Referring to FIGS. The flood switch 60 is controlled by a float customarily located within the washing tub at a level so that excess water in the tub will cause the float to rise and open the flood switch connected thereto. The flood switch is connected in series with the water solenoid 80 in a normally closed configuration. When the flood switch opens it interrupts the circuit path from the associated relay 50 to the water solenoid 80 and immediately shuts off the water supply to the appliance.
This function is indicated in FIG. When switch 60 opens it provides an input via the optoisolator 54 to the microprocessor either through the input matrix 56 or, as illustrated in FIG. The microprocessor, upon detecting the overfill or flood condition, executes a flood control routine described in connection with FIGS.
In general, the flood control routine discontinues normal operation of the appliance and initiates a drain cycle which persists until flood switch 60 returns to its normally closed position indicating a safe water level in the appliance. The drain solenoid 74 is actuated by the associated relay 50 in order to initiate draining of water from the appliance.
The mechanical arrangement of the drain system is illustrated in FIG. When the solenoid is operated, the drain feedback switch 62 is closed thereby providing an input to the microprocessor 64 via optoisolator The feedback switch is periodically polled during the course of the drain cycle. The drain diverter valve, the linkage of which controls actuation of the drain switch, is mechanically arranged to permit the switch to open when water has been pumped out of the appliance.
Thus, during normal operation, the drain feedback switch 62 should, initially, be closed when the solenoid is actuated and subsequently, within predictable time limits, the switch should open indicating completion of the drain cycle.
If the switch fails to go on at the beginning of a drain cycle, the microprocessor identifies a drain system failure DS. If the switch stays closed longer than normal for a specified quantity of water, the microprocessor identifies a long drain situation LD indicative of partial drain blockage or other service problem. Similarly, if the switch stays closed for an unlimited period of time the microprocessor identifies a plugged drain PD situation and terminates operation of the appliance to prevent flooding.
This operation is detailed in connection with FIGS. This mechanical design is intended for a dishwasher appliance and in some respects is conventional. It will be recognized that other drain arrangements are possible as long as the drain feedback switch 62 is positioned to detect operation of the drain diverter valve. In the usual dishwasher construction the pump housing defines a water flow path from a pump not shown upwardly through a channel into the tub of the appliance indicated at In this manner water is forced into the appliance for washing and rinsing purposes.
Water is withdrawn from the tub through openings not shown to complete the circuit whereby steady water circulation is obtained. When it is desired to discharge the water from the appliance, a diverter valve , which is hingedly attached to the housing at point , is positioned across the opening to divert water from the tub into a drain line Except when draining, the diverter seals the drain line to prevent water from leaking out of the appliance.
Once the diverter valve has been moved to a horizontal position across the opening the pressure of the water against the valve will maintain it in place until substantially all of the water has been discharged into the drain line.
At that point the valve should automatically return to the FIG. The diverter valve is controlled by the drain solenoid 74 to which it is connected by an armature assembly and a linkage As will be apparent, when the solenoid is energized the armature retracts into the solenoid rotating the linkage in the direction indicated by the arrow thus moving the diverter valve to its horizontal position.
According to one embodiment of the invention, the feedback switch 62 includes a finger positioned in the path of the armature assembly whereby downward rotation of the assembly closes the switch and upward rotation opens the switch.
The condition of the switch is monitored by the microprocessor in the manner described in connection with FIGS. Based upon the state of the switch and the time elapsed from the beginning of the drain cycle, the microprocessor is programmed to detect drain system failures of the type previously indicated and, if necessary, to abort cycle operation to prevent flooding.
The purpose of the cancel-drain logic is two-fold. First, it interrupts any appliance cycle in progress by resetting the microprocessor. Second, it initiates a drain cycle to remove any water from the appliance before permitting further user operation.
The logic of FIG. The FIG. Switch S12 FIG. Switch S12 is also connected as one input to gate The output of gate is provided as one input to gate The outputs from gates and are provided to the J and K inputs, respectively, of a flipflop The Q and Q output of flipflop are connected to the J and K inputs of a second flipflop The flipflops are clocked by the zero crossing detector 66 FIG.
Operation of the cancel-drain logic is as follows. When switch S12 is closed, a low signal or a logical zero is produced by gate as an input to gate The Q output of flipflop is also low and, therefore, of gate is high or a logical one. This signal is applied to the j input of flipflop producing a high Q output when the flipflop is clocked by the zero crossing circuit This output, on line , is inverted and connected to the microprocessor reset port. When this signal goes high the microprocessor reset port goes low initating a reset after S12 is released.
The microprocessor begins stepping through the power up routine described in connection with FIG. During the next clock cycle applied to the flipflops the high output on line produces a Q output from the flipflops signalling the microprocessor that a cancel-drain cycle is desired.
This causes a branch in program execution to the cancel-drain routine described in connection with FIG. In order to reset the cancel-drain circuit it is necessary that the flipflops be reset and this is accomplished by the connection between the Q output of flipflop and the input to gate Thus, when the Q output goes high the Q output goes low producing a high output from gate This output is applied to the K input of flipflop effective for resetting both flipflops to their initial, low state.
As indicated previously, the microprocessor utilized in the present invention is in a single chip device including an on board ROM in which the control program is permanently installed prior to shipment of the appliance to the user. Based on the disclosure given to this point, it is believed that a programmer of ordinary skill in the art could produce an appropriate firmware structure to implement the various operating cycles commonly found in washing appliances.
Nevertheless, to insure that a complete disclosure of the invention is given, there follows a detailed description of the firmware structure employed and a discussion of the flow diagrams relating to each program routine necessary to implement an operative device. Based on the following disclosure, the development of specific program statements is a routine matter dependent upon the particular mmicroprocessor selected, its corresponding instruction set and the desires of the designer in selecting the type of user selectable options which will be incorporated into the firmware.
In the ordinary course of events it is contemplated that once the appliance has been delivered to an end user no change in the control program will be made. However, it is, of course, possible to make changes by substituting a new chip containing a revised program and thus field modification of the appliance to add additional options is contemplated. It consists of a base level program subject to interruption by external interrupt routine and internal interrupt routine Additionally, upon power up, a power up reset routine is performed prior to entry into the base level control program.
The base level program includes a number of software routines including the cancel-drain routine , a main routine , execution routine , and cycle interruption routine The latter routine may be further divided into a door monitor routine and a flood control routine Each of the indicated routines will now be identified and briefly described in connection with the corresponding figure. Turning to FIG. Each zero crossing produces an external interrupt, as indicated at and As will be described in connection with the interrupt program routines, every time an external interrupt occurs further external interrupts are prevented by disabling the external interrupt port of the microprocessor.
This prevents extraneous noise on the power line from causing improper operation of the control circuit. Microprocessors in the home Here are some examples of devices in your home that contain microprocessors: Washing machines Microwave cookers Dishwashers Electric kettles Fridges DVD players Remote control television Hairdryers Electric toothbrushes Central heating systems Burglar Alarm system External Security lights Device.
Challenge see if you can find out one extra fact on this topic that we haven't already told you Click on this link: Hardware. Controls the electronic display on the front of the machine Controls the different wash cycle programmes and ensures that the machine goes through each stage correctly Controls the amount of water allowed in through the valves Controls the speed the motor spins in order to rotate the drum during the spin cycle Controls the temperature of the water according to the programme chosen and the stage in the wash cycle.
WordPress Shortcode. Next SlideShares. Download Now Download to read offline and view in fullscreen. Business , Technology. Download Now Download Download to read offline. Microprocessor in washing machine Download Now Download Download to read offline.
Sandeep Kamath Follow. Arduino projects-list-aboutprojects. Using microcontroller based washing machine control ppt. G2 Waterless Washing Machine.
Android persentation. Oracle architecture. Oracle advanced. Related Books Free with a 30 day trial from Scribd. Related Audiobooks Free with a 30 day trial from Scribd. Motors to open and close the windows to the glass house in order to control the temperature Motors to pump water from storage containers into the soil to water the plants.
Thermostat temperature setting to trigger the motors. Vibration sensors — if the machine is incorrectly loaded and vibrates too much, the machine will switch off to avoid damage to the machine and avoid a potenital leak. Turn on the motors that spin the machine Turn on the draining pumps Turn on the heating coil that heats the water. The washing temperature The cycle type eco, intense, soak The spin speed.
Automatic Cookers Automatic cookers are becoming increasingly popular, especially for those people who want to eat quality home-cooked food, but work full-time. They can be used to cook a variety of meals and foods, including: Slow-cooked stews Pies, Pastries and Bread Rice.
0コメント