Abstract: A spa communication system for establishing a communication link between a central spa box having a control module and spa components in a spa system. The spa control module is connected to the spa components through a communication link, and the spa control module sends command signals to at least one spa component and receives status information from at least one spa component on the communication link.

Abstract: An oven temperature controller for regulating temperature to a temperature setpoint over a temperature range in an oven compartment comprising a microprocessor and memory storage means. The memory storage means stores temperature setpoint related information for temperature setpoints over the temperature range and this information is used by the microprocessor for establishing an upper control limit curve and a lower control limit curve. The upper control limit curve and lower control limit curve have no discontinuities over a majority of the temperature range and at least one of these curves is non-parallel to a temperature setpoint line, the temperature setpoint line formed in a stepwise linear manner between temperature setpoints as the temperature setpoint is varied over the temperature range.

Abstract: A rotary encoded switch having a plurality of stationary discrete micro switches operated by a rotor having a plurality of concentric cam tracks. The cam tracks and switches are disposed such that for each rotary position of the rotor at least two switches, on opposite sides of the rotor are actuated and a discrete combination of switches is actuated for each position of the rotor. The number of microswitches required is less than half the number of rotary positions.

Abstract: In a clothes dryer, the air exiting the dryer for wet clothes has a high relative humidity compared to the relative humidity when the load is dry. A change in the relative humidity of the air leaving the dryer indicates a change in dryness of the load. The relative humidity is measured by using two thermistors located in an air outlet of the dryer. The first thermistor is nonself-heating and uses a relatively low current to detect the temperature of the air in the air outlet. The second thermistor is self-heating and operates at a higher current so that its temperature is higher than the air temperature. As the air moves across the heated thermistor it will conduct more heat away from the thermistor when the relative humidity of the air is high than when it is low. The air temperature and heated thermistor temperature are compared frequently during the drying cycle. When the load is wet the difference between the two thermistors is small. When the load is dry the difference is greater.