Two-wire layered heater system

Double-layer heating system

The present invention generally relates to electric heaters and controllers, and more specifically relates to temperature sensing of layered heaters.

Layered heaters are generally used in limited space, when the heating output needs to be changed across a surface, or in extreme purification or aggressive chemical applications. Layered heaters generally include layers of different materials, that is, dielectric materials and resistive materials that are applied to the substrate. The dielectric material is first applied to the substrate and provides electrical isolation between the substrate and the resistive material while minimizing current leakage during operation. The resistive material is applied to the dielectric material under a predetermined pattern, and a resistive heater circuit is provided. The layered heater also includes a wire, which connects the resistance heater circuit to the heater controller, and an over-molded material, which can protect the interface between the wire and the resistance circuit. As mentioned earlier, the layered heater is a heater that can be used in a variety of changes to meet customer needs.

Layered heaters may be "thick" films, "thin" films, or "thermal spray", among others, among which the main difference between these types of layered heaters is the method of forming the layers. For example, the layers of thick film heaters are generally formed by processes such as screen printing circuits, pasting applications, or film print heads and other processes. The layers used for thin film heaters are generally formed by deposition processes such as ion plating, sputtering, chemical vapor deposition (CVD), and physical vapor deposition (PVD) and others. There are other processes that are different from thin and thick film technologies, which are thermal spraying, which may include, for example, flame spraying, plasma spraying, arc spraying, and HVOF (high velocity flame spraying), and others.

Known systems using layered heaters generally include a separate temperature sensor, which is connected to the controller via another set of electrical wires, plus another set of wires for the resistive heater circuit. The temperature sensor is usually a thermocouple located close to the film heater and/or at a certain position of the processor that provides the heater with temperature feedback for heater control. In any case, thermocouples occupy a relatively large volume, require additional electrical wires, and are relatively inefficient. Instead, an RTD (Resistance Temperature Detector) can be incorporated in the layered heater as a different layer, in order to obtain more accurate temperature readings, and can reduce the cost compared to traditional thermocouples. The space needed. Unfortunately, the RTD also needs to be connected to the controller via an additional set of electrical wires. For a system employing a large number of temperature sensors, the number of associated electrical wires for each sensor is substantially large and results in increased volume and complexity of the overall heating system.

For example, one of these applications is the increased volume and complexity of electrical wires for heating systems with injection molding systems added. Injection molding systems, and especially hot runner systems, usually contain a large number of nozzles for highly cavitation molding, where several parts are molded in a single cycle or injection. The nozzles are usually heated to improve resin flow. Therefore, for each nozzle in the system, the associated electrical wiring set for the nozzle heater and at least one temperature sensor ( For example, the electric wire group of thermocouple must be routed to each nozzle by a control system. The winding of the electrical wires is generally done by using an umbilical cord, which is distributed from the control system to the hot runner molding system. In addition, the winding groove is generally rolled into the plate of the molding system to wind the wire to each nozzle. Therefore, increasing the number of electrical wires will increase the cost and complexity of the external heating runner molding system, and result in the overall injection molding. The molding system increases the volume.

In a preferred configuration, the present invention provides a heating system including a thick film heater and a dual circuit controller. The thick film heater is composed of a substrate, a dielectric layer arranged on the substrate, and a resistive layer arranged on the dielectric layer. The resistive layer has a sufficient temperature coefficient of resistance characteristics, so that the resistive layer It is a heating element and a temperature sensor. In addition, a protective layer is arranged on the resistance layer and the dual-circuit controller uses the resistance value of the resistance layer to determine the temperature of the thick film heater, and thereby control the heater temperature.

In another configuration, the present invention provides a layered heater including at least one resistance layer, wherein the resistance layer has a sufficient temperature coefficient of resistance characteristics, so that the resistance layer is a heating element and a temperature sensor. The layered heater further includes a dual circuit controller connected to the resistance layer, wherein the dual circuit controller uses the resistance of the resistance layer to determine the temperature, and thus controls the heater temperature. In different configurations of the present invention, the layered heater is a thick film layer heater, a thin film layer heater, a thermal spray heater, and a sol-gel heater.

In another configuration, the present invention provides at least one hot runner nozzle and at least one resistance layer disposed near the hot runner nozzle, wherein the resistance layer has sufficient temperature coefficient of resistance characteristics, so that the resistance layer is A heating element and a temperature sensor. The heating system further includes a dual-line controller connected to the resistance layer, wherein the dual-line controller uses the resistance of the resistance layer to determine the temperature, and thereby controls the heater temperature.

In addition, the present invention provides a heating system that can be used in an existing temperature controller with at least one temperature sensor input and one power output. The present invention is an improved type including at least one layered heater with at least one resistance layer, wherein the resistance layer has a sufficient temperature coefficient of resistance characteristics, so that the resistance layer is a heating element and a temperature sensor. The improvement further includes at least one dual circuit module connected to the layered heater and the temperature controller, wherein the dual circuit module uses the resistance of the resistive layer to determine the temperature of the layered heater and transmits the layered heater The temperature is input to the temperature controller, and the temperature controller transmits power to the dual-circuit module.

In another configuration, the present invention provides a layered heater including at least one resistance layer, wherein the resistance layer has a sufficient temperature coefficient of resistance characteristics, so that the resistance layer is a heating element and a temperature sensor. The heating system further includes an electric wire connected to the resistance layer, and a controller connected to the resistance layer via the electric wire, wherein the controller uses the resistance of the resistance layer to determine the temperature, and thus controls the heater temperature. In addition, a common circuit device connected to the layered heater and a power source is connected to the controller, wherein the common circuit device provides an electrical circuit from the layered heater to the controller, so that only a single winding is required. For the operation of the heating system.

According to a method of the present invention, the operation of the provided layered heater includes supplying power to the heater via a set of wires connected to the resistive element of the layered heater, and via a set of wires connected to the layered heater The dual circuit controller calculates the temperature of the resistance element, where the resistance element is a heating element and a temperature sensor. In another version, the method is used to operate a layered heater in conjunction with a hot runner nozzle.

Further fields of the present invention will be clearly understood from the detailed description provided below. It should be understood that although the detailed description and specific examples indicate preferred specific examples of the present invention, they are only for the purpose of illustration and not intended to limit the scope of the present invention.

The following description is only an example of the characteristics of preferred specific examples, and is not intended to limit the present invention, its application, or use.

FIG. 1 illustrates a simplified heating system block diagram style of a structure of the present invention, and is roughly labeled with reference number 10. The heating system 10 includes a one-layer heater 12, a dual-line controller 14, which is preferably microprocessor-based, and a power source 16 located in the dual-line controller 14 or connected to the dual-line controller 14 . The patterned layered heater 12 is connected to the dual circuit controller 14 via a single set of electrical wires 18. Electric power is supplied to the layered heater 12 via the electrical wire 18, and the temperature information of the layered heater 12 is provided by a command sent to the same set of electrical wires 18 of the dual circuit controller 14. More specifically, the dual circuit controller 14 determines the temperature of the layered heater 12 based on the calculated resistance. One of its techniques will be described as follows. The dual-line controller 14 then sends a signal to the power source 16 to control the temperature of the layered heater 12. Therefore, only a single set of electrical wires 18 is required instead of one set for heaters and one set for temperature sensors.

Next, referring to FIG. 2, it shows a structure of the layered heater 12, which includes a plurality of layers arranged on a substrate 20, wherein the substrate 20 may be an individual element arranged close to the member or device to be heated, Or the component or device itself. As shown in the figure, the sheet layer preferably includes a dielectric layer 22, a resistive layer 24, and a protective layer 26. The dielectric layer 22 provides electrical isolation between the substrate 20 and the resistive layer 24, and corresponds to the power output of the layered heater 12 in terms of the thickness disposed on the substrate 20. The resistive layer 24 is disposed on the dielectric layer 22 and provides two main functions according to the present invention. First, the resistive layer 24 is a resistive heater circuit for the layered heater 12, so the substrate 20 can be heated. Furthermore, the resistance layer 24 is also a temperature sensor, wherein the resistance of the resistance layer 24 is used to determine the temperature of the layered heater 12, which will be described later. The protective layer 26 is preferably an insulator. In any case, other materials such as conductive materials can also be used according to the requirements of a specific heating application, which are all within the scope of the present invention.

To further illustrate, the terminal pad 28 is disposed between the dielectric layer 22 and the resistance layer 24 and contacts the resistance layer 24. As mentioned above, the electrical wire 30 contacts the terminal pad 28 and connects the resistive layer 24 to the dual circuit controller 14 (not shown in the figure) for power input and for transmitting heater temperature information to the dual circuit controller 14. In addition, the protective layer 26 is disposed on the resistive layer 24, and is preferably a dielectric material for electrical isolation and protects the resistive layer 24 with respect to operation. Because the resistive layer 24 functions as both a heating element and a temperature sensor, only one set of electrical wires 30 (for example, two wires) is required for the heating system 10, instead of one set for the layered heater 12 and the other set. For a separate temperature sensor. Therefore, by using the heating system 10 according to the present invention, the number of electrical wires used in any given heating system can be reduced by up to 50%. In addition, because the entire resistance layer 24 is a temperature sensor plus a heating element, the temperature of the entire heating element can be detected instead of the traditional temperature sensor such as a thermocouple which can only detect the temperature at a single point.

In another configuration of the present invention as shown in FIG. 3a, the resistive layer 24 in this manner is disposed on the substrate 20, where the substrate 20 is not conductive and does not need to be electrically isolated via a separate dielectric layer. As shown in the figure, the protective layer 26 is disposed on the entire resistive layer 24 as previously described. In another structure shown in FIG. 3b, the resistive layer 24 is disposed on the substrate 20, and the dielectric layer 22 and the protective layer 26 are not provided. As mentioned above, the heating system 10 of the present invention can be operated with at least one layer (that is, the resistive layer 24), wherein the resistive layer 24 is both a heating element and a temperature sensor. Other combinations of functional layers not described in this article can be used according to the requirements of specific applications, and they all fall within the scope of the present invention.

Generally speaking, the layered heater 12 is configured to operate in addition to various devices that need to be heated, one of which is a hot runner nozzle used in an injection molding system as described later. In addition, the layer heater 12 is preferably a thick film heater, which is manufactured by using a film print head of the present invention. The sheet layer adopting the thick film layer process is as proposed and described in US Patent Publication No. 5,973,296, and is jointly assigned to the applicant in this case and its full text is incorporated herein by reference. In addition, thick film processing can include exemplified methods such as screen printing, spraying, rolling, and transfer.

In any case, in another configuration, the layered heater 12 is a thin film layer heater, in which the layers adopt ion plating, sputtering, chemical vapor deposition (CVD), and physical vapor deposition (PVD). , And other thin film layer processes. For example, the film manufacturing processes disclosed in US Patent Publication Nos. 6,305,923, 6,341,954, and 6,575,729, are incorporated herein by reference in their entirety, and can be used in the heating system 10 described herein, all of which belong to the present invention Within range. In another configuration, the layered heater 12 is a thermal spraying heater, in which the layer adopts such as flame spraying, plasma spraying, arc spraying, and HVOF (high velocity flame spraying), and other thermal spraying processes Constructed. In another configuration, the layered heater 12 is a "sol-gel" heater, in which the sheet layer is constructed of a sol-gel material. Generally speaking, the sol-gel sheet layer is formed by processes such as dipping, spinning, or painting, and other processes. Therefore, the term "layer heater" used in this article should be constructed to include at least one functional layer (for example, only the resistance layer 24, the resistance layer 24 and the protective layer 26, the dielectric layer 22 and the resistance Layer 24 and protective layer 26, and other) heaters, wherein the formation of the sheet layer is related to thick film layer, thin film layer, thermal spraying, or sol-gel, and other processes, applying or The accumulated material is formed on the substrate or another layer. These processes are also referred to as "layered processes" or "layered heater processes".

In order for the resistance layer 24 to provide two functions of a temperature sensor plus a heating element, the resistance layer 24 is preferably composed of a resistance material (TCR) with a relatively high temperature coefficient. When the resistance of metal increases with temperature, the resistance at any temperature t (°C) is: R=R₀(1+α t) (Formula 1)

Where: R₀Is the resistance at some reference temperature (usually 0°C), and α is the temperature coefficient of resistance (TCR). Therefore, in order to determine the temperature of the heater, the resistance of the heater is calculated as described by the dual circuit controller 14 hereinafter. In one configuration, the terminal voltage and current flowing through the heater are measured by the dual-line controller 14, and the resistance is calculated according to Ohm's law. Those who are familiar with the temperature measurement technology can use Equation 1 or similar formulas to calculate the temperature of the resistive layer 24 and use it to control the heater based on resistance temperature detectors (RTDs) and known TCRs.

Therefore, in one configuration of the present invention, a relatively high TCR is preferable, so that a small change in temperature causes a large change in resistance. Therefore, materials such as platinum (TCR=0.0039 Ω/Ω/°C), nickel (TCR=0.0041 Ω/Ω/°C), or copper (TCR=0.0039 Ω/Ω/°C), and alloy components in them are more It is preferably used for the resistance layer 24.

In any case, in other configurations of the present invention, the material used for the resistance layer 24 need not necessarily have a high TCR. For example, a negative TCR material or a non-linear TCR material should also fall within the scope of the present invention, as long as the TCR is predictable. If the TCR of the given material is known, if it is measured within the necessary accuracy range, and if it is repeatable or predictable, then the material can be used to determine the temperature of the heating system 10. These TCRs (including the relatively high TCR materials as described) are hereinafter referred to as having sufficient TCR characteristics. As mentioned above, the materials described in this article and their associated high TCR should not be constructed to limit the scope of the present invention. The relatively high TCR described in this article is a preferred configuration of the present invention.

As for other sufficient TCR characteristics, the material used for the resistance layer 24 must not exhibit excessive "drift", which is the tendency of various resistance elements to change characteristics, such as volume resistivity or TCR, and time delay. Therefore, the material used for the resistance layer 24 is preferably stable or predictable in terms of drift. In any case, the drift over time can be compensated by the adjustment of the dual-line controller 14, which will be described later. In addition, the drift can be reduced or omitted by the "burn-in" of the heater to induce any resistance drift that may occur across the time history. As mentioned above, the resistance layer 24 is a preferable material with a relatively high temperature coefficient resistance, and it is stable in terms of drift relationship. In any case, if the drift is predictable, the material can be used for the resistive layer while falling within the scope of the present invention.

In one configuration of the present invention, the resistive layer 24 is formed by printing a resistive material on the dielectric layer 22 as described above. In particular, when the two resistance materials RI1 and RI2 are tested and used in the present invention, the TCR of RI1 is between close to 0.0008 Ω/Ω/°C and close to 0.0016 Ω/Ω/°C, and the TCR of RI2 is close to 0.0026 Ω /Ω/°C and close to 0.0040 Ω/Ω/°C. In addition, the temperature drift of RI1 and RI2 was tested at different temperatures, and the drift change was about 3% of RI1 and about 10% of RI2. Through the aforementioned "burn-in", it is shown that the drift has been reduced to approximately 2% of RI1 and approximately 4% of RI2. The materials used for the resistance layer 24 and their corresponding TCR values and temperature drift are described herein as exemplary characteristics, and are not intended to limit the scope of the present invention. It is previously proposed that any resistive material with sufficient TCR characteristics can be used for the resistive layer 24, which falls within the scope of the present invention.

Because several layered heaters with temperature sensor capabilities are used in accordance with the present invention, the dual circuit controller 14 must have specific information about the heater (and especially about the resistance layer 24) in order to properly adjust the overall heating system . The necessary parameters for these adjustments include cold resistance, the temperature at which the cold resistance value is measured, and specific TCR characteristics (TCR at a temperature and/or across a temperature range), calculated from the resistance of the heater The temperature of the heater. Preferably, the system will use the dual-line controller 14 to automatically calculate the cold resistance of each layer heater 12 based on the measured voltage and current as described below. In addition, the TCR characteristics of each layered heater 12 must be input into the system (for example, the dual circuit controller 14) by manual and/or electrical methods. These values can be entered individually or as a single value for all layered heaters 12, depending on whether the material used for the resistive layer 24 comes from a common manufacturing lot. In any case, the adjustment data, that is, the cold resistance, the cold temperature, and the TCR of each layer heater 12 are preferably input into the dual circuit controller 14 for more accurate and control the operation of the heating system 10.

There are a variety of methods for providing the TCR characteristics and cold resistance data of each layer heater 12 to the dual circuit controller 14 that can be used, and they all fall within the scope of the present invention. For example, each layer heater 12 may include a code, which can be scanned by the operator to download the cold resistance data and TCR characteristics to the dual circuit controller 14. In another embodiment, a chip smart card or other electrical device can be attached to each layered heater 12, which can be similarly scanned by the operator to download the calibration data to the dual-circuit controller 14. At the same time, in another configuration, the adjustment data can be downloaded to the dual-line controller 14 via the Internet (for example, via a supplier's webpage). In an alternative embodiment, TCR characteristics and cold tolerance data can be pre-programmed into the dual circuit controller 14.

In addition to the adjustment of the resistance data and TCR, the compensation for the resistance of the electrical wire 30 will also be provided by the heating system 10 according to the present invention. Because the electrical wire 30 will increase the resistance of the circuit, if the increased resistance is not compensated, it may cause temperature errors. In addition, the material used for the electrical wire 30 may have a TCR value higher than the TCR value of the resistance layer 24, which will cause more resistance in the portion of the electrical wire 30 exposed to a higher temperature. Therefore, the dual-line controller 14 also provides adjustments for wire resistance.

The dual-line controller 14 is preferably designed with temperature adjustment capability, which further reduces long-term temperature errors due to drift. One of the temperature adjustment methods is to use one or more existing thermocouples or other existing temperature sensors to determine both temperature and temperature stability. The temperature data from the thermocouple is then sent to the dual-line controller 14 to calculate the resistance. In addition, the measured change in the cold resistance of the layered heater 12 can be used to properly calculate the new TCR characteristic value. In another form of temperature adjustment, the dual-line controller 14 preferably includes an adjustment compensation feature for input of temperature compensation parameters. When the position of the layered heater 12 is a certain distance away from the optimal position where the temperature is desired to be sensed, such compensation is desired. Therefore, the temperature compensation parameter can be used, so that the temperature provided by the heating system 10 is closer to the actual temperature representing the optimal position.

Next, the structure of the layered heater 12 shown in FIGS. 4a-4c will be described. The resistive layer 24 is preferably arranged on the dielectric layer 22, and its pattern 40 will produce the desired substrate or element to be heated. Has the temperature profile. The resistance layer 24a shown in FIG. 4a is a rectangular pattern 40a generated based on the rectangular outline of the substrate 20a. The resistance layer 24b shown in FIG. 4b is a circular pattern 40b generated based on the circular outline of the substrate 20b. The resistance layer 24c shown in FIG. 4c is a spiral pattern 40c generated according to the cylindrical profile of the substrate 20c. In addition, the width "W" and/or the pitch "P" of the patterns 40a-c may also be changed according to the specific heating requirements of the heating system. Therefore, the pattern of the resistance layer 24a is preferably customized for each application of the heating system 10. The styles exemplified in this article are only examples, and are not intended to limit the scope of the present invention.

The layered heater 12 includes each of its layers and the terminal gasket 28 can also be constructed in accordance with U.S. Patent Publication Nos. 6,410,894, 6,222,166, 6,037,574, 5,973,296, and 5,714,738, which collectively assign the present invention and the full text of which is incorporated by reference. Incorporated into this text for reference, they are all within the scope of the present invention. In addition, other characteristics related to the clarification and reference of the patent case, which are not included in the text, are related to other materials, manufacturing techniques, and construction processing methods, and these other characteristics will be incorporated into this article for reference.

<b>Dual line controller (14)</b>

One of the structures of the dual-line controller 14 is shown in the block diagram of FIG. 5. The dual circuit controller 14 shown in the figure roughly includes a power supply 50, a voltage and current measuring component 52, a power regulator component 54, and a microprocessor 56 connected to the layered heater 12. The microprocessor 56 is also connected to a communication component 58, in which specific outputs (such as temperature readings) from the heating system 10 are delivered and at the same time can provide these inputs (such as updated TCR values, adjustment data, temperature Set point, resistance set point) to heating system 10.

Next, referring to FIG. 6, the voltage measuring element 52 of the dual-line controller 14 will be described in more detail. Generally speaking, the dual-line controller 14 applies a DC bias or low-intensity DC to the layered heater 12 during the alternating current cycle crossing the zero value, so that the current value is multiplied by a nominal heater resistance to generate a voltage, which is The voltage higher than the full waveform voltage that crosses the zero value is maintained for a period of time on each side of the zero value. During this period, the voltage of the layered heater 12 is amplified and compared to the reference voltage, and then the power supplied to the layered heater 12 is controlled, which will be further described in this article. U.S. Patent Publication No. 4,736,091 further explains the application of direct current bias, which jointly grants the application of the present invention, and is incorporated herein by reference in its entirety. In another configuration of the present invention, AC current can be used for bias voltage instead of DC bias voltage to determine the resistance of layered heater 12.

The dual circuit controller 14 shown in the figure includes a transistor 60, a diode 62, and a first resistor 64. The first resistor 64 combined with the layered heater 12 forms a voltage divider. For the DC bias voltage, the transistor 60 is turned on for a short period of time (for example, 200 μs) during the zero value period, and the current is further restricted from flowing through the power supply 50 during the negative half-cycle period when the heater is receiving power (not shown in the figure). Shows). In addition, during the positive half-cycle period of the layered heater 12 receiving power, the diode 62 can limit the current flowing through the power source 50. The output of the layered heater 12 is then transmitted through a second resistor 66 and enters an operational amplifier circuit 68 including an amplifier 70 and resistors 72, 74, and 76. Therefore, the output voltage of the amplifier 70 is used to calculate the resistance and determine the temperature of the layered heater 12, wherein the output voltage of the amplifier 70 is read by analog-to-digital conversion in the microprocessor 56. In addition, during the DC bias period, the output voltage of the amplifier 70 is converted from an analog signal to a digital signal, and if the calculated resistance or the temperature of the layered heater 12 is determined by a control algorithm, it needs to be derived from the layered type. The additional power of the heater 12, a strobe pulse from the gate control 80 will be delivered to the layered heater 12. As further shown, the field effect transistor 82 pins the input of the amplifier 70, thereby preventing the amplifier 70 from being over-driven during the positive and negative half cycles during the positive reception of power.

It will be further described that the following microprocessor 56 is generally connected to the displayed circuit via an output control 84, a bias control 86, and a heater input 88. In addition, the microprocessor 56 further includes firmware 90 and/or software (not shown in the figure). The firmware 90 can be programmed for a variety of functions, including but not limited to allowing half-cycle power delivery or full-cycle power according to IEEE 519 to improve controllability. In a further example, the firmware 90 may include a control algorithm to compensate for the thermal transient response and other adjustment data as described above. Therefore, the microprocessor 56 is used in conjunction with a DC bias circuit to determine the temperature of the layered heater 12 and more effectively control the supply of power to the layered heater 12.

The dual-line controller 14 is further decomposed in FIG. 7. The power supply 50 is preferably non-isolated and capacitively coupled to the linear regulator 100 as shown in the figure. Therefore, the AC power of the regulated power supply 50 is down to a specific value according to the operation requirements. It is further shown that the positive rotating wave (direct current bias) from the power supply 50 that is connected to the microprocessor 56 crosses a value of zero. During the period of crossing the zero value, the DC bias voltage is applied through the transistor 102, the diode 104, and the resistor 106. The voltage across the layer heater 12 is amplified and compensated by the amplifier 108, and the amplifier 110 is used as a reference for the analog-to-digital conversion of temperature variation in the microprocessor 56.

The measurement of the changes in the voltage and current values at the terminal of the layered heater 12 is done by using dual amplifiers 112, 114 and analog switches 116, 118, where the voltage signal is changed through the amplifier 112 and the analog switch 116, and the current changes It goes through the amplifier 114 and the analog switch 118. As further shown, the change in current is measured using the parallel resistor 116. In addition, the dual-line controller 14 includes a gate control 120 that is non-conductive during the crossing of the zero value and conductive during each half cycle. During the DC bias period, if the measured resistance is determined by the control algorithm to require additional power from the layered heater 12, an analog-to-digital conversion will occur and the gate circuit control 120 will deliver a pulse. Therefore, the circuit diagram shown in FIG. 7 provides two methods for calculating resistance, namely, a DC bias circuit and a parallel resistance circuit. In addition, although the present invention preferably measures voltage and current to determine resistance, alternative methods such as voltage gates or currents can also be used to determine resistance, which fall within the scope of the present invention.

In another configuration, the gate control 120 is preferably a random trigger gate control, so that the layered heater 12 can be triggered at a high conduction angle to reduce the amount of energy delivered to the layered heater 12 during sampling. For example, activating the layered heater 12 at conduction angles of 160 degrees and 340 degrees can allow sufficient sampling at 120 Hz while reducing the energy delivered to the layered heater 12. Instead, sampling only at 160 degrees or only at 340 degrees should produce a sampling rate of 60 Hz while further halving the energy input. In addition, when using random trigger gate control, when the temperature (or resistance in other configurations) approaches the set point, any rate function can be used to deliver energy in smaller increments. Therefore, the layered heater 12 is triggered to enter a full-line cycle at increasingly higher conduction angles.

As further shown, the communication in and out of the dual-line controller 14 occurs on the opposite side of the microprocessor 56. The communication component 58 includes a series of optical isolators 122, 124, and 126, plus a radio transceiver 128. Therefore, communication can be accomplished through a variety of communication protocols, including RS-485 communication as an example in this article. In addition to other functions, you can use this communication interface to input adjustment data.

The firmware 90 is loaded into the microprocessor 56 via the connected ISP (Online Programming and Development Software) as shown in the figure. Therefore, the specific modified settings in the dual-line controller 14 (including the input adjustment data as described above) can be completed in an effective manner.

The specific circuit elements described in detail in FIG. 7 together with the values and structures of the circuit elements (such as resistance values, capacitance values, and others) are examples of a structure of the dual-line controller 14 and should not constitute the limitation of the present invention. As mentioned above, alternative circuit elements, structures, values, and resistance measurement circuit topology logic can be applied to the dual-line controller defined in this article, which all fall within the scope of the present invention.

<b>Hot runner nozzle application</b>

A known application method of the heating system 10 according to the principle of the present invention is a hot runner nozzle used in an injection molding system as shown in FIG. 8. The hot runner nozzle 150 is generally configured in the thermal operation mold system 152, which further includes a plurality of mold winding grooves 154, which are provided for the winding of electrical wires (not shown in the figure), which are arranged in Close to the hot runner nozzle 150 to the dual circuit controller described in this article (not shown in the figure). Because each heater has both a heating element and a temperature sensor, each heater only needs to have a set of wires instead of a set of wires for the heater and a set of wires for the temperature sensor. As a result, the number of wires distributed through the die winding slot 154 is reduced by half, and the associated volume and complexity can be greatly reduced.

In addition, the injection molding molding system equipment generally includes an umbilical cord 164, which is distributed from the controller to the thermal operation mold system 152, and all wires and other wire electrical components are arranged in it. By drastically reducing the number of wires in the present invention, the size and volume of the umbilical cord 164 are also drastically reduced. In addition, because the temperature is sensed by the entire resistance layer of the heater, the sensed temperature spans a length instead of a spot like a traditional thermocouple.

As shown in Figures 9 and 10, the heating system for the hot runner nozzle 150' is described in more detail. The heating system 200 includes a layered heater 202 disposed around the body 203 of the hot runner nozzle 150 , and a dual-line controller 204 connected to the layered heater 202 via a single set of wires 205. The layered heater 202 further includes a substrate 206, which is configured to be closely attached to the geometric shape (the pattern is a cylinder) of the hot runner nozzle 150'. The layered heater 202 further includes a resistive layer 208 arranged on the substrate 206, a resistive layer 210 arranged on the resistive layer 208, and a protective layer 214 arranged on the protective layer 214. As further shown, the terminal pad 216 is disposed on the resistive layer 208 and is in contact with the resistive layer 210. As mentioned above, the electrical wire 205 contacts the terminal pad 216 and connects the resistive layer 210 to the dual circuit controller 204. As a result, only one set of electrical wires 205 is required for the heating system 200, instead of one set for the layered heater 202 and another set for different temperature sensors.

As shown in FIG. 11, the layered heater 202' in another configuration is arranged on the outer surface 220 of the hot runner nozzle 150' instead of on a different substrate as previously described. Similarly, the layered heater 202' includes a dielectric layer 208' arranged on the outer surface 220, a resistive layer 210' arranged on the dielectric layer 208', and a resistive layer 210' arranged on the resistive layer 210' Protective layer 214'. The terminal pad 216' is similarly configured on the dielectric layer 208' and contacts the resistive layer 210'. As further shown, a single set of wires 205' connects the heater 202' to the dual-wire controller 204'.

In another configuration of the present invention, a modular approach according to the present invention can be used in the existing separate temperature sensors (such as thermocouples, resistance temperature detectors) as set and illustrated in FIG. 12 Controller, update the heating system. As shown in the figure, the dual circuit module 230 is arranged between the layered heater 232 and the existing temperature controller 234. The temperature controller 234 includes a temperature sensor input 236 and a power output 238. The dual-line module 230 therefore includes the aforementioned dual-line resistance measurement circuit, and the temperature calculated in the dual-line module 230 is transmitted to the temperature sensor input 236 of the existing temperature controller 234. Based on these temperature inputs, the temperature controller 234 controls the layered heater 232 via the power output 238. As shown in the figure, it should be understood that the power control may be a part of the temperature controller 234 or may be a separate power controller 240, which falls within the scope of the present invention. As mentioned above, the existing temperature controller can be updated together with the dual circuit module 230 to realize the heating system of the present invention, without the need to almost completely remake and modify the existing system.

Referring to FIG. 13, another structure of the heating system according to the present invention can exemplify the reduction of electrical wires, and is roughly labeled with reference number 300. The heating system 300 includes a one-layer heater 302 and a controller 304 that operates as described above, wherein a resistive layer (not shown in the figure) of the layered heater 302 is both a heating element and a temperature sensor. . The heating system 300 further includes a power source 306, which is preferably a low-voltage one in the configuration of the present invention, which provides power to the layered heater 302. The layered heater 302 shown in the figure is connected to the controller 304 via a single electrical wire 308 and via a body or structure of a device 310 (such as a hot runner nozzle system module) set as a common circuit or a neutral end. The common circuit device 310 provides an electrical circuit from the layered heater 302 to the layered heater 302. The heating system 300 uses the electrical conductivity characteristics of the material of the device 310 to complete the electrical circuit, and therefore it is necessary to limit the current intensity of the power source 306 flowing through the device 310. Therefore, because the device structure 310 is used to connect the layered heater 302 to the controller 304, another electrical wire can be omitted, making the controller 304 equivalent to a "single harness controller".

The description of the present invention is only an example of the characteristics, so any variation that does not depart from the essence of the present invention falls within the scope of the present invention. Such variations should not be regarded as departing from the spirit and scope of the present invention.

<p>10Heating system</p><p>12Layer heater</p><p>14Dual line controller</p><p>16Power source</p><p>18Electrical wire</p><p>20Substrate</p><p>22Dielectric layer</p><p>24Resistance layer</p><p>26Protection layer</p><p>28Terminal liner</p><p>30Electrical Wire</p><p>40Style</p><p>50Power source</p><p>52Voltage measuring components</p><p>54Power Conditioner Components</p><p>56Microprocessor</p><p>58Communication components</p><p>60Transistor</p><p>62Second Polar Body</p><p>64First resistor</p><p>66Second resistor</p><p>68Operation amplifier circuit loop</p><p>70Amplifier</p><p>72Resistor</p><p>74Resistor</p><p>76Resistor</p><p>80Gateway control</p><p>82Field Effect Transistor</p><p>84Output control</p><p>86Bias control</p><p>88Heater input</p><p>90Firmware</p><p>100Linear regulator</p><p>102Transistor</p><p>104Diode</p><p>106Resistor</p><p>108Amplifier</p><p>110Amplifier</p><p>112Amplifier</p><p>114Amplifier</p><p>116Parallel resistance</p><p>116Analog Switch</p><p>118Analog Switch</p><p>120Transceiver</p><p>120Gateway control</p><p>122Optical isolator</p><p>124Optical isolator</p><p>126Optical isolator</p><p>150Hot runner nozzle</p><p>150'Hot runner nozzle</p><p>152Heat operating mold system</p><p>154Die winding groove</p><p>164umbilical cord</p><p>200Heating System</p><p>202'Heater</p><p>203Ontology</p><p>204Dual line controller</p><p>204'Dual line controller</p><p>205Electrical wire</p><p>205'Wire</p><p>206Substrate</p><p>208Resistance layer</p><p>208'Dielectric layer</p><p>210Resistance layer</p><p>210'Resistance layer</p><p>214Protection layer</p><p>214'Protection layer</p><p>216Terminal liner</p><p>216'Terminal liner</p><p>220Appearance</p><p>230Dual line module</p><p>232Layer heater</p><p>234Temperature Controller</p><p>236Temperature sensor input</p><p>238Power output</p><p>240Power Controller</p><p>300Heating System</p><p>302Layer heater</p><p>304controller</p><p>306Power source</p><p>308Electrical wire</p><p>310Shared loop device</p>

The present invention will be easier to fully understand through the following detailed description and accompanying drawings, in which: Figure 1 is a block diagram of a heating system based on the principles of the present invention; Figure 2 is a diagram of a layered heater based on the principles of the present invention An enlarged cross-sectional view; FIG. 3a is an enlarged cross-sectional view of a layered heater including a resistive layer and a protective layer according to the principles of the present invention; An enlarged cross-sectional view of a layered heater; Fig. 4a is a plan view of a resistive layer pattern constructed according to the content of the present invention; Fig. 4b is a plan view of a second resistive layer pattern constructed according to the principles of the present invention; Fig. 4c is a basis An elevation view of a third resistive layer pattern constructed based on the principles of the present invention; FIG. 5 is a block diagram of a dual-circuit control system based on the principles of the present invention; FIG. 6 is a simplified view of a dual-circuit control system constructed based on the content of the present invention Circuit schematic diagram; Figure 7 is a detailed circuit schematic diagram of a dual circuit control system constructed according to the present invention; Figure 8 is an injection molding die constructed according to the present invention applied to a heating system with additional hot runner nozzle injection The elevation view of the high-cavity molding system of the manufacturing system; Figure 9 is a side view of a hot runner nozzle heating system constructed according to the content of the present invention; A side cross-sectional view of a heating system for a runner nozzle; FIG. 11 is a side cross-sectional view of an alternative specific example of a hot runner nozzle heating system constructed according to the content of the present invention; A schematic diagram of the system; and Figure 13 is a block diagram of a heating system using a single wire harness according to the principles of the present invention.

In the drawings, the same reference numbers indicate the same parts.