JP2015053243A - Switch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switch device capable of detecting a short circuit failure of an operation switch.SOLUTION: A switch state recognition unit 101 successively sets strobe signals COM1-COM4, output from output ports Po1-Po4 of a microcomputer 100, to be a low level, to select a switch contact point one-by-one from first switch contact points M1, H1 and second switch contact points M2, H2 of first series circuits 10, 20 and first switch contact points S1, G1 and second switch contact points S2, G2 of second series circuits 30, 40. From voltages SW1, SW2 of a first common input unit 405 and a second common input unit 406, the switch state recognition unit 101 recognizes an operation state and a failure of operation switches M, H, S, G.

Description

  The present invention relates to a switch device that recognizes an operation state of an operation switch.

  2. Description of the Related Art Conventionally, there has been known a switch device that is provided in, for example, a cooking utensil and recognizes an operation state such as an operation switch (for example, see Patent Document 1).

  In addition, in order to detect that a disconnection failure has occurred in the wiring between the switch contact of the operation switch and the input part of the switch contact, check the conduction status of the conduction path formed in parallel with the switch contact. A switch device has been proposed (see, for example, Patent Document 2).

JP 2006-90598 A JP 2012-112576 A

  In the switch device described in Patent Document 2, a disconnection failure between the switch contact of the operation switch and the input portion of the switch contact can be detected, but a short-circuit failure between the switch contact and the input portion is detected. Can not do it. For this reason, it has not been possible to detect that a short circuit failure has occurred between the switch contact and the input unit and the instrument cannot be operated.

  The present invention has been made in view of such a background, and an object thereof is to provide a switch device capable of detecting a short-circuit failure of an operation switch.

The present invention has been made to achieve the above object, and the switch device of the present invention comprises:
A plurality of operation switches having a first switch contact and a second switch contact that are switched in conjunction with a conduction state and a cutoff state according to a user's operation;
A first end side resistor, the first switch contact, the second switch contact, and a second end side resistor are formed individually for each of the operation switches, and between the first end and the second end. And a plurality of series circuits connected in series in this order,
The first circuit is provided separately for each series circuit, and switches between a state in which the first end is connected to the first potential unit and a state in which the first end is disconnected from the first potential unit. One end side switching circuit;
The second circuit is individually provided for each of the series circuits, and switches between a state in which the second end is connected to the second potential unit and a state in which the second end is disconnected from the second potential unit. A two-end side switching circuit;
A common input section in which the plurality of series circuits are divided into a plurality of groups, and the connection points of the first switch contacts and the second switch contacts of the series circuits belonging to the same group are individually provided for each group. And each common input unit is connected to the first potential unit via a first resistor individually provided for each common input unit, and individually provided for each common input unit. An input common circuit connected to the second potential portion via a second resistor;
From each of the groups, the first switch contact or the second switch contact of the series circuit is sequentially selected one by one, and the first switch contact is selected in each selection step by the first end side switching circuit. The first end of the series circuit having the selected first switch contact is connected to the first potential portion, the first end of the other series circuit is disconnected from the first potential portion, and the second end With the part side switching circuit, the second end of all the series circuits is cut off from the second potential part,
For the group in which the second switch contact is selected, the second end side switching circuit connects the second end portion of the series circuit having the selected second switch contact to the second potential portion, so that another series Each common input unit is configured such that the second end of the circuit is cut off from the second potential unit, and the first end of all the series circuits are cut off from the first potential unit by the first end side switching circuit. Recognizes the voltage level of
A switch state recognition unit for recognizing an operation state and a failure of the plurality of operation switches based on a voltage level of each common input unit recognized in each selection stage.

  According to the present invention, the series circuit formed for a plurality of operation switches is divided into a plurality of groups by the input common circuit, and the first switch contact and the second switch contact of the series circuit belonging to the same group. Is connected to a common input section provided individually for each group. Further, the common input unit is connected to the first potential unit via the first voltage dividing resistor and to the second potential unit via the second voltage dividing resistor by the input common circuit.

  Therefore, if all of the first switch contacts and the second switch contacts of the plurality of operation switches are in the cut-off state, the voltage level of each common input section is the first voltage divided between the first potential and the second potential. The reference level is divided by the pressure resistance and the second voltage dividing resistance.

  As will be described in detail later, the first switch contact or the second switch contact of the series circuit is selected one by one from the groups, and the first contact is selected for the group in which the first contact is selected. The switching circuit connects the first end portion of the series circuit having the selected first switch contact to the first potential portion, disconnects the first end portion of the other series circuit from the first potential portion, and With the second end side switching circuit, the second end portion of all the series circuits is cut off from the second potential portion, and for the group in which the second switch contact is selected, the second end side switching circuit The second end portion of the series circuit having the selected second switch contact is connected to the second potential portion, the second end portion of the other series circuit is disconnected from the second potential portion, and the first end portion Side switching circuit to connect the first end of all series circuits to the first When a state of being cut off from the potential portion, when the operation switch having a switch contact which is selected is operated, the voltage level of the common input unit is changed to the first potential or the second potential.

  In addition, when a short circuit failure or a disconnection failure due to a short circuit between adjacent series circuits or the like occurs, the energization path between the first potential unit and the second potential unit is different from the normal time, so the voltage level of the common input unit is It will be different from normal time.

  For this reason, the switch state recognizing unit detects an operation state of the plurality of operation switches (conducting and blocking states of the first switch contact and the second switch contact) and a short-circuit failure based on the voltage level of each common input unit. It is possible to detect a failure state including.

  The switch state recognition unit shuts off the first end of all the series circuits from the first potential unit by the first end side switching circuit, and disconnects the second ends of all the series circuits. A failure of the operation switch is recognized based on a voltage level of each of the common input units in a state where the second end side switching circuit is disconnected from the second potential unit.

  According to this configuration, when a disconnection failure occurs between the common input unit and the switch state recognition unit, the first end of all the series circuits is disconnected from the first potential unit, and all When the second end of the series circuit is disconnected from the second potential unit, the reference voltage set by the input common circuit is not recognized by the switch state recognition unit. Therefore, the switch state recognition unit can detect a disconnection failure of the operation switch based on the voltage level of the common input unit.

The input common circuit bisects the plurality of series circuits into a first group and a second group which are the plurality of groups, and a first switch of a first series circuit which is a series circuit belonging to the first group A connection point between the contact and the second switch contact is connected to the first common input unit that is the common input unit for the first group, and the second series circuit is a series circuit belonging to the second group. A connection point between the first switch contact and the second contact is connected to a second common input unit which is the common input unit for the second group;
The switch state recognizing unit recognizes operation states and failures of the plurality of operation switches based on voltage levels of the first common input unit and the second common input unit.

  According to this configuration, regardless of the number of the plurality of operation switches, the operation state and failure of each operation switch can be recognized by the two input units, the first common input unit and the second common input unit. it can.

The block diagram of the switch apparatus of 1st Embodiment. The timing chart of the process which recognizes the operation state of an operation switch, and a failure. The block diagram of the switch apparatus of 2nd Embodiment. The block diagram of the switch apparatus of 3rd Embodiment.

  An embodiment of the present invention will be described with reference to FIGS.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS. Referring to FIG. 1, a switch device 1 of the present embodiment is used by being incorporated in a gas stove, and includes an operation switch M for ignition / extinguishing a medium thermal power burner (not shown), and a high thermal power burner (not shown). ) Ignition / extinguishing operation switch H, low-power burner (not shown) ignition / extinguishing operation switch S, and grille (not shown) ignition / extinguishing operation switch G. recognize.

  The switch device 1 includes an operation board 300 on which operation switches M, H, S, and G are mounted, and a control board 200.

  The operation switch M has a first switch contact M1 and a second switch contact M2 connected in series. The first switch contact M1 and the second switch contact M2 are interlocked when the user presses the operation switch M, and are interlocked when the user is not pressing.

  Similarly, the operation switch H has a first switch contact H1 and a second switch contact H2, the operation switch S has a first switch contact S1 and a second switch contact S2, and the operation switch G is a first switch contact G1. And a second switch contact G2.

  For the operation switch M, a first end side resistor 11, a first switch contact M1, a second switch contact M2, and a second end side are provided between the first end 401 and the second end 409. A series circuit 10 in which the resistor 12 is connected in order is formed.

  For the operation switch H, between the first end 403 and the second end 411, the first end side resistor 21, the first switch contact H1, the second switch contact H2, and the second end side. A series circuit 20 in which a resistor 22 is connected in order is formed.

  For the operation switch S, between the first end 402 and the second end 408, the first end side resistor 31, the first switch contact S1, the second switch contact S2, and the second end side. A series circuit 30 in which a resistor 32 is connected in order is formed.

  For the operation switch G, a first end side resistor 41, a first switch contact G1, a second switch contact G2, and a second end side are provided between the first end 404 and the second end 410. A series circuit 40 in which the resistor 42 is connected in order is formed.

  The control board 200 includes a microcomputer 100 (hereinafter referred to as a microcomputer 100) configured by a CPU, a memory, an input / output circuit, and the like. The microcomputer 100 executes a control program for a gas stove held in the memory. By doing so, it functions as the switch state recognition unit 101 that recognizes the operation state and failure of the operation switches M, H, S, and G. The microcomputer 100 has output ports Po1 to Po4 and AD (analog / digital conversion) input ports AD1 and AD2.

  The output ports Po1 to Po4 are connected to switching elements 51 to 54 (corresponding to the first end side switching circuit of the present invention) individually provided for the series circuits 10, 20, 30, and 40, and strobe signals COM1 to COM4. Is output. The switching element 51 is connected between the output port Po1 of the microcomputer 100 and the first end 401. When the COM1 is at a high level (≈Vcc), the first end 401 is connected to the Vcc potential portion (the present invention). The first end 401 is connected to the Vcc potential portion when COM1 is at a low level (≈GND).

  The switching element 52 is connected between the output port Po2 of the microcomputer 100 and the first end 402. When the COM2 is at a high level, the first end 402 is disconnected from the Vcc potential portion, and the COM2 is low. When the level is reached, the first end 402 is connected to the Vcc potential portion.

  The switching element 53 is connected between the output port Po3 of the microcomputer 100 and the first end 403. When the COM3 is at a high level, the first end 403 is disconnected from the Vcc potential portion, and the COM3 is low. When it is at the level, the first end 403 is connected to the Vcc potential portion.

  The switching element 54 is connected between the output port Po4 of the microcomputer 100 and the first end 404 of the series circuit 40. When the COM4 is at a high level, the first end 404 is cut off from the Vcc potential portion. , COM4 is at a low level, the first end 404 is connected to the Vcc potential section.

  Moreover, the output part of the switching elements 51-54 is the switching elements 61-64 (equivalent to the 2nd edge part side switching circuit of this invention) provided with respect to the series circuits 10, 20, 30, 40 separately. It is input one to one. The switching element 61 is connected between the switching element 51 and the second end portion 408. When the output of the switching element 51 is at a low level, the second end portion 408 is connected to the GND potential portion (the second potential portion of the present invention). When the output of the switching element 51 is at a high level, the second end portion 408 is connected to the GND potential portion.

  The switching element 62 is connected between the switching element 52 and the second end 409. When the output of the switching element 52 is at a low level, the second end 409 is cut off from the GND potential portion, and the switching element 62 When the output of 52 is at a high level, the second end 409 is connected to the GND potential portion.

  The switching element 63 is connected between the switching element 53 and the second end portion 410. When the output of the switching element 53 is at a low level, the second end portion 410 is cut off from the GND potential portion. When the output of 53 is at a high level, the second end portion 410 is connected to the GND potential portion.

  The switching element 64 is connected between the switching element 54 and the second end 411. When the output of the switching element 54 is at a low level, the second end 411 is cut off from the GND potential part, and the switching element 64 is switched. When the output of the element 54 is at a high level, the second end 411 is connected to the GND potential portion.

  The series circuits 10, 20, 30, and 40 are divided into two groups, a first group to which the series circuits 10 and 20 belong and a second group to which the series circuits 30 and 40 belong. Hereinafter, the series circuits 10 and 20 belonging to the first group are also referred to as first series circuits 10 and 20, and the series circuits 30 and 40 belonging to the second group are also referred to as second series circuits 30 and 40.

  The connection point between the first switch contact M1 and the second switch contact M2 of the first series circuit 10 and the connection point between the first switch contact H1 and the second switch contact H2 of the first series circuit 20 are both the first common. It is connected to the input unit 405.

  Further, the connection point between the first switch contact S1 and the second switch contact S2 of the second series circuit 30 and the connection point between the first switch contact G1 and the second switch contact G2 of the second series circuit 40 are both Two common input units 406 are connected.

  The first common input unit 405 is connected to the Vcc potential unit via the first voltage dividing resistor 71 of the pull-up circuit 70 and is connected to the GND potential unit via the second voltage dividing resistor 81 of the pull-down circuit 80. ing. The second common input unit 406 is connected to the Vcc potential unit via the third voltage dividing resistor 72 of the pull-up circuit 70 and is connected to the GND potential unit via the fourth voltage dividing resistor 82 of the pull-down circuit 80. ing.

  The first common input unit 405 is connected to the AD input port AD1 of the microcomputer 100 via the resistor 90, and the second common input unit 406 is connected to the AD input port AD2 of the microcomputer 100 via the resistor 91. A capacitor 92 is connected between the AD input port AD1 and GND, and a capacitor 93 is connected between the AD input port AD2 and GND.

  The AD input ports AD1 and AD2 convert the analog voltage into an 8-bit digital value (0 to 255) and input it. The switch state recognition unit 101 uses the digital value to convert the first common input unit 405 and the second common input unit. The voltage level of 406 is recognized.

  Note that the input common circuit of the present invention is constituted by a circuit that connects the series circuits 10, 20, 30, and 40 to the first common input unit 405 and the second common input unit 406, the pull-up circuit 70, and the pull-down circuit 80. Composed.

  Next, according to the timing chart shown in FIG. 2, the operation state and failure recognition processing of the operation switches M, H, S, and G by the switch state recognition unit 101 will be described.

  T1 to t6 in FIG. 2 is one cycle of processing for recognizing the operation state and failure of the operation switches M, H, S, and G. ST1 (t1 to t2), ST2 (t2 to t3), ST3 (t3 t4), ST4 (t4 to t5), and ST5 (t5 to t6).

  In ST to ST4, the operation states and failures of the operation switches M, H, S, G are recognized for each of the first switch contacts M1, H1, S1, G1 and the second switch contacts M2, H2, S2, G2. . In ST5, a failure in the connection path between the operation switches M, H, S, G and the microcomputer 100 is recognized.

  In ST1 to ST4, as shown in Table 1 below, the switch state recognition unit 101 sequentially selects and outputs the strobe signals COM1 to COM4 one by one and outputs the first series circuits 10 and 20 belonging to the first group. Switch contacts M1, H1 and second switch contacts M2, H2 of the first switch contacts S1, G1 and second switch contacts S2, G2 of the series circuits 30 and 40 belonging to the second group. The first switch contact or the second switch contact) is sequentially selected one by one. In Table 1, the strobe is represented by STB and the switch is represented by SW.

  In ST1, the strobe signal COM1 is output, and the first switch contact M1 of the operation switch M and the second switch contact S2 of the operation switch S are selected. In ST2, the strobe signal COM2 is output, and the second switch contact M2 of the operation switch M and the first switch contact S1 of the operation switch S are selected.

  In ST3, the strobe signal COM3 is output, and the first switch contact H1 of the operation switch H and the second switch contact G2 of the operation switch G are selected. In ST4, the strobe signal COM4 is output, and the second switch contact H2 of the operation switch H and the first switch contact G1 of the operation switch G are selected.

  For example, in ST1, the switch state recognition unit 101 sets the strobe signal COM1 output from the output port Po1 to the low level and sets the strobe signals COM2 to COM4 output from the output ports Po2 to Po4 to the high level.

  As a result, the first switch contact M1 of the first series circuit 10 is selected from the first group, and the second switch contact S2 of the second series circuit 30 is selected from the second group. In this state, among the series circuits 10, 20, 30, 40, only the first end 401 of the first series circuit 10 is connected to the Vcc potential section, and the first ends of the other series circuits 20, 30, 40 are connected. The parts 402 to 404 are cut off from Vcc. For this reason, the voltage SW2 of the first common input unit 405 is changed according to the conduction / cutoff of the first switch contact M1 of the operation switch M.

  Of the series circuits 10, 20, 30, and 40, only the second end 408 of the second series circuit 30 is connected to GND, and the second ends 409 to 411 of the other series circuits 10, 20, and 40 are connected. Is cut off from the GND potential portion. Therefore, the voltage SW2 of the second common input unit 406 changes according to the conduction / cutoff of the second switch contact S2 of the operation switch S.

  Therefore, as shown in Table 2 below, in step ST1, the first contact M1 of the operation switch M is turned on (conducted) / off (cut off), and the second contact S2 of the operation switch S is turned on / off. Can be recognized.

  As shown in FIG. 2, the switch state recognition unit 101 sequentially switches among the control signals COM1 to COM4 output from the output ports Po1 to Po4 of the microcomputer 100 that are set to the low level. As a result, as shown in Tables 1 and 2, the switch state recognition unit 101 switches the selection of the operation switches M, S, H, and G to be recognized as the operation state, and the operation switches M and S are switched. , H, G, the first switch contacts M1, S1, H1, G1 and the second switch contacts M2, S2, H2, G2 are detected on / off states, and the operation switches M, S, H, G Recognize the operation status of.

  The switch state recognition unit 101 recognizes that an operation switch in which both the first switch contact and the second switch contact are in an ON state is an operation state, and an operation switch in which both the second switch contact and the second switch contact are in an OFF state. Is recognized as not operating.

  Here, the resistance value R71 of the first voltage dividing resistor 71 and the resistance value R81 of the second voltage dividing resistor 81 are set to the same value. Therefore, when the selected operation switch is not pushed, SW1 becomes Vcc / 2 (reference potential).

  Further, when the selected operation switch is pushed and the first contact is ON (conducting), the first voltage dividing resistor 71 or the third voltage dividing resistor 72 from the Vcc and the first end side resistance 11 , 21, 31, 41 is energized to the first common input unit 405 or the second common input unit 406 through a parallel circuit. Therefore, the level of SW1 or SW2 becomes higher than the reference potential.

  Therefore, as shown in Table 3 below, the switch state recognition unit 101, when the level of the detection signals SW1 and SW2 is within the off range (Aoff) contacted near the reference potential, the first switch contact M1. Is in an OFF state (blocking state). Further, when the level of the detection signals SW1 and SW2 is in the first on range (Aon1) set based on the parallel resistance value of the first voltage dividing resistor 71 and the first end side resistor 11, the first switch contact M1 is Recognized as ON state (conducting state).

  Further, when the voltage level of SW1 or SW2 is out of the off range (Aoff) and the first on range (Aon1), a short circuit failure with other circuits in the middle of the series circuits 10, 20, 30, 40, etc. It can be determined that a disconnection failure has occurred in the connection path between the series circuit 10, 20, 30, 40 and the microcomputer 100.

  Therefore, in this case, the switch state recognition unit 101 displays an error on the display unit 105 to notify the user that the operation switch has failed.

  Next, when the selected operation switch is pushed and the second switch contact is turned on (conductive), the second voltage dividing resistor 81 or the second voltage dividing resistor 81 or the second common input unit 406 is turned on. The GND is energized through a parallel circuit of the voltage-dividing resistor 82 and any one of the second end side resistors 12, 22, 32, and 42. Therefore, the level of SW1 or SW2 is lower than the reference potential.

  Therefore, the switch state recognition unit 101 selects the detection signal SW1 (the second switch contact M2 of the first series circuit 10 or the second switch contact H2 of the first series circuit 20 as shown in Table 4 below). ), SW2 (when the second switch contact S2 of the second series circuit 30 or the second switch contact G2 of the second series circuit 40 is selected), based on the level of the second switch contact M2, H2, Recognize the states of S2 and G2.

  Further, when the voltage level of SW1 or SW2 is out of the off range (Aoff) and the second on range (Aon2), a short circuit failure with other circuits in the middle of the series circuits 10, 20, 30, 40, etc. It can be determined that a disconnection failure has occurred in the connection path between the series circuit 10, 20, 30, 40 and the microcomputer 100.

  Therefore, in this case, the switch state recognition unit 101 displays an error on the display unit 105 to notify the user that the operation switch has failed.

  Next, in step ST5, the switch state recognition unit 101 sets all of the strobe signals COM1 to COM4 to a high level, and cuts off the first ends 401 to 404 of the series circuits 10, 20, 30, and 40 from the Vcc potential unit. At the same time, the second end portions 408 to 411 are cut off from the GND potential portion.

  When one or both of SW1 and SW2 are out of the off range (Aoff) in this state, a failure due to disconnection or short circuit occurs in the connection path between the operation switches M, H, S, G and the microcomputer 100. It can be determined that it has occurred. Therefore, also in this case, the switch state recognition unit 101 displays an error on the display unit 105 to notify the user that the operation switch has failed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. In the switch device of the second embodiment, in addition to the above-described four burner ignition / extinguishing operation switches M, H, S, and G on the operation board 310, two burner ignition / extinguishing operations are performed. Switches J and K are provided.

  In FIG. 3, the control board is omitted and only the operation board 310 is shown. In the control board of the second embodiment, the switch state recognition unit 101 of the microcomputer 100 shown in FIG. 1 sequentially outputs six strobe signals COM1 to COM6 to the first end portions 501 to 506 and the second end portions 510 to 515. Thus, the voltage SW1 of the first common input unit 507 and the voltage SW2 of the second common input unit 508 are input.

  The switch state recognition unit 101 recognizes the operation states and failures of the six operation switches M, H, S, G, J, and K by the voltage SW1 and the second common input unit SW2 of the first common input unit 507. In addition, about the structure similar to the operation board 300 of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The series circuit 10 formed for the operation switch M is connected between the first end 501 and the second end 511. The series circuit 20 formed for the operation switch H is connected between the first end 503 and the second end 513.

  For the operation switch J, a first end-side resistor 26, a first switch contact J1, a second switch contact J2, and a second end are provided between the first end 505 and the second end 515. A series circuit 25 is formed in which the part-side resistor 27 is connected in order.

  The series circuit 30 formed for the operation switch S is connected between the first end portion 502 and the second end portion 510. The series circuit 40 formed for the operation switch G is connected between the first end 504 and the second end 512.

  For the operation switch K, a first end side resistor 46, a first switch contact K1, a second switch contact K2, and a second end are provided between the first end 506 and the second end 514. A series circuit 45 in which the part-side resistor 47 is connected in order is formed.

  The series circuits 10, 20, 25, 30, 40, and 45 are divided into a first group to which the series circuits 10, 20, and 25 belong and a second group to which the series circuits 30, 40, and 45 belong. Hereinafter, the series circuits 10, 20, 25 belonging to the first group are also referred to as first series circuits 10, 20, 25, and the series circuits 30, 40, 45 belonging to the second group are referred to as the second series circuits 30, 40, 45. Also called.

  The connection point between the first switch contact M1 and the second switch contact M2 of the first series circuit 10, the connection point between the first switch contact H1 and the second switch contact H2 of the first series circuit 20, and the first series circuit 25. The first switch contact J1 and the second switch contact J2 are both connected to the first common input unit 507.

  Further, the connection point between the first switch contact S1 and the second switch contact S2 of the second series circuit 30, the connection point between the first switch contact G1 and the second switch contact G2 of the second series circuit 40, and the second series. The connection locations of the first switch contact K1 and the second switch contact K2 of the circuit 45 are both connected to the second common input unit 508.

  Similarly to the first end portions 401 to 404 of the operation board 300 of the first embodiment, the first end portions 501 to 506 are disconnected from the Vcc potential portion by the strobe signals COM1 to COM6. Switched to the activated state. Similarly to the second end portions 408 to 411 of the operation board 300 of the first embodiment, the second end portions 510 to 515 are disconnected from the state connected to the GND potential portion and from the GND potential portion by the strobe signals COM1 to COM6. Switched to the activated state.

  Then, as shown in Table 5 below, the switch state recognition unit 101 sequentially outputs the strobe signals COM1 to COM6 one by one, and outputs the first series circuits 10, 20, and 25 belonging to the first group. The switch contacts M1, H1, J1 and the second switch contacts M2, H2, J2, and the first switch contacts S1, G1, K1 and the second switch contacts S2, of the second series circuits 30, 40, 45 belonging to the second group. From G2 and K2, switch contacts (first switch contact or second switch contact) are sequentially selected one by one. In Table 3, the strobe is represented by STB and the switch is represented by SW.

  For example, when the strobe signal COM1 is selected (COM1 is at a low level and COM2 to COM6 are at a high level), the first series circuits 10, 20, and 25 belonging to the first group are connected to the first series circuit 10. The first end portion 501 is connected to the Vcc potential portion, and the other first end portions 503 and 505 are disconnected from the Vcc potential portion. Further, the second end portions 511, 513, and 515 are disconnected from the GND potential portion.

  For the second series circuits 30, 40, 45 belonging to the second group, the second end 510 connected to the second series circuit 30 is connected to the GND potential portion and the other second end 512. , 514 are disconnected from the GND potential portion. Further, the first ends 502, 504, 506 are isolated from Vcc.

  The switch state recognition unit 101 outputs the voltage SW1 of the first common input unit 507 and the second common input unit 508 when the strobe signals COM1 to COM6 are sequentially output and when all the output of the strobe signals COM1 to COM6 are stopped. By determining the level of the voltage SW2 under the conditions shown in Tables 3 and 4, the operation state and failure of each operation switch M, H, J, S, G, K are recognized.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. As in the second embodiment, the switch device of the third embodiment includes six operation switches M, H, J, S, G, and K on the operation board 320.

  In FIG. 4, the control board is omitted and only the operation board 320 is shown. In the control board of the third embodiment, the switch state recognition unit 101 of the microcomputer 100 shown in FIG. 1 sequentially outputs four strobe signals COM1 to COM4 to the first end portions 601 to 606 and the second end portions 611 to 616. Thus, the voltage SW1 of the first common input unit 607, the voltage SW2 of the second common input unit 608, and the voltage SW3 of the third common input unit 609 are input.

  The switch state recognizing unit 101 includes six operation switches M, H, S, and a voltage SW1 of the first common input unit 607, a voltage SW2 of the second common input unit 608, and a voltage SW3 of the third common input unit 609. Recognize G, J, and K operation states and failures. In addition, about the structure similar to the operation board 300 of 1st Embodiment, and the operation board 310 of 2nd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The series circuit 10 formed for the operation switch M is connected between the first end 601 and the second end 613. The series circuit 20 formed for the operation switch H is connected between the first end 603 and the second end 616. The series circuit 25 formed for the operation switch J is connected between the first end 604 and the second end 612.

  The series circuit 30 formed for the operation switch S is connected between the first end 602 and the second end 611. The series circuit 40 formed for the operation switch G is connected between the first end 605 and the second end 615. A series circuit 45 formed for the operation switch K is connected between the first end 606 and the second end 614.

  The series circuits 10, 20, 25, 30, 40, 45 include a first group to which the series circuits 10, 20 belong, a second group to which the series circuits 30, 40 belong, and a third group to which the series circuits 25, 45 belong. It is divided into. Hereinafter, the series circuits 10 and 20 belonging to the first group are also referred to as the first series circuits 10 and 20, and the series circuits 30 and 40 belonging to the second group are also referred to as the second series circuits 30 and 40 and belong to the third group. The series circuits 25 and 45 are also referred to as third series circuits 25 and 45.

  The connection point between the first switch contact M1 and the second switch contact M2 of the first series circuit 10 and the connection point between the first switch contact H1 and the second switch contact H2 of the first series circuit 20 are the first common input. Connected to the unit 607.

  The connection point between the first switch contact S1 and the second switch contact S2 of the second series circuit 30 and the connection point between the first switch contact G1 and the second switch contact G2 of the second series circuit 40 are the second common input. Connected to the unit 608.

  The connection point between the first switch contact J1 and the second switch contact J2 of the third series circuit 25 and the connection point between the first switch contact K1 and the second switch contact K2 of the third series circuit 45 are the third common input. Connected to the unit 609.

  The first end portions 601 to 606 are switched between a state connected to the Vcc potential portion and a state disconnected from Vcc, similarly to the first end portions 401 to 404 of the operation board 300 of the first embodiment. Similarly to the second end portions 408 to 411 of the operation board 300 of the first embodiment, the second end portions 611 to 616 are switched between a state connected to the GND potential portion and a state disconnected from the GND potential portion. .

  Then, as shown in Table 6 below, the switch state recognition unit 101 sequentially outputs the strobe signals COM1 to COM4 one by one, and the first switch contacts of the first series circuits 10 and 20 belonging to the first group. M1, H1 and the second switch contact M2, H2, the first switch contact S1, G1 and the second switch contact S2, G2 of the second series circuit 30, 40 belonging to the second group, and the third group belonging to the third group. Switch contacts (first switch contact or second switch contact) are sequentially selected one by one from the first switch contacts J1, K1 and the second switch contacts J2, K2 of the series circuits 25, 45. In Table 6, the strobe is represented by STB and the switch is represented by SW.

  For example, when the strobe signal COM1 is selected, for the first series circuits 10 and 20 belonging to the first group, the first end 601 connected to the first series circuit 10 is connected to the Vcc potential section. The other first end 603 is cut off from the Vcc potential portion. Further, the second end portions 613 and 616 are disconnected from the GND potential portion.

  As for the second series circuits 30 and 40 belonging to the second group, the second end 611 connected to the second series circuit 30 is connected to the GND potential part, and the other second end 615 is connected to the GND. It is cut off from the potential part. Further, the first end portions 602 and 605 are disconnected from the Vcc potential portion.

  As for the third series circuits 25 and 45 belonging to the third group, the second end 611 connected to the third series circuit 25 is connected to the GND potential part, and the other second end 614 is connected to the GND. It is cut off from the potential part. Further, the first end portions 604 and 606 are disconnected from the Vcc potential portion.

  Then, the switch state recognition unit 101 outputs the voltage SW1 of the first common input unit 607 and the second common input unit 608 when the strobe signals COM1 to COM4 are sequentially output and when the output of the strobe signals COM1 to COM4 is stopped. By determining the voltage SW2 and the voltage SW3 of the third common input unit 609 under the conditions shown in Tables 3 and 4 above, the operation state and failure of each operation switch M, H, J, S, G, K Recognize

  In the present embodiment, a switch device including four operation switches and six switches is shown. However, if the switch device includes a plurality of operation switches, the present invention is performed by performing similar grouping. Can be applied.

  In the present embodiment, the switch device used by being incorporated in a gas stove is shown, but the present invention can be applied to any device provided with a plurality of operation switches that are pushed by a user.

  In the present embodiment, the switch device including the control board 200 and the operation board 300 is shown. However, the switch apparatus may be configured by components mounted on a single board.

  In the present embodiment, all the first end portions 401 to 404 of the series circuits 10, 20, 30, and 40 are disconnected from the Vcc potential portion and all the second end portions 408 to 411 are connected to the GND in step ST5. Although the process of detecting a failure in the connection path between the operation switches M, H, S, and G and the microcomputer 100 is performed as a state in which the electric potential unit is disconnected, the present invention is applicable even when this process is not performed. The effect of can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Switch apparatus, M, H, S, G ... Operation switch, M1, H1, S1, G1 ... 1st switch contact, M2, H2, S2, G2 ... 2nd switch contact, 10, 20, 30, 40 ... Series circuit, 11, 21, 31, 41 ... first end side resistance, 12, 22, 32, 42 ... second end side resistance, 50 ... first end side switching circuit, 60 ... second end side Switching circuit, 70, 80 ... reference potential setting circuit, 100 ... microcomputer, 101 ... switch state recognition unit, 200 ... control board, 300 ... operation board, 401-404 ... first end, 405 ... first common input unit , 406 ... second common input section, 408 to 411 ... second end section.

Claims (3)

A plurality of operation switches having a first switch contact and a second switch contact that are switched in conjunction with a conduction state and a cutoff state according to a user's operation;
A first end side resistor, the first switch contact, the second switch contact, and a second end side resistor are formed individually for each of the operation switches, and between the first end and the second end. And a plurality of series circuits connected in series in this order,
The first circuit is provided separately for each series circuit, and switches between a state in which the first end is connected to the first potential unit and a state in which the first end is disconnected from the first potential unit. One end side switching circuit;
The second circuit is individually provided for each of the series circuits, and switches between a state in which the second end is connected to the second potential unit and a state in which the second end is disconnected from the second potential unit. A two-end side switching circuit;
A common input section in which the plurality of series circuits are divided into a plurality of groups, and the connection points of the first switch contacts and the second switch contacts of the series circuits belonging to the same group are individually provided for each group. And each common input unit is connected to the first potential unit via a first resistor individually provided for each common input unit, and individually provided for each common input unit. An input common circuit connected to the second potential portion via a second resistor;
From each of the groups, the first switch contact or the second switch contact of the series circuit is sequentially selected one by one, and the first switch contact is selected in each selection step by the first end side switching circuit. The first end of the series circuit having the selected first switch contact is connected to the first potential portion, the first end of the other series circuit is disconnected from the first potential portion, and the second end With the part side switching circuit, the second end of all the series circuits is cut off from the second potential part,
For the group in which the second switch contact is selected, the second end side switching circuit connects the second end portion of the series circuit having the selected second switch contact to the second potential portion, so that another series Each common input unit is configured such that the second end of the circuit is cut off from the second potential unit, and the first end of all the series circuits are cut off from the first potential unit by the first end side switching circuit. Recognizes the voltage level of
A switch device comprising: a switch state recognition unit for recognizing an operation state and a failure of the plurality of operation switches based on a voltage level of each common input unit recognized in each selection stage. The switch device according to claim 1,
The switch state recognition unit shuts off the first end of all the series circuits from the first potential unit by the first end side switching circuit, and the second end of all the series circuits as the first end. A switch device characterized by recognizing a failure of the operation switch based on a voltage level of each of the common input sections in a state of being cut off from the second potential section by the two end side switching circuit. In the switch device according to claim 1 or 2,
The input common circuit bisects the plurality of series circuits into a first group and a second group which are the plurality of groups, and a first switch contact of a first series circuit which is a series circuit belonging to the first group; A connection point with the second switch contact is connected to the first common input section which is the common input section for the first group, and the first of the second series circuit which is a series circuit belonging to the second group. A connection point between the switch contact and the second contact is connected to a second common input unit which is the common input unit for the second group;
The switch state recognition unit recognizes an operation state and a failure of the plurality of operation switches based on voltage levels of the first common input unit and the second common input unit.