JP4523698B2 - Dishwasher switch circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a switch circuit used in a dishwasher including a water supply solenoid valve for water supply, a heater for heating cleaning water, a cleaning pump for cleaning water circulation, and a drain pump for draining cleaning water.
[0002]
[Prior art]
Conventionally, in this type of dishwasher, a power switch is soft touched by combining a tact switch and a relay in place of a mechanical switch, and the mainstream.
[0003]
FIG. 2 shows an example of a conventional switch circuit in which the power switch is soft touched. However, in FIG. 2, for the sake of simplicity, the operation switches other than the tact switch as the power switch are not shown.
[0004]
The switch circuit shown in FIG. 2 is used in a dishwasher including a water supply solenoid valve 1, a heater 2, a washing pump 3, a drainage pump 4, a fan 5, and the like. When the operation is performed, the control unit 19a constituted by a microcomputer or the like detects the ON operation (due to the contact closed state), and drives the power relay 10 to close the contact 10a, thereby turning on the power. It becomes the composition which becomes.
[0005]
By the way, the tact switch for the power switch generally constitutes an operation unit together with other operation tact switches, and a so-called microcomputer is used for detecting the operation (pushing operation) for each tact switch. A dynamic circuit is often employed.
[0006]
FIG. 3 shows an example of a conventional switch circuit composed of a dynamic circuit, and FIG. 4 is an explanatory diagram of an operation example of the dynamic circuit. However, in FIG. 3, for the sake of simplicity, illustration of configurations other than those related to the dynamic circuit is omitted.
[0007]
In the switch circuit shown in FIG. 3, the control unit (microcomputer) 19b transmits operation detection signals having a predetermined pulse width from the three output lines A to C at different times, and these signals are input to the input lines. It is configured to detect whether or not an on operation has been performed on the tact switch depending on whether or not the signal has been received via the tact switch connected to each of the ac switches.
[0008]
For example, when the ON operation is performed on the tact switch SW7, the signal transmitted from the output line A is received by the input line a via the tact switch SW7 as shown by “SW7 ON” in FIG. Thus, it becomes possible to detect the on operation for the tact switch SW7. Similarly, when the turn-on operation is performed on the tact switches SW6 and SW9, the signals transmitted from the output lines A and B are changed to the tact switches SW9 and SW6 as shown by “SW6 and SW9 on” in FIG. Therefore, it is possible to detect the ON operation for the switches SW6 and SW9.
[0009]
As described above, when a dynamic circuit is adopted as the switch circuit, operations for each tact switch are performed with a smaller number of signal lines compared to a so-called static circuit that detects operations for each tact switch via an individual input line. Can be detected. For example, as shown in FIG. 3, when detecting an operation on nine tact switches SW1 to SW9, nine input lines are required in the static circuit, whereas three output lines A to in the dynamic circuit are required. A total of six signal lines including C and three input lines a to c are sufficient.
[0010]
[Problems to be solved by the invention]
However, when an operation on a tact switch as a power switch is detected by a dynamic circuit as in the conventional switch circuit described above, a power relay corresponding to the power switch is turned on due to noise generated when other home appliances are operated. There was a problem that bugs were likely to occur.
[0011]
In other words, in the dynamic circuit, the number of signal lines can be reduced by sharing the signal lines, but on the other hand, a detection delay of the on operation for the tact switch is inevitably generated, so that a person does not feel the delay. Therefore, it is necessary to time-divide each output line by setting several tens of milliseconds (about 20 ms is a limit) as one cycle TM, so that a filter circuit having a hardware configuration can be provided for each tact switch. It becomes easy to be affected by noise as shown in “Noise from other home appliances” in FIG. 5, and as a result, if the tact switch is operated, the control unit is likely to be erroneously detected. . Also, in recent years, home appliances that radiate high-frequency noise such as inverters are increasing, so that it is desired to prevent malfunction due to the erroneous detection.
[0012]
The present invention has been made in view of the above circumstances, and can reduce the number of operation detection signal lines for each switch as compared to a static circuit, and can be noise generated when other home appliances are operated. It is an object of the present invention to provide a switch circuit for a dishwasher that can prevent the occurrence of a problem that a relay corresponding to a power switch is turned on.
[0013]
[Means for Solving the Problems]
In order to solve the above problems, the invention described in claim 1 is used in a dishwasher equipped with a water supply solenoid valve for water supply, a heater for heating washing water, a washing pump for washing water circulation, and a drainage pump for washing water drainage. A main power relay for turning on / off the main power, and for turning on / off the power of the water supply solenoid valve, the heater, the washing pump, and the drainage pump via the main power relay, respectively. A plurality of sub power relays, a power switch for small signals, a plurality of operation switches for small signals, and on / off control of the main power relay according to an operation on the power switch, and the plurality of operations in response to an operation to switch a control unit for performing on / off control of said plurality of sub power relay, the power switch circuit for operation detection for the power switch Connected individually via the input line constituted by a static circuit which detects the operation to the power switch, the plurality of predetermined pulse width circuit at different time points to a plurality of output lines for operation detection on the operation switch And a dynamic circuit for detecting an operation switch operated from the plurality of operation switches based on an input line to which the signal is input and an output line to which the signal is transmitted. .
[0014]
In this configuration, the operation detection circuit for the plurality of operation switches is configured by a dynamic circuit, so that the number of operation detection signal lines for each switch is smaller than that of the static circuit, and operation detection for the power switch is performed. By configuring the circuit as a static circuit, it is possible to provide a hardware-configured filter circuit in the vicinity of the input terminal of the control unit to which the power switch is connected. This occurs when other household appliances are activated (continuous). The trouble that the power supply relay corresponding to the power switch is turned on by noise is less likely to occur.
[0015]
According to a second aspect of the present invention, in the switch circuit of the dishwasher according to the first aspect, the dishwasher includes a drying fan, and the plurality of sub power relays are connected to the water supply electromagnetic via the main power relay. The valves, heaters, cleaning pumps, drainage pumps, and fans are turned on / off. Even in this configuration, the number of operation detection signal lines for each switch is smaller than that of the static circuit, and the power relay corresponding to the power switch is turned on by noise generated when other home appliances are activated. It becomes difficult.
[0016]
According to a third aspect of the present invention, in the switch circuit of the dishwasher according to the first or second aspect, the control unit is configured such that after the dishwasher starts by an on operation on the power switch and an operation on the plurality of operation switches, No operation other than the power switch and the temporary stop switch that is one of the plurality of operation switches is accepted. According to this configuration, the probability of malfunction occurrence is reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing an embodiment of a switch circuit of a dishwasher according to the present invention, and this embodiment will be described below with reference to this figure.
[0018]
As shown in FIG. 1, the switch circuit includes a water supply solenoid valve 1 for supplying water, a heater 2 for heating cleaning water, a cleaning pump 3 for cleaning water circulation, a drain pump 4 for draining cleaning water, and a fan 5 for drying. And a door switch 6 for detecting door opening / closing, a water level switch 7 for detecting water level, a thermistor 8 for temperature detection, a water leakage sensor 9 for water leakage detection, and the like.
[0019]
The switch circuit then turns on / off the power supply solenoid valve 1, the heater 2, the cleaning pump 3, the drainage pump 4, and the fan 5 via the power supply relay 10 for power on / off and the power relay 10. Relays 11 to 15 for turning off, a power switch 16 for small signals composed of tact switches, a plurality of operation switches 17a to 17p for small signals composed of tact switches, a course display LED group, a dry display LED, and the like On / off control of the power supply relay 10 is performed according to an operation on the display unit 18 and the power switch 16, and on / off control of the relays 11-15 is performed according to a predetermined program according to an operation on the operation switches 17a-17p. And a control unit (microcomputer) 19 that performs display according to the operating state through the display unit 18 Includes, circuitry for operating the detection with respect to the power supply switch 16 is composed of a static circuit, the circuit for operating the detection to the operation switch 17a~17p is constituted by dynamic circuit.
[0020]
However, the power relay 10 is composed of contacts 10a and 10b and a power relay coil 10c for opening and closing the contacts 10a and 10b, and the relay 11 is composed of a contact 11a and a water supply electromagnetic valve relay coil 11b for opening and closing the contact 11a. 12 is composed of a contact 12a and a heater relay coil 12b for opening / closing the contact 12a. The relay 13 is composed of contacts 13a, 13b and a cleaning pump relay coil 13c for opening / closing the contacts 13a, 13b. The relay 14 is composed of a contact 14a. The contact 15a is composed of a drain pump relay coil 14b for opening / closing, and the relay 15 is composed of a contact 15a and a fan relay coil 15b for opening / closing the contact 15a. Note that each of the power supply relay coil, the water supply solenoid valve relay coil, the heater relay coil, the washing pump relay coil, the drainage pump relay coil, and the fan relay coil is also simply referred to as a relay coil.
[0021]
T is a transformer having a primary winding n1 and a secondary winding n2. A commercial power supply and a control unit 19 are connected to the primary winding n1 side and the secondary winding n2 side of the transformer T, respectively. ing.
[0022]
Next, the control operation by the control unit 19 of this switch circuit will be described. For example, when the power supply relay 10 is turned off and the power switch 16 is turned on, the contacts 10a and 10b of the power supply relay 10 are turned on through the power relay coil 10c in response to the turn-on operation. Control is performed.
[0023]
Thereafter, when an operation such as selection and start of a desired course is performed on the operation switches 17a to 17p, the contacts of the relays 11 to 15 are respectively connected to the relays according to a program set in advance for the selected course. Control to turn on / off the relay coils 11 to 15 is performed.
[0024]
Here, in the conventional switch circuit as shown in FIG. 3, since about 20 ms is divided into 3 to 4 as one cycle, the pulse width of the operation detection signal becomes about 5 to 6 ms. In this case, a filter having a hardware configuration that needs to set a time constant smaller than the pulse width cannot be provided in the vicinity of the input terminal of the control unit (19b) to which the input lines (ac) are connected. Therefore, in the conventional dynamic circuit, a method of detecting presence / absence of single noise by performing comparison of signals from the input line several times and applying a filter on software has been adopted.
[0025]
However, although such a technique can prevent malfunction due to single noise, it can prevent malfunction due to the influence of continuous noise as shown in FIG. 5 from home appliances including an inverter or the like. Can not.
[0026]
Therefore, in this embodiment, as described above, the operation detection circuit for the power switch 16 is configured by a static circuit, and the operation detection circuit for the operation switches 17a to 17p is configured by a dynamic circuit. As a result, as shown in the example of FIG. 1, a pull-up resistor R1 having a small resistance value and a capacitor C1 having a large capacitance can be provided near the input terminal of the control unit 19 to which the power switch 16 is connected. It is possible to prevent malfunction due to noise. Although not shown in FIG. 1, a high-pass, low-pass or band-pass filter can be provided as necessary, so that noise countermeasures can be suitably taken.
[0027]
As described above, according to the present embodiment, by configuring the operation detection circuit for the operation switches 17a to 17p with a dynamic circuit, the number of operation detection signal lines for each switch can be reduced as compared with the static circuit. In addition, since the operation detection circuit for the power switch 16 is configured as a static circuit, a hardware-configured filter circuit can be provided near the input terminal of the control unit 19 to which the power switch 16 is connected. It is possible to prevent the occurrence of a problem that the power relay 10 corresponding to the power switch 16 is turned on due to noise generated when the home appliance is activated. Accordingly, since the power relay 10 is prevented from being turned on due to noise, the problem that the dishwasher starts before is prevented. Thereby, a highly reliable dishwasher can be provided.
[0028]
In the above-described embodiment, after the dishwasher is started by an on operation on the power switch 16 and an operation on the operation switches 17a to 17p, the power switch 16 and a temporary stop switch (any one of the operation switches 17a to 17p) The control unit 19 may be configured not to accept other operations.
[0029]
For example, when the power relay 10 is in an off state, only an operation for the power switch 16 is accepted, and when the power relay 10 is in a standby state, all the switches are accepted and the dishwasher is started during the course operation. In this case, only the operation for the power switch 16 and the temporary stop switch is accepted, and when the course operation is completed, the control unit 19 is configured to accept only the operation for the power switch 16. Here, the waiting time is normally about 10 minutes at the longest, and during this time, courses such as dry, reservation, rinse, rinse and dry are selected. Moreover, the time during course driving is about 60 to 120 minutes. Further, when the course operation is completed, the auto-off function is activated and the power supply relay 10 is automatically turned off without performing an off operation on the power switch 16.
[0030]
In this way, when the control unit is configured, since the time for receiving only the operation on the power switch 16 (= 24 hours− (10 minutes + 60 to 120 minutes)) is usually long, the probability of occurrence of malfunction becomes very small. Furthermore, during course driving, since operations other than the power switch 16 and the temporary stop switch are not accepted, the probability of occurrence of malfunction can be further reduced.
[0031]
【The invention's effect】
As is clear from the above, according to the first aspect of the present invention, the water supply solenoid valve for water supply, the heater for heating the cleaning water, the cleaning pump for cleaning water circulation, and the drain pump for draining the cleaning water are provided. A switch circuit used in a dishwasher, wherein a main power supply relay for turning on / off a main power supply, and a power supply solenoid valve, a heater, a washing pump, and a drainage pump are turned on / off via the main power supply relay, respectively. A plurality of sub power relays for turning off, a power switch for small signals, a plurality of operation switches for small signals, and on / off control of the main power relay according to the operation on the power switch, and a control unit for performing on / off control of said plurality of sub power supply relay in accordance with an operation with respect to the plurality of operation switches, wherein the circuit for operating the detection with respect to the power switch Source via a connected separate input lines to the switch constituted by a static circuit which detects the operation to the power switch, the predetermined at different time points of the circuit for operating the detection for the plurality of operation switches to a plurality of output lines And a dynamic circuit that detects an operation switch operated from the plurality of operation switches based on an input line to which the signal is input and an output line to which the signal is transmitted. As a result, the number of operation detection signal lines for each switch can be reduced as compared with the static circuit, and the relay corresponding to the power switch is turned on by noise generated when other home appliances are operated. Occurrence can be prevented.
[0032]
According to a second aspect of the present invention, in the switch circuit of the dishwasher according to the first aspect, the dishwasher includes a drying fan, and the plurality of sub power relays are connected to the main power relay through the main power relay. Power supply solenoid valves, heaters, cleaning pumps, drainage pumps, and fans are powered on / off, respectively, and even with this configuration, the number of operation detection signal lines for each switch can be reduced as compared to static circuits. At the same time, it is possible to prevent the occurrence of a problem that the relay corresponding to the power switch is turned on by noise generated when other home appliances are operated.
[0033]
According to a third aspect of the present invention, in the switch circuit of the dishwasher according to the first or second aspect, the control unit starts the dishwasher by an on operation on the power switch and an operation on the plurality of operation switches. After that, since operations other than the power switch and the temporary stop switch that is one of the plurality of operation switches are not accepted, the probability of occurrence of malfunction can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a switch circuit of a dishwasher according to the present invention.
FIG. 2 is a diagram illustrating an example of a conventional switch circuit in which a power switch is soft touched.
FIG. 3 is a diagram illustrating an example of a conventional switch circuit configured by a dynamic circuit.
4 is an explanatory diagram of an operation example of the dynamic circuit shown in FIG. 3; FIG.
FIG. 5 is a diagram illustrating noise and the like from other home appliances.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Water supply solenoid valve 2 Heater 3 Washing pump 4 Drainage pump 5 Fan 10 Power supply relay 11-15 Relay 16 Power supply switch 17a-17p Operation switch 18 Display part 19 Control part

Claims (3)

A switch circuit used in a dishwasher comprising a water supply solenoid valve for water supply, a heater for washing water heating, a washing pump for washing water circulation and a drainage pump for washing water drainage,
A main power relay for main power on / off;
A plurality of sub power relays for turning on / off the power of the water supply solenoid valve, the heater, the washing pump, and the drainage pump, respectively, via the main power relay;
A power switch for small signals, a plurality of operation switches for small signals, and on / off control of the main power relay according to the operation on the power switch, and the operation according to the operation on the plurality of operation switches A control unit that performs on / off control of a plurality of sub power relays, and
The operation detection circuit for the power switch is configured by a static circuit that detects an operation to the power switch via an individual input line connected to the power switch, and the operation detection circuit for the plurality of operation switches. An inspection signal having a predetermined pulse width is sent to a plurality of output lines at different points in time, and is operated from among the plurality of operation switches based on the input line to which the signal is input and the output line to which the signal is transmitted. A switch circuit for a dishwasher comprising a dynamic circuit for detecting an operation switch . The dishwasher includes a drying fan, and the plurality of sub power relays turn on / off the power supply solenoid valve, heater, washing pump, drainage pump, and fan via the main power relay, respectively. The switch circuit of the dishwasher according to claim 1.   After the dishwasher is started by an on operation on the power switch and an operation on the plurality of operation switches, the control unit is other than the power switch and a pause switch that is one of the plurality of operation switches. The switch circuit of the dishwasher according to claim 1 or 2, wherein the operation of is not accepted.

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