DE4034611A1 - Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate - Google Patents

Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate

Info

Publication number
DE4034611A1
DE4034611A1 DE19904034611 DE4034611A DE4034611A1 DE 4034611 A1 DE4034611 A1 DE 4034611A1 DE 19904034611 DE19904034611 DE 19904034611 DE 4034611 A DE4034611 A DE 4034611A DE 4034611 A1 DE4034611 A1 DE 4034611A1
Authority
DE
Germany
Prior art keywords
stage
heating
ntc
water heater
resistor
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.)
Withdrawn
Application number
DE19904034611
Other languages
German (de)
Inventor
Lutz Dr Ing Asperger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Stiebel Eltron GmbH and Co KG
Original Assignee
Stiebel Eltron GmbH and Co KG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Stiebel Eltron GmbH and Co KG filed Critical Stiebel Eltron GmbH and Co KG
Priority to DE19904034611 priority Critical patent/DE4034611A1/en
Publication of DE4034611A1 publication Critical patent/DE4034611A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24HFLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H1/00Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
    • F24H1/10Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium
    • F24H1/12Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium
    • F24H1/14Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form
    • F24H1/142Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium by tubes, e.g. bent in serpentine form using electric energy supply

Abstract

The water flows through a tube (1) on which an electrically insulated but thermally conductive layer (2) is deposited and overlaid with an ohmic resistive heating element (3). This first stage of heating is turned on and off by a switch (4). Downstream, the second stage is constituted by a resistance (5) with negative temp. coefft. on a separate insualted layer (6). The switch (7) in this stage is closed when the rate of flow attains e.g. 5 1/min, giving a gradual rise of temp. ADVANTAGE - Temp. peaks occurring when second-stage heating element is switched-on minimised.

Description

Die Erfindung betrifft einen elektrischen Durchlauferhitzer mit wenigstens zwei nacheinander einschaltbaren elektrischen Heizstufen.The invention relates to an electrical Instantaneous water heater with at least two in succession switchable electrical heating levels.

In dem DE-GM 19 60 779 ist ein Durchlauferhitzer beschrieben, bei dem als Heizwiderstand Kaltleiter vorgesehen sind. Auch in der älteren Patentanmeldung P 39 23 392.8 ist ein Durchlauferhitzer mit einem PTC- Heizkörper beschrieben. Bei solchen Heizkörpern steigt der ohmsche Widerstand bei einer Erhöhung der Temperatur. Dementsprechend erniedrigt sich die Heizleistung. Diese Erscheinung kann zur Begrenzung von Ubertemperaturen ausgenutzt werden.In DE-GM 19 60 779 is a water heater described, with the PTC thermistor as a heating resistor are provided. Also in the earlier patent application P 39 23 392.8 is a continuous flow heater with a PTC Radiator described. With such radiators increases the ohmic resistance when the temperature increases. Accordingly, the heating power is reduced. These Appearance can limit excess temperatures be exploited.

Untersuchungen mit PTC-Heizkörpern haben jedoch gezeigt, daß die Temperatur des PTC-Heizkörpers im wesentlichen von der aufgenommenen elektrischen Energie bestimmt ist und die Temperatur des Wassers, mit der im Durchlauferhitzer der PTC-Heizkörper in wärmeleitender Verbindung steht, den Widerstand des PTC-Heizkörpers praktisch nicht beeinflußt. Jedenfalls findet eine hinreichend schnelle Anpassung der Temperatur des PTC- Heizkörpers an die Wassertemperatur kaum statt. Dies ist auf die geringe Wärmeleitfähigkeit des PTC-Heizkörpers zurückzuführen.However, studies with PTC radiators have shown that the temperature of the PTC heater is essentially is determined by the electrical energy absorbed and the temperature of the water with which Continuous-flow heater of the PTC radiators in heat-conducting Connection is established, the resistance of the PTC radiator practically not affected. Anyway, one finds Sufficiently quick adjustment of the temperature of the PTC Radiator to the water temperature hardly take place. This is the low thermal conductivity of the PTC radiator attributed.

In der Praxis werden PTC-Widerstände eingesetzt, wenn eine dauerhafte Überhitzung des Heizsystems verhindert werden soll oder große Temperaturdifferenzen mit vergleichsweise kleinen Regelleistungen ausgeglichen werden sollen.In practice, PTC resistors are used when prevents the heating system from overheating permanently should be or large temperature differences with comparatively small balancing powers balanced  should be.

Ein weiterer Nachteil von PTC-Heizkörpern besteht in dem hohen Einschaltstrom. Beim Einschalten hat der PTC- Heizkörper Umgebungstemperatur und ist damit wesentlich kälter als bei Betriebstemperatur. Sein Widerstand ist dementsprechend gering, wobei der hohe Einschaltstrom zu einer Heizleistungsspitze und damit Temperaturspitze führt.Another disadvantage of PTC radiators is that high inrush current. When switching on, the PTC- Radiator ambient temperature and is therefore essential colder than at operating temperature. His resistance is accordingly low, with the high inrush current increasing a peak heat output and thus a temperature peak leads.

Aufgabe der Erfindung ist es, einen Durchlauferhitzer der eingangs genannten Art vorzuschlagen, bei dem Temperaturspitzen beim Einschalten der nachrangigen Heizstufe möglichst kleingehalten sind.The object of the invention is to provide a water heater to propose the type mentioned at the beginning, in which Temperature peaks when switching on the subordinate Heating level are kept as small as possible.

Erfindungsgemäß ist obige Aufgabe bei einem Durchlauferhitzer der eingangs genannten Art dadurch gelöst, daß der elektrische Widerstandswert der nachrangig einzuschaltenden Heizstufe eine Heißleiter (NTC)-Charakteristik hat, so daß beim Einschalten dieser Heizstufe zunächst ein Strom fließt, der kleiner ist als der sich danach einstellende Heizstrom.According to the invention, the above task is for one Water heater of the type mentioned in the introduction solved that the electrical resistance value of the a thermistor (NTC) characteristic, so when you turn this Heating level, a current that is less than the heating current that follows.

Dadurch ist erreicht, daß beim Einschalten der nachrangigen Heizstufe deren Heizleistung zunächst reduziert ist, so daß beim Einschalten keine hohen Einschaltstromspitzen und Temperaturspitzen auftreten.This ensures that when the subordinate heating level whose heating output initially is reduced so that no high when switching on Inrush current peaks and temperature peaks occur.

In einer Ausgestaltung der Erfindung besteht die nachrangige Heizstufe aus einem ohmschen Heizwiderstand und einem zu diesem in Reihe geschalteten NTC-Widerstand. Beim Einschalten dieser Heizstufe ist der NTC-Widerstand zunächst noch kalt und weist damit einen hohen Widerstand auf, so daß der Strom durch den Heizwiderstand entsprechend klein ist. Um die Verlustwärme des NTC- Widerstands mit zur Erwärmung des Wassers auszunutzen, kann der NTC-Widerstand mit dem den Durchlauferhitzer durchströmenden Wasser in wärmeleitender Verbindung stehen. Es kann auch vorgesehen sein, den NTC-Widerstand beim Erreichen der Betriebstemperatur des ohmschen Heizwiderstands kurzzuschließen.In one embodiment of the invention subordinate heating level from an ohmic heating resistor and an NTC resistor connected in series with this. When this heating level is switched on, the NTC resistor is initially still cold and thus shows a high resistance on so that the current through the heating resistor is correspondingly small. To the heat loss of the NTC Using resistance to heat the water, the NTC resistor can be used with the instantaneous water heater flowing water in a thermally conductive connection  stand. The NTC resistor can also be provided when the operating temperature of the ohmic is reached Short-circuit the heating resistor.

Bei einer anderen Ausführung der Erfindung ist die nachrangige Heizstufe selbst von einem NTC-Widerstand gebildet, der mit dem Wasser in wärmeleitender Verbindung steht. In diesem Fall dient der NTC-Widerstand selbst der Erwärmung des Wassers.In another embodiment of the invention subordinate heating level itself from an NTC resistor formed that with the water in thermally conductive connection stands. In this case, the NTC resistor itself serves Warming the water.

Vorteilhafte Ausgestaltungen der Erfindung ergeben sich aus der folgenden Beschreibung eines Ausführungsbeispiels. In der Zeichnung zeigen:Advantageous refinements of the invention result from the following description of a Embodiment. The drawing shows:

Fig. 1 schematisch einen Durchlauferhitzer, Fig. 1 schematically shows a water heater,

Fig. 2 ein Strom-Zeit-Diagramm und Fig. 2 is a current-time diagram and

Fig. 3 ein Temperatur-Volumenstrom-Diagramm. Fig. 3 is a temperature-volume flow diagram.

Ein Durchlauferhitzer weist als Wasserweg eine Rohrleitung (1) auf. Diese wird in Richtung des Pfeiles W beim Öffnen eines nicht näher dargestellten Zapfventils von Wasser durchströmt.A water heater has a pipe ( 1 ) as the water path. Water flows through this in the direction of arrow W when a nozzle valve (not shown) is opened.

An der Rohrleitung (1) ist über eine elektrisch isolierende, jedoch wärmeleitende Schicht (2) als erste Heizstufe ein ohmscher Heizwiderstand (3) angeordnet, der über einen ersten Schalter (4) einschaltbar ist.An ohmic heating resistor ( 3 ), which can be switched on via a first switch ( 4 ), is arranged on the pipeline ( 1 ) via an electrically insulating but heat-conducting layer ( 2 ) as the first heating stage.

In Richtung W der Wasserströmung folgt dem Heizwiderstand (3) ein NTC-Widerstand (5) als nachrangige Heizstufe. Der NTC-Widerstand (5) ist über eine elektrisch isolierende, jedoch wärmeleitende Isolationsschicht (6) an der Rohrleitung (1) angeordnet. Er ist mittels eines zweiten Schalters (7) einschaltbar. In the W direction of the water flow, the heating resistor ( 3 ) is followed by an NTC resistor ( 5 ) as a subordinate heating stage. The NTC resistor ( 5 ) is arranged on the pipeline ( 1 ) via an electrically insulating but heat-conducting insulation layer ( 6 ). It can be switched on by means of a second switch ( 7 ).

In Fig. 2 zeigt die Kurve (a) den Stromverlauf des NTC-- Widerstands (5) als Funktion der Zeit. Ersichtlich tritt kein den Betriebsstrom überschwingender Einschaltstrom auf. Die Kurve (b) zeigt ein PTC-Verhalten. Dabei tritt ein Einschaltstrom auf, der größer ist als der Betriebsstrom. Ein solches Einschaltverhalten kann auch ein ohmscher Heizwiderstand zeigen.In Fig. 2, curve (a) shows the current profile of the NTC resistor ( 5 ) as a function of time. Obviously there is no inrush current that exceeds the operating current. The curve (b) shows a PTC behavior. An inrush current occurs that is greater than the operating current. An ohmic heating resistor can also show such switch-on behavior.

Die Funktionsweise der beschriebenen Einrichtung wird anhand von Fig. 3 erläutert: Bei einem Mindestvolumenstrom durch die Rohrleitung (1) wird zunächst der Heizwiderstand (3) eingeschaltet. Mit zunehmenden Volumenstrom verläuft dann die Temperatur des Wassers auf dem Ast (c) der Kurve nach Fig. 3.The operation of the described device is explained with reference to FIG. 3: With a minimum volume flow through the pipeline ( 1 ), the heating resistor ( 3 ) is first switched on. The temperature of the water on branch (c) of the curve according to FIG. 3 then runs with increasing volume flow.

Bei einem höheren Volumenstrom, beispielsweise 5 l/min wird auch der Schalter (7) geschlossen, so daß nun auch der NTC-Widerstand (5) eingeschaltet ist. Da dieser zunächst kalt ist, weist er einen hohen Widerstand auf, so daß sich die Temperatur nur langsam erhöht, wie dies der Ast (d) in Fig. 3 zeigt. Es tritt jedenfalls keine Temperaturspitze (e) auf, wie sie sich ergeben würde, wenn auch die nachrangige Schaltstufe nur von einem ohmschen Heizwiderstand gebildet wäre.At a higher volume flow, for example 5 l / min, the switch ( 7 ) is also closed, so that the NTC resistor ( 5 ) is now also switched on. Since this is initially cold, it has a high resistance, so that the temperature increases only slowly, as the branch (d) in FIG. 3 shows. In any case, there is no temperature peak (e) as would result if the subordinate switching stage were only formed by an ohmic heating resistor.

Claims (5)

1. Elektrischer Durchlauferhitzer mit wenigstens zwei nacheinander einschaltbaren elektrischen Heizstufen, dadurch gekennzeichnet, daß der elektrische Widerstandswert der nachrangig einzuschaltenden Heizstufe (5) eine Heißleiter (NTC)-Charakteristik hat, so daß beim Einschalten dieser Heizstufe zunächst ein Strom fließt, der kleiner ist als der sich danach einstellende Heizstrom.1. Electrical instantaneous water heater with at least two electrical heating stages that can be switched on in succession, characterized in that the electrical resistance value of the heating stage ( 5 ) to be switched on subordinately has a thermistor (NTC) characteristic, so that when this heating stage is switched on, a current initially flows that is less than the heating current that follows. 2. Durchlauferhitzer nach Anspruch 1, dadurch gekennzeichnet, daß die nachrangige Heizstufe (5) aus einem ohmschen Heizwiderstand und einem zu diesem in Reihe geschalteten NTC-Widerstand besteht.2. instantaneous water heater according to claim 1, characterized in that the subordinate heating stage ( 5 ) consists of an ohmic heating resistor and an NTC resistor connected in series with this. 3. Durchlauferhitzer nach Anspruch 2, dadurch gekennzeichnet, daß der NTC-Widerstand mit dem den Durchlauferhitzer durchströmenden Wasser in wärmeleitender Verbindung steht.3. instantaneous water heater according to claim 2, characterized characterized in that the NTC resistor with the Water heater flowing through water is a thermally conductive connection. 4. Durchlauferhitzer nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß der NTC-Widerstand beim Erreichen der Betriebstemperatur des ohmschen Heizwiderstands kurzgeschlossen wird.4. instantaneous water heater according to claim 2 or 3, characterized characterized in that the NTC resistance when reaching the Operating temperature of the ohmic heating resistor is short-circuited. 5. Durchlauferhitzer nach Anspruch 1, dadurch gekennzeichnet, daß die nachrangige Heizstufe von einem NTC-Widerstand (5) gebildet ist, der mit dem Wasser in wärmeleitender Verbindung steht.5. instantaneous water heater according to claim 1, characterized in that the subordinate heating stage is formed by an NTC resistor ( 5 ) which is in heat-conducting connection with the water.
DE19904034611 1990-10-31 1990-10-31 Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate Withdrawn DE4034611A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19904034611 DE4034611A1 (en) 1990-10-31 1990-10-31 Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19904034611 DE4034611A1 (en) 1990-10-31 1990-10-31 Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate

Publications (1)

Publication Number Publication Date
DE4034611A1 true DE4034611A1 (en) 1992-05-07

Family

ID=6417369

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19904034611 Withdrawn DE4034611A1 (en) 1990-10-31 1990-10-31 Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate

Country Status (1)

Country Link
DE (1) DE4034611A1 (en)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4233676A1 (en) * 1992-10-07 1994-04-14 Ego Elektro Blanc & Fischer Electric radiator for media, especially flow heaters
EP1138341A3 (en) * 2000-03-21 2003-08-13 FISHER & PAYKEL LIMITED Humidification apparatus
US7111624B2 (en) 2000-03-21 2006-09-26 Fisher & Paykel Healthcare Limited Apparatus for delivering humidified gases
US7120354B2 (en) 2000-03-21 2006-10-10 Fisher & Paykel Healthcare Limited Gases delivery conduit
CN100400980C (en) * 2005-12-14 2008-07-09 欧永源 Anti-electric shock type electric water heater
US7588029B2 (en) 2000-03-21 2009-09-15 Fisher & Paykel Healthcare Limited Humidified gases delivery apparatus
US7997270B2 (en) 2001-08-20 2011-08-16 Map Medizin-Technologie Gmbh Apparatus for supplying respiratory gas and a method for controlling the apparatus
US8733349B2 (en) 2009-07-31 2014-05-27 Resmed Limited Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus
US20160354573A1 (en) 2012-11-14 2016-12-08 Matthew Liam Buswell Zone heating for respiratory circuits
US9572949B2 (en) 2013-02-01 2017-02-21 Resmed Limited Wire heated tube with temperature control system for humidifier for respiratory apparatus
US9802022B2 (en) 2008-03-06 2017-10-31 Resmed Limited Humidification of respiratory gases
US9855398B2 (en) 2006-11-08 2018-01-02 Resmed Limited Humidifier for respiratory apparatus
US10293121B2 (en) 2000-10-16 2019-05-21 Fisher & Paykel Healthcare Limited Apparatus used for the humidification of gases in medical procedures
US10751498B2 (en) 2014-03-17 2020-08-25 Fisher & Paykel Healthcare Limited Medical tubes for respiratory systems
US10814091B2 (en) 2013-10-24 2020-10-27 Fisher & Paykel Healthcare Limited System for delivery of respiratory gases
US10828482B2 (en) 2013-12-20 2020-11-10 Fisher & Paykel Healthcare Limited Humidification system connections
US10960167B2 (en) 2015-09-09 2021-03-30 Fisher & Paykel Healthcare Limited Zone heating for respiratory circuits
US11007340B2 (en) 2004-08-20 2021-05-18 Fisher & Paykel Healthcare Limited Apparatus for measuring properties of gases supplied to a patient
US11013875B2 (en) 2005-08-15 2021-05-25 ResMed Pty Ltd Low cost CPAP flow generator and humidifier assembly
US11058844B2 (en) 2012-12-04 2021-07-13 Fisher & Paykel Healthcare Limited Medical tubes and methods of manufacture
US11311695B2 (en) 2016-12-22 2022-04-26 Fisher & Paykel Healthcare Limited Medical tubes and methods of manufacture
US11318270B2 (en) 2011-06-03 2022-05-03 Fisher & Paykel Healthcare Limited Medical tubes and methods of manufacture

Cited By (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4233676A1 (en) * 1992-10-07 1994-04-14 Ego Elektro Blanc & Fischer Electric radiator for media, especially flow heaters
US5434388A (en) * 1992-10-07 1995-07-18 E.G.O. Elektro-Gerate Blanc U. Fischer Electrical heater for media, particularly flow heater
EP1681072A2 (en) * 2000-03-21 2006-07-19 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
EP1790370A1 (en) * 2000-03-21 2007-05-30 Fisher & Paykel Healthcare Limited Humidification apparatus
US9555210B2 (en) 2000-03-21 2017-01-31 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
EP1681072A3 (en) * 2000-03-21 2006-08-02 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US7111624B2 (en) 2000-03-21 2006-09-26 Fisher & Paykel Healthcare Limited Apparatus for delivering humidified gases
US7120354B2 (en) 2000-03-21 2006-10-10 Fisher & Paykel Healthcare Limited Gases delivery conduit
US7146979B2 (en) 2000-03-21 2006-12-12 Fisher & Paykel Healthcare Limited Humidifier with parallel gas flow paths
US6918389B2 (en) 2000-03-21 2005-07-19 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US10525225B2 (en) 2000-03-21 2020-01-07 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US7588029B2 (en) 2000-03-21 2009-09-15 Fisher & Paykel Healthcare Limited Humidified gases delivery apparatus
EP1138341A3 (en) * 2000-03-21 2003-08-13 FISHER & PAYKEL LIMITED Humidification apparatus
US8235041B2 (en) 2000-03-21 2012-08-07 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US8550072B2 (en) 2000-03-21 2013-10-08 Fisher & Paykel Healthcare Limited Apparatus for delivering humidified gases
US9750917B2 (en) 2000-03-21 2017-09-05 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US10293121B2 (en) 2000-10-16 2019-05-21 Fisher & Paykel Healthcare Limited Apparatus used for the humidification of gases in medical procedures
US11197967B2 (en) 2000-10-16 2021-12-14 Fisher & Paykel Healthcare Limited Apparatus used for the humidification of gases in medical procedures
US10112027B2 (en) 2001-08-20 2018-10-30 Resmed R&D Germany Gmbh Apparatus for supplying respiratory gas and a method for controlling the apparatus
US7997270B2 (en) 2001-08-20 2011-08-16 Map Medizin-Technologie Gmbh Apparatus for supplying respiratory gas and a method for controlling the apparatus
US8671936B2 (en) 2001-08-20 2014-03-18 Resmed R&D Germany Gmbh Apparatus for supplying respiratory gas and a method for controlling the apparatus
US11007340B2 (en) 2004-08-20 2021-05-18 Fisher & Paykel Healthcare Limited Apparatus for measuring properties of gases supplied to a patient
US11911564B2 (en) 2004-08-20 2024-02-27 Fisher & Paykel Healthcare Limited Apparatus for measuring properties of gases supplied to a patient
US11458273B2 (en) 2004-08-20 2022-10-04 Fisher & Paykel Healthcare Limited Apparatus for measuring properties of gases supplied to a patient
US11679224B2 (en) 2004-08-20 2023-06-20 Fisher & Paykel Healthcare Limited Apparatus for measuring properties of gases supplied to a patient
US11013875B2 (en) 2005-08-15 2021-05-25 ResMed Pty Ltd Low cost CPAP flow generator and humidifier assembly
US11298482B2 (en) 2005-08-15 2022-04-12 ResMed Pty Ltd Low cost CPAP flow generator and humidifier assembly
CN100400980C (en) * 2005-12-14 2008-07-09 欧永源 Anti-electric shock type electric water heater
US11712535B2 (en) 2006-11-08 2023-08-01 ResMed Pty Ltd Humidifier for respiratory apparatus
US11338104B2 (en) 2006-11-08 2022-05-24 ResMed Pty Ltd Humidifier for respiratory apparatus
US9855398B2 (en) 2006-11-08 2018-01-02 Resmed Limited Humidifier for respiratory apparatus
US9802022B2 (en) 2008-03-06 2017-10-31 Resmed Limited Humidification of respiratory gases
US10086158B2 (en) 2009-07-31 2018-10-02 Resmed Limited Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus
US11033698B2 (en) 2009-07-31 2021-06-15 ResMed Pty Ltd Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus
US11607512B2 (en) 2009-07-31 2023-03-21 ResMed Pty Ltd Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus
US8733349B2 (en) 2009-07-31 2014-05-27 Resmed Limited Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus
US11707587B2 (en) 2009-07-31 2023-07-25 ResMed Pty Ltd Wire heated tube with temperature control system, tube type detection, and active over temperature protection for humidifier for respiratory apparatus
US11318270B2 (en) 2011-06-03 2022-05-03 Fisher & Paykel Healthcare Limited Medical tubes and methods of manufacture
US20160354573A1 (en) 2012-11-14 2016-12-08 Matthew Liam Buswell Zone heating for respiratory circuits
US11129954B2 (en) 2012-11-14 2021-09-28 Fisher & Paykel Healthcare Limited Zone heating for respiratory circuits
US10589050B2 (en) 2012-11-14 2020-03-17 Fisher & Paykel Healthcare Limited Zone heating for respiratory circuits
US11058844B2 (en) 2012-12-04 2021-07-13 Fisher & Paykel Healthcare Limited Medical tubes and methods of manufacture
US11260186B2 (en) 2013-02-01 2022-03-01 ResMed Pty Ltd Wire heated tube with temperature control system for humidifier for respiratory apparatus
US10363382B2 (en) 2013-02-01 2019-07-30 ResMed Pty Ltd Wire heated tube with temperature control system for humidifier for respiratory apparatus
US11779719B2 (en) 2013-02-01 2023-10-10 ResMed Pty Ltd Wire heated tube with temperature control system for humidifier for respiratory apparatus
US9572949B2 (en) 2013-02-01 2017-02-21 Resmed Limited Wire heated tube with temperature control system for humidifier for respiratory apparatus
US10814091B2 (en) 2013-10-24 2020-10-27 Fisher & Paykel Healthcare Limited System for delivery of respiratory gases
US10828482B2 (en) 2013-12-20 2020-11-10 Fisher & Paykel Healthcare Limited Humidification system connections
US11826538B2 (en) 2013-12-20 2023-11-28 Fisher & Paykel Healthcare Limited Humidification system connections
US10751498B2 (en) 2014-03-17 2020-08-25 Fisher & Paykel Healthcare Limited Medical tubes for respiratory systems
US10960167B2 (en) 2015-09-09 2021-03-30 Fisher & Paykel Healthcare Limited Zone heating for respiratory circuits
US11311695B2 (en) 2016-12-22 2022-04-26 Fisher & Paykel Healthcare Limited Medical tubes and methods of manufacture

Similar Documents

Publication Publication Date Title
DE4034611A1 (en) Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate
DE2504237B2 (en) Electric hair treatment device
EP0582795B1 (en) Circuit arrangement for electrical heating appliances
DE2646126A1 (en) Automatic control circuit for electric devices - has triac whose control electrode is connected to output of voltage divider with PTC resistor
DE610471C (en) Electrically heated device
DE3426046A1 (en) Electrical continuous-flow heater having a controllable outlet temperature
DE4224666A1 (en) Electric circuit for a mains electric cooker - has temperature-controlled relay to reconnect element across two phases for voltage boost, subsequently reverting to phase-neutral connection
EP0629103B1 (en) Method and circuit for controling the temperature of AC operated heating apparatus
DE3601551C2 (en)
DE2743325C2 (en) Electric air heating system
AT219737B (en) Switching device for electrical heating devices
DE836513C (en) Starting resistor arrangement, especially for universal current radio receivers
DE1132670B (en) Switching device with PTC thermistor
DE3522546A1 (en) CIRCUIT ARRANGEMENT IN ELECTRIC OVENS FOR HEATING POWER CONTROL
EP0784416B1 (en) Heating element
DE3108640A1 (en) Signalling device for indicating the temperature state of cooking appliances
DE2353667C3 (en) Instantaneous water heater with thermal control
DE603107C (en) Heat timer
DE1814381C (en) Electrically heated pump hot water collecting heating system
DE3818070A1 (en) Safety temperature cutout (limiter)
DE3923392A1 (en) Through-flow electric water heater - has three=way valve at junction between parallel hot and cold flows
DE19522748A1 (en) Control device for hotplate radiant heating
DE3906829C2 (en)
DE2829105A1 (en) Motor vehicle door lock heater - has adjustable heating time and protects transistor in switching circuit with potted components
DE708312C (en) Regulation of air heating, especially for railway vehicles

Legal Events

Date Code Title Description
8125 Change of the main classification

Ipc: H05B 1/02

8130 Withdrawal