Electric power controllers

Abstract

A power controller for controlling the intermittent supply of current to a load, such as a cooker hotplate, has a pivotally mounted snap switch controlled by a heated bimetal member which is heated in dependence upon the connected power. A compensating bimetal strip, for taking ambient temperature into account, is arranged on the snap switch and parallel thereto. A control cam acts on the free end of the compensating bimetal strip. The latter is shielded from the heat of the heated bimetal member.

We claim:  .[.1. A power controller for the controllable supply of electrical power intermittently to a load, comprising: 
     
        opening..]. 14. .[.A controller according to claim 1, which is.]. .Iadd.A power controller for the controllable supply of electrical power intermittently to a load, comprising: a housing;   a snap switch having a snap switch carrier on which a snap spring, bearing a switching contact, is mounted, said snaps with carrier being pivotably mounted on a fulcrum point in said housing;   an L-shaped bimetal member pivotally mounted in said housing and having a lever by which it acts on said snap switch, said lever extending at an angle to said bimetal member and substantially parallel to said snap switch carrier;   means for heating said bimetal member in dependence upon the power supplied to said load via said snap switch;   a compensation bimetal strip secured to said snap switch carrier at the fulcrum point side thereof and extending substantially parallel thereto;   control cam means acting upon a free end of said compensation bimetal strip, said bimetal member and said snap switch carrier forming an L-shaped arrangement running along two sides of the housing, said control cam means being arranged in the middle area of the housing and inside the angle of said L-shaped arrangement; and, said controller being .Iaddend.adapted to operate with alternating current and .[.which.]. further .[.comprises.]. .Iadd.comprising .Iaddend.a diode and auxiliary switch means actuable by said control cam means for connecting said diode in circuit with said heating means for said bimetal member, only in an upper power range but not in a lower power range. .[.15. A controller according to claim 2 in which an adjusting screw is associated with said longer limb and spring means is provided for biassing said longer limb against said housing via said adjusting screw..]. .[.16. A controller according to claim 6 in which said compartment is provided with heat shield means..]. .[.17. A controller according to claim 6 in     
     
     
        which said compartment is provided with ventilating means..]. 18. A controller according to claim 14 in which said diode is located on a rear side of said housing remote from the opening side thereof and is disposed 
     
     
        directly on said auxiliary switch means. 19. A controller according to claim 18 in which said control cam means combines a control body which has a control cam thereon, and an adjusting shaft which is received in a hole in said control body and protrudes from the housing at the operating side thereof, and in which the housing has a bearing opening at its side remote from the operating side and said control body has an integrally moulded 
     
     
        bearing pin which is journalled in said bearing opening. 20. A controller according to claim 19, in which said bearing pin on said control body defines thereon a switching cam for said auxiliary switch means.