Austritten der Hellstrahler unterbrochenen Kreisringes haben. Der Dämpfungswiderstand 21 kann an beliebiger Stelle angeordnet sein, beim Beispiel in der mittleren Heizzone 14a.FIG. 4 shows a plan view of a two-circuit radiant heater which, with the structure similar to that of FIG. 1, has an inner heating zone 14a and an outer heating zone 14b which are delimited from one another by an intermediate edge 13a. In each heating zone there is a light radiator 15a, 15b and a dark radiator 18a, 18b. The outer light emitter can be designed such that its ends 16 lie on both sides of the ends 16 of the inner light emitter 15a and the dark emitter 18b can be in the form of a possibly at the exits the light emitter has an interrupted circular ring. The damping resistor 21 can be arranged at any point, in the example in the central heating zone 14a.

Die Schaltung nach Fig. 5 zeigt, daß die zur mittleren Heizzone 14a gehörende Serien-Schaltung von Hellstrahler 15a und Dunkelstrahler 18a ohne Dämpfungswiderstand vorgesehen ist, während der Dämpfungswiderstand 21 der Heizzone T4b zugeordnet und der Heizwiderstandskombination 15b, 18b in Reihe zugeschaltet ist. Eine Dämpfungseinrichtung 22 der bereits vorher schon beschriebenen Art schaltet den Dämpfungswiderstand 21 nach der Anheizphase des Hellstrahlers 15b durch Kurzschließen ab.The circuit according to FIG. 5 shows that the series circuit of light emitter 15a and dark emitter 18a belonging to the central heating zone 14a is provided without a damping resistor, while the damping resistor 21 is assigned to the heating zone T4b and the heating resistor combination 15b, 18b is connected in series. A damping device 22 of the type already described above switches the damping resistor 21 off by short-circuiting after the heating phase of the light radiator 15b.

Die Regelung oder Schaltung kann der anhand von Fig. 2 beschriebenen gleichen. Es ist jedoch ein nicht dargestellter Zusatzschalter vorgesehen, mit dem der inneren Heizzone, die bei Einschaltung des Strahlheizkörpers stets in Betrieb ist, die äußere Heizzone 14b bei Bedarf zugeschaltet werden kann. Die innere Heizzone hat meist eine kleinere Leistung, so daß hier ggf. die Dämpfung durch die Reihenschaltung des Dunkelstrahlers 18a ausreichen kann, während die äußere Heizzone eine höhere Leistung hat und dementsprechend der Dämpfungswiderstand für einen ausreichend geringen Einschaltstrom sorgt. Es ist auch möglich, die gleichzeitigen Einschaltstromspitzen beider Hellstrahler bei solchen Zweikreis-Heizkörpern dadurch zu vermeiden, daß eine Verzögerungsschaltung zwischen den beiden Heizzonen 14a, 14b wirksam wird, die selbst bei sofortiger Einschaltung beider Heizzonen diese um eine kurze Zeit, beispielsweise 1 oder 2 Sekunden gegeneinander versetzt wirksam werden läßt, um die Einschaltstromspitzen nicht gleichzeitig wirksam werden zu lassen.The regulation or switching can be the same as that described with reference to FIG. 2. However, an additional switch (not shown) is provided with which the inner heating zone, which is always in operation when the radiant heater is switched on, can be connected to the outer heating zone 14b as required. The inner heating zone usually has a lower power, so that the damping through the series connection of the dark radiator 18a may be sufficient here, while the outer heating zone has a higher power and accordingly the damping resistance ensures a sufficiently low inrush current. It is also possible to avoid the simultaneous inrush current peaks of both light emitters in such dual-circuit radiators in that a delay circuit between the two heating zones 14a, 14b is effective, which, even when the two heating zones are immediately switched on, for a short time, for example 1 or 2 seconds can be offset against each other so that the inrush current peaks do not take effect simultaneously.

Fig. 6 zeigt eine Schaltung eines Zweikreis-Strahlhelzkörpers, bei der nur der inneren Heizzone 14a ein Dunkelstrahler 18a in Reihe zum Hellstrahler 15a zugeordnet ist, während die äußere Heizzone 14b nur einen Hellstrahler l5b enthält, dem jedoch ein Dämpfungswiderstand 21, der in der beschriebenen Weise geschaltet wird, zugeordnet ist.Fig. 6 shows a circuit of a two-circuit radiator body, in which only the inner heating zone 14a is assigned a dark radiator 18a in series with the light radiator 15a, while the outer heating zone 14b contains only one light radiator 15b, to which, however, a damping resistor 21, which is switched in the manner described, is assigned.

Fig. 7 zeigt eine Anordnung der gleichen Art, bei der jedoch kein gesonderter Dämpfungswiderstand vorhanden ist, sondern der Dunkelstrahler 18c der inneren Heizzone 14a beim Einschalten beiden Hellstrahlern 15a und 15b vorgeschaltet wird.Fig. 7 shows an arrangement of the same type, but in which there is no separate damping resistor, but the dark radiator 18c of the inner heating zone 14a is connected upstream of the two bright radiators 15a and 15b when switched on.

Als Dämpfungsschaltung ist hier eine elektronische Dämpfungsschaltung angedeutet, die gegenüber einem Relais mit Spannungsspule bevorzugt ist, weil hier mit Sicherheit eventuelle Flatter-Erscheinungen im Schaltbereich durch eine entsprechend stabile Schwellwert-Schaltung vermieden werden können. Derartige elektronische Schaltungen sind allgemein bekannt. Sie können so ausgelegt werden, daß nach einmaligem Ansprechen (Überschreitung des Spannungs-Schwellwertes) eine Ausschaltung erst wieder erfolgt, nachdem der gesamte Strang spannungsfrei geschaltet ist. Dies kann mit einem Zusatzschalter geschehen, wie er in Fig. 8 mit dem Bezugszeichen 35a dargestellt ist. Die Funktion dieses Zusatzschalters könnte auch vom Kontakt des Leistungssteuergerätes übernommen werden. Eine elektronische Schwellwert-Schalteinrichtung 22 kann auch auf andere Kriterien ansprechen als die Spannungsdifferenz am Hellstrahler oder die Zeit. Es wäre beispielsweise auch eine Schalteinrichtung denkbar, die die Dämpfungseinrichtung in Abhängigkeit von dem unmittelbaren Effekt der Hellstrahler betätigt, nämlich seiner Lichtausstrahlung. In diesem Falle könnte die Einrichtung von einer Fotodiode oder ähnlichem gesteuert werden. Obwohl die Dämpfungsschalteinrichtung zum einzelnen Strahlheizkörper gehört, ist sie jedoch vorzugsweise (bis auf den Dämpfungswiderstand) außerhalb des Strahlheizkörpers, beispielsweise an seinem äußeren oder anderen Stellen des Kochgerätes angeordnet. Im Falle der Fig. 7 betätigt die Dämpfungsschalteinrichtung 22 einen Kontakt 24, der als Umschaltkontakt ausgebildet ist und den Leitungszweig der äußeren Heizzone 14b gleichzeitig unterbricht, wenn sie den Hellstrahler 15b in der beschriebenen Weise in den Leitungszweig der inneren Heizzone 14a einschaltet.An electronic damping circuit is indicated here as the damping circuit, which is preferred over a relay with a voltage coil because any fluttering phenomena in the switching range can be avoided with a correspondingly stable threshold value circuit. Such electronic circuits are generally known. They can be designed in such a way that after a single response (exceeding the voltage threshold value) the device is only switched off again after the entire line has been disconnected from the power supply. This can be done with an additional switch, as shown in Fig. 8 with the reference numeral 35a. The function of this additional switch could also be taken over by the contact of the power control unit. An electronic threshold value switching device 22 can also respond to criteria other than the voltage difference on the light radiator or the time. It would also be conceivable, for example, for a switching device which actuates the damping device as a function of the direct effect of the light emitters, namely its light emission. In this case the device could be controlled by a photodiode or the like. Although the damping switching device belongs to the individual radiant heater, it is preferably arranged (except for the damping resistance) outside the radiant heater, for example at its outer or other locations on the cooking appliance. In the case of FIG. 7, the damping switching device is actuated 22 a contact 24 which is designed as a changeover contact and at the same time interrupts the line branch of the outer heating zone 14b when it switches the light radiator 15b on in the manner described in the line branch of the inner heating zone 14a.

Fig. 8 zeigt eine Ausführung, bei der bei zwei Hellstrahlern 15a, 15b nur ein Dämpfungswiderstand 21 vorhanden ist, der beiden Hellstrahlern vorgeschaltet ist und von einer Einrichtung 22 wie der anhand von Fig. 7 beschriebenen überbrückt werden kann. Die Leistungssteuerung erfolgt wiederum mit einem taktenden Leistungssteuergerät 27, das, wie bereits erwähnt, zusätzlich einen Kontakt 35a betätigen kann, der beim Zuschalten des äußeren Heizkreises kurzzeitig die gesamte Schaltung spannungsfrei macht und dadurch den in der Dämpfungsschalteinrichtung enthaltenen Schwellwert-Schalter wieder neu aktiviert. Diese Abschaltung könnte auch durch den manuellen Schalter 35 vorgenommen werden. Über den Schalter 33 wird die äußere Heizzone bei Bedarf zugeschaltet. Die elektronische Schalteinrichtung 22 wird dadurch auch bei der Zuschaltung des Hellstrahlers 15b zum bereits betriebenen Hellstrahler 15a wirksam, so daß dann kurzfristig der Dämpfungswiderstand 21 nochmals eingeschaltet wird. Vorteilhaft ist auch, daß durch die Dämpfungseinrichtung der optische Effekt des Hellstrahlers, insbesondere auch bei der taktenden Regelung, etwas gemildert wird.8 shows an embodiment in which there is only one damping resistor 21 in the case of two light emitters 15a, 15b, which is connected upstream of the two light emitters and can be bridged by a device 22 such as that described with reference to FIG. 7. The power control takes place in turn with a clocking power control device 27, which, as already mentioned, can additionally actuate a contact 35a, which briefly de-energizes the entire circuit when the external heating circuit is switched on and thereby reactivates the threshold switch contained in the damping switching device. This shutdown could also be done by the manual switch 35. The outer heating zone is switched on as required via the switch 33. The electronic switching device 22 is thereby also effective when the light emitter 15b is connected to the light emitter 15a already in operation, so that the damping resistor 21 is then briefly switched on again. It is also advantageous that the damping device somewhat alleviates the optical effect of the light emitter, in particular also in clocked regulation.

Claims (9)

  1. Radiant element, particularly for glass ceramic hotplates, with several electrical light radiators (15a, 15b) and a series resistor (21), with a temporarily acting damping switching device (22) for energizing the light radiator (15a), characterized in that the damping switching device (22) is a circuit which is reactivatable on switching in the further light radiator (15b), which switches into the light radiator the series resistor (21) during the warming-up phase of each of the independently switchable light radiators.
  2. Radiant element according to claim 1, characterized in that the damping switching device (22) automatically disconnects the series resistor (21) following the heating of the light radiator (15a).
  3. Radiant element according to one of the preceding claims, characterized in that the damping switching device (22) acts as a function of the voltage drop at the light radiator (15a) and in particular contains a threshold switching device responding to the voltage drop.
  4. Radiant element according to claim 3, characterized in that the threshold switching device is an electronic circuit preferable tripping on reaching a desired voltage and which is advantageously reactivated through disconnecting the voltage and for this purpose an isolating switch (35) is provided in a switching or regulating member for the radiant element (11).
  5. Radiant element according to one of the preceding claims, characterized in that the damping device contains a delay circuit.
  6. Radiant element according to one of the preceding claims, characterized in that the series resistor is a separate damping resistor (21), which is preferably arranged in the vicinity of the radiant element (11).
  7. Radiant element according to one of the preceding claims, characterized in that upstream of the series resistor is connected a dark radiator (18), optionally permanently in series with the light radiator (15a) and/or comprises the dark radiator (18).
  8. Radiant element according to one of the preceding claims, characterized in that the damping device acts during each switching on operation of the light radiator (15), particularly during each timing cycle of a timing power control device (27) and/or the temperature limiter (20).
  9. Radiant element according to one of the preceding claims, characterized in that in the case of a radiant element (11) with several light radiators (15a, 15b) which are preferably arranged in different heating zones (14a, 14b), one or more series resistors (18, 21) can be connected upstream of either different and/or both light radiators (15a, 15b) and in particular a dark radiator e.g. associated with an inner heating zone (14a) and connected in series with an inner light radiator (15a), through the damping switching device, in the warming-up phase can additionally be connected upstream of a light radiator (15b) of an e.g. outer heating zone (14b) in the form of a damping resistor.
EP89120765A 1988-11-30 1989-11-09 Radiant heating element Expired - Lifetime EP0371295B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3840360A DE3840360A1 (en) 1988-11-30 1988-11-30 RADIATION RADIATOR
DE3840360 1988-11-30

Publications (3)

Publication Number Publication Date
EP0371295A2 EP0371295A2 (en) 1990-06-06
EP0371295A3 EP0371295A3 (en) 1991-08-21
EP0371295B1 true EP0371295B1 (en) 1996-01-17

Family

ID=6368176

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89120765A Expired - Lifetime EP0371295B1 (en) 1988-11-30 1989-11-09 Radiant heating element

Country Status (9)

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US (1) US5004892A (en)
EP (1) EP0371295B1 (en)
JP (1) JPH02189884A (en)
KR (1) KR900008348A (en)
AT (1) ATE133311T1 (en)
AU (1) AU626943B2 (en)
DE (2) DE3840360A1 (en)
ES (1) ES2081828T3 (en)
YU (1) YU224189A (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4002322A1 (en) * 1990-01-26 1991-08-01 Bosch Siemens Hausgeraete COOKING AREA
FR2669803B1 (en) * 1990-11-27 1993-09-24 Atlantic Ste Fse Developp Ther HEATING DEVICE, ESPECIALLY A TRANSMITTER OF INFRA-RED.
ES2049180B1 (en) * 1992-09-17 1996-11-01 Eika S Coop Ltda IMPROVEMENTS IN RADIANT HEATERS.
DE4441204A1 (en) * 1994-11-19 1996-05-23 Ego Elektro Blanc & Fischer Radiation heater body for mounting beneath cooker plate, esp. glass ceramic plate
GB2307629B (en) * 1995-11-20 2001-01-10 Strix Ltd Electric heaters
KR20040077211A (en) * 2003-02-28 2004-09-04 삼성전자주식회사 Apparatus of driving light device for display device
FI20070868L (en) * 2007-11-15 2009-05-16 Uponor Innovation Ab Adjusting the subsurface heating/cooling
JP4620164B1 (en) * 2009-07-15 2011-01-26 日本調理機株式会社 Electric rotary pot
EP2315493B1 (en) * 2009-10-21 2017-05-10 Mahle Behr France Rouffach S.A.S Heating device, in particular for a motor vehicle air conditioning device
US11098923B2 (en) * 2016-03-31 2021-08-24 Gd Midea Environment Appliances Mfg Co., Ltd. Electric radiator

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4421993A (en) * 1982-05-28 1983-12-20 General Electric Company Load resistance control circuitry
US4523429A (en) * 1983-04-01 1985-06-18 Rca Corporation Cold start surge current limiting system for a hydrazine thruster augmentation heater
GB8412339D0 (en) * 1984-05-15 1984-06-20 Thorn Emi Domestic Appliances Heating apparatus
EP0176027B1 (en) * 1984-09-22 1989-02-01 E.G.O. Elektro-Geräte Blanc u. Fischer Radiative heating body for a cooking apparatus
DE3503648C2 (en) * 1984-09-22 1994-08-11 Ego Elektro Blanc & Fischer Radiant heaters for cooking appliances
DE3437726A1 (en) * 1984-10-15 1986-04-17 Bosch Siemens Hausgeraete Heating device
DE3516788A1 (en) * 1985-05-09 1986-11-13 Bosch-Siemens Hausgeräte GmbH, 8000 München Radiant heating device for cooking apparatuses, especially for glass-ceramic cooking hobs
GB8514785D0 (en) * 1985-06-11 1985-07-10 Micropore International Ltd Infra-red heaters
DE3526892A1 (en) * 1985-07-26 1987-02-05 Bosch Siemens Hausgeraete ARRANGEMENT FOR SWITCHING HEATER COMBINATIONS
GB8527683D0 (en) * 1985-11-09 1985-12-11 Thorn Emi Appliances Control circuit
GB8602507D0 (en) * 1986-02-01 1986-03-05 Micropore International Ltd Electric radiation heater
DE3726535A1 (en) * 1987-08-10 1989-02-23 Philips Patentverwaltung METHOD FOR LOW-SWITCHING POWER CONTROL OF ELECTRICAL LOADS

Also Published As

Publication number Publication date
AU626943B2 (en) 1992-08-13
EP0371295A2 (en) 1990-06-06
DE3840360A1 (en) 1990-05-31
ATE133311T1 (en) 1996-02-15
DE58909575D1 (en) 1996-02-29
AU4549889A (en) 1990-06-07
EP0371295A3 (en) 1991-08-21
YU224189A (en) 1992-09-07
US5004892A (en) 1991-04-02
ES2081828T3 (en) 1996-03-16
JPH02189884A (en) 1990-07-25
KR900008348A (en) 1990-06-04

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