EP0326048A2 - Vorrichtung zur Überwachung der Wäschetrocknung in einem Wäschetrockner - Google Patents

Vorrichtung zur Überwachung der Wäschetrocknung in einem Wäschetrockner Download PDF

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Publication number
EP0326048A2
EP0326048A2 EP89101046A EP89101046A EP0326048A2 EP 0326048 A2 EP0326048 A2 EP 0326048A2 EP 89101046 A EP89101046 A EP 89101046A EP 89101046 A EP89101046 A EP 89101046A EP 0326048 A2 EP0326048 A2 EP 0326048A2
Authority
EP
European Patent Office
Prior art keywords
laundry
microprocessor
drying
output
heater element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89101046A
Other languages
English (en)
French (fr)
Other versions
EP0326048A3 (en
EP0326048B1 (de
Inventor
Fernando Russo
Elvio Zanon
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Industrie Zanussi SpA
Original Assignee
Industrie Zanussi SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Industrie Zanussi SpA filed Critical Industrie Zanussi SpA
Priority to AT89101046T priority Critical patent/ATE93907T1/de
Publication of EP0326048A2 publication Critical patent/EP0326048A2/de
Publication of EP0326048A3 publication Critical patent/EP0326048A3/en
Application granted granted Critical
Publication of EP0326048B1 publication Critical patent/EP0326048B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F34/00—Details of control systems for washing machines, washer-dryers or laundry dryers
    • D06F34/08—Control circuits or arrangements thereof
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F2101/00—User input for the control of domestic laundry washing machines, washer-dryers or laundry dryers
    • D06F2101/20—Operation modes, e.g. delicate laundry washing programs, service modes or refreshment cycles
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
    • D06F2103/02—Characteristics of laundry or load
    • D06F2103/08—Humidity
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F2103/00—Parameters monitored or detected for the control of domestic laundry washing machines, washer-dryers or laundry dryers
    • D06F2103/02—Characteristics of laundry or load
    • D06F2103/08—Humidity
    • D06F2103/10—Humidity expressed as capacitance or resistance
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F2105/00—Systems or parameters controlled or affected by the control systems of washing machines, washer-dryers or laundry dryers
    • D06F2105/28—Electric heating
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F58/00—Domestic laundry dryers
    • D06F58/32—Control of operations performed in domestic laundry dryers 
    • D06F58/34—Control of operations performed in domestic laundry dryers  characterised by the purpose or target of the control
    • D06F58/36—Control of operational steps, e.g. for optimisation or improvement of operational steps depending on the condition of the laundry
    • D06F58/38—Control of operational steps, e.g. for optimisation or improvement of operational steps depending on the condition of the laundry of drying, e.g. to achieve the target humidity

Definitions

  • the invention relates to an electronic control device for a laundry drier adapted to permit the execution of drying cycles for determining the drying of the laundry in a preselected manner.
  • Known laundry driers are designed to permit the execution of different laundry drying cycles selected in accordance with the type and quantity of the tissues to be dried and with the degree of dryness to be obtained. These drying cycles are adapted to be selected by the preliminary adjustment of a respective program control unit of the machine, which may comprise a conventional electromechan­ical timer or an electronic microprocessor, or by actuating respective push-button selectors associated to an electronic control device with which the machine is additionally provided for controlling the degree to which the laundry is to be dried.
  • a respective program control unit of the machine which may comprise a conventional electromechan­ical timer or an electronic microprocessor, or by actuating respective push-button selectors associated to an electronic control device with which the machine is additionally provided for controlling the degree to which the laundry is to be dried.
  • each drying cycle thus selected is automatically controlled by the program control unit by successively energizing and deenergizing the various electric components of the machine, while the pre-selected degree of dryness of the laundry is obtained thanks to the presence of the elctronic control device which is effective, in response to the moisture content of the laundry as detected by means of two detector elect­rodes disposed in the drum of the machine, to repeatedly energize and deenergize the heater element of the machine.
  • control devices comprising a load circuit substantially composed of a rectangular-pulse generator connected to an electric capacitor through a differentiating element, an amplifier, a diode and a limiting resistor, said capacitor having its terminal connected respectively to ground and to a first detector electrode together with said charge circuit.
  • the second detector electrode of the machine on its part is electrically insulated from the first detector electrode and is otherwise connected to ground.
  • Such control devices further comprise an electronic com­parator the input terminals of which are connected respect­ively to the electric capacitor, together with the first detector electrode and said charge circuit, and to a reference voltage source the voltage level of which is adjustable in accordance with the degree of dryness of the laundry to be attained, the output terminal of said com­parator being connected to the heater element of the machine through a flip-flop circuit and a control relay.
  • control device is operable to constantly charge the capacitor to a preselected voltage level through the charge circuit, while the capacitor on its part is partially discharged to ground through the detector electrodes when the latter are short-circuited by the wet laundry contained in the drum of the machine and coming into contact with the electrodes during the rotation of the drum.
  • the actual charge voltage level of the capacitor is applied to one input of the comparator and continually compared to the reference voltage applied to the other input of the comparator, until the charge voltage is higher than the reference voltage, whereupon there is no output signal at the output terminal of the comparator.
  • the comparator causes the heater element of the machine to be maintained in the energized state, with the result that the laundry is progressively dried.
  • the comparator When on the other hand the charge voltage is lower than the reference voltage, indicating that the laundry has been dried to the desired degree of dryness, the comparator supplies a positive signal at its output for causing the heater element to be deenergized through the flip-flop circuit and the control relay.
  • the program control unit may control the energization of a blower for the laundry cooling phase of the cycle, and for the subsequent termination of the selected drying cycle.
  • an electronic control device for a laundry drier having a rotatable drum for containing the laundry and at least one variable-output heater element
  • said device comprising at least one microprocessor containing encoded informations defining the drying cycles capable of being selected and adapted to control the execution of the selected cycles; first, second and third selector means operable respectively to select drying cycles with the rated output and reduced output of the heater element and to maintain said heater element energized for a supplement­ary period;
  • said devcie further comprising integrator means composed of a plurality of electric capacitors connected in parallel to one another to two sensor electrodes dis­posed in said drum and adapted to be short-circuited by the moist laundry, and comparator means adapted to control the energization and deenergization of said heater element through said microprocessor in response to the comparison of the charge voltage levels of said integrator means to a predetermined reference voltage.
  • a control device of this type is characterized according to the invention in that said microprocessor is adapted to identify each drying cycle selected by means of said first, second or third selector means through said integrator means, with the aid of an enabling signal generated by said microprocessor and supplied simultaneously to said integrator means and to said second and third selector means.
  • an electronic control device 1 for controlling the laundry drying process in a laundry drier substantially comprising a microprocessor 2 including a memory containing initially stored informations defining all drying cycles which can be executed by the respective drier.
  • Microprocessor 2 is also adapted to automatically control the execution of any drying cycle selected in the manner to be described; the control device further includes first, second and third selector means 3, 4 and 5 in the form of conventional push-button switches mounted in the control panel of the drier and adapted to be manually and separately actuated for selecting respective drying cycles at different drying temperatures.
  • the heater element 6 of the drier may be conventionally subdivided into several separate sections (in the present case two sections 7 and 8 adapted to be connected in parallel to one another). These heater element sections may be energized separately or in combination as required for generating the heat energy required for the drying process.
  • Heater element 6 on its part is connected to a power supply conductor 9 of the drier, and its energization is controlled by microprocessor 2 through a switch element 10 in the form for instance of a triac, a relay or the like, microprocessor 2 being otherwise connected to the other power supply conductor 11 of the drier.
  • First and second selector means 3 and 5 are both operable to select conventional drying cycles for cotton fabrics and resistant synthetics to be executed with the maximum heat output, to which purpose all sections of heater element 6 are interconnected for obtaining a predetermined degree of dryness of the laundry; in the second case, heater element 6 is maintained in the energized state for a predetermined supplementary period so as to determine the complete drying of the laundry (these drying cycles are denoted as "extra dry cycles").
  • Second selector means 4 on its part is operable to select drying cycles with reduced heat output for drying delicate synthetic fabrics, providing for the energization of only one section of heater element 6 for a sufficient period for attaining the preselected degree of dryness of the laundry (these drying cycles are referred to as "acrylic drying cycles").
  • the present control device further com­prises an integrator circuit 12 composed of a plurality of electric capacitors 13 connected, in parallel to one an­other, to limiter resistors, diodes and other per se known electronic components (all of which are now shown), and to two sensor electrodes 14 and 15 disposed in the rotating drum (not shown) of the drier adapted to contain the moist laundry to be dried, sensor electrodes 14 and 15 being connected respectively to integrator circuit 12 and to ground 16 and adapted to be short-circuited by the moist laundry to be dried.
  • Integrator circuit 12 is energized at a low voltage and adapted, in response to the selection of respective drying cycles by means of first, second and third selector means 3, 4 and 5, corresponding to predetermined degrees of dryness of the laundry, to vary the time constant of capacitors 13.
  • integrator circuit 12 is connected to first and second selector means 3 and 4, respectively, via respective conductors 17 and 18, and to third selector means 5 via a conductor 19 itself connected to conductor 18 and to a logic inverter 20 of conventional type, the function of which will become evident as the description proceeds.
  • the present control device finally comprises an electronic comparator 21 having its input terminals 22 and 23 connected respectively to integrator circuit 12 and to a fixed-level reference voltage source, and its output terminal 24, to a further conductor 25 adapted to connect second and third selector means 4 and 5 in parallel, and to microprocessor 2 through an optoinsulator 26 or a similar insulating element provided for electrically separating microprocessor 2, which is energized with the mains voltage through the respective conductors 9 and 11, from the components energized at low voltage (and comprising integrator circuit 12, selector means 3, 4 and 5, and electronic comparator 21).
  • Comparator 21 serves the purpose of comparing the charge voltage level of capacitors 13 of integrator circuit 12 as preselected by first, second or third selector means 3, 4 or 5, to the predetermined reference voltage level, for thus controlling, in response to the result of the compar­ison, the energization and deenergization of heater element 6 through microprocessor 2 and switch element 10 in the manner to be described.
  • microprocessor 2 For permitting microprocessor 2 to identify each drying cycle selected in the manner described, microprocessor 2 is arranged to furnish at its output 27 a continuous enabling signal of rectangular shape to be applied to an associated input 28 of microprocessor 2 and simultan­eously to integrator circuit 12 and second and third selector means 4 and 5, to which purpose output 27 is connected to conductors 18 and 19 through conductor 29 and a further optoinsulator 30 or a similar insulating element provided for electrically separating microprocessor 2 from the low-voltage elements defined above.
  • microprocessor 2 is responsive to the absence or presence at output 24 of comparator 21 of said enabling signal when a drying cycle to be executed has been selected by actuating first or second selector means 3 or 4, respectively, and of an enabling signal identical but complementary to the first-named signal, when a drying cycle has been selected by actuating third selector means 5.
  • the absence of the enabling signal at output 24 of comparator 21 results from the fact that different voltage levels are applied to the two inputs 22 and 23 of comparator 21.
  • the presence of the enabling signal at output 24 of comparator 21 results from the actuation of second selector means 4.
  • the comple­mentary enabling signal is obtained as a result of the presence of logic inverter 20 connected in series with third selector means 5.
  • microprocessor 2 operates to initiate the respective cycle by causing heater element 6 to be energized in accordance with the required heat output and to subsequently control in an automatic manner the execution of the selected cycle for the full duration thereof.
  • capacitors 13 of integrator circuit 12 are progressively charged when the enabling signal applied to integrator circuit 12 is at a high level, and are partially discharged to ground 16 via sensor electrodes 14, 15, as they are short-circuited by the moist laundry, when the enabling signal is at a low level.
  • comparator 21 furnishes a signal at output 24, causing heater element 6 to be deenergized by the action of microprocessor 2 and switch element 10.
  • microprocessor 2 may initiate the cooling phase by causing the blower (not shown) of the drier to be energized to thereby cool the laundry and the metallic parts of the drum and the housing of the drier as the conclusion of the selected drying cycle.
  • this device permits to contemporanously obtain, during the selection of the drying cycle to be executed by the actuation of first, second or third selector means 3, 4 or 5, respectively, the identification and subsequent control of the selected cycle by micro­processor 2, and the adjustment of the degree of dryness required for the respective laundry by the variation of the time constant of capacitors 13 of integrator circuit 12 due to the presence of the enabling signal furnished by the microprocessor.
  • the present control device is of a simple construction elim­inating the need of expensive electromechanical devices for controlling the execution of the drying cycles, thanks to the fact that these operations are directly controlled by the microprocessor which is energized from the electric circuit of the drier and electrically separated by opto-­insulators 26 and 30 from the low-voltage electrical components of the control device itself.
  • This device also permits a combined selection of the drying cycle and of the desired degree of dryness to take place by solely acting on selector means 3, 4 and 5, thus eliminating the need of separate push-button actuators for selecting the degree of moisture (or of dryness) of the laundry as required in previous solutions, with the resultant simplification of the overall construction of the laundry drier.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Control Of Washing Machine And Dryer (AREA)
  • Drying Of Solid Materials (AREA)
EP89101046A 1988-01-25 1989-01-20 Vorrichtung zur Überwachung der Wäschetrocknung in einem Wäschetrockner Expired - Lifetime EP0326048B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT89101046T ATE93907T1 (de) 1988-01-25 1989-01-20 Vorrichtung zur ueberwachung der waeschetrocknung in einem waeschetrockner.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT4570288 1988-01-25
IT45702/88A IT1220738B (it) 1988-01-25 1988-01-25 Dispositivo di controllo dell'asciugatura della biancheria per macchina asciugabiancheria

Publications (3)

Publication Number Publication Date
EP0326048A2 true EP0326048A2 (de) 1989-08-02
EP0326048A3 EP0326048A3 (en) 1990-05-30
EP0326048B1 EP0326048B1 (de) 1993-09-01

Family

ID=11257352

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89101046A Expired - Lifetime EP0326048B1 (de) 1988-01-25 1989-01-20 Vorrichtung zur Überwachung der Wäschetrocknung in einem Wäschetrockner

Country Status (4)

Country Link
EP (1) EP0326048B1 (de)
AT (1) ATE93907T1 (de)
DE (1) DE68908727T2 (de)
IT (1) IT1220738B (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2239700A (en) * 1990-01-05 1991-07-10 Hotpoint Ltd Spin control in combination washing and drying machines
EP0940494A1 (de) * 1998-03-03 1999-09-08 Whirlpool Corporation Trommeltrockner mit Prozesssteuerung und Leitfähigkeitsmesswertaufnehmer
AU2002243077B2 (en) * 2001-03-29 2004-06-03 Lg Electronics Inc. Method and device for heater control in drying apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4142473A (en) * 1976-08-26 1979-03-06 Akihiko Itoh Micro processor controlled sewing machine pattern generator
EP0039645A1 (de) * 1980-05-06 1981-11-11 Thomson-Brandt Wäschetrockner mit elektronischer Programmsteuerung
US4385452A (en) * 1981-06-03 1983-05-31 Whirlpool Corporation Low voltage sensor for dryer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4142473A (en) * 1976-08-26 1979-03-06 Akihiko Itoh Micro processor controlled sewing machine pattern generator
EP0039645A1 (de) * 1980-05-06 1981-11-11 Thomson-Brandt Wäschetrockner mit elektronischer Programmsteuerung
US4385452A (en) * 1981-06-03 1983-05-31 Whirlpool Corporation Low voltage sensor for dryer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2239700A (en) * 1990-01-05 1991-07-10 Hotpoint Ltd Spin control in combination washing and drying machines
GB2239700B (en) * 1990-01-05 1993-11-24 Hotpoint Ltd Combination washing and drying machine
EP0940494A1 (de) * 1998-03-03 1999-09-08 Whirlpool Corporation Trommeltrockner mit Prozesssteuerung und Leitfähigkeitsmesswertaufnehmer
AU2002243077B2 (en) * 2001-03-29 2004-06-03 Lg Electronics Inc. Method and device for heater control in drying apparatus

Also Published As

Publication number Publication date
EP0326048A3 (en) 1990-05-30
DE68908727D1 (de) 1993-10-07
IT1220738B (it) 1990-06-21
ATE93907T1 (de) 1993-09-15
DE68908727T2 (de) 1993-12-16
IT8845702A0 (it) 1988-01-25
EP0326048B1 (de) 1993-09-01

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