Foshan Chuandong Magnetic Electronic Co., Ltd.

Abstract: This paper attempts to analyze the technical focus and trend of power reset temperature controller in recent years from the perspective of patent, hoping that it could inspire relevant enterprises in the field.

Key words: Power reset; Temperature controller; Resistance; Manual;

I. Preface

Temperature controller as a temperature-sensitive controller driven by automatic electric, is widely used in the field of household electrical appliances after industrial application in the 1950s. According to standards stipulated in Safety of Household and Similar Electrical Appliances-General Requirements at home and abroad, it must be installed with thermostats and temperature-limited protection components without reset function, it is safe accessory in the field of home appliances.

In SUL148056, it discloses the combination mode of one temperature controller and one fuse. Because the fuse belongs to onetime-fuse type protection component, it must be replaced with new one, which is not convenient. But the temperature controller with automatic reset function affects service life of electronic product and causes energy consumption during repeated reconnection and disconnection.

Because the combination mode of one temperature controller and one temperature controller with manual reset function which could be reset manually repeatedly, it becomes widely used. In order to realize this function better, Professor Zhang Jinxiu from Zhongshan University put forward in his patent of CN86103184 in 1986 the concept of combined thermostat as temperature controller and temperature limiter without automatic reset function. It adapts specific mechanical structure which disables bimetal to go back to normal position after quick action so it couldn’t be reset automatically to conduct circuit. But these two plans all need to be reset manually by professional maintenance personnel.

According to Patent CN2289295 disclosed in 1994, it could keep circuit shutoff by adding a bypass heat-holding resistance of PTC component, because the bimetal conduct the bypass resistance after quick action and make it hot, in this way, bimetal’s temperature is kept above the critical point of quick action. And it can be reset easily by cutting off the power. This combination not only enables to use fuses repeatedly, but also improves the situation that reset must be done manually by professional maintenance personnel because it could be reset easily by just cutting off power, a very user-friendly operation.

II. Distribution of power reset temperature controller patent application

To generally analyze the technology development trend of power reset temperature controller field, firstly, all relevant Chinese inventions and utility model patents of this field should be retrieved. Retrieval database is CNIPR, keywords for retrieving are:

((Cut off power or cut off or shut off circuit or manual or by hand-made or by man-made) and reset and (temperature control or limit temperature or thermostat or temperature control or temperature-sensitive or thermal protection or thermal sensor or thermal control or thermal-induction) /AB and (H01H% or H02H% or G23D% or G05D%) / SIC after the artificial selection, 102 inventions and utility model patents meet the requirements.

Specific analyses of the retrieval structure are as follows.



The annually average number of patent applications is no more than 4 for utility model inventions of power reset temperature controller before 2000 and it keeps increasing year by year after that. Since 2004, the number of patent applications of power reset temperature controller has increased a lot. In 2012 numbers of invention and utility model patent applications reached to the highest point, but still about 10.



The data of 22% for power reset thermostat patents and 78% for utility models, it shows that the innovation level of this field is not high and the number of invention patents is comparatively less.


From the number of patent applications in provinces (regions or countries), it reflects that Guangdong Province is the most active in the study of this field, taking up almost half of the national patent applications, up to 44. This shows that GuangdongProvincetakes a leading role in the field ofChina.


26 patent applications of power reset thermostat are from Foshan, occupying the most of applications of this field in GuangdongProvince, even much more than the total number of patent application ofJiangsuProvincein this field. This reflects main industry players of this technical field are located in Foshan.


According to the number of patentees in provinces (regions or countries), 70 units and individuals applied the power reset thermostat patent, with 29 from GuangdongProvince. It also demonstrates the leading role ofGuangdongin this field.


The above table includes the top 21 patent applicants in China, who are active participants in the market of this field. It can be seen that, patents applied are scattered and the amount of patent application for all applicants is not too large.


As shown above, the most of patents in the filed have expired and still 49 patents are valid.


近年来，基于陶瓷基体的膜电阻浆料、丝印技术、烧结工艺的技术发展，厚膜电路成为全球公认的经济的电热电路方法，在产品的功能集成化和微型化上发挥着越来越大的作用。 本文尝试从已公开的专利技术方案的角度分析断电复位温控器近年来的相关技术热点，一点浅见，希望能对行业领域相关人员带来小小的启发，鉴于作者在本行业资历尚浅，还请同行和前辈们多多指教，谢谢大家！
Among valid patents, GuangdongProvinceowns 22, taking an absolutely dominant role in all provinces. Its amount has far surpassed the 8 ofJiangsuProvincewhich is in the second place, and is larger than the sum of that ofJiangsu,ZhejiangandShandong.

III.Technical focus and development trend

In terms of technical improvement, trying to change the combined mechanical structure of two bimetals which is originally raised by Zhang Jinxiu, professor of Zhongshan University, the patent number of adapting PTC (positive temperature coefficient) component to heat and keep the bimetal temperature has increased in recent years. Obviously, it is popular with manufactures and is greatly related to the improvement of manufacturing technology for heating component.

Here are revelations obtained through comprehensive analysis of recent patent documents:

1. After publicity of Patent CN2289295 with PTC component for power reset temperature controller by keeping heat in 1996, AuOne company improved it in Patent 200420046361.1 and patents have been released like 201120536514.0 of Tianpeng temperature controller and 201220120835.7 of Huanuo temperature controller;

2. PTC component used to adapt PTC sheet before. However, since 2007, patent of 200720043280, X has been released of glass glaze resistor with ceramic substrate (guide frame) based on the mutual technology of film resistor. In 201220420573.6, Peng Jianhua changed electricity connection, and recently 201320037223.6 of Sensate Electronic Company and 201320314601.0 of New Southeast Electronic Company are also disclosed;

3. The thermal protection technology of PTC component has been widely used in field of thermal protector. It has improved the technology of thermal protection and heat conduction as well as the electrical connection by applying the two above plans to temperature controller;

4. Compared with PTC sheet plan, PTC film resistor is more effective in implementation of the miniaturation, lightweight and thinning for temperature controller volume;

In recent years, thick film circuit has been universally recognized as the economical heater circuit based on the technical development of film resistor paste of ceramic substrate, screen printing and sintering process. It is playing more and more important role in products’ function-integration and miniaturization.

However, the use of thick film circuit in the field of power reset temperature controller is inevitable to require more for the composition and process (surface roughness) of alumina substrate and for resistor trimming device and process after molding. Further, it is believed that the application and promotion of film resistor power reset temperature controller could boost the development of other technical industries, having a strong linkage effect.

Generally speaking, the update of PTC component depends on the technology itself for power reset temperature with PTC sheet, but PTC film resistors can not only promote paste, screen printing, sintering and trimming technologies, but also is possible to update itself because of these technology improvement. However, on the condition of product performance guarantees, PTC film resistors plan has already made substantial progress in miniaturation structure of power reset temperature controller.

After all, the future trend for power reset temperature controller will be centered in Foshan temperature controller industrial base [1] of PTC sheet plan? Or it will take PTC film resistor spread in places as the mainstream?

Furtherly speaking, with the combined products of appliance industry being recognized by the market increasingly and some series of products being added to standards and revision plan of relevant national standards, it’s certainly that standard formulation for combination power reset temperature controller will be speeded up in order to regulate industry and to avoid disorderly competition by grasping trend of combination power reset temperature controller and technical opportunities and through promotion of products in the field of electric appliances.

This paper attempts to analyze the relevant technical key points of power reset temperature controller in recent year from perspective of the published patent technology. It's hoped to inspire relevant people of this field. Being not very experienced in this field, any comments from my peer and senior will be appreciated greatly. Thank you.

Cited Reference

[1] The largest Production Base of Temperature Controller in China [J]. Science and Technology of Household Electric Appliance. 1992 (3):46.