Temperature controller for fluid in an apparatus having a plurality of operation cycles

• US 3,875,424 A
• Filed: 08/27/1973
• Issued: 04/01/1975
• Est. Priority Date: 03/02/1972
• Status: Expired due to Term

• Current Assignee: Charles L. Hopkins
• Original Assignee: Charles L. Hopkins
• Inventors: Hopkins, Charles L.
• Primary Examiner(s): Schaffer, Robert K.
• Assistant Examiner(s): Ginsburg, M.
• Application Number:
  US05/391,974
• Time in Patent Office: 582 Days
• Field of Search: 307/116,117 219/494,497,499,486
• US Class Current: 307/117
• CPC Class Codes: D06F 2103/16 Washing liquid temperature
• CPC Class Codes: D06F 2105/04 from separate hot and cold water inlets
• CPC Class Codes: D06F 2105/10 Temperature of washing liquids; Heating means therefor
• CPC Class Codes: D06F 33/30 Control of washing machines characterised by the purpose or target of the control controlling processes of washer-dryers D06F33/50
• CPC Class Codes: D06F 34/24 Liquid temperature
• CPC Class Codes: G05D 23/1912 whose output amplitude can take more than two discrete values
• CPC Class Codes: G05D 23/24 the sensing element having a resistance varying with temperature, e.g. a thermistor

Abstract

A temperature controller for controlling the temperature of water in a washing machine during each one of the operation cycles of the washing machine. A separate circuit for each operation cycle of the machine is provided for producing a signal representative of a selected water temperature during that cycle. A single temperature indicating device indicates the water temperature during each one of the cycles and a single thermistor circuit produces a signal representative of the actual water temperature during each one of the cycles. The signal from the temperature selection circuit and the thermistor circuit is applied to a comparison means which produces an output signal dependent on a predetermined relationship of the two input signals and causes water of a temperature required to reach desired water temperature to be added to the washing machine. A programmer selects the cycle in which the washing machine is to operate and also actuates the temperature selection circuit which is to control the water temperature of the operation cycle selected. Actuation of any one temperature selection circuit produces an output which blocks any output from the other temperature selection circuits to the comparison means so that there will be no interference with the comparison of the signal from the actuated temperature selection circuit and the signal from the thermistor circuit.

Claims

1. A control circuit for controlling the temperatUre of a fluid in an apparatus having a plurality of operation cycles comprising:

first circuit means comprises a separate signal circuit for each one of said operation cycles, each signal circuit having an output signal condition and producing a predetermined first signal representative of a desired fluid temperature during each one of said operation cycles when in said condition, no more than one of said signal circuits having an output signal condition at any given time, the other signal circuits having a normal signal condition, said first circuit means includes blocking circuit means responsive to the output signal condition of said one of the signal circuits to block the normal signal condition of the other signal circuits;

second circuit means for producing a second signal representative of the actual fluid temperature and indicating said actual temperature during each one of said operation cycles; and

third circuit means connected to said first and second circuit means and being responsive to the first and second signals for comparing the levels of said first and second signals during each one of said operation cycles and producing an actuating signal when the levels of said first and second signals have a predetermined relationship.

2. The combination according to claim 1 wherein:

each signal circuit has an output terminal; and

said blocking circuit means comprises a different diode connected between each signal circuit and the third circuit means, all diodes being commonly connected together between said diodes and the third circuit means.