Abstract: A method and apparatus are provided for maintaining a temperature between a first value and a second value. The method and apparatus utilize a heat transfer device capable of cycling through a series of cycles, the device being capable of changing the temperature from the second value to the first value when operational. During each cycle the device transfers heat for a first period of time when the temperature reaches the second volume until the first value is reached and thereafter the device stops transferring heat. The first period of time is compared to a desired cycle-on period of time during each cycle and the second temperature value then is adjusted for a subsequent cycle of the device so the first period of time when the device transfers heat approaches the desired cycle-on period of time. There may also be provided temperature controls for a liquid heater having a jacket containing the liquid. The jacket has an inner heated wall and an outer wall spaced apart from the inner wall.

Abstract: A device for rotating with a rotatable first member includes a second member having a portion engageable with the first member. The portion has a first part and a second part which is resiliently biased away from the first part. The second member tightly engages the first member. There may be a device for measuring rotation of the shaft such as a potentiometer. The rotation measuring device may include an electrical connector for the potentiometer including a socket and a post which is pressable into the socket. The device may also include a rotationally adjustable connector. There may be a coupling connected to the second member which includes a third member with a portion having n sides and a fourth member with a portion having n sides which receives the portion of the third member in a mating relationship, thereby allowing the device to be adjusted to a total of at least m.n rotational positions.

Abstract: A burner head assembly for a burner includes a housing having a hollow interior and an exterior. There is a control module within the hollow interior. The module has internal connectors within the hollow interior and external connectors on the exterior of the housing, whereby electrical connections to the module can be made internally and externally with respect to the housing without requiring apertures in the housing and wiring extending through the apertures. For example, the control module may include a circuit board, the circuit board having a portion within the hollow interior and which extends to the exterior. The exterior and interior connectors are connected to the circuit board. The housing may have two portions, the control module being fitted between the two portions of the housing. Preferably the control module is sealingly received between the two portions of the housing.