Dishwasher and control therefor

• US 5,760,493 A
• Filed: 11/18/1996
• Issued: 06/02/1998
• Est. Priority Date: 11/21/1995
• Status: Expired due to Fees

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Meyers, Theodore F., Outcalt, Alan G., Mundy, David W., Roth, Ryan K., Ashton, Robert H.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US08/751,604
• Time in Patent Office: 561 Days
• Field of Search: 307/38, 307/37, 307/115, 307/132 E, 307/139, 307/141.4, 364/400, 361/191, 134/58 D, 134/57 D, 318/461, 318/462, 318/471, 318/489, 318/254, 318/434, 318/138, 68/12.01, 68/12.02
• US Class Current: 307/38
• CPC Class Codes: A47L 15/0049 Detection or prevention of malfunction, including accident prevention arrangements to prevent clogging of filters A47L15/4208; safety arrangements for preventing water damage A47L15/421
• CPC Class Codes: A47L 15/4293 Arrangements for programme selection, e.g. control panels; Indication of the selected programme, programme progress or other parameters of the programme, e.g. by using display panels
• CPC Class Codes: A47L 15/46 Devices for the automatic control of the different phases of cleaning ; Controlling devices A47L15/449 takes precedence
• CPC Class Codes: A47L 2301/00 Manual input in controlling methods of washing or rinsing machines for crockery or tableware, i.e. information entered by a user
• CPC Class Codes: A47L 2501/05 Drain or recirculation pump, e.g. regulation of the pump rotational speed or flow direction
• CPC Class Codes: A47L 2501/06 Water heaters

Abstract

The invention is a dishwasher and a control therefore in which the control comprises multiple parallel loads, including a motor. The motor and the other loads are connected to one side of a power source by a motor relay, which is controlled by a processor. All the loads, except the motor, are connected to the other side of a power source by semiconductor switches with each load having a corresponding switch. The motor has an unswitched connection to the other side of the power source. The power to all the loads, including the motor, is controlled by the motor relay. If one of the switches fails in such a way that the circuit for one of the loads is closed, then the load will be shut off when the motor relay is opened to shut off power to the motor. Thus, it is possible to prevent the failed load circuit from operating during the entire wash cycle.

Claims

1. An appliance comprising:

at least a first electrical load and a second electrical load that are connected in parallel and are energized by a power source having first and second supply lines;

a relay having contacts and the relay contacts connecting the first electrical load and the second electrical load in series to the first supply line;

a solid state device connecting the second electrical load in series to the second supply line; and

the first electrical load is connected directly to the second supply line such that energization of the first electrical load is controlled by closing and opening the relay contacts and whereby if the solid state device fails in the closed position, power to the second load can be controlled by opening and closing the relay contacts such that the second load is de-energized when the first load is de-energized during the appliance operation.

2. An appliance as claimed in claim 1, wherein the first load has first and second free ends and the first free end is connected to the relay contacts and the second free end is connected to the second supply line to form the direct connection.

3. An appliance as claimed in claim 2, wherein the second load has first and second free ends and the first free end is connected to the relay contacts and the second free end is connected to the solid state device.

4. An appliance as claimed in claim 1, wherein the first load is an electric motor.

5. An appliance as claimed in claim 4, wherein the electric motor comprises at least a main winding and the main winding is the first load.

6. An appliance as claimed in claim 1, wherein the second load is an actuator.

7. An appliance as claimed in claim 6, wherein the actuator is a solenoid.

8. An appliance as claimed in claim 6, wherein the actuator is a heater.

9. An appliance as claimed in claim 1, and further comprising a processor connected to the relay and to the solid state device for controlling the operation of the relay and the solid state device.

10. An appliance as claimed in claim 9, wherein the processor is a microcomputer.

11. An appliance as claimed in claim 9, and further comprising a switch module connected to the processor for receiving user inputs and supplying corresponding inputs to the processor.

12. An appliance comprising:

a motor and at least one other electrical load that are connected in parallel and are energized by a power source having first and second supply lines;

a relay having contacts and the relay contacts connecting the motor and the at least one other electrical load in series to the first supply line, the motor being connected directly to the second supply line;

a solid state device connected in series with the at least one other electrical load; and

a microcomputer interconnected to the relay and the solid state device for controlling their operation and for selectively energizing the first electrical load and the second electrical load,

wherein if the solid state device fails in the closed position, power to the second load can be controlled by the control means opening and closing the relay contacts during the appliance operation.