×

Temperature-responsive circuit for load control apparatus

  • US 4,675,777 A
  • Filed: 12/13/1984
  • Issued: 06/23/1987
  • Est. Priority Date: 12/13/1984
  • Status: Expired due to Fees
First Claim
Patent Images

1. A temperature-responsive circuit, operating with a load-control apparatus having a control input at which is adjusted the magnitude of power applied to a load from a source and having an element providing a reference for the magnitude of load voltage, comprising:

  • means for sensing the temperature in the vicinity of said load-control apparatus;

    means for converting the temperature sensed by said sensing means to the magnitude of an electrical parameter;

    means for providing a reference electrical parameter having a magnitude predeterminately selected to equal the magnitude of said electrical parameter at a maximum desired temperature To; and

    means, having a selected gain, for providing a control signal to the control input of said load-control apparatus responsive to a comparison between said electrical parameter and said reference electrical parameter, said control signal having a magnitude respectively insufficient and sufficient to substantially affect and proportionally reduce the magnitude of power applied to said load if the magnitude of said electrical parameter is respectively less than and greater than the magnitude of said reference electrical parameter, and said gain is selected to gradually decrease the power applied to said load to a preselected minimum magnitude when a second temperature T1, greater than the desired temperature TO, is sensed by said sensing means;

    said control-signal-providing means also having an active semiconductor device connected to said load-control apparatus element and operative to reduce said load voltage as said sensed temperature is increased above said temperature TO.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×