JP2001299667A - Switch circuit for dishwasher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a relay corresponding to a power switch from switching on troublingly by noise on actuation of an electric household appliance, by reducing the number of operation detecting signal conductors for each switch below that of a static circuit. SOLUTION: This switch circuit for a dishwasher comprises a power relay 10 for power on-off control; relays 11 to 15 for respective power on-off control on a solenoid-operated feed valve 1, a heater 2, a washing pump 3, a drainage pump 4 and a fan 5 via the power relay 10; a power switch 16; control switches 17a to 17p; a display part 18; and a control part 19 for on-off control on the power relay 10 depending on an operation on the power switch 16, for on-off control on the relays 11 to 15 depending on an operation on the control switches 17a to 17p, and for display control via the display part 18 depending on the operating status. The operation detecting circuit for the power switch 16 consists of a static circuit, and the operation detecting circuit for the control switches 17a to 17p consists of a dynamic circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch circuit used in a dishwasher having a water supply solenoid valve for supplying water, a heater for heating washing water, a washing pump for circulating washing water, and a drainage pump for draining washing water. It is about.

[0002]

2. Description of the Related 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.

FIG. 2 shows an example of a conventional switch circuit in which a power switch is soft-touched. However, in FIG. 2, for simplicity, operation switches and the like other than a tact switch as a power switch are not shown.

The switch circuit shown in FIG. 2 is used in a dishwasher provided with 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 ON operation is performed, the control unit 19a including a microcomputer or the like is performed.
Detects the ON operation (closed state of the contact), drives the power relay 10 to close the contact 10a,
Thereby, the power is turned on.

The tact switch for the power switch generally constitutes an operation section together with other operation tact switches, and a microcomputer is provided on the operation section for detecting an operation (push operation) for each tact switch. The so-called dynamic circuit used is often adopted.

FIG. 3 shows an example of a conventional switch circuit composed of a dynamic circuit, and FIG. 4 shows an explanatory diagram of an operation example of the dynamic circuit. However, in FIG. 3, illustration of components other than those related to the dynamic circuit is omitted for simplicity.

In the switch circuit shown in FIG. 3, a control unit (microcomputer) 19b transmits operation detection signals of a predetermined pulse width from three output lines A to C at different points in time, and converts these signals. , According to whether or not reception has been performed via the tact switch connected to each of the input lines a to c, whether or not the tact switch has been turned on is detected.

For example, when the tact switch SW7 is turned on, the signal transmitted from the output line A is changed to the tact switch SW7 as shown in "SW7 ON" in FIG.
Since the signal is received by the input line a via the switch 7, the ON operation of the tact switch SW7 can be detected. Similarly, when the tact switches SW6 and SW9 are turned on, the signals transmitted from the output lines A and B are applied to the tact switches SW9 and SW6 as shown in "SW6 and SW9 ON" in FIG. Is received on the input line c via
It is possible to detect the ON operation of the switches SW6 and SW9.

As described above, when a dynamic circuit is employed as the switch circuit, the operation of each tact switch can be
Compared to a so-called static circuit that detects via individual input lines, operations for many tact switches can be detected with a smaller number of signal lines. For example, as shown in FIG. 3, nine tact switches SW1 to SW9
To detect the operation for
While three input lines are required, the dynamic circuit has a total of six output lines A to C and three input lines a to c.
Only a single signal line is needed.

[0010]

However, when an operation on a tact switch as a power switch is detected by a dynamic circuit as in the above-described conventional switch circuit, noise generated when other home electric appliances are operated causes the power switch to be turned off. There is a problem that a power relay corresponding to the above is likely to be turned on.

That is, in the dynamic circuit, the number of the entire signal lines can be reduced by sharing the signal lines. On the other hand, however, a delay in detecting the ON operation of the tact switch is inevitably generated. Dozens of milliseconds (approximately 20 ms is the limit)
Needs to be time-divided for each output line as one cycle TM, so that a filter circuit having a hardware configuration cannot be provided for each tact switch.
Therefore, the control unit is likely to be erroneously detected that an operation has been performed on the tact switch, as shown in “Noise from Other Home Appliances”. In recent years, home appliances that emit high-frequency noise, such as inverters, have been increasing. Therefore, it is desired to prevent malfunctions due to the erroneous detection.

The present invention has been made in view of the above circumstances, and it is possible to reduce the number of signal lines for operation detection for each switch as compared with a static circuit, and to generate a signal when other home appliances are operated. It is an object of the present invention to provide a switch circuit of a dishwasher which can prevent a problem that a relay corresponding to a power switch is turned on due to noise.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 comprises a water supply solenoid valve for supplying water, a heater for heating cleaning water, a cleaning pump for circulating cleaning water, and a cleaning pump for discharging cleaning water. A switch circuit used for a dishwasher provided with a drain pump, wherein a main power relay for turning on / off a main power, and the water supply solenoid valve through the main power relay,
A plurality of sub-power relays for turning on / off a heater, a washing pump, and a drain pump respectively; a power switch for a small signal; a plurality of operation switches for a small signal;
A control unit that performs on / off control of the main power relay according to an operation on the power switch, and performs on / off control of the plurality of sub-power relays according to an operation on the plurality of operation switches, The circuit for detecting operation of the power switch is constituted by a static circuit, and the circuit for detecting operation of the plurality of operation switches is constituted by a dynamic circuit.

In this configuration, the operation detection circuit for the plurality of operation switches is constituted 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 the operation for the power switch is reduced. By configuring the detection circuit with a static circuit, a filter circuit having a hardware configuration can be provided near the input terminal of the control unit to which the power switch is connected. The problem that the power relay corresponding to the power switch is turned on due to noise is less likely to occur.

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 via the main power relay. The power supply of the water supply electromagnetic valve, the heater, the cleaning pump, the drainage pump, and the fan is turned on / off. Even with 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 due to the noise generated when other home appliances operate. It becomes difficult.

The third aspect of the present invention is the first or second aspect.
In the switch circuit for a dishwasher according to the above, the control unit may be any one of the power switch and the plurality of operation switches after the dishwasher is started by turning on the power switch and operating the plurality of operation switches. No operation other than the operation of the temporary stop switch is accepted. According to this configuration, the probability of occurrence of a malfunction is reduced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing one embodiment of a switch circuit of a dishwasher according to the present invention, and the embodiment will be described below with reference to this drawing.

As shown in FIG. 1, the present switch circuit includes a water supply solenoid valve 1 for supplying water, a heater 2 for heating cleaning water, a cleaning pump 3 for circulating cleaning water, a drain pump 4 for draining cleaning water, and a drying pump for drying drying. Used for a dishwasher with a drying function, which includes a door switch 6 for detecting door opening / closing, a water level switch 7 for detecting a water level, a thermistor 8 for detecting a temperature, and a leak sensor 9 for detecting a leak. ing.

The switch circuit supplies power to the water 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 turning on / off the power supply. Relays 11 to 15 for turning on / off, a small signal power switch 16 composed of a tact switch, a plurality of small signal operation switches 17 a to 17 p composed of a tact switch, a course display LED group and a dry display The on / off control of the power supply relay 10 is performed according to the operation of the display unit 18 including an LED and the power switch 16, and the on / off control of the relays 11 to 15 is performed according to the operation of the operation switches 17 a to 17 p. In addition to the control unit (my program), a control unit (My And a down) 19, circuit 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.

However, the power supply relay 10 has contacts 10a,
10b and a power supply relay coil 10c for opening and closing the contacts 10a and 10b.
a and a contact water supply electromagnetic valve relay coil 11b for opening and closing the contact 11a. The relay 12 is constituted by a contact 12a and a heater relay coil 12b for opening and closing the contact 12a. The relay 14 includes a contact 14a and a drain pump relay coil 14b for opening and closing the contact 14a, and the relay 15 includes a contact 15a and a fan relay coil for opening and closing the contact 15a. 15b. Each of the power supply relay coil, the water supply solenoid valve relay coil, the heater relay coil, the cleaning pump relay coil, the drainage pump relay coil, and the fan relay coil is hereinafter simply referred to as a relay coil.

T is a primary winding n1 and a secondary winding n
2, a commercial power supply, a control unit 19, and the like are connected to the primary winding n1 side and the secondary winding n2 side of the transformer T, respectively.

Next, the control operation of the control circuit 19 of the present switch circuit will be described. For example, when the power switch 16 is turned off and the power switch 16 is turned on, the contacts 10a and 10b of the power relay 10 are turned on through the power relay coil 10c in accordance with the on operation. Control is performed.

Thereafter, when operations such as selection and start of a desired course are performed on the operation switches 17a to 17p, the contacts of the relays 11 to 15 are switched according to a preset program for the selected course. Is controlled to be turned on / off through the relay coils of the relays 11 to 15, respectively.

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 is 5 to 6 m.
s. In this case, it is not possible to provide a filter having a hardware configuration that needs to set the time constant to be smaller than the pulse width with a margin near 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 the presence or absence of single-shot noise by performing comparison of signals from the input line several times continuously and applying a filter on software has been adopted.

However, with such a method, although it is possible to prevent a malfunction due to a single noise, it is possible to prevent a malfunction due to a continuous noise as shown in FIG. 5 from a home appliance including an inverter or the like. Can not do it.

Therefore, in the present embodiment, as described above, the circuit for detecting the operation of the power switch 16 is constituted by a static circuit, and the circuit for detecting the operation of the operation switches 17a to 17p is constituted by a dynamic circuit. Thereby, 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, and are continuous. Malfunction due to the influence of noise can be prevented. Although not shown in FIG. 1, a filter such as a high-pass, a low-pass, or a band-pass can be provided as necessary.
Noise measures can be taken appropriately.

As described above, according to this embodiment, the circuit for detecting the operation of the operation switches 17a to 17p is constituted by a dynamic circuit, so that the number of signal lines for detecting the operation of each switch is reduced as compared with the static circuit. In addition, by configuring a circuit for detecting operation of the power switch 16 with a static circuit, a filter circuit having a hardware configuration can be provided near an input terminal of the control unit 19 to which the power switch 16 is connected. Therefore, it is possible to prevent a problem that the power relay 10 corresponding to the power switch 16 is turned on due to noise generated when another household electric appliance is operated. Therefore, since the power supply relay 10 is prevented from being turned on due to noise, it is possible to prevent a problem that the dishwasher is started. Thereby, a highly reliable dishwasher can be provided.

In the above embodiment, the power switch 16 is turned on and the operation switches 17a to 17a are operated.
After the dishwasher is started by the operation for 7p, the control unit 19 may be configured so as not to receive any operation other than the power switch 16 and the temporary stop switch (one of the operation switches 17a to 17p).

For example, when the power relay 10 is off, only the operation on the power switch 16 is accepted.
When the power relay 10 is on standby, all switches are accepted. When the dishwasher is in course operation, only operations on the power switch 16 and the pause switch are accepted, and the course operation ends. In such a case, the control unit 19 is configured to accept only the operation on the power switch 16. Here, the waiting time is usually at most about 10 minutes, during which courses such as dry, reservation, rinse, rinse and dry are selected. The time during course driving is 60-1.
It takes about 20 minutes. Further, when the course operation is completed, even if the power switch 16 is not turned off, the auto-off function operates and the power relay 10 is automatically turned off.

When the control unit is configured as described above, usually,
Since the time for accepting only the operation on the power switch 16 (= 24 hours− (10 minutes + 60 to 120 minutes)) is long, the probability of occurrence of a malfunction is extremely 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]

As is apparent from the above, according to the first aspect of the present invention, a water supply solenoid valve for supplying water, a heater for heating cleaning water, a cleaning pump for circulating cleaning water, and a cleaning pump for discharging cleaning water. A switch circuit used in a dishwasher equipped with a drain pump, comprising: a main power relay for turning on / off a main power, and a power supply solenoid valve, a heater, a cleaning pump, and a drain pump through the main power relay. A plurality of sub-power relays for respectively turning on / off the power, a small-signal power switch, a plurality of small-signal operation switches, and on / off of the main power relay in response to an operation on the power switch A control unit for performing control and performing on / off control of the plurality of sub-power relays in accordance with an operation on the plurality of operation switches; Is constituted by a static circuit, and a circuit for operation detection for the plurality of operation switches is constituted by a dynamic circuit. Therefore, the number of signal lines for operation detection for each switch is reduced as compared with the static circuit. In addition to the above, it is possible to prevent a problem that a relay corresponding to a power switch is turned on due to noise generated when another home appliance is operated.

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 via the main power relay. Therefore, the power supply of the water supply electromagnetic valve, the heater, the cleaning pump, the drain pump and the fan is turned on / off, respectively, and also in this configuration, the number of operation detection signal lines for each switch is reduced as compared with the static circuit. In addition to the above, it is possible to prevent a problem that a relay corresponding to the power switch is turned on due to noise generated when another home appliance is operated.

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 to perform an ON operation on the power switch and an operation on the plurality of operation switches to operate the dishwasher. After the start of the operation, no operation other than the power switch and the temporary stop switch, which is one of the plurality of operation switches, is not accepted, so that the probability of occurrence of a malfunction can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a switch circuit of a dishwasher of the present invention.

FIG. 2 is a diagram showing 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.

FIG. 4 is an explanatory diagram of an operation example of the dynamic circuit shown in FIG. 3;

FIG. 5 is a diagram illustrating noise and the like from other home electric appliances.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water supply solenoid valve 2 Heater 3 Washing pump 4 Drain pump 5 Fan 10 Power relay 11-15 Relay 16 Power switch 17a-17p Operation switch 18 Display part 19 Control part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenji Marusasa 1-152 Oka, Minami-shi, Minato-ku, Osaka City F-term in Harman Co., Ltd. 3B082 DA02 DC06 5G057 AA13 BB07 BC06 KK16 KK18 KK32 RS01 XX12 YY01

Claims (3)

[Claims] 1. A switch circuit used in a dishwasher provided with a water supply solenoid valve for supplying water, a heater for heating washing water, a washing pump for circulating washing water, and a drainage pump for draining washing water, comprising: A main power supply relay for on / off, and a water supply solenoid valve, a heater,
A plurality of sub-power relays for turning on / off the power of the washing pump and the drain pump; a power switch for a small signal; a plurality of operation switches for a small signal; A control unit that performs on / off control of a power relay and performs on / off control of the plurality of sub-power relays according to an operation on the plurality of operation switches; and a circuit for detecting operation of the power switch. A switch circuit for a dishwasher, comprising a static circuit, and a circuit for detecting the operation of the plurality of operation switches being a dynamic circuit. 2. The dishwasher includes a drying fan, and the plurality of sub power relays respectively supply power to the water supply solenoid valve, the heater, the cleaning pump, the drain pump, and the fan via the main power relay. The switch circuit according to claim 1, wherein the switch circuit is turned on / off. 3. The control unit, after the dishwasher is started by an on operation of the power switch and an operation of the plurality of operation switches, by the operation switch of any one of the power switch and the plurality of operation switches. 3. The switch circuit of a dishwasher according to claim 1, wherein an operation other than a certain stop switch is not accepted.