CN108566690A - Resistance heater wire structures - Google Patents

Abstract

The invention discloses a wiring structure of a resistance heating body, which can make EMC control indicators such as high-power harmonic current and voltage flicker meet the requirements of relevant standards. A wiring structure of a resistance heating element, comprising a thermally conductive insulating base, on which a connecting area and a distribution area are sequentially distributed in one direction, and more than two sets of heating resistors are printed on the thermally conducting insulating base, at least two sets of heating resistors Different power levels are formed due to the inconsistent power of different power levels. The heating resistors of each power level are mainly distributed in independent blocks, and the heating resistors with different power levels are partially parallel to the heating resistors with smaller power levels. The connection end of the heating resistor extends to the connection area.

Description

Wiring structure of resistance heating element

technical field

The invention belongs to the technical field of heating devices, and in particular relates to a wiring structure of a resistance heating element.

Background technique

Figure 1 is the traditional 1/3, 1/3, 1/3 power wiring scheme for heating systems below 2000W, which requires three sets of independent control circuits to control three sets of heating resistors. The three groups of heating resistors are routed in parallel, and the temperature of the three groups of heating resistors is basically the same at any time by alternately energizing C-1, C-2, and C-3 at equal times, so the power of the three groups of heating resistors is also basically the same , A power distribution of 1:1:1 is basically realized among the three groups of heating resistors.

Figure 2 is another wiring scheme, that is, 1/3 and 2/3 power wiring schemes. There are three heating resistors wired in parallel, one of which provides 2/3 of the power for two heating resistors connected in parallel; the other group is a single heating resistor The resistance is independently controlled to provide 1/3 of the heating power. When the temperature of the two sets of heating resistors is the same, the power of C-1 and C-2 is approximately 2:1. But in actual use, because the heating power is inversely proportional to the resistance value, the resistance increases with the temperature rise R=ρl(T ₀ +t)/S(T ₀ ) (T ₀ is the standard temperature, t is relative to the standard temperature Temperature rise), so the heating power and temperature rise are inversely proportional. Since the heating time of the two sets of heating resistors cannot always be guaranteed to be equal when using this wiring scheme to adjust the power, the working temperature of the two sets of parallel wiring resistors is very different, and the temperature is deeply coupled to each other, so it cannot be stable between the two sets of resistors. Realize the power distribution relationship of 1:2; when the power is adjusted, the power fluctuates greatly, so that the EMC control indicators such as high-power harmonic current and voltage flicker do not meet the requirements of relevant standards.

Contents of the invention

The object of the present invention is to provide a wiring structure of a resistance heating element, which can make EMC control indicators such as high-power harmonic current and voltage flicker meet the requirements of relevant standards.

For solving the problems of the technologies described above, the purpose of the present invention is achieved in that:

A wiring structure of a resistance heating element, comprising a thermally conductive insulating base, on which a connecting area and a distribution area are sequentially distributed in one direction, and more than two sets of heating resistors are printed on the thermally conducting insulating base, at least two sets of heating resistors Different power levels are formed due to the inconsistent power of different power levels. The heating resistors of each power level are mainly distributed in independent blocks, and the heating resistors with different power levels are partially parallel to the heating resistors with smaller power levels. The connection end of the heating resistor extends to the connection area.

On the basis of the above solution and as a preferred solution of the above solution: one end of all heating resistors is connected together to form a common terminal, and the other end is the terminal of the group of heating resistors.

On the basis of the above solution and as a preferred solution of the above solution: there are two sets of heating resistors.

On the basis of the above solution and as a preferred solution of the above solution: the power of the heating resistor with a larger power level is twice that of the heating resistor with a smaller power level.

On the basis of the above solution and as a preferred solution of the above solution: there are 3 sets of heating resistors.

On the basis of the above scheme and as the preferred scheme of the above scheme: there are two groups of heating resistors with smaller power levels having the same power; 2 times, two sets of heating resistors with the same power are set in parallel.

On the basis of the above scheme and as the preferred scheme of the above scheme: the power of any two groups of heating resistors is not the same, and the power of the heating resistor with the larger power level among the two groups of heating resistors with similar power levels is the one with the lower power level. 2 times the power of a small heating resistor.

Compared with the prior art, the present invention has outstanding and beneficial technical effects as follows:

The wiring structure of the resistance heating element of the present invention adopts a structure in which the heating resistors of each power level are mainly distributed in independent blocks, which reduces the working temperature coupling and temperature mutual influence of the two sets of heating resistors in the case of unequal heating. , by adjusting the area of the first zone and the second zone, the distribution relationship according to the power value ratio of the two groups of heating resistors can be realized relatively stably, so that when the power is adjusted, the power fluctuation is reduced, and the high-power harmonic current and voltage flicker And other EMC control indicators meet the requirements of relevant standards.

Description of drawings

Figure 1 is a traditional wiring structure for resistance heating elements below 2000W.

Figure 2 is a traditional wiring structure of resistance heating elements according to 1/3 and 2/3 power.

Fig. 3 is a wiring structure of a resistance heating element according to an embodiment of the present invention.

Fig. 4 is a wiring structure of a resistance heating element according to another embodiment of the present invention.

Fig. 5 is a wiring structure of a resistance heating element according to another embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments. Obviously, the described embodiments are only a part of the application Examples, not all examples. Based on the given embodiments, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of It is convenient to describe the application and simplify the description, but not to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the application.

In the description of the present application, the terms "first", "second" and so on are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features.

In the description of this application, the term "close in power" refers to the premise that there is a difference in the power of the two sets of heating resistors. Still considered the same power.

In the description of the present application, the terms "higher power" and "lower power" are used as pronouns rather than specific power values.

In the description of the present application, "above" includes the original number.

The invention discloses a wiring structure of a resistance heating body, which comprises a heat-conducting and insulating base 1 . Usually, the thermally conductive insulating base is made of ceramic material. The thermally conductive insulating matrix can adopt a tubular structure or a sheet structure. The connection area 100 and the distribution area distributed sequentially in one direction are formed on the thermally conductive insulating substrate, and more than two groups of heating resistors 10, 20, 30 are printed on the thermally conductive insulating substrate 1, and at least two groups of heating resistors have inconsistent powers to form different The heating resistors of each power level are mainly distributed in independent blocks. The heating resistors with higher power levels are located in blocks relatively far from the connection area, and the heating resistors with smaller power levels are located in blocks relatively close to the connection area. , and the heating resistor with a larger power level is partially parallel to the heating resistor with a smaller power level so that the connection end of the heating resistor extends to the connection area, and the heating resistor with a larger power level is located in the heating resistor with a smaller power level and form a semi-enclosed layout structure.

In one embodiment, referring to FIG. 3 , the total power of the resistance heating element is 1200 watts, and it has 2 sets of heating resistors 20 , 10 . The power of the larger heating resistor 20 is 800 watts, and the power of the smaller heating resistor 10 is 400 watts. In this embodiment, the power of the heating resistor 20 with higher power is twice that of the heating resistor 10 with lower power. It should be pointed out that the power of the heating resistors can also be configured according to other powers, for example, one group is 500 watts, and the other group is 700 watts.

In this embodiment, a connection area 100 and a distribution area are sequentially provided on the thermally conductive insulating substrate 1 from left to right. As shown in FIG. 3 , the distribution area includes a first area 201 and a second area 202 . The first area 201 and the second area 202 are distributed from left to right in sequence on the right side of the connection area. The heating resistors 10 with a power of 400 watts are mainly distributed in the first area 201 . The heating resistors 20 with a power of 800 watts are mainly distributed in the second area 202 . In this embodiment, most of the heating resistor 20 with a power of 800 watts is located in the second region 202 to form a layout design mainly distributed in the second region 202, and a small part thereof protrudes toward the connection region so that the connection end falls on the connection region. District 100. Most of the heating resistor 10 with a power of 400 watts is located in the first area 201 to form a layout design mainly distributed in the first area. And the heating resistance 10 of power 400 watts, the small part of the heating resistance 20 of power 800 watts protrude to connection area 100 and make its connecting end fall on connection area 100, and the part of heating resistance 20 with larger power level and power level Local parallelism of smaller heating resistors 10 .

On the whole, the heating resistor 20 with a power of 800 watts is located outside the heating resistor 10 with a power of 400 watts and forms a semi-enclosed layout structure. As shown in FIG. 3 , at the left end of the connection area, the heating resistor 20 with a power of 800 watts is not partially distributed to the left side of the heating resistor 10 with a power of 400 watts.

With this structure, the working temperature coupling and temperature mutual influence between the two sets of heating resistors under the condition of unequal heating are reduced. By adjusting the area of the first zone and the second zone, the power ratio of 1:2 can be realized relatively stably. Distribution relationship, that is, the distribution relationship according to the power value ratio of two groups of heating resistors.

Preferably, as shown in FIG. 3 , the heating resistor with a power of 400 watts first protrudes toward the second area and then turns back until the connecting end falls in the connecting area.

Through this structure, the influence of temperature coupling is avoided to a large extent, and the detection heat can be provided to the circuit protection system in time. If the heating resistor with a higher power level and the heating resistor with a smaller power level are located in two blocks completely independently, when one of the heating resistors is short-circuited and continues to generate heat, if the temperature sensor is located on the other heating resistor, then Since the two are completely independently located in the two blocks, the temperature transfer is slow, and then the temperature sensor takes a long time to sense it, resulting in a corresponding extension of the time for starting the power-off protection. It should be pointed out that, in order to achieve the above purpose, a small part of the middle position of the heating resistor can also be extended into another block.

In addition, in application, when a heating power of 500 watts is required, the heating resistor of 400 watts works intermittently at a duty ratio of 3/4, and in the remaining 1/4 of the time, the heating resistor of 400 watts stops heating, and the heating resistor of 800 watts The heating resistor works, so that the average power=400*3/4+800/4=300+200=500 watts in the macroscopic view, and the largest power jump in the microscopic view is only 400-0=400 watts, or 800-400 = 400 watts, reducing power fluctuations and improving EMI performance. When using a single heating resistor of 1200 watts, the power fluctuation in microscopic control is 1200-0=1200 watts, which has a greater impact on the power supply system.

Similarly, when a heating power of 1000 watts is required, the heating resistor of 800 watts works all the time, and the heating resistor of 400 watts works intermittently with a duty ratio of 1/2, so the average power in the macroscopic view=400*1/2+800= 1000 watts, and the maximum power jump in microcosm is only 400-0=400 watts.

It may be understood that, in any working state of the ceramic heating element during the working process, the maximum power jump range is not more than 400 watts, which greatly reduces the EMI index.

In this embodiment, one end of all heating resistors is connected together to form a common terminal, and the other end forms a terminal for each heating resistor to be electrically connected.

Embodiment two,

Referring to Fig. 4, in this embodiment, there are 3 groups of heating resistors.

Among them, two groups of heating resistors 10 with smaller power levels have the same power; and the power of heating resistors 20 with larger power levels is twice that of the heating resistors with smaller power levels.

In this embodiment, there are two groups of heating resistors 10 with a smaller power level of 750 watts, and the two are arranged in parallel. There is 1 group of heating resistors 20 with larger power of 1500 watts. As shown in FIG. 4 , a connection area 100 and a distribution area are sequentially arranged on the thermally conductive insulating substrate 1 from left to right. The distribution area includes a first area 201 and a second area 202 . The first area 201 and the second area 202 are distributed from left to right in sequence on the right side of the connection area. Most of the heating resistors 20 with a power of 1500 watts are located in the second area 202 relatively far from the connecting area, and most of the heating resistors with a power of 750 watts are located in the first area 201 relatively close to the connecting area. In this embodiment, two groups of heating resistors with the same power of 750 watts are of a power level as a whole, and most of them are distributed in the first zone, and most of the heating resistors with a larger power of 1500 watts are distributed in the second zone. And the small part of heating resistor 20 of power 750 watts, heating resistor 10 of power 1500 watts stretches out to connection area, forms the larger heating resistor of power grade and also has the part parallel with the part of heating resistor of smaller power grade to make heating The connections of the resistors extend to the structure of the connection region 100 .

On the whole, the heating resistor 20 with a power of 1500 watts is located outside the heating resistor 10 with a power of 750 watts and forms a semi-enclosed layout structure.

This structure is adopted, which reduces the working temperature coupling and temperature mutual influence of the two groups of heating resistors under the condition of unequal heating. By adjusting the area of the two areas, the power can be relatively stable to achieve 1: 2 Distribution relationship, that is, the distribution relationship according to the power value ratio of two groups of heating resistors.

In terms of providing detected heat to the circuit protection system in a timely manner, this embodiment can also adopt the structure in which the heating resistor in the first implementation extends to another block.

Embodiment three,

In this embodiment, there are 3 groups of heating resistors. The power of any two groups of heating resistors is different, and among the two groups of heating resistors with similar power levels, the power of the heating resistor with a higher power level is twice that of the heating resistor with a smaller power level.

As shown in FIG. 5 , a group of heating resistors 30 has a power of 3200 watts, a group of heating resistors 20 has a power of 1600 watts, and a group of heating resistors 10 has a power of 800 watts. The 3200-watt heating resistor and the 1600-watt heating resistor are two sets of heating resistors with similar power levels. The 1600-watt heating resistor and the 800-watt heating resistor are two sets of heating resistors with similar power levels. The 3200-watt heating resistor and the 800-watt heating resistor do not belong to two groups of heating resistors with similar power levels.

As shown in FIG. 5 , a connection area 100 and a distribution area are sequentially provided on the thermally conductive insulating substrate 1 from left to right. The distribution area includes a first area 201 , a second area 202 and a third area 203 . The first zone, the second zone and the third zone are distributed from left to right in turn on the right side of the connection zone. In this embodiment, most of the 800W heating resistor 10 , the 1600W heating resistor 20 , and the 3200W heating resistor 30 are mainly distributed in the independent first area 201 , second area 202 and third area 203 . The heating resistor 30 of 3200 watts is partially parallel with the heating resistor 20 of 1600 watts so that the connecting end of the heating resistor extends to the connection area. Similarly, the heating resistor 20 of 1600 watts also has a part and the heating resistor 10 of 800 watts The local parallel of the heating resistor extends to the connection area 100. The heating resistor of 3200 watts is located outside the heating resistor of 1600 watts and forms a semi-enclosed layout structure; the heating resistor of 1600 watts is located outside the heating resistor of 800 watts And form a semi-enclosed layout structure.

Adopting this structure, the use of this structure reduces the working temperature coupling and temperature mutual influence of the two sets of heating resistors in the case of unequal heating. By adjusting the area of the two areas, the power can be relatively stable by 1: 2 Distribution relationship, that is, the distribution relationship according to the power value ratio of two groups of heating resistors.

In terms of providing timely detection of heat to the circuit protection system, this embodiment can also adopt the structure of extending the heating resistor to another block in the first implementation.

In the above embodiment, the thermally conductive insulating base 1 includes a ceramic base and a ceramic insulating layer, the heating resistor is located between the ceramic base and the ceramic insulating layer, and the connection end of the heating resistor is exposed outside the ceramic insulating layer, that is to say, the ceramic insulating The area of the layer is slightly smaller than the ceramic base so that the ceramic insulating layer does not completely cover the ceramic base, and the connection end of the heating resistor is located in the uncovered part. The ceramic base and the ceramic insulating layer are sintered together.

In the present invention, the power of the heating resistor with the smallest power is usually equal to or less than 900 watts, so as to effectively control the EMI index. Since the power of at least some of the heating wires is different, a power difference is formed to reduce the number of heating wires. At the same time, the minimum power of the heating wire is limited to match the heating power, so that the control scheme is relatively simple, below 2500 watts The constant temperature control system only needs 2 sets of independent electronic control circuits, and the high-power constant temperature control system between 2500 watts and 5600 watts only needs 3 sets of independent electronic control circuits, and can effectively control the EMI index, simplifying the control system , improves reliability and reduces system cost.

The foregoing embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made according to the structures, shapes and principles of the present invention shall be covered by the protection of the present invention. within range.

Claims (7)

1. a kind of resistance heater wire structures, including heat conductive insulating matrix, on heat conductive insulating matrix by a direction formed according to The bonding pad and distributed area of secondary distribution, are printed with heating resistor more than two on heat conductive insulating matrix, it is characterised in that：At least There is the power of two groups of heating resistors inconsistent and form different power grades, the heating resistor of each power grade respectively mainly divides Cloth is in independent block, and the larger heating resistor of power grade also has the office of part and the smaller heating resistor of power grade Portion is parallel and the connecting pin of heating resistor is made to reach bonding pad.

2. resistance heater wire structures according to claim 1, it is characterised in that：One end of all heating resistors connects It is connected together and forms common terminal, the terminals for each heating resistor that the other end is.

3. resistance heater wire structures according to claim 1 or 2, it is characterised in that：The heating resistor is 2 groups.

4. resistance heater wire structures according to claim 3, it is characterised in that：The larger heating resistor of power grade Power be 2 times of power of the smaller heating resistor of power grade.

5. resistance heater wire structures according to claim 1 or 2, it is characterised in that：The heating resistor is 3 groups.

6. resistance heater wire structures according to claim 5, it is characterised in that：Wherein there are two groups of power grades smaller Heating resistor power it is identical；And the power of the larger heating resistor of power grade is the smaller heating resistor of power grade 2 times of power, the identical two groups of heating resistors of power are in parallel setting.

7. resistance heater wire structures according to claim 1 or 2, it is characterised in that：Arbitrary two groups of heating resistors Power is all different, and in two groups of heating resistors that power grade is close the larger heating resistor of power grade power It is 2 times of the power of the smaller heating resistor of power grade.