Method for microwave defrosting

• US 4,525,615 A
• Filed: 01/16/1984
• Issued: 06/25/1985
• Est. Priority Date: 01/16/1984
• Status: Expired due to Fees

• Current Assignee: Amana
• Original Assignee: Amana Refrigeration, Inc. (Whirlpool Corporation)
• Inventors: Wyland, Alvin D.
• Primary Examiner(s): Leung, Philip H.
• Application Number:
  US06/571,158
• Time in Patent Office: 526 Days
• Field of Search: 219/10.55 M, 219/10.55 B, 219/10.55 R, 219/10.55 E, 219/492, 426/243, 426/241, 426/524, 99/325, 99/327, 99/451, 99/DIG. 14, 99/332
• US Class Current: 219/703
• CPC Class Codes: H05B 6/6435 Aspects relating to the user interface of the microwave heating apparatus
• CPC Class Codes: H05B 6/6464 using weight sensors
• CPC Class Codes: H05B 6/688 for thawing
• CPC Class Codes: H05B 6/725 Rotatable antennas
• CPC Class Codes: Y10S 99/14 Induction heating

Abstract

A method for defrosting in a microwave oven wherein maximum or 100 percent power is applied until the surface temperature of the food reaches 110° F. and the the power is reduced to a level which holds the surface at 110° F. until the food is defrosted. The time periods are calculated in a microcomputer in accordance with the weight which is provided by an oven based scale. The reduced power level is either 10 percent or 20 percent as determined by the food category as input to the microcomputer by the operator.

Claims

1. The method of defrosting a food body in a microwave oven, comprising the steps of:

providing microwave energy at maximum power of said oven until the surface temperature of said food body rises to approximately 110°

F.; and

providing microwave energy in a sequential step at a predetermined power level reduced from said maximum power to maintain said surface temperature of said food body at approximately 110°

F. until said food body is defrosted.

2. The method recited in claim 1 wherein said predetermined power level is approximately 10 percent of said maximum power.

3. The method of defrosting a food body in a microwave oven, comprising the steps of:

providing microwave energy at maximum power of said oven for a first time period, said first time period being equal to the time to raise the surface temperature of said food body from frozen to approximately 110°

F. at said maximum power; and

providing microwave energy at a reduced power level for a second time period sequentially following said first time period, said reduced power level holding the surface temperature of said food body at approximately 110°

F., said second time period being equal to the time required to complete defrosting of said food body at said reduced power level after said first time period at maximum power.

4. The method recited in claim 3 wherein said reduced power level is approximately 10 percent of said maximum power.

5. The method recited in Claim 3 wherein said second time period is ten times as long as said first time period.

6. The method of defrosting a food body in a microwave oven, comprising the steps of:

positioning said food body in the cavity of said microwave oven;

providing to a microcomputer a signal corresponding to the weight of said food body as positioned in said cavity;

calculating in said microcomputer in response to said signal a first time period required to raise the surface temperature of said food body from frozen to approximately 110°

F. at 100 percent power of said oven;

calculating in said microcomputer in response to said signal a second time period required to completely thaw said food body in a sequential step following said first time period at a reduced power level which holds the surface temperature of said food body at approximately 110°

F.; and

controlling the magnetron of said microwave oven with said microcomputer wherein said magnetron is operated at said 100 percent power for said first time period and then sequentially at said reduced power level for said second time period.

7. The method recited in claim 6 wherein said reduced power level is approximately 10 percent power.

8. The method recited in claim 6 wherein said second time period is approximately 10 times as long as said first time period.

9. The method of defrosting of a food body in a microwave oven, comprising the steps of:

providing microwave energy at 100 percent power for a first time period calculated by the equation T₁ =60(W+0.1)RP where T₁ is the first time period, R equals 0.025, and P is a factor used to compensate for said microwave oven having maximum output power other than 700 watts;

said first time period raises the surface temperature of said food body to approximately 110°

F.; and

providing microwave energy at 10 percent power for a second time period calculated by the equation T₂ =60(W+0.1)RP where T₂ is the second time period, R equals 0.250, and P is a factor used to compensate for said microwave over having a maximum output power other than 700 watts, said second time period sequentially following said first time period and said food body is held at approximately 110°

F. during said second time period.

10. The method of defrosting a food body in a microwave oven, comprising the steps of:

providing microwave energy at 100 percent power for a first time period calculated by the equation

space="preserve" listing-type="equation">T.sub.1 =68(W+0.1)RP

where

T₁ is the first time period, R is 0.025, and P is a factor used to compensate for said microwave oven having a maximum output power other than 700 watts;

providing microwave energy sequential to said first time period at 20 percent power for a second time period calculated by the equation

space="preserve" listing-type="equation">T.sub.2 =56(W+0.1)RP

where

T₂ is the second time period, R equals 0.125 and P is a factor used to compensate for said microwave oven having a maximum output power other than 700 watts; and

providing no microwave energy for an equilibrium time period equal to the sum of T₁ and T₂ while continuing to operate the blower motor of the magnetron so as to make the equilibrium time period nondiscernible to the operator from said first and second time periods.