Energy control system
First Claim
1. A frypan control system for controlling a supply of electrical power to a heating element associated with said frypan, said control system being adapted to control said supply of power in a first mode for simmering and in a second mode for cooking, comprising:
- sensing means arranged in a heat conducting relationship with said heating element for sensing the temperature of said heating element;
setting means for setting the required operating temperature for said frypan;
microprocessor means receiving output from said sensing means and said setting means for providing in said first mode a control signal comprising control periods each having a first duration and a duty cycle which is related to the difference between the temperature of said setting means and the temperature of said sensing means, and in said second mode a control signal comprising control periods each having a second duration, said second duration being greater than said first duration; and
switching means responsive to said control signals for switching said supply of electrical power to said heating element for control periods having said first duration and duty cycle in said first mode and for control periods having said second duration in said second mode.
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Accused Products
Abstract
A control system for controlling the supply of electrical power to a heating element associated with an electrical appliance such as a frypan. The application of power to the heating element is controlled in two distinct modes, a first mode for simmering and a second mode for cooking. The two modes are characterized by a control signal which exhibits control periods having a relatively short duration during the simmer mode and a relatively long duration during the cooking mode. The present invention also delays actuation of a switching element responsive to the control signal in order to compensate for inertial delays caused by the opening and closing of the switching element. The switching element is thus actuated at a time delayed from a zero crossover of an alternating current power supply by an amount corresponding to the opening or closing delay time associated with the switching element such that switching occurs at times which coincide with the zero crossover points of the alternating current power. As a result, a more rapid response and improved control are achieved at relatively low temperature settings while the control of temperature over a broad range is maintained.
19 Citations
22 Claims
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1. A frypan control system for controlling a supply of electrical power to a heating element associated with said frypan, said control system being adapted to control said supply of power in a first mode for simmering and in a second mode for cooking, comprising:
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sensing means arranged in a heat conducting relationship with said heating element for sensing the temperature of said heating element; setting means for setting the required operating temperature for said frypan; microprocessor means receiving output from said sensing means and said setting means for providing in said first mode a control signal comprising control periods each having a first duration and a duty cycle which is related to the difference between the temperature of said setting means and the temperature of said sensing means, and in said second mode a control signal comprising control periods each having a second duration, said second duration being greater than said first duration; and switching means responsive to said control signals for switching said supply of electrical power to said heating element for control periods having said first duration and duty cycle in said first mode and for control periods having said second duration in said second mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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- 18. A method of switching a switching element which exhibits a closing/opening delay time following actuation, said switching element controlling a supply of alternating current electrical power to a load, wherein said switching element is actuated at a time delayed from a zero cross-over of the alternating current power by a feedback technique, said feedback being provided by cumulative storage of inductive supply induced transients as a charge level on a capacitor, said delayed time corresponding to said closing/opening delay time associated with said switching element.
Specification