FR2497243A1 - DEVICE FOR CONTROLLING A LAUNDRY DRYER - Google Patents

Abstract

THE PRESENT INVENTION RELATES TO A CONTROL DEVICE FOR A LAUNDRY DRYER. THE DEVICE INCLUDES A DEVICE FOR DETECTION OF A CERTAIN PREDETERMINED INTERMEDIATE HUMIDITY LEVEL, DEVICE BASED ON THE MEASUREMENT OF THE CONDUCTIVITY OF THE LAUNDRY, TO WHICH IS ASSOCIATED A TIMING DEVICE INTENDED TO OBTAIN THE DESIRED FINAL HUMIDITY LEVEL AND A SELECTOR THIS FINAL HUMIDITY LEVEL DESIRED BY THE USER. IT FURTHER INCLUDES A DEVICE FOR MEASURING SUCCESSIVE HUMIDITY LEVELS EXISTING BEFORE THE PREDETERMINED INTERMEDIATE HUMIDITY LEVEL IS REACHED, A DEVICE FOR DETERMINING THE SLOPE OF THE CURVE OF THE EVOLUTION OF THE CONDUCTIVITY OF THE LAUNDRY, DEPENDING ON THE TIME, A DEVICE FOR MEMORIZING THE SAID SLOPE, AND MEANS FOR DETERMINING THE TIME STILL NECESSARY TO OBTAIN THE FINAL LEVEL OF HUMIDITY DESIRED, AS A FUNCTION OF THE SAID SLOPE.

Description

The present invention relates to the control devices of dryers to

  laundry, dryers having a rotating drum containing the laundry and a forced hot air device. These control devices include a

  device for detecting a predetermined intermediate rate of humidity

  dity, device based on the measurement of the conductivity of the laundry, which is associated with a delay device for obtaining the humidity level

  desired end-point, and a selector of this final moisture content desired by the use

  lisateur. In known control devices of this type, such as that described in French Patent No. 2,091,558, the delay period selected by the user to obtain the desired final moisture content rate begins when the predetermined intermediate humidity level. is reached, and stops automatically at the end of the delay, regardless of

  of the nature and quantity of the laundry contained in the drum, so without

  take into account the drying speed of the laundry. This is a disadvantage because the desired final moisture content, which has been selected by the user,

  is not obtained in all cases. It can vary about 5%.

  The control device according to the invention is characterized in that

  that it comprises a device for measuring successive humidity levels,

  successive temperatures, existing before the inter-

  predetermined moisture level is reached, and a device for determining

  nation of the slope of the curve of the evolution of the laundry conductivity, respectively the evolution of the temperature of the laundry, depending on the

  time. The control device further comprises a memory device

  of said slope, and means for determining the time still

  necessary to obtain the desired final moisture content, depending on the

slope.

  An advantageous embodiment variant can be used in the case where

  the control device comprises a device for measuring the humidity level

  successive stages before the intermediate moisture content prede-

  completed, and a device for determining the slope of the

  curve of the evolution of the conductivity of the linen as a function of time.

  In this case, the device for memorizing said slope and the means

  to determine the time still necessary to obtain the final rate of human

  desired moisture content, as a function of said slope, are constituted by a condensation

  Sator fed through a current generator device controlled by two voltage threshold detectors, detectors whose inputs are connected to two rubbers constantly in contact with the laundry. One of the detectors is set to detect a lower conductivity threshold than

  the other. The first is intended to control the loading of the conden-

  sator, the second to interrupt this charge and to position an input of a third threshold detector, provided to control the stopping of the drying when the capacitor voltage discharged through at least one resistor of the final moisture content selector, is below a predetermined threshold of voltage. The control device, according to the invention, proposes in particular to overcome the disadvantages of the prior art. It allows to obtain accurately the final moisture content of the laundry, desired by the user, in

  taking into account the nature and quantity of linen.

  The attached drawing illustrates, by way of example, ways of

  according to the present invention.

  Fig. 1 represents the electrical connection diagram of the first

  and the third embodiment.

  Fig. 2 represents the organization chart of the Capital Management Program.

  in the first embodiment.

  Fig. 3 represents the diagram of electrical connection of a second

embodiment.

  Fig. 4 graphically represents the evolution of the voltage at the terminals

  during the drying of the linen, as a function of time, in

  the same second embodiment.

  Fig. 5 graphically represents the evolution, during the same time,

the voltage Uc.

  Fig. 6 represents the organizational chart of the Capital Management Program.

  in the third embodiment.

  Fig. 7 represents the organizational chart of a management subprogram of

  the temperature, in the same third embodiment.

  As shown in FIG. 1, the control device com-

  carries an integrated circuit 1, which is in our example the TMS 1000 microcomputer from Texas Instruments Incorporated, which has four KI inputs,

  K2, K4 and K8 and outputs S1, S2, S3, F4, S5, S6 ..... S11. The circuit

  tegree includes an instruction address register 3 connected to a memory

  ROM 9, which contains a number of cells in which are

  following instructions corresponding to the program which must be

  be executed by the integrated circuit 1.

  The ROM mainly comprises three distinct programs: the keyboard and display management program 19, the time management program 20 and the temperature control and humidity measurement program 21. These three programs use the functions of a

  analog demultiplexer 14 and an analog-to-digital converter13.

  RAM 8, read-write, used to store data

  created temporarily, is also linked to the instruction decoder register.

  4 and the address register 3. Moreover, in this integrated circuit 1, the addressing registers 3 are connected to an output network 6, and to

  an arithmetic and logical unit 5 capable of carrying out the operations of

  instructions and order the sequencing of the different cycles required by these instructions. The arithmetic and logical unit 5 is

  also able to read the logical levels of the inputs KI, K2, K4 and K8.

  The output network 6 is connected to the outputs S1, S2, and the groups of

  outputs S3-S6, S -SI1 of the microcomputer. This output network 6 is

  switched by the switching circuits allowing the outputs SI to SI1 of

  take the logical levels zero or one.

  A clock 7 is connected to the memory 8, to the address register of inserts.

  truction 3, the instruction decoder register 4, the arithmetic logic unit 5, and the output network 6. It synchronizes the operation

  of these various elements, and the transmissions between them.

  The output SI is connected to switches t1 and t2 and to a display circuit 10. Output S2 is connected to switches t3 and t4 and to display circuit 11. The switches t1 and t4 are connected to the input K2, the switches t2 and t3, to the input K1. The switches t1 to t4

  constitute the control means of the selector of the final moisture content.

  The input K8 is connected to the power supply 2. The outputs S7 to S11 are connected to

  linked, through a network of interfaces 12, to the organs of the

  machine to be ordered.

  The output S3 is connected to the analog demultiplexer 14. The converter

  Digital analog transmitter 13 is itself also connected to the input K4 of the integrated circuit 1 and the analog demultiplexer 14. The outputs S5-S6

  are also connected to the analog-to-digital converter.

  I, I2 and I3 of the analog demultiplexer 14 are respectively connected

  temperature probes 16 and 17 and the capacitor 18 which

  The same is also connected to the rubbers 15 of the drum.

  A DC power supply 2 mains mains supply feeds the circuit

  integrated bake 1, the interface block 12, the display circuits 10 and 11, the analog-digital converter 13 and the analog demultiplexer 14. The RAM 8 comprises a register 22 "conversion code", a

  timer counter 23, an area for storing the data

  tantanées 24 and an "averaged" data storage area.

  The elements 125, 126, 127, 128 shown in phantom in FIG. 1, relate only to the third embodiment, described

further.

  As shown schematically in FIG. 2, the management program

  sensors has several subroutines 25 to 37. The subprogram

  The conversion program 25 includes instructions, the last of which precedes the first instruction of the conversion code increment routine 26. The last instruction of this subroutine 26 precedes the first instruction of the zero conversion code test subroutine 27 whose last instruction is a conditional call instruction to the address of the first instruction of subroutine 36. management of the

  temperature probe 16 or at the address of the first instruction of the sub-

  program 28 to test the conversion code to one.

  The last instruction of subprogramme 28 is also an

  conditional call truction to the address of the first instruction of the temperature sensor management subroutine 37 or to the address

  of the first instruction of subroutine 29 for memorizing the result of

  state of the conversion. The last instruction of subroutine 29 precedes the first instruction of test routine 30 from the current address to 8.

  The last instruction of subroutine 30 is a command instruction

  conditional at the address of the first instruction of the subroutine

  25 or the address of the first instruction of subprogram 31

  ass of the average value. The last instruction of subprogramme 31 pre-

  gives the first instruction of the next memory routine 32

  the principle of a FIFO register of the average value calculated in the sub-

  31. The last instruction of subprogramme 32 precedes the first

  first instruction of the test subprogram 33 of the average value.

  The last instruction of subroutine 33 is an instruction of

  conditional at the address of the first instruction of the subroutine

  24 address or the first instruction of the subprogram 34 of the

  the time required to obtain the selected moisture content

tioned.

  The last instruction of subroutine 34 precedes the first

  truction subprogram 35 execution of the timer. The last

  subprogrammes 36 and 37 are instructions for

  address to the first instruction of subroutine 26.

  During the operation of the control device, the program

  held in the memory 9 of the integrated circuit 1 successively manages the time using the mains signal, rectified and formatted (present signal

  on-input K8), the keys, that is to say the switches t1 to t4, the

  logical training from the digital analog converter 13 and the

  control of the lamps 10 and 11 which indicate to the user the state of the

  tomatisme. The integrated circuit 1, through the interface block 12, controls the elements of the tumble dryer such as the drum drive motor and

  of the fan, the heating resistor, and the solenoid valve

  if the dryer is of the condensing type.

  The integrated circuit 1, from the commands given by the user using the switches t1 to t4, uses the subroutines described by the flowchart (FIG 2), for the control of the temperature in the dryer at using the probes 16 and 17, and for controlling the humidity with the

  rubbers 15 located on the drum of the dryer. The integrated circuit 1

  of the digital analog converter 13 using the subroutine 25

  to obtain a binary number corresponding to the analog value of the

  present at the input of the converter. In this example, the conversion program takes two seconds. According to the conversion code, the integrated circuit 1 controls the analog demultiplexer 14 (via its outputs S3 and

  S4) so that the voltage at the terminals of the probe 16 (conversion code)

  sion = zero), at the terminals of the probe 17 (conversion code = one) or

  terminals of the rubbers 15 (conversion code = two), either present at

  analog converter 13.

  As described in the flowchart (FIG 2), the integrated circuit

  1 successively control the temperature given by the probe 16, then

  the temperature given by the probe 17 and the voltage across the terminals

  15. Since the conversion program lasts two seconds, a measurement

  the tension of the rubbers 15 takes place every six seconds.

  In the case of using a TL 507 analog digital converter from Texas Instruments, this measurement is stored in the form

  of seven bits (converter capacity) in the RAM 8 of the integrated circuit 1.

  These measurements of the tension of the rubbers 15 are stored at eight

  succession (the current address from zero to seven) corresponds to

  24. When eight measurements are stored, the integrated circuit 1, using the subroutine 31, calculates the average value of these eight measurements and stores this value in a FIFO register (first in,

  first out) o are successively ranked the average values.

  When the FIFO register is filled, for each new data to

  moriser, is lost the oldest average value. The reason for

  what the measurements are grouped, then "averaged" is that the information transmitted by the rubbers 15 is far from perfect and fluctuates without stop depending on the position of the laundry in the drum. This technique makes it possible to obtain reliable information on the conductivity of the linen located

in the drum.

  When the calculated average value corresponds to the maximum value

  this principle of measuring the conductivity makes it possible to carry out the subroutine 34 of the integrated circuit I using the data stored in the FIFO register,

  determines the time required to reach the selected humidity level.

  born. More precisely, this subroutine 34 is the sum of the differences between the average values recorded in the FIFO register and the maximum measurable value. This sum represents well the evolution of the moisture of the laundry in the drum, and the integrated circuit 1 compares this sum with a

  table to determine the final delay.

  Then, the integrated circuit 1, with the subprogram 35, realizes this.

  the delay. At the end of this chosen time period, the

  linen has a moisture content corresponding to that selected previously. -

  In the second embodiment of the invention, shown in FIG. 3, the control device is supplied with direct current by a circuit 51 and has two threshold detectors 59 and 64 which control a charging circuit 69 of a capacitor 70, another threshold detector 76 and a control device. the advance of the dryer programmer

  Resistor 56, shown in broken lines, represents the

  variable resistance of the laundry between two wipers 54 and 55. These wipers 54 and 55 are connected to the terminals of a capacitor 53. The wiper 55 is joined to the minus terminal of the supply 51 and the wiper 54 is connected to

  the terminal plus of the power supply 51 via a resistor 52.

  The wiper 54 is also connected to the input plus of the detector 59

  whose input is connected to a resistance bridge57 and 58, which

  xe the potential UI of this input. The output of the threshold detector 59 is connected to the resistor 66 and to a zener diode 68 of the charge control circuit 69. The wiper 54 is also connected to the plus input / threshold detector 64 whose less input is connected. to a bridge of resistors 62 and

  63, which sets the voltage U2 of this input. The output of this detector -

  threshold 64 is connected, through a resistor 65, to the base of a transistor 67 of the charging circuit 69. This transistor 67 is connected, by its base to the zener diode 68, by its emitter to the resistor 66 and by its collector at capacitor 70, at resistor 74 and at the input of threshold detector 76. Capacitor 70 and resistor 74 are also connected to

less than food 51.

  The selector 85 of the final moisture content is constituted by the resistance

  74 and by two push switches 81 and 82 connected, on the one hand to the capacitor 70 and the collector of the transistor 67, and on the other hand at least of the supply 51 through respectively resistors 83 and 84.

  The plus input of the threshold detector 76 is connected to a reset bridge

249724?

  sistances 72 and 73, which sets the voltage U3 thereof. This bridge of resistance

  The output of the threshold detector 76 is connected, through a resistor 78, to the base of a transistor 79 whose emitter is connected to at least one of the power supply 51. the collector, to the relay 80 coil which is also connected

more than food 51.

  To understand the operation of this control device, it

  see fig. 3, 4 and 5. The user activates the interrup-

  81 and 82 of the selector 85 of the final moisture content to select the desired final moisture content, for example from 5% to 20%. During operation, the capacitor 53 charges through the resistor 52 and discharges into the resistor 56 which represents the variable resistor of the resistor 52.

  machine. When the laundry is very wet, the voltage at the terminals of the condensa-

  53 is low, then, as the drying progresses, the voltage

  This capacitor 53 increases as shown in FIG. 4. When the level of the voltage across the capacitor 53 reaches the value of the

  potential Ul, the voltage of the output of the threshold detector 59 becomes

  The threshold detector 59 supplies power to the capacitor charge device 70. As long as the voltage across the capacitor 53 is lower than the voltage U2, the voltage of the detector output threshold 64 is close to zero (or at least that of the power supply 51) and the transistor 67 isLonductor; The assembly of this

  transistor 67 with the resistor 66 and the zener diode 68 provides the general

  constant current for the charge of the capacitor 70.

  As soon as the voltage at the terminals of the capacitor 53 reaches the voltage U2 fixed by the resistor bridge 62 and 63, the output of the threshold detector 64 becomes close to the larger of the supply 51 and causes the blocking of the

charging circuit 69.

  The capacitor 70 then discharges into at least one of the resistors 74, 83, 84 of the selector 85. The threshold detector 76 controls the relay 80 via the transistor 79, when the potential of the capacitor falls below the voltage U3 set by the resistance bridge 72

and 73.

  This method makes it possible to obtain, after the detection of the voltage U2 cor-

  corresponding to the maximum limit voltage given by the rubbers 54 and 56,

  the capacitor 53 and the resistor 52, a delay whose duration

  depends on the time elapsed between the detection of the voltage levels U1 and U2,

  therefore, the drying speed of the laundry.

  In this embodiment, the measurements of the moisture content successively

  In practice, the resistor 52 and the capacitor 53 reduce the voltages measured by the threshold detectors 59 and 64. The second of the successive humidity levels measured corresponds to the voltage U2 which also corresponds to the humidity level. predetermined intermediate. In the third embodiment, shown in FIGS. 6, 7, the control device has, for the part, the same structure as that

  previously described with reference to FIG. 1, in the first mode of

  lisation. This fig. 1 remains valid. Only four elements have been added to the structure shown in FIG. 1: a slope storage register 125, a slope storage indicator register 126, a present temperature storage register 127 and a past temperature storage register 128 contained in the RAM memory

  8. They are shown in broken lines in FIG. 1.

  As shown schematically in FIGS. 6 and 7, the sensor management program comprises several subroutines 25 to 31, 35 and 37 identical to those of the first embodiment. The management program

  further comprises subprogrammes 132, 133, 134, 135 and 137. The sub-program

  conversion program 25 includes instructions, the last of which precedes the first instruction of the subprogram 26 of incrementing the

  conversion code. The last instruction in this subprogram 26

  of the first instruction of the subroutine 27 for testing the conversion code.

  the last instruction is a conditional call instruction.

  the first instruction of subroutine 137 for calculating the slope of increasing temperatures measured with probe 16, or the address of the first instruction of subroutine 28 for testing the conversion code at one. The last instruction of subroutine 28 is also a conditional call instruction to the address of the first instruction of subroutine 37 for managing the temperature probe 17.

  or the address of the first instruction of memory subprogram 29

  the result of the conversion. The last instruction of the sub-pro-

  gram 29 precedes the first instruction of routine 30 to test the current address at 8. The last instruction of subroutine 30 is a conditional call instruction at the address of the first instruction

  subprogramme 26 or at the address of the first sub-program instruction

  program 31 for calculating the average value. The last instruction of subroutine 31 precedes the first instruction of subroutine 132 of

  testing the average value against a predetermined value. The last

  Subprogram instruction 132 is a conditional call instruction.

  address at the address of the first instruction of the subroutine 26 or the address of the first instruction of the subroutine 133 of

  the slope memory indicator 126. The last instruction

  program 133 precedes the first of the subroutine test routine 134.

  their average. The last instruction of subroutine 134 is an

  conditional call to the address of the first instruction of the subroutine 26 or the address of the first instruction of the subroutine 135 for calculating the delay required to obtain the rate

humidity selected.

  The last instruction of subroutine 135 precedes the first

  truction subprogram 35 execution of the timer. The last

  instructions of subprogrammes 137 and 37 are instructions from

  connect to the address of the first instruction of the subroutine 26.

  Subprogram 137, shown in detail in FIG. 7, includes several subroutines 39 to 43. This subroutine 137 begins with a

  subprogramme 39 for the transfer of information, register 127 for

  tion of the present temperature, to the memory register 128 of

  the temperature passed. The last instruction of subprogramme 39 above

  of the first instruction of the subroutine 40 of storing the result of the digital analog conversion in the register 127 for storing the present temperature. The last instruction of subprogram 40 precedes the first instruction of subroutine 41 for calculating the slope

  (rate of change of temperature). The last instruction of the sub-

  program 41 precedes the first instruction of the test routine 42

  register 126 slope storage indicator. The last instruction

  subprogramme 42 is a conditional appeal instruction to the

  establishes the first instruction of subroutine 26 or the first instruction of subroutine 43 for transferring the calculation result of the

  slope in the slope memory register 125. The last instruction

  Subprogram 43 is a branch instruction to address

  of the first instruction of subroutine 26.

  The operation of the third embodiment of the control device is identical to that of the first embodiment previously described (Figures 1 to 5), until the time when the subroutine 31 calculates the va

  their average of the eight measurements stored in the memory 24.

  Subprogram 137, after each measurement of the analog converter

  that digitall 3 determines, using the values contained in the registers 127 and 128, the curvature slope of the evolution of the laundry temperature as a function of time and stores this slope in the register 125 of memo

slope.

  When the average value calculated in subprogramme 31 cor-

  set to a predetermined value, the program 33 sets the register 126 slope storage flag, so that using subprogram 42, the slope of the rise in temperature remains stored in the register

memorizing slope.

  Without departing from the scope of the present invention, the storage of the slope of the rise in temperature could be carried out at another instant, for example when a predetermined temperature is reached. The method of calculating the slope of the rise in temperature could also be

done in a different way.

  When the calculated average value corresponds to the maximum value

  Surprising by this principle of conductivity measurement, the subroutine of the integrated circuit 1, using the memory stored in the slope storage register, determines the time required to reach

  the selected humidity level. Then, the integrated circuit], with the sub-

  program 36, realizes this delay.

Claims (2)

  1. Apparatus for controlling a clothes dryer, dryer having a drum   rotational bur containing the laundry and a forced hot air device, the   said control device comprising a device for detecting a predetermined intermediate moisture level, a device based on measuring the conductivity of the laundry, which is associated with a delay device for obtaining the desired final moisture content, and   a selector of this final moisture content desired by the user,   characterized in that it comprises a device for measuring the humidity level   suaessive, respectively successive temperatures, existing before the predetermined intermediate moisture level is reached, a device for determining the slope of the curve of evolution   of the conductivity of the linen, respectively of the evolution of the temperature   a method for storing said slope, and means for determining the time still necessary to obtain the desired final moisture content, according to said time, as a function of time.   2. Control device according to claim 1, comprising a device   tif (59, 64) of successive moisture content measurements before   the predetermined intermediate moisture content is reached, and a   positive (60) for determining the slope of the curve of the change in the conductivity of the laundry as a function of time, characterized in that   the device for memorizing said slope and the means for deter-   undermine the time still needed to obtain the final moisture content   desired, as a function of said slope, are constituted by a condensation   power source (69) controlled by two voltage threshold detectors (59, 64), whose inputs are connected to two wipers (54, 55) constantly   in contact with the laundry, one (59) of the detectors being set to de-   sensing a lower conductivity threshold (64), the first (59) being provided to control the charging of the capacitor (70), the second (64) for interrupting this load and for positioning an input of a third threshold detector (76), provided to control the cessation of drying when the voltage Uc of the capacitor (70) discharged through at least one resistance (74, 83, 84) of the selector 85 of the rate   of final humidity, is below a predetermined threshold of voltage U3.