System and method for direct heater diagnostics for hot melt liquid dispensing systems

Abstract

Systems and methods for direct heater diagnostics for hot melt liquid dispensing systems are disclosed. At least one of a current measurement or a voltage measurement is received from a corresponding current and / or voltage sensor positioned at an electrical circuit supplying electrical power to a heater associated with the dispensing system. The heater can be for an applicator or heated hose attached to the dispensing system, a melter of the dispensing system, or a pump of the dispensing system. A state of the electrical circuit is determined based on the at least one of the current or voltage measurement.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 903,423, filed September 20, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates generally to liquid distribution, and more specifically to direct diagnostics associated with heaters and related components of a hot melt liquid distribution system. Background Technology

[0004] Hot melt liquid dispensing systems have applications in a wide variety of situations. For example, such systems can apply hot melt adhesives during the manufacture of disposable hygiene products. As another example, hot melt liquid dispensing systems can apply hot melt adhesives to assemble and / or seal various types of packaging, such as paper-based packaging for food and beverages.

[0005] In an example configuration of a hot melt liquid dispensing system, a solid form of hot melt adhesive is supplied to a melter comprising a heated reservoir and / or a heated grid to produce molten hot melt adhesive. After heating, the molten adhesive can be pumped via a heated hose to an applicator comprising valves and nozzles, sometimes referred to as a dispensing “gun” or gun module. The applicator then dispenses the supplied molten adhesive, typically as a series of dots or lines, onto the desired surface or substrate. In many applications, the adhesive should be applied with precise positioning, timing, and volume. For example, insufficient volume of dispensed adhesive can result in ineffective bonding, while excessive volume can not only lead to material waste but also cause undesirable flow once the adhesive is applied to the surface.

[0006] Proper operation of the various heater components in a hot melt liquid dispensing system is one of the key factors in achieving the desired results in the dispensed adhesive. For example, a faulty heater component may fail to raise and / or maintain the molten adhesive at the specified temperature, resulting in an excessively high viscosity molten adhesive. This, in turn, can negatively affect the volume and placement of the dispensed adhesive. Conversely, an overheated molten adhesive may have insufficient viscosity. This could cause, for example, excessive fluid to be applied to the surface in each dispensing cycle. Low viscosity may also cause the dispensed adhesive to exhibit undesirable flow once applied to the surface. Excessive heat applied to the molten adhesive, such as in the melter, can also cause carbonization. Carbonized adhesive can lead to clogging of filters and applicators, discoloration of the dispensed adhesive, and seal breakage.

[0007] However, diagnosing various faults that can occur in the heater components and associated circuitry can present many challenges. For example, a fault can not be apparent for some time after it has occurred. For example, it can be several minutes before actual adhesive dispensing is negatively affected by a heater fault. It can not even be immediately apparent which of the various heater components involved (e.g., applicator heater, hose heater, or melter heater) has failed. In these cases, any issues with the heater components or associated circuitry can have to be inferred indirectly based on, for example, temperature behavior. Efficient heater diagnosis can also require a great deal of training and expertise on the part of the operator.

[0008] These shortcomings and other shortcomings are addressed in the present disclosure. SUMMARY

[0009] Disclosed herein are systems and methods for direct diagnosis associated with heaters and related components of hot melt liquid dispensing systems.

[0010] An example hot melt liquid dispensing system can include a melter configured to melt a solid or semi-solid material into a hot melt liquid. The hot melt liquid dispensing system can include a circuit configured to supply electrical power to a heater associated with the hot melt liquid dispensing system. The circuit can include at least one of a current sensor or a voltage sensor. The hot melt liquid dispensing system can include a controller. The controller can be configured to receive at least one of a current measurement or a voltage measurement from the at least one of the current sensor or the voltage sensor. The controller can be further configured to determine a state of the circuit based on the at least one of the current measurement or the voltage measurement.

[0011] In an example method, at least one of a current measurement or a voltage measurement can be received. The at least one of the current measurement or the voltage measurement can be associated with a circuit configured to supply electrical power to a heater associated with a hot melt liquid dispensing system. A state of the circuit can be determined based on the at least one of the current measurement or the voltage measurement. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description, serve to explain the principles of the methods and systems:

[0013] Figure 1A illustrates a perspective view of an adhesive dispensing apparatus according to embodiments of the present disclosure;

[0014] Figure 1B illustrates Figure 1A an alternative perspective view of the adhesive dispensing apparatus shown in

[0015] Figure 1C illustrates Figure 1A another alternative perspective view of the adhesive dispensing apparatus shown in

[0016] Figure 2 illustrates Figure 1A the adhesive dispensing apparatus shown in Figure 1A a cross-sectional view of the adhesive dispensing apparatus shown in

[0017] Figure 3 illustrates Figure 1A the adhesive dispensing apparatus shown in Figure 1A an alternative cross-sectional view of the adhesive dispensing apparatus shown in

[0018] Figure 4 illustrates a schematic diagram of a circuit board configuration in accordance with an embodiment of the present disclosure;

[0019] Figure 5 illustrates a dataflow graph in accordance with an embodiment of the present disclosure; and

[0020] Figure 6 illustrates a method flowchart in accordance with an embodiment of the present disclosure.

[0021] Aspects of the present disclosure will now be described in detail with reference to the drawings, where like reference numerals are used to refer to like elements throughout and in which: DETAILED DESCRIPTION

[0022] Systems and methods of the present disclosure relate to diagnostic techniques for heaters and associated components and elements of hot melt liquid dispensing systems. Although variously referred to as "heater diagnostics," the techniques described herein are not limited to diagnostics for a heater or heater system as a whole, but can also be used to diagnose various malfunctions, conditions, etc. of any component, subcomponent, or element associated with a heater or heater system. This includes heating elements, circuitry, wires, conductors, traces (e.g., PCB copper traces), fuses, power control switches, or any component, subcomponent, or element that interacts with or affects the operation of a heater. For example, the diagnostic techniques described herein can detect an open heating element or a blown fuse. As another example, the diagnostic techniques can detect a broken or disconnected wire leading from a temperature control board to a heating element.

[0023] Reference is made to Figures 1A to 3An adhesive dispensing apparatus 10 according to an embodiment of the present invention is shown. The adhesive dispensing apparatus 10 includes a melting module 12 and a control module 14 electrically and / or physically coupled to the melting module 12. The melting module 12 is configured to include components associated with receiving and melting solid adhesive, while the control module 14 is configured to include electronic components for controlling the operation of the melting module 12, each of which will be described in further detail below. Each of the melting module 12 and the control module 14 can be mounted to and supported by a base 18. The base 18 may include a metal body and is configured to be releasably coupled to each of the melting module 12 and the control module 14, such as by fasteners that may include bolts, screws, etc., but it is also contemplated that in other embodiments the melting module 12 and the control module 14 may alternatively be coupled to the base 18.

[0024] When the molten module 12 and the control module 14 are coupled to the base 18, a thermal gap 32 can be defined between the molten module 12 and the control module 14. The thermal gap 32 can be configured to minimize and / or substantially eliminate heat transfer from the molten module 12 to the control module 14 to prevent heat generated by the molten module 12 from damaging the electronic components contained in the control module 14. The thermal gap 32 may include the space between the molten module 12 and the control module 14. Furthermore, it is conceivable that the thermal gap 32 may also include materials configured to prevent heat transfer, such as various types of insulation, but no particular type of material or structure is required.

[0025] like Figure 1C As shown, the adhesive dispensing device 10 can define a specific occupancy area F. The lower end of the base 18 can define the occupancy area F, which can be defined as the cross-sectional shape and region defined by the lower end of the base 18. Additionally or alternatively, the occupancy area F can also be defined by the lower end of the assembly of the melting module 12 and the control module 14.

[0026] The adhesive dispensing device 10 may include a fusion module cover 26 and a control module cover 30, which are configured to provide selective access to a fusion module 12 and a control module 14, respectively. The fusion module cover 26 is configured to receive components of the fusion module 12 and at least partially insulate the fusion module 12 from the surrounding environment, while the control module cover 30 is configured to receive components of the control module 14 and insulate the control module 14 from the fusion module 12 and the surrounding environment. A previously described thermal gap 32 may be specifically defined between the fusion module cover 26 and the control module cover 30.

[0027] The control module 14 can include a controller 36. The controller 36 can include any suitable computing device configured to host software applications for monitoring and controlling various operations of the adhesive dispensing apparatus 10 as described herein. It should be appreciated that the controller 36 can include any suitable integrated circuit. In particular, the controller 36 can include a memory and be in signal communication with a human-machine interface (HMI) device 34. The memory can be volatile, such as some types of RAM, non-volatile, such as ROM, flash, etc., or a combination thereof. The controller 36 can include additional storage, e.g., removable storage and / or non-removable storage including, but not limited to, magnetic tapes, flash memory, smart cards, CD-ROMs, digital versatile disks (DVDs) or other optical storage, magnetic cassettes, magnetic tape storage or other magnetic storage devices, universal serial bus (USB) compatible memory, or any other medium that can be used to store information and that can be accessed by the controller 36. The memory of the controller 36 can be configured to store and call upon, as needed, various metering operations to be performed by the adhesive dispensing apparatus 10. The control module 14 can also include electrical connections 44 that extend through the control module cover 30, which can be configured to establish connections with the applicator and / or heated hose in order to transmit power to the applicator and / or hose and exchange communication signals.

[0028] As noted above, the control module 14 can include an HMI device 34 in signal communication with the controller 36. In the depicted embodiment, the HMI device 34 can include a display, such as an OLED screen. However, it is contemplated that the HMI device 34 can additionally or alternatively include various types of inputs that provide the ability to control the controller 36 via, for example, buttons, soft keys, a mouse, a voice-actuated control, a touchscreen, movement of the controller 36, visual cues (e.g., moving a hand in front of a camera on the controller 36), etc. The HMI device 34 can provide output including visual information, such as a visual indication of the current conditions within the adhesive dispensing apparatus 10, via a graphical user interface and provide acceptable ranges for these parameters via the display. Other output can include audio information (e.g., via a speaker), mechanically (e.g., via a vibrating mechanism), or a combination thereof. In various configurations, the HMI device 34 can include a display, a touchscreen, a keyboard, a mouse, a motion detector, a speaker, a microphone, a camera, or any combination thereof. The HMI device 34 can also include any suitable device for inputting biometric information, such as, for example, fingerprint information, retinal information, voice information, and / or facial feature information, in order to require specific biometric information to access the controller 36. In addition to the HMI device 34, the control module 14 can include a pressure dial 40 for readily displaying pressure readings, such as air pressure readings.

[0029] Additionally, the controller 36 can be in signal communication with a remote device 38 (schematically shown in Figure 1A FIG. 1) that is spaced apart from the control module 14. In one embodiment, the remote device 38 can include a display, such as an OLED display, that is spaced apart from the control module 14, although various types of conventional displays are contemplated. Alternatively, the remote device 38 can include an external computing device, examples of which include a processor, a desktop computing device, a server computing device, or a portable computing device, such as a laptop computer, a tablet, or a smartphone. Thus, the remote device 38 can provide an operator with the ability to interact with and control the controller 36 at a distance from the adhesive dispensing apparatus 10. The remote device 38 can be used as part of a cloud control system for the adhesive dispensing apparatus 10.

[0030] The melt module 12 will be described in greater detail. The melt module 12 includes a melter subassembly 75 that is configured to receive solid or semi-solid pellets of adhesive material from a manual fill by opening the top cap assembly 50 or from a fill by an automated fill mechanism. The melter subassembly 75 can heat the pellets to a specified temperature to form a molten adhesive. The melt module 12 can also include a pump 150 that is configured to pressurize and dispense the molten adhesive to one or more downstream applicators 144 (schematically shown in Figure 1B FIG. 1). The applicators 144 can also be referred to as dispenser guns. As used herein, an applicator 144 can refer to an applicator module that is configured with an applicator set.

[0031] The melt module 12 can include a manifold 140 that is configured to receive pressurized molten adhesive from the pump 150 and dispense the adhesive to one or more output ports 54 at an exterior portion of the manifold 140. Some portions of the manifold 140 and the pump 150 can be unitized as a single structural component (e.g., a manifold block). For example, a fluid chamber 158 portion of the pump 150 can extend into such a common structural component to supply pressurized molten adhesive to the manifold 140 portion. The manifold 140 can be configured with one or more heaters 148 (e.g., heating elements) to maintain the adhesive flowing through the manifold 140 at a specified temperature. The heaters 148 can also be used to re-melt any adhesive material that has cooled within the manifold 140.

[0032] The manifold 140 can include an outer manifold cover 142 having an opening for the output port 54. The manifold cover 142 can be integral with the manifold 140 or can be separately attachable and detachable. A heated hose 146 can be attached to the output port 54 to receive pressurized molten adhesive from the manifold 140 and carry the adhesive to an applicator 144 for dispensing. The applicator 144 and the heated hose 146 can each be configured with one or more heaters to maintain the adhesive at a specified temperature. The heaters of the applicator 144 and the heated hose 146 can also be used to re-melt any adhesive material that has cooled within the components. The heaters of the applicator 144 and the heated hose 146, as well as the heaters 148 of the manifold 140, can be in signal communication with the controller 36 to send status information (e.g., temperature readings) to the controller 36 and receive control signals from the controller 36. Each of the plurality of output ports 54 can be sealed using a plug when not connected to the applicator 144.

[0033] The melting module 12 can include a melter subassembly 75 that can define a receiving space 94 configured to receive solid material and to contain melted adhesive. A top wall of the melter subassembly 75 can define an opening 86 in communication with the receiving space 94 such that material can be manually placed into the receiving space 94 through the opening 86 when the top cover assembly 50 is pivoted to an open position, but the top cover assembly 50 can prevent adhesive from being introduced into the receiving space 94 through the opening 86 when the top cover assembly 50 is in the closed position. The receiving space 94 can be defined as a particular volume designed for a particular adhesive operation. For example, the receiving space 94 can be configured to receive 4 kilograms (kg) of adhesive, but other sizes are contemplated.

[0034] The melter subassembly 75 can also include a level sensor 98 disposed within the receiving space 94. In particular, the level sensor 98 can be attached to an inner surface of one of the side walls of the melter subassembly 75 and can be in signal communication with the controller 36 of the control module 14. The level sensor 98 can include a capacitive level sensor, but other types of level sensors are contemplated. In operation, the level sensor 98 can monitor a level of material within the receiving space 94 and send a signal to the controller 36 indicative of the level of adhesive.

[0035] The melter subassembly 75 can also include a heater 114 configured to melt the adhesive. Although depicted as being attached to the base of the melter subassembly 75 and extending at least partially through the base of the melter subassembly 75, the heater 114 can alternatively or additionally be attached to any portion of the melter subassembly 75. It should be appreciated that the heater 114 can include any type of known heating device configured to melt the adhesive within the melter assembly. The melter subassembly 75 can also include a plurality of fins 118 extending upward from the base and into the receiving space 94, where the fins 118 are configured to be heated by the heater 114 and provide increased surface area for heating and melting the adhesive. Although a particular number, arrangement, and configuration of fins 118 are shown, it is contemplated that the fins 118 can alternatively be configured as desired. Further, an outlet 122 can be defined in the base and in fluid communication with the receiving space 94, where the melted adhesive is configured to flow through the outlet 122 and exit the receiving space 94. A cage 130 can be positioned adjacent to the outlet 122, where the cage 130 is configured to act as a filter to prevent unmelted adhesive chunks of a particular size from reaching the outlet 122, as such adhesive chunks can congeal and clog the outlet 122 around the outlet 122.

[0036] The passageway 126 can extend from the outlet 122 to the pump 150 to supply the pump 150 with melted adhesive from the melter subassembly 75. The pump 150 can be a double acting piston pump, although other types of pumps are contemplated. The pump 150 can be operated to expel melted adhesive from one or more of the output ports 54 via the manifold 140. The pump 150 can be controlled by the controller 36 of the control module 14 to deliver a desired flow of melted adhesive through the output ports 54.

[0037] Figure 4 A schematic diagram 400 of various circuit boards (e.g., printed circuit boards (PCBs) or printed circuit assemblies (PCAs)) and other electronic components of the adhesive dispensing apparatus 10 shown in Figures 1A to 1C , Figure 2 and Figure 3 is illustrated. The circuit boards and other components can be mounted within the control module 14, particularly within the control module cover 30. Figure 4 One or more of the circuit boards and other components shown in Figure 2 and Figure 3 may implement the controller 36 shown in Figure 1Bheater of the heated hose 146) and applicator (e.g., Figure 1B The control module 14 includes a first temperature control board 413, a second temperature control board 414, and a third temperature control board 414 for temperature control (and supply of alternating current (AC) power) to the applicators 144). For user interaction, the control module 14 includes a user interface (UI) board 406, a membrane switch panel 407, and a USB (universal serial bus) interface 404. Related to pump operation and control, the control module 14 also includes a pump solenoid valve 409, a barometric sensor board 410, a pump pressure control valve 411, and a pump direction solenoid valve 412.

[0038] In some cases, the various types of circuit boards described herein can include one or more sub-boards. Additionally or alternatively, the circuit boards can be collectively referred to as several integrated circuit boards. The circuit boards (including any constituent sub-boards or integrated boards) can be variously referred to herein as modules. For example, the first temperature control board 413 can refer to a temperature control module.

[0039] To power the adhesive dispensing apparatus 10 and any connected heated hoses and applicators, a power distribution board 401 receives incoming AC power via an AC connection point 441. The heated hoses and applicators are referred to herein as “H / As”. The AC power is provided to a DC power source 408 via a connection point 445 on the power distribution board 401 and a connection point 446 on the DC power source 408. From there, the DC power source 408 provides DC power (e.g., 24V) to the control board 402 via a connection point 447 on the DC power source 408 and a connection point 448 on the control board 402.

[0040] For AC power to the internal heaters of the melting module 12, the AC power is sent to the first temperature control board 413 via a connection point 443 on the power distribution board 401 and a connection point 422 on the first temperature control board 413. For AC power to the heaters of the first and second H / As, the AC power is sent to the first temperature control board 413 via a connection point 443 on the power distribution board 401 and a connection point 426a on the first temperature control board 413. In cases where the system includes more than two applicators (up to six in the illustrated embodiment), the AC power is sent to a power distribution expansion board 416 via a connection point 451 on the power distribution board 401 and a connection point 452 on the power distribution expansion board 416. For AC power to the heaters of the third and fourth H / As, the AC power is sent to the second temperature control board 414 via a connection point 455 on the power distribution expansion board 416 and a connection point 426b on the second temperature control board 414. For AC power to the heaters of the fifth and sixth H / As, the AC power is sent to the third temperature control board 415 via a connection point 456 on the power distribution expansion board 416 and a connection point 426c on the third temperature control board 415.

[0041] The power distribution board 401 is configured with a plurality of fuses 444 associated with corresponding power connections of the power distribution board 401. If the current on the associated power connection exceeds a threshold current, one of the fuses 444 may blow. The power distribution board 401, as well as many other boards, includes several indicators, such as LED indicators. These indicators may reflect various conditions and states associated with the various circuits of the adhesive dispensing device 10, control signals communicating between the boards and other components of the adhesive dispensing device 10, etc. As an example, an indicator 442 on the power distribution board 401 may illuminate when AC power is available to the power distribution board 401. To name just a few examples, other indicators may illuminate or change color to indicate control signal availability, board status, power availability, or component status (e.g., pump status or heater status).

[0042] Control board 402 typically performs control functions over many aspects of adhesive dispensing equipment 10 and associated components (e.g., H / A). For example, control board 402 may generate pump pressure control signals, control signals for activating or deactivating the filling system, and power relay control signals to power distribution board 401. Control board 402 may provide a communication interface (wired and / or wireless) with external control systems such as cloud control systems. Control board 402 may include a CPU to execute software or other such computer instructions, such as for heater diagnostics. Control board 402 may connect to USB interface 404 to receive, for example, preset recipes and output, for example, event logs.

[0043] UI board 406 and membrane switch panel 407 can achieve Figure 1A and Figure 1C The HMI device 34 shown has a membrane switch panel 407 that can receive direct manual input from the user. A UI panel 406 processes the user input and transmits it to a control panel 402. The control panel 402 can then activate the user input. For example, the user can input a temperature setpoint for the heater 114 of the melt subassembly 75 using the membrane switch panel 407, and via the UI panel 406, the control panel 402 can maintain that temperature setpoint for the heater 114.

[0044] The first temperature control board 413 is configured to supply AC power to and control internal heaters of the fusing module 12. Such internal heaters can include the heater(s) (e.g., heater 114) of the fuser subassembly 75 that initially melt the adhesive material provided to the receiving space 94. Such internal heaters can also include the heater(s) (e.g., heater 148) within the manifold 140 that maintain the molten adhesive at a specified temperature as the molten adhesive is pumped and dispensed to the lead channels (e.g., output ports 54) from the manifold 140 to the attached H / As. The first temperature control board 413 supplies AC power to the internal heaters via connection points 424. Temperature input signals from temperature sensors (e.g., resistance temperature detectors (RTDs)) positioned at the internal heaters are received at the first temperature control board 413 via connection points 450. Based on the temperature input signals of the internal heaters and using one or more controllers (e.g., PID controllers) implemented at the first temperature control board 413, the first temperature control board 413 supplies AC power to the internal heaters to maintain the heaters at respective temperature set points (e.g., within respective threshold ranges). The one or more controllers of the first temperature control board 413 can be implemented on a per-heater basis. Additionally or alternatively, one controller of the first temperature control board 413 can be used for the heater(s) of the fuser subassembly 75 and another controller can be used for the heater(s) of the manifold 140. The AC power can be supplied intermittently (e.g., controlled by a switch). Respective duty cycles of the internal heaters can be based on the supplied AC power.

[0045] The first temperature control board 413 is also configured to supply AC power to and control the respective heaters of the first and second H / As. The heated hoses of the first and second H / As (and other H / As described herein) are connected to respective outlets 54 of the manifold 140 to receive molten adhesive. The first temperature control board 413 supplies AC power to the heaters of the first and second H / As via connection points 428a and 429a, respectively, of the first temperature control board 413. The connection points 428a, 429a are also used to receive temperature input signals from temperature sensors positioned at the heaters of the first and second H / As, respectively. Thus, the connection points 428a, 429a comprise input / output connections. Similar to the internal heater control, the first temperature control board 413 implements one or more controllers (e.g., PID controllers) for the heaters of the first and second H / As that cause AC power to be supplied to the heaters of the first and second H / As, respectively, based on the input temperature control signals. The AC power to the heaters of the first and second H / As can be supplied intermittently (e.g., controlled by a switch), and the duty cycle of the respective heaters of the first and second H / As can be based on the AC power supplied to the heaters. The heaters of the first H / A and the heaters of the second H / A can be independently controlled and powered from one another. For example, a separate controller can be implemented for each H / A or for each individual heater thereof. The controllers can also be implemented on a per-applicator or per-heated hose basis. A single controller can be implemented to control both the internal heater and the heaters of the first and second H / As.

[0046] With respect to H / A heater control for additional H / As, the second temperature control board 414 and the third temperature control board 415 can function similarly to the first temperature control board 413. That is, the second temperature control board 414 and the third temperature control board 415 can use separately implemented controllers and control AC power supply to the heaters of the associated H / As based on temperature input signals received from the heaters. In particular, the second temperature control board 414 is configured with input / output connection points 428b that receive temperature input signals from temperature sensors of the third H / A’s heaters and output AC power supply to the third H / A’s heaters. The second temperature control board 414 is also configured with input / output connection points 429b that receive temperature input signals from temperature sensors of the fourth H / A’s heaters and output AC power supply to the fourth H / A’s heaters. The second temperature control board 414 implements one or more controllers to control the AC power supplied (e.g., intermittently) to the third and fourth H / A’s heaters based on the respective temperature input signals from the heaters. The duty cycle of the third or fourth H / A’s heaters can be set according to the AC power received intermittently from the second temperature control board 414. The power control can cause the heaters to reach or maintain a specified temperature setpoint (e.g., threshold range).

[0047] The third temperature control board 415 is similarly configured with input / output connection points 428c, 429c that receive temperature input signals from and supply AC power to the respective heaters of the fifth and sixth H / As. The third temperature control board 415 implements one or more controllers to control the AC power supplied to the fifth and sixth H / A’s heaters. The heater control is based on the received temperature input signals. The AC power can be supplied to the heaters intermittently, and the duty cycle of the heaters can be regulated to reach or maintain a specified temperature setpoint (e.g., threshold range). Other embodiments can include additional temperature control boards to accommodate additional H / As. However, other embodiments can include only the first temperature control board 413, or only the first temperature control board 413 and the second temperature control board 414, if fewer H / As are needed.

[0048] The first temperature control board 413, the second temperature control board 414, and the third temperature control board 415 can each include one or more sub-boards or PCAs. For example, the first temperature control board 413, the second temperature control board 414, and the third temperature control board 415 can each include a base board and an additional or integrated sub-board or PCA. The base board can include connection points for receiving AC power from the power distribution board 401 and connection points for providing AC power and control signals to the corresponding heater(s). The sub-board or PCA can implement temperature control for the corresponding heater(s) (e.g., a PID controller), as well as send and receive communication signals to or from various other boards or components, such as other temperature control boards or the control board 402. The second temperature control board 414 includes a sub-board or PCA 414a, and the third temperature control board 415 includes a sub-board or PCA 415a.

[0049] Each of the first temperature control board 413, the second temperature control board 414, and the third temperature control board 415 is configured with a set of one or more current sensors and / or a set of one or more AC voltage sensors. The first temperature control board 413, the second temperature control board 414, and the third temperature control board 415 each respectively include a set of [one or more] current sensors 438a, 438b, 438c and a set of [one or more] voltage sensors 440a, 440b, 440c. The set of current and / or voltage sensors can be used for direct diagnostics of the heaters and associated components and elements (e.g., heating elements, heater circuitry, conductors, wires, PCB traces, connectors, fuses, power control switches, etc.). The current and / or voltage measurements can be taken in real-time or near real-time for direct heater diagnostics. The current sensors can include current sensor transformers (e.g., toroidal transformers) or inline current sensors, such as Hall effect sensors. The voltage sensors can include an optical isolator-based circuit configured to take one or more voltage measurements. The voltage measurements can include an indicator of the presence or absence of AC voltage, an AC voltage magnitude, and / or an AC line frequency. Although the set of sensors is represented as a single element in Figure 4 The set of current sensors and / or the set of voltage sensors can include one or more sensors of the respective type, although the set of sensors is represented as a single element in

[0050] It should also be understood that the diagnostic techniques described herein can be performed based on current measurements (to the exclusion of voltage measurements), voltage measurements (to the exclusion of current measurements), or both current and voltage measurements. Thus, although the specific example described herein is based on current measurements, the diagnostic techniques described herein can be performed based on voltage measurements, current and voltage measurements, or a combination thereof. Figure 4The first, second, and third temperature control boards 413, 414, and 415, respectively, are each configured with both current and voltage sensors, although the present disclosure is not so limited, and the control boards can be configured with only current sensor(s), voltage sensor(s), or both current and voltage sensor(s).

[0051] As described above, the first temperature control board 413 includes a set of current sensors 438a and a set of voltage sensors 440a. The set of current sensors 438a measures the current of the AC power circuit(s) supplying AC power to the internal heater and the heaters of the first and second H / As connected to the first temperature control board 413. The set of voltage sensors 440a takes voltage measurements (e.g., voltage presence / absence, voltage magnitude, and / or alternating current (AC) line frequency) of the AC power circuit(s). In some embodiments, additional sets of current and voltage sensors can be provided to take current and voltage measurements of the AC power circuit(s) supplying AC power to the internal heater separately from the current and voltage measurements of the first and second H / As.

[0052] The set of current sensors 438a and the set of voltage sensors 440a can each include a sensor that generally takes current and voltage measurements, respectively, of the AC power circuit at the first temperature control board 413. Alternatively, the set of current sensors 438a and the set of voltage sensors 440a can each include two sensors: one current sensor and one voltage sensor to take current and voltage measurements, respectively, of the AC power circuit supplying power to the internal heater (e.g., at connection point 422); and a second current sensor and a second voltage sensor to take current and voltage measurements, respectively, of the AC power circuit supplying power to the heaters of the first and second H / As (e.g., at connection point 426a). Further, the set of current sensors 438a and the set of voltage sensors 440a can separately take current and voltage measurements of the AC power circuit supplying power to the first H / A (e.g., at connection point 428a) and the AC power circuit supplying power to the second H / A (e.g., at connection point 429a), respectively. That is, the set of current sensors 438a and the set of voltage sensors 440a can take current and voltage measurements on a per-channel basis. Further, current and voltage measurements can be taken on a per-heater basis. The measured current and voltage measurements can be communicated back to the control board 402, e.g., for direct heater diagnostics.

[0053] Similarly, the second temperature control board 414 is configured with a set of current sensors 438b and a set of voltage sensors 440b, and the third temperature control board 415 is configured with a set of current sensors 438c and a set of voltage sensors 440c. The set of current sensors 438b and the set of voltage sensors 440b take current and voltage measurements, respectively, of the AC power circuit(s) supplying power to the heaters of the third and fourth H / As connected to the second temperature control board 414. Likewise, the set of current sensors 438c and the set of voltage sensors 440c take current and voltage measurements, respectively, of the AC power circuit(s) supplying power to the heaters of the fifth and sixth H / As connected to the third temperature control board 415. The current sensor sets 438b, 438c and the voltage sensor sets 440b, 440c can each include a single sensor of the respective type and can generally take current and voltage measurements of the AC power circuit at the respective second and third temperature control boards 414, 415 (e.g., at the connection points 426b, 426c). Alternatively, the set of current sensors 438b and the set of voltage sensors 440b on the second temperature control board 414 can each include two sensors; a first current sensor and a first voltage sensor can take current and voltage measurements, respectively, of the AC power circuit supplying power to the heaters of the third H / A (e.g., at the connection point 428c), and a second current sensor and a second voltage sensor can take current and voltage measurements, respectively, of the AC power circuit supplying power to the heaters of the fourth H / A (e.g., at the connection point 429c). The set of current sensors 438c and the set of voltage sensors 440c of the third temperature control board 415 can be similarly configured with respect to the AC power circuit supplying power to the heaters of the fifth and sixth H / As connected to the third temperature control board 415.

[0054] It will be appreciated that the first, second, and third temperature control boards 413, 414, 415 implement independent, distributed temperature control and AC heater power supply for the adhesive dispensing apparatus 10. Many benefits are realized by this configuration. For example, the temperature control boards provide electrical isolation between the internal heaters and the H / A heaters and other circuit boards and components of the adhesive dispensing apparatus 10, particularly those that operate at relatively low voltages as compared to the high voltage AC power provided to the various heaters (e.g., the low voltage control board 402). Thus, an AC fault in the circuit supplying power to the heaters, a temperature signal line from a temperature sensor, or the temperature control board itself will not propagate through the affected temperature control board, thereby preventing damage to other boards or components.

[0055] Moreover, the temperature control board configuration provides modularity. For example, if one temperature control board becomes defective, it can be swapped out for a new temperature control board with relatively little effort. The independent temperature and power control aspects of the other temperature control boards are not affected. Moreover, the adhesive dispensing apparatus 10 can be customized to accommodate various numbers of H / As depending on current or future needs. As noted above, another temperature control board can be added to the configuration shown in Figure 4 to control additional H / As. Conversely, if fewer numbers of H / As are needed for the present application, temperature control boards can be removed.

[0056] Figure 5 An example data flow diagram 500 related to direct heater diagnostics is illustrated, which can be used with the adhesive dispensing apparatus 10 of Figures 1A to 1C , Figure 2 and Figure 3 . In particular, heater diagnostics can be performed to determine the status of the circuitry supplying power (e.g., AC power) to the heaters of the adhesive dispensing apparatus 10 or heaters associated with the adhesive dispensing apparatus 10. Although primarily discussed in the context of hot melt adhesive, the data flow diagram 500 (and generally the disclosure) can be applicable to any hot melt liquid or hot melt liquid dispensing system.

[0057] First, a current sensor 502 (such as a current transformer) is coupled to the heater power supply circuitry. The current sensor 502 is configured to measure the current supplied to the heater(s) of the adhesive dispensing apparatus 10. The current sensor 502 is coupled to a microcontroller 504 (e.g., a microcontroller unit (MCU)) that is configured to receive the measured current from the current sensor 502. Figure 4One or more current measurements 506 are received from the current sensors 438a, 438b, 438c (any of which can be the current sensor 438a, 438b, 438c in FIG. 4). Additionally or alternatively, one or more voltage measurements 508 are received from the voltage sensors 504 (such as any of the voltage sensors 440a, 440b, 440c). As described above, the diagnostic techniques described herein can be performed using only the current sensor(s) 502, only the voltage sensor(s) 504, or both the current sensor 502 and the voltage sensor 504 (and similarly with respect to the current measurements 506 and the voltage measurements 508). The current sensor 502 and the voltage sensor 504 can be associated with a heater or an associated component of the adhesive dispensing apparatus 10. For example, the heater can include the heater 114 of the melter subassembly 75, the heater 148 of the manifold 140, a heater connected to the applicator 144 of the adhesive dispensing apparatus 10, or a heater of the heated hose 146 connecting the applicator 144 to the adhesive dispensing apparatus 10. The current measurements 506 can include current flow (e.g., amperes) in an electrical heater circuit supplying electrical power to the heater associated with the current sensor 502. The voltage measurements 508 can include a voltage presence / absence indicator, a voltage magnitude, an AC line frequency, and any combination thereof. The current measurements 506 and the voltage measurements 508 can include a plurality of measurements, such as measurements taken at regular intervals over a period of time. This can allow for predictive analysis, such as to preemptively replace or repair a part before a failure occurs.

[0058] The current sensor 502 and the voltage sensor 504 can be positioned on the first temperature control plate 413, the second temperature control plate 414, and / or the third temperature control plate 415. Using the first temperature control plate 413 as an example, the first temperature control plate 413 can at least partially define an electrical heater circuit supplying power to one of an internal heater or a heater of the first or second H / A connected to the first temperature control plate 413. For the internal heater, the electrical heater circuit can include a connection point 422 receiving AC power from the power distribution board 401, a connection point 424 transferring the AC power to the internal heater, and one or more heating elements of the internal heater. For the heater of the H / A, the electrical heater circuit can include a connection point 426a on the first temperature control plate 413 receiving AC power from the power distribution board 401, one of connection points 428a, 429a on the first temperature control plate 413 transferring the AC power to the heater of the H / A, and one or more heating elements of the heater of the H / A. The connection point 422 or 426a of the first temperature control plate 413 via which it receives AC power can be considered a voltage source or a current source of the electrical heater circuit. The heating elements of the heater can be considered resistive or electrical loads driven by the voltage source or the current source.

[0059] In some examples, the electrical heater circuit can additionally or alternatively include one or more of the power distribution components on the power distribution board 401. For example, the electrical heater circuit can include one or more of the plurality of fuses 444 as applicable. As another example, the electrical heater circuit can include the AC connection points 441. If the power distribution extension board 416 is used, the electrical heater circuit can include the power distribution components of that board, including the connection points 452 (and the corresponding connection points 451 on the power distribution board 401) for receiving AC power from the power distribution board 401 and the connection points 455, 456 for sending AC power to the second temperature control board 414 and the third temperature control board 415, respectively.

[0060] The electrical heater circuit for purposes of heater diagnostics can be specific to a particular heater. For example, the electrical heater circuit can be specific to carrying AC power to a particular channel of a heater. The electrical heater circuit can include a single-channel electrical heater circuit. Additionally or alternatively, two or more heaters (e.g., for H / A, a heated hose heater and an applicator heater) can be supplied with AC power via a common electrical heater circuit. For example, the electrical heater circuit can be specific to a dual-channel connection for supplying power to a heated hose / applicator pair (H / A). The electrical heater circuit can include a dual-channel electrical heater circuit. Additionally or alternatively, all heaters connected to a temperature control board can share an electrical heater circuit. For example, the electrical heater circuit associated with the first temperature control board 413 can provide AC power to the heaters of the first H / A, the heaters of the second H / A, and the internal heaters for the melter and manifold. The electrical heater circuit can include a four-channel or six-channel electrical heater circuit.

[0061] Based on the current measurements 506 and / or the voltage measurements 508, heater diagnostics 510 are performed to determine a status of the electrical heater circuit of the subject heater (i.e., heater circuit status 512). The heater diagnostics 510 can be performed in real-time or near real-time, or the heater diagnostics 510 can be performed at certain defined intervals (e.g., every 10 seconds, every 30 seconds, or every minute). The heater diagnostics 510 can be performed by one or more of the controller 36, the control board 402, the first temperature control board 413, the second temperature control board 414, or the third temperature control board 415, or a remote device (e.g., the remote device 38 of FIG. 1). Figure 1A

[0062] ​The heater diagnostics 510 can include a comparison of the current measurements 506 to a pre-defined current (e.g., amperage) threshold range. Similarly, the heater diagnostics 510 can include a comparison of the voltage measurements 508 to one or more pre-defined voltage threshold ranges. The voltage threshold range(s) can be with respect to voltage presence / absence, voltage magnitude, AC line frequency, or a combination thereof. The heater diagnostics 510 can be performed based on the timing of the current measurements 506 and / or the voltage measurements 508. For example, the AC power to the heater can be intentionally turned on and off intermittently to maintain the heater at a temperature setpoint. The heater diagnostics 510 can include determining whether any current is flowing or has flowed through the electric heater circuit to the heater when the heater is intended to be deactivated.

[0063] The heater diagnostics 510 can be performed using multiple current measurements 506 and / or voltage measurements 508 over a period of time (i.e., a time series of measurements). For example, using a time series of current measurements 506 and / or voltage measurements 508, a predictive analysis with respect to the current and / or voltage can be performed. As some examples, the predictive analysis can include linear trend estimation, moving average, weighted moving average, or linear regression techniques. Based on the time series of current measurements 506 or voltage measurements 508, a trend or predicted value can be determined in which the current measurements 506 or voltage measurements 508 are expected to fall outside of the corresponding threshold range. Additionally or alternatively, a rate of change of the current measurements 506 or voltage measurements 508 over the time series can be determined and compared to the corresponding threshold range.

[0064] While the heater diagnostics 510 can be performed based on only one of the current measurements 506 or voltage measurements 508, in some instances it can be beneficial for the heater diagnostics 510 to utilize both measurements. For example, a current measurement 506 of zero amperes can be caused by a problem with the heating element or associated wiring of the heater, or can be caused by any of a variety of issues related to the voltage supply, such as a blown fuse, a disconnected AC power connection from the power distribution panel 401, or a failure at the external AC power source. But by using both the current measurements 506 and voltage measurements 508, the heater diagnostics 510 can eliminate the latter voltage supply issues as a potential cause of the lack of current (assuming that the voltage measurements 508 do indicate proper voltage in the heater circuit). That is, the heater diagnostics 510 can separate any issues with the source voltage supply from issues with the load (e.g., the heater element) attached thereto, and vice versa. Furthermore, the heater diagnostics 510 can use the voltage measurements 508 to perform two or more of a voltage presence / absence indicator, a voltage magnitude, or an AC line frequency.

[0065] The heater diagnostic 510 is used to determine a heater circuit status 512. The heater circuit status 512 can indicate various fault conditions related to the electrical heater circuit of the heater. For example, the heater circuit status 512 can indicate that the current in the electrical heater circuit is outside (e.g., above or below) a current threshold range. Similarly, the heater circuit status 512 can indicate that the voltage amplitude or AC line frequency in the heater circuit is outside (e.g., above or below) a corresponding voltage threshold range. The heater circuit status 512 can indicate the presence or absence of voltage in the heater circuit.

[0066] The heater circuit status 512 can indicate additional fault conditions related to excessive, insufficient, or non-existent current or voltage. For example, the heater circuit status 512 can indicate a blown / faulty fuse, such as one of the plurality of fuses 444 on the power distribution board 401, a fuse on one of the first temperature control board 413, the second temperature control board 414, or the third temperature control board 415, or a fuse on the power distribution expansion board 416. A blown fuse can be associated with a lack of measured voltage and current at the corresponding voltage or current sensor.

[0067] As another example, the heater circuit status 512 can indicate an open heater element of the heater or a disconnected or broken wire from one of the first temperature control board 413, the second temperature control board 414, or the third temperature control board 415 to the heater. Such an open heater element or disconnected or broken wire can be associated with the presence of voltage at the voltage sensor and an excessively low current (including no current or a current very close to zero) across the heater element.

[0068] As another example, the heater circuit status 512 can indicate an intermittent fault, including an intermittent wire fault in the connection between one of the first temperature control board 413, the second temperature control board 414, or the third temperature control board 415 and the associated heater or an intermittent wire fault in the AC voltage supply. Such an intermittent fault can be associated with intermittent or fluctuating current and / or voltage readings. For example, the current measurements 506 and / or the voltage measurements 508 can individually or in combination with the presence of current and / or voltage at an expected time indicate the presence of current and / or voltage at an unexpected time.

[0069] As another example, the heater circuit status 512 can indicate an overload of a TRIAC (Triode for Alternating Current) circuit of the heater circuit. The overload of the TRIAC circuit can be associated with an excessive current (e.g., current across the heater element). The heater circuit status 512 can indicate a shorted TRIAC, which can be associated with current flow at an unintended time. As another example, the heater circuit status 512 can indicate an incorrect AC line frequency.

[0070] As another example, the heater circuit status 512 can indicate a predicted failure condition (including a probability interval for such a predicted failure condition). The predicted failure condition can be based on a predictive analysis performed in the heater diagnostics 510. Relatedly, the heater circuit status 512 can indicate a trend in the current measurements 506 and / or the voltage measurements 508 over a period of time. Thus, the heater circuit status 512 can indicate a predicted time of failure of a component of the adhesive dispensing apparatus 10, such as a component related to heater power and control. For example, the predicted time of failure can be for a heating element. The predicted failure condition, trend, or predicted time of component failure can be used to perform preventative maintenance, repair, or replacement.

[0071] The heater circuit status 512 is not limited to only failure conditions, but can also include general conditions of the heater circuit (e.g., expected conditions or non-failure conditions). For example, the heater circuit status 512 can indicate that the current measurements 506 or the voltage measurements 508 are within an acceptable threshold range. As another example, the heater circuit status 512 can indicate that a predicted condition is within an acceptable threshold range or that a current or voltage trend is flat or stable.

[0072] Based on the heater circuit status 512, a notification 514 can be generated. The notification 514 can indicate the heater circuit status 512. Some heater circuit statuses 512 can warrant the notification 514, while other heater circuit statuses can not warrant the notification 514. For example, when the heater circuit status 512 indicates a failure condition, the notification 514 can be generated. However, when the heater circuit status 512 indicates a non-failure condition, the notification 514 can not be generated.

[0073] The notification 514 can be in the form of an email or text message to an operator or other production facility personnel. The notification 514 can be in the form of an alert or message on the HMI device 34 of the adhesive dispensing apparatus 10 to notify the operator. The notification 514 can also be in the form of an audio alert. The notification 514 can prompt the operator to take corrective action, particularly when the heater circuit status 512 can cause damage to the adhesive dispensing apparatus 10. For example, an excessive current flowing through a heater element can cause damage to the heater element.

[0074] The adhesive dispensing device 10 and / or any external controller can initiate corrective actions based on the heater circuit status 512, particularly when the heater circuit status 512 indicates a fault condition. For example, if a fault associated with the heater of the applicator or attached heated hose is identified, the applicator can be automatically deactivated. Because the temperature controls and AC power supply to the heater are independently distributed among the first temperature control board 413, the second temperature control board 414, and the third temperature control board 415, corrective actions (e.g., deactivation) can be taken against only one or two of the first temperature control board 413, the second temperature control board 414, and the third temperature control board 415 without affecting the functionality of the other temperature control boards. For example, if a damage fault condition associated with the second temperature control board 414 is indicated, the AC power supply to the second temperature control board 414 can be cut off, while AC power can still be supplied to the first temperature control board 413 and the third temperature control board 415.

[0075] Figure 6 The diagram illustrates a system for at least partially performing tasks related to the hot melt liquid dispensing system (e.g., Figures 1A to 1C , Figure 2 and Figure 3 An example method flowchart of a method 600 for diagnosing the direct heater of an adhesive dispensing device 10). Such diagnosis may generally involve the heater, but may also involve various components, sub-components, and other elements associated with the heater of the hot melt liquid dispensing system and identify faults therein. As examples, this includes heating elements, heater circuits, conductors, wires, traces (e.g., PCB copper traces), connectors, fuses, power control switches, etc. The hot melt liquid dispensing system may include: a melter (e.g., melt module 12 or melter sub-assembly 75) configured to melt solid or semi-solid materials into a hot melt liquid; and a pump (e.g., pump 150) configured to pump the hot melt liquid to an associated applicator (e.g., applicator 144). The method may be at least partially controlled by a controller of the hot melt liquid dispensing system (such as...). Figure 3 Controller 36 Figure 4 Control panel 402 Figure 4 One or more of the first temperature control board 413, the second temperature control board 414, or the third temperature control board 415, or Figure 1A The remote device 38) is used to execute.

[0076] At step 602, at least one of a current measurement result or a voltage measurement result is received. The current measurement result and / or voltage measurement result may be associated with a circuit configured to supply electrical power (e.g., AC power) to a heater associated with a hot melt liquid distribution system (“distribution system”). The current measurement result (e.g., voltage measurement result) may be obtained from a current sensor located at the circuit.Figure 4 The current sensor (one of 438a, 438b, or 438c) receives current measurement results. The current measurement results can indicate the number of amperes flowing through the circuit. Multiple current measurement results may be included. Current measurement results can be acquired at regular time intervals, thus creating a time series of current readings.

[0077] A voltage sensor located at the circuit (e.g., Figure 4 The voltage sensor (one of 440a, 440b, 440c) receives voltage measurement results. The voltage measurement results may include one or more of voltage amplitude, voltage presence / absence, or AC line frequency. Multiple voltage measurement results may be included. Voltage measurement results may be acquired at regular time intervals, thus forming a time series of voltage readings. Current measurement results and voltage measurement results may be acquired at the same time(s) or at different times(s).

[0078] The heater may include a heater for the applicator, a heater configured to deliver hot melt liquid to a heated hose (e.g., heated hose 146) of the applicator, a heater for the melter, or a heater configured to direct hot melt liquid from a pump to a distribution system manifold (e.g., manifold 140) of the applicator.

[0079] At step 604, the state of the circuit is determined based on at least one of the current measurement result or the voltage measurement result (e.g., Figure 5 (The heater circuit state 512). In some embodiments, the circuit state can be determined based on both current measurement results and voltage measurement results. The circuit state can be determined according to... Figure 5 The heater diagnostics 510 determine this. The state of the circuit can be determined by comparing(one or more) current and / or voltage measurements, respectively, with predetermined current and / or voltage threshold ranges. Determining the state of the circuit may include performing a predictive analysis on at least one of the current or voltage measurements. For example, determining the state of the circuit may include determining the rate of change of at least one of the current or voltage measurements over a period of time. Determining the rate of change of the current and / or voltage measurements may reveal a trend in the current and / or voltage measurements from which predicted current or voltage measurements can be determined.

[0080] The state of a circuit may include one or more of the following: a blown fuse, a disconnected wire, a broken wire, an intermittent fault, a voltage amplitude outside the threshold range, an AC line frequency outside the threshold range, an open-circuit heater element, a current outside the threshold range, and current flow occurring outside a predetermined time period.

[0081] In some embodiments, the distribution system may include a power distribution module (e.g., Figure 4 The system includes a power distribution board 401, a low-voltage control module (e.g., a control board 402), and a temperature control module (e.g., a first temperature control board 413, a second temperature control board 414, or a third temperature control board 415). The temperature control module can be connected to the heater. The temperature control module can perform temperature control functions (e.g., a PID controller) on the heater based on temperature readings from temperature sensors on the heater. The temperature control module can supply (and control) power to the heater. The operation of the heater (e.g., duty cycle) can be controlled by switching or intermittently supplying power to the heater. Current and voltage sensors can be located on the temperature control module. The temperature control module can at least partially implement or define the circuitry for supplying power to the heater. For example, the temperature control module may include a power connection point for receiving power from the power distribution module and a power connection point for transmitting power to the heater. The circuitry may include these two power connection points, as well as the heater itself (e.g., a heating element) and wire connections (e.g., power and temperature control connections) between the temperature control module and the heater. The circuitry may include wire connections between one or more temperature sensors at the heater and one or more temperature control modules. The circuit may include power supply elements on the power distribution module (including power input from an external power source), power connection points to the temperature control module, and various fuses associated with the power supply to the temperature control module and / or the heater.

[0082] Method 600 may also include circuit-based state generation notification (e.g., Figure 5 (Notification 514). Notifications can indicate the status of the circuit. Notifications may include emails, text messages, notifications or indicators on the user interface of a distribution system or remote control system, or audio alarms.

[0083] Those skilled in the art will understand that the systems and methods disclosed herein can be implemented via a computing device, which may include, but is not limited to, one or more processors, system memory, and a system bus that connects various system components, including the processors, to the system memory. For example, a computing device (e.g., a controller) may include one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the computing device to perform one or more of the methods or techniques described herein, such as method 600.

[0084] For purposes of illustration, the application and other executable program components such as operating systems are illustrated herein as discrete blocks, although it is understood that such programs and components can reside at various times in different storage components of the computing device, and that the various programs and components can be executed by a data processor(s) of the computer. Implementation of the services software can be stored on or transmitted across some form of computer readable media. Any of the disclosed methods can be performed by computer readable instructions embodied on a computer readable medium. Computer readable media can be any available media that can be accessed by a computer. By way of example, and not meant to be limiting, computer readable media can comprise "computer storage media" and "communications media." "Computer storage media" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Exemplary computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Application programs, etc. and / or the storage media can be implemented at least in part in a remote system.

[0085] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of the ranges are significant, both in relation to the other endpoint, and independently of the other endpoint.

[0086] Unless specifically stated otherwise, any methods described herein are not intended to be construed as requiring their steps be performed in any particular order. Accordingly, in an embodiment, the steps of a method can be performed in any order or simultaneously, unless otherwise specified in the claims or specification. This applies equally to any method claims and any steps within a method claim. This is intended to cover any and all permutations of method steps that are present in any claim.

[0087] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope or spirit. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit being indicated by the following claims.

Claims

1. A hot melt liquid dispensing system comprising: a melter comprising at least one internal heater configured to melt a solid or semi-solid material into a hot melt liquid; at least one heater implemented in at least one or more of an adhesive applicator, an adhesive manifold, and / or a heated adhesive hose; circuitry associated with the hot melt liquid dispensing system, the circuitry comprising a plurality of temperature control circuits; each of the plurality of temperature control circuits comprising a set of current sensors and a set of voltage sensors; the set of current sensors configured to measure a current of power supplied to the at least one internal heater and / or the at least one heater; the set of voltage sensors configured to measure a voltage of power supplied to the at least one internal heater and / or the at least one heater; and a controller configured to: receive, from the set of current sensors and the set of voltage sensors, a time series of current measurements and a time series of voltage measurements over a period of time, and perform a diagnostic test that uses the time series of current measurements and the time series of voltage measurements in order to determine a state of the circuitry, wherein the diagnostic test comprises one or more comparisons between the time series of current measurements and a predetermined current threshold range value, and wherein the diagnostic test comprises one or more comparisons between the time series of voltage measurements and a predetermined voltage threshold range value, and based on the one or more comparisons, the diagnostic test determines whether the state of the circuitry includes a fault condition; and wherein, in response to the state of the circuitry including a fault condition, the controller is configured to apply a corrective action to at least one of the plurality of temperature control circuits.

2. The hot melt liquid dispensing system of claim 1, the at least one heater is implemented in an adhesive applicator and / or a heated adhesive hose of the hot melt liquid dispensing system; wherein wherein the heated adhesive hose is connected to the melter and / or an adhesive manifold of the hot melt liquid dispensing system; and wherein the heated adhesive hose is configured to direct hot melt liquid from a pump of the hot melt liquid dispensing system to the adhesive applicator.

3. The hot melt liquid dispensing system of claim 1, the fault condition of the circuitry includes one or more of: a blown fuse, a disconnected wire, an intermittent fault, a voltage amplitude outside of a threshold range, an alternating current line frequency outside of a threshold range, an open heater element of the at least one heater and / or the at least one internal heater, a current outside of a threshold range, and a current flow occurring outside of a predetermined period of time. wherein 4. The hot melt liquid dispensing system of claim 1, the fault condition of the circuitry includes a broken wire. wherein 5. The hot melt liquid dispensing system of claim 1, ​ wherein the controller is configured to perform the diagnostic test to determine a rate of change of at least one of a time series of current measurements or a time series of voltage measurements over a period of time; and wherein the rate of change is compared to a corresponding threshold range to determine a trend or prediction that the current measurements or voltage measurements are expected to fall outside of the corresponding threshold range.

6. The hot melt fluid dispensing system of claim 1, wherein the temperature control circuit is connected to one of the at least one heater and / or the at least one internal heater; and wherein the temperature control circuit is configured to supply electrical power to one of the at least one heater and / or the at least one internal heater.

7. The hot melt fluid dispensing system of claim 6, wherein the temperature control circuit includes a temperature controller, and wherein the temperature controller controls the electrical power supplied to the at least one heater and / or the at least one internal heater based on temperature signals received from temperature sensors associated with the at least one heater and / or the at least one internal heater.

8. The hot melt fluid dispensing system of claim 1, wherein, the time series of voltage measurements includes at least one of a voltage magnitude, a presence / absence of voltage, and / or an alternating current line frequency.

9. The hot melt fluid dispensing system of claim 1, wherein, the controller is further configured to send a notification based on the state of the circuit; and wherein the notification includes an alert or message generated on a human-machine interface device.

10. The hot melt fluid dispensing system of claim 1, wherein, after the diagnostic test, the controller is configured to determine a future fault condition of the circuit.

11. The hot melt fluid dispensing system of claim 10, wherein, the controller is configured to determine when future current measurements or future voltage measurements are predicted to be outside of the predetermined current threshold range value or the predetermined voltage threshold range value.

12. The hot melt fluid dispensing system of claim 10, wherein, the controller is configured to determine when a rate of change of current or voltage is predicted to be outside of the predetermined current threshold range value or the predetermined voltage threshold range value.

13. The hot melt fluid dispensing system of claim 10, wherein, the controller is configured to determine the future fault condition based on at least one of a linear trend estimation, a moving average, a weighted moving average, and a linear regression technique.

14. The hot melt fluid dispensing system of claim 1, wherein, the fault condition includes an excessive current or voltage that is greater than a predetermined current threshold range value or a predetermined voltage threshold range value, or an insufficient current or voltage that is lower than a predetermined current threshold range value or a predetermined voltage threshold range value.

15. The hot melt fluid dispensing system of claim 1, wherein, the controller is configured to take a corrective action, the corrective action including deactivating a component associated with the fault condition.

16. The hot melt fluid dispensing system of claim 5, wherein the controller is configured to determine a predicted time of failure of a component of the hot melt fluid dispensing system.

17. A diagnostic method associated with a hot melt fluid dispensing system, comprising: receive a time series of current measurements and a time series of voltage measurements from a set of current sensors and a set of voltage sensors, wherein the time series of current measurements and the time series of voltage measurements are associated with a circuit configured to supply electrical power to at least one internal heater and at least one heater associated with a hot melt liquid dispensing system, wherein the at least one internal heater is implemented in a melter configured to melt a solid or semi-solid material into a hot melt liquid; the at least one heater is implemented in at least one of an adhesive applicator, an adhesive manifold, and / or a heated adhesive hose; the circuit is implemented with a plurality of temperature control circuits; and each of the plurality of temperature control circuits is implemented with one or more of the set of current sensors and the set of voltage sensors; perform one or more comparisons between the time series of current measurements and a predetermined current threshold range value and one or more comparisons between the time series of voltage measurements and a predetermined voltage threshold range value; and using the comparisons, perform a diagnostic test to: i) determine a condition indicative of a fault condition of the circuit; and ii) predict a future measurement expected to fall outside of the predetermined current threshold range value and / or the predetermined voltage threshold range value based on a rate of change of the measurements over time.

18. The method of claim 17, wherein, performing the diagnostic test includes determining a rate of change of the time series of current measurements and the time series of voltage measurements over a period of time; and wherein the rate of change is compared to a corresponding threshold range to determine a trend or prediction that a current measurement or a voltage measurement is expected to fall outside of the corresponding threshold range.

19. The method of claim 17, further comprising: control electrical power supplied to the at least one internal heater and the at least one heater using a temperature controller based on temperature signals received from temperature sensors associated with the at least one internal heater or the at least one heater.

20. The method of claim 17, further comprising: generate a notification based on the condition, wherein the notification includes an alert or a message produced on a human-machine interface device.

21. A controller associated with a hot melt liquid dispensing system, the controller comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the controller to: receiving time series of current measurements and time series of voltage measurements from a set of current sensors and a set of voltage sensors, wherein the time series of current measurements and the time series of voltage measurements are associated with an electrical circuit, wherein the electrical circuit is configured to supply electrical power to at least one internal heater and at least one heater associated with a hot melt liquid dispensing system, wherein the at least one internal heater is implemented in a melter configured to melt a solid or semi-solid material into a hot melt liquid; and the at least one heater is implemented in at least one of an adhesive applicator, an adhesive manifold, and / or a heated adhesive hose; the electrical circuit is implemented with a plurality of temperature control circuits; and each of the plurality of temperature control circuits is implemented with one or more of the set of current sensors and the set of voltage sensors; and performing a diagnostic test that determines a circuit status of a heater using the time series of current measurements and the time series of voltage measurements, wherein the diagnostic test includes: i) a first comparison between the time series of current measurements and a predetermined current threshold range value, and ii) a second comparison between the time series of voltage measurements and a predetermined voltage threshold range value; wherein, based on the first comparison and the second comparison, the diagnostic test determines whether the circuit status of the heater includes a fault condition; and wherein, in response to the diagnostic test determining a fault condition, a corrective action is applied to at least one temperature control circuit.

22. The controller of claim 21, wherein, the corrective action includes deactivating at least one temperature control circuit while supplying electrical power to another temperature control circuit.

23. The controller of claim 21, wherein, the controller is configured to perform the diagnostic test so as to determine a rate of change of at least one of the time series of current measurements or the time series of voltage measurements over a period of time; wherein the rate of change is compared to a corresponding threshold range so as to determine a trend or prediction that a current measurement or a voltage measurement is expected to fall outside of the corresponding threshold range; and wherein the controller is configured to determine a predicted time of failure of a component of the hot melt liquid dispensing system.

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