PRODUCT OPERATION
SYSTEM OVERVIEW
ELECTRONICS
The functions of controlling the motor and the user interface console are combined into a single
The micro controller also controls a transformerless 85 watt switchmode power supply. The power supply uses a large drop- ping resistor on the heater plate and phase control of the line voltage to produce a variable voltage supply. The micro controller can sup- ply 5 - 85 volts to the various components.
The user interface has a circuit board for front controls and a touch switch panel for internal controls.
MOTOR & HALL SENSOR
The electronically controlled 80V, 60w, 3 phase,
The hall sensor is mounted on a small circuit board clipped to the motor case, and monitors motor speed and rotation.
HEATER PLATE
The heater plate is a porcelain enameled steel plate that supports the motor at the base of the tub and is clamped in place by a lock ring nut. A thick film resistive circuit for the heater ele- ment and the power supply dropping resistor are printed on the dry side of the heater plate.
The heater element is only activated during wash cycles. It is not used for drying. Tempera- ture is maintained by the thermistor. Overheat protection is provided by a thermal fuse located on the heater plate.
AMOUNT OF WATER
The tub fills with 0.8 gallons of water, approxi- mately level with the base of the spray arm. Once this level is reached, the wash is primed to pump water through the spray arm, which will then rotate.
The load on the wash pump is constantly monitored throughout the wash cycle and the water level adjusted if necessary.
TUB HOME SENSOR
Using an infrared transmitter and receiver mounted on the controller circuit board, the tub home sensor detects when the tub is closed and ready to start a cycle.
The transmitter sends infrared light through an optical light pipe to the side of the tub. Another optical light pipe leads from the infrared re- ceiver to the side of the tub. When the tub is closed, the two light pipes are optically con- nected via a prism mounted in the side of the chassis.
DETERGENT/RINSE AID
DISPENSER
The detergent/rinse aid dispenser door is opened manually to load detergent, and then manually closed to transport the detergent to the tub by the inlet water. An electronically- controlled inlet water diverter valve enables each detergent chamber to be dispensed sepa- rately.
A positive displacement pump and storage tank is incorporated within the dispenser to supply rinse agent. The electronic controller regulates the amount of rinse agent dispensed. A red light on the tank filler cap indicates an empty rinse agent tank.