Claims
- 1. A control system for controlling the heating of a product in a dielectric oven, comprising:
- at least one dielectric heating circuit including an electromagnetic energy source having an anode operating at a frequency determined by at least one inductor and electrically connected to a pair of capacitors, wherein each capacitor includes two capacitor plates and at least one of said capacitor plates is moveable, such that said pair of capacitors forms a variable capacitor in which said product to be heated is a dielectric;
- at least one ammeter, electrically connected to said anode, for measuring actual current at said anode;
- a motor, mechanically connected to at least one of the plates of at least one of said capacitor, for continuously increasing or decreasing a distance between the plates of said capacitor, thereby adjusting the electromagnetic energy applied to said product; and
- a processor, connected to said at least one ammeter and said motor, for receiving ammeter measurements whereby the distance between said pair of capacitor plates is determined; for receiving, storing, and retrieving a requested anode current; for comparing the requested anode current to the actual anode current to determine whether to increase or decrease the distance between the plates of at least one of said capacitors thereby increasing or decreasing said actual anode current; and for instructing said motor to adjust said distance between said plates.
- 2. The control system of claim 1, wherein said electromagnetic energy source has an anode voltage adjusted by a voltage control device and said processor is connected to said voltage control device and includes a timer, whereby actual average anode current is determined and said processor receives, stores, and retrieves a requested anode current and compares said requested average anode current to the actual average anode current to determine whether to increase or decrease the anode voltage and thereby increase or decrease said actual average anode current.
- 3. The control system of claim 1, wherein said processor is connected to said electromagnetic energy source and deactivates said electromagnetic energy source when the actual anode current exceeds a safety limit for anode current.
- 4. The control system of claim 1, wherein said oven has at least one intake port and at least one exhaust port and a thermometer monitors the heating of the product by measuring a temperature difference between said at least one intake and said at least one exhaust port and transmits said temperature difference to said processor.
- 5. The control system of claim 1, wherein said oven has at least one intake port and at least one exhaust port and a thermometer monitors the heating of the product by measuring a temperature change over time at said at least one exhaust port and transmits said temperature change to said processor.
- 6. The control system of claim 1, wherein said oven has at least one intake port and at least one exhaust port and a humidity sensor monitors the heating of the product by measuring a humidity difference between said at least one intake and said at least one exhaust port and transmits said humidity difference to said processor.
- 7. The control system of claim 1, wherein said oven has at least one intake port and at least one exhaust port and a humidity sensor monitors the heating of the product by measuring a humidity change over time at said at least one exhaust port and transmits said humidity change to said processor.
- 8. The control system of claim 1, wherein said product is heated in a tray filled with a heating fluid and a tray thermometer monitors the heating of the product by measuring a temperature of said heating fluid and transmits said temperature to said processor.
- 9. The control system of claim 1, wherein said processor is a microprocessor.
- 10. The control system of claim 1 further comprising a data entry device for inputting a product and product heating parameters to said processor and wherein said processor includes a data storage component for receiving, storing, and selectively retrieving heating parameters for a plurality of products.
- 11. The control system of claim 1, wherein said electromagnetic energy source includes a triode vacuum tube.
- 12. A control system for controlling the heating of a product in a dielectric oven, comprising:
- at least one dielectric heating circuit including an electromagnetic energy source having an anode and a selectable duty cycle operating at a frequency determined by at least one inductor and electrically connected to at least a pair of capacitors, wherein each capacitor includes two capacitor plates, such that each pair of capacitors forms a variable capacitor in which said product to be heated is a dielectric;
- at least one ammeter electrically connected to said anode for measuring an actual current at said anode;
- a keying device connected to said electromagnetic energy source for adjusting said duty cycle;
- a processor, including a timer and connected to said ammeter and said keying device, for receiving ammeter measurements, whereby the actual average anode current is determined; for receiving, storing, and retrieving a requested average anode current; for comparing said requested average anode current to said actual average anode current to determine whether to increase or decrease said duty cycle thereby increasing or decreasing said actual average anode current; and for instructing said keying device to adjust said duty cycle.
- 13. The control system of claim 12, wherein said electromagnetic energy source has an anode voltage adjusted by a voltage control device and said processor is connected to said voltage control device, whereby actual average anode current is determined and said processor receives, stores, and retrieves a requested anode current and compares said requested average anode current to the actual average anode current to determine whether to increase or decrease the anode voltage and thereby increase or decrease said actual average anode current.
- 14. The control system of claim 12, wherein said processor is connected to said electromagnetic energy source and deactivates said electromagnetic energy source when the actual average anode current exceeds a safety limit for anode current.
- 15. The control system of claim 12, wherein and at least one exhaust port intake port and at least one exhaust port and a thermometer monitors the heating of the product by measuring a temperature difference between said at least one intake and said at least one exhaust port and transmits said temperature difference to said processor.
- 16. The control system of claim 12, wherein said oven has at least one intake port and at least one exhaust port and a thermometer monitors the heating of the product by measuring a temperature change over time at said at least one exhaust port and transmits said temperature change to said processor.
- 17. The control system of claim 12, wherein said oven has at least one intake port and at least one exhaust port and a humidity sensor monitors the heating of the product by measuring a humidity difference between said at least one intake and said at least one exhaust port and transmits said humidity difference to said processor.
- 18. The control system of claim 12, wherein said oven has at least one intake port and at least one exhaust port and a humidity sensor monitors the heating of the product by measuring a humidity change over time at said at least one exhaust port and transmits said humidity change to said processor.
- 19. The control system of claim 12, wherein said product is heated in a tray filled with a heating fluid and a thermometer monitors the heating of the product by measuring a temperature of said heating fluid and transmits said temperature to said processor.
- 20. The control system of claim 12, wherein said processor is a microprocessor.
- 21. The control system of claim 12 further comprising a data entry device for inputting a product and product heating parameters to said processor and wherein said processor includes a data storage component for receiving, storing, and selectively retrieving heating parameters for a plurality of products.
- 22. A control system for controlling the heating of a product in a dielectric oven, comprising:
- at least one dielectric heating circuit including an electromagnetic energy source having an anode operating at a frequency determined by at least one inductor and electrically connected to at least a pair of capacitors, wherein each capacitor includes two capacitor plates and one of said capacitor plates is moveable, such that each pair of capacitors forms a variable capacitor in which said product to be heated is a dielectric;
- at least one ammeter electrically connected to said anode for measuring actual current at said anode;
- a voltage control device for controlling a first voltage provided to a power supply, said power supply providing an anode voltage at said anode; and
- a processor, including a timer and connected to said at least one ammeter and said voltage control device, for receiving ammeter measurements, whereby the actual average anode current is determined; for receiving, storing, and retrieving a requested average anode current; for comparing said requested average anode current to said actual average anode current to determine whether to increase or decrease said anode voltage thereby increasing or decreasing the actual average anode current; and for instructing said voltage control device to adjust said anode voltage whereby said actual average anode current is adjusted.
- 23. The control system of claim 22, wherein said electromagnetic energy source includes a triode vacuum tube.
- 24. The control system of claim 22, wherein said processor is connected to said electromagnetic energy source and deactivates said electromagnetic energy source when the actual anode current exceeds a safety limit for anode current.
- 25. The control system of claim 22, wherein said oven has at least one intake port and at least one exhaust port and a thermometer monitors the heating of the product by measuring a temperature difference between said at least one intake and said at least one exhaust port and transmits said temperature difference to said processor.
- 26. The control system of claim 22, wherein said oven has at least one intake port and at least one exhaust port and a thermometer monitors the heating of the product by measuring a temperature change over time at said at least one exhaust port and transmits and temperature change to said processor.
- 27. The control system of claim 22, wherein said oven has at least one intake port and at least one exhaust port and a humidity sensor monitors the heating of the product by measuring a humidity difference between said at least one intake and said at least one exhaust port and transmits said humidity difference to said processor.
- 28. The control system of claim 22, wherein said oven has at least one intake port and at least one exhaust port and a humidity sensor monitors the heating of the product by measuring a humidity change over time at said at least one exhaust port and transmits said humidity change to said processor.
- 29. The control system of claim 22, wherein said product is heated in a tray filled with a heating fluid and a tray thermometer monitors the heating of the product by measuring a temperature of said heating fluid and transmits said temperature to said processor.
- 30. The control system of claim 22, wherein said processor is a microprocessor.
- 31. A process of controlling the heating of a product in a dielectric oven comprising, an electromagnetic energy source having an anode, a resonant circuit including at least one inductor and a pair of capacitors electrically connected to said energy source, wherein each of said capacitors has a pair of capacitor plates and said product is located between said pair of capacitors, and a processor connected to said energy source and said resonant circuit, comprising the steps of:
- requesting an anode current for the electromagnetic energy source;
- measuring an actual anode current of the electromagnetic energy source during heating;
- comparing said requested anode current to said actual anode current to determine whether to increase or decrease a distance between said pair of capacitor plates, thereby increasing or decreasing said actual anode current; and
- adjusting said distance continuously between said pair of capacitor plates.
- 32. The process of claim 31 further comprising the steps of:
- selecting an anode voltage for the electromagnetic energy source;
- determining an actual average anode current and a requested average anode current;
- comparing said requested average anode current to said actual average anode current to determine whether to increase or decrease said anode voltage, thereby increasing or decreasing said actual average anode current; and
- adjusting said anode voltage for the electromagnetic energy source.
- 33. The process of claim 31 further comprising the steps of: comparing the actual anode current to a safety limit for anode current and deactivating said electromagnetic energy source when the actual anode current exceeds said safety limit.
- 34. The process of claim 31 further comprising the steps of: monitoring at least one heating performance sensor to measure product heating; and confirming whether to increase or decrease the actual anode current.
- 35. A process of controlling the heating of a product in a dielectric oven comprising an electromagnetic energy source having an anode and a selectable duty cycle, a resonant circuit including at least one inductor and at least a pair of capacitors, which are electrically connected to said energy source, wherein each of said capacitors has a pair of capacitor plates and said product is located between at least said pair of capacitors, and a processor connected to said energy source and said resonant circuit, comprising the steps of:
- measuring an anode current of the electromagnetic energy source during heating;
- selecting a duty cycle for said electromagnetic energy source;
- determining an actual average anode current and a requested average anode current;
- comparing said requested average anode current to said actual average anode current to determine whether to increase or decrease said duty cycle thereby increasing or decreasing said actual average anode current; and
- adjusting said duty cycle of the electromagnetic energy source during heating.
- 36. The process of claim 35 further comprising the steps of:
- selecting an anode voltage for the electromagnetic energy source;
- determining an actual average anode current and a requested average anode current;
- comparing said requested average anode current to said actual average anode current to determine whether to increase or decrease said anode voltage, thereby increasing or decreasing said actual average anode current; and
- adjusting said anode voltage of the electromagnetic energy source during heating.
- 37. The process of claim 35 further comprising the steps of:
- comparing said actual anode current to a safety limit for anode current; and
- deactivating said electromagnetic energy source when said actual anode current exceeds said safety limit.
- 38. The process of claim 35 further comprising the steps of:
- monitoring at least one heating performance sensor to measure product heating; and
- confirming whether to increase or decrease said actual average anode current.
- 39. A process of controlling the heating of a product in a dielectric oven comprising an electromagnetic energy source having an anode, a voltage control device for adjusting a voltage provided to said anode, a resonant circuit including at least one inductor and at least a pair of capacitors, which are electrically connected to said energy source, wherein each of said capacitors has a pair of capacitor plates and said product is located between at least said pair of capacitors, and a processor connected to said energy source, said voltage control device, and said resonant circuit, comprising the steps of:
- measuring an anode current of the electromagnetic energy source during heating;
- selecting said anode voltage for the electromagnetic energy source;
- determining an actual average actual anode current and a requested average anode current;
- comparing said requested average anode current to said actual average anode current to determine whether to increase or decrease said anode voltage thereby increasing or decreasing said actual average anode current; and
- adjusting said anode voltage of the electromagnetic energy source during heating.
- 40. The process of claim 39 further comprising the steps of:
- comparing said actual anode current to a safety limit for anode current; and
- deactivating said electromagnetic energy source when said actual anode current exceeds said safety limit.
- 41. The process of claim 39 further comprising the steps of:
- monitoring at least one heating performance sensor to measure product heating; and
- confirming whether or to increase or decrease said actual average anode current.
Parent Case Info
This application is a continuation of application Ser. No. 08/239,524, filed May 9, 1994 U.S. Pat. No. 5,556,567 entitled "SYSTEM AND PROCESS FOR CONTROLLING DIELECTRIC OVENS".
US Referenced Citations (23)
Foreign Referenced Citations (2)
Number |
Date |
Country |
W812947 |
Dec 1989 |
EPX |
3205124 |
Aug 1983 |
DEX |
Continuations (1)
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Number |
Date |
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Parent |
239524 |
May 1994 |
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