Preheat timer for use in oven
Patent 4742246 Issued on May 3, 1988. Estimated Expiration Date: 
February 3, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 3, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3646560 Device, method and system for controlling the supply of power to an electrical load Control system for blue-flame oil burner Light switch delay circuit Electronic time switch Power switch Patent #: 4538074 InventorApplicationNo. 07/014080 filed on 02/03/1987US Classes:307/141.4, Electrically initiated307/140Power circuit controlledExaminersPrimary: Pellinen, A. D.Assistant: Jennings, Derek S. Attorney, Agent or FirmInternational ClassesF24C 7/08 (20060101)G05D 23/19 (20060101) Foreign Application Priority Data1983-02-25 JPAbstractA preheating timer for use in an oven unit ensuring uniform finish of cooked (or baked) food independent of high and low initial temperatures in the oven chamber, by applying a simplified electric circuit wherein it automatically determines the preheating time in response to the initial temperature in the oven chamber comprising; a capacitor simulating a temperature characteristics; the first resistor for charging the capacitor from the DC voltage circuit through a reverse-current inhibit diode; a voltage detection circuit composed of zener diode(s) and a transistor for detecting a voltage in the capacitor terminal; and the second resistor for discharging capacitor from the output terminal of the reverse-current inhibit diode. | |
