Electric blanket and control

  • US 6,222,162 B1
  • Filed: 09/30/1999
  • Issued: 04/24/2001
  • Est. Priority Date: 06/03/1999
  • Status: Expired due to Term
First Claim
Patent Images

1. An electric blanket, said blanket comprising:

  • a heating element extending through said blanket so that, upon receiving electric current from a power source, said element heats said blanket;

    a resistive element having a resistance (R1) and being disposed electrically in series between said power source and said heating element;

    a full-wave rectifier disposed between said power source and said heating element so that said rectifier fully rectifies said current applied to said heating element; and

    a regulator circuit connected to said heating element, said regulator circuit including a processor in communication with said power source and said resistive element and configured to measure a voltage drop (V1) across said power source and a voltage drop (V2) across said resistive element, wherein said processor is configured to divide V2 by R1, thereby determining a current (I)through said heating element, divide V1 by I, thereby determining a resistance (R2) having a known relationship to the resistance of said heating element, control delivery of said electric current from said power source to said heating element responsively to R2 so that said heating element heats to a desired temperature, and discontinue delivery of said electric current from said power source to said heating element when I exceeds a predetermined threshold.

View all claims
    ×
    ×

    Thank you for your feedback

    ×
    ×