JP2006163878A - Switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switching device for adding switching elements without increasing a manufacturing cost and discriminating closed switching elements when a plurality of switching elements are simultaneously closed. <P>SOLUTION: A plurality of filters 15 having signal pass-bands not overlapping with one another are serially inserted to each switching elements SW1-SWx between an output terminal 12 and each input terminal 13a, 13b of a signal processor. The signal processor periodically outputs signals with different frequencies n1-nx (Hz) corresponding to respective pass-band of filters 15 disposed correspondingly to respective switching element SW1-SWx to the output terminal 12 without overlapping with one another and detects the closed switching elements SW1-SWx on the basis of a signal fed back to the first input terminal 13a through the filters 15 each connected to the closed switching elements SW1-SWx. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a switching device having a function of detecting a switching element operated by an operator.

  2. Description of the Related Art Conventionally, for example, a switching device using a matrix circuit is known as a switching device that is incorporated in a remote control provided with a plurality of switches and detects which switch is operated (for example, Patent Document 1). reference.). The switching device includes a plurality of signal lines arranged in a matrix along the X axis and the Y axis, switching elements provided at intersections of the signal lines, and signal lines along the X axis. A microcomputer having a plurality of input terminals to be connected and a plurality of output terminals to which each signal line along the Y-axis is connected (hereinafter referred to as a microcomputer), and is output from the output terminal to the input terminal. A switching element that is closed is detected by a microcomputer from a combination of signal lines through which the returned signal passes.

In addition to the switching device described above, a plurality of switching elements connected in parallel between the input terminal of the microcomputer and the power supply, and each switching element and the power supply are inserted in series in each switching element. A plurality of resistors having different resistance values, and voltage detection for determining which switching element is closed from the value of the voltage applied to the input terminal of the microcomputer when the switching element is closed A switching circuit of the formula is known.
Japanese Patent No. 3199805 (page 3-4, FIG. 1)

  However, in the switching device using the conventional matrix circuit described above, since each signal line is connected to the input terminal or output terminal of the microcomputer, the switching element is connected to newly add a switching element. When a new signal line is added, input / output terminals for connecting the signal line need to be newly provided according to the number of added signal lines. For this reason, an increase in manufacturing cost is caused, and a switching element cannot be easily added.

  On the other hand, in the above-described conventional voltage detection type switching device, each switching element is connected in parallel between the input terminal of the microcomputer and the power supply. Simply connecting a resistor to the switching element is sufficient, and there is no need to add an input terminal for the microcomputer. However, since the voltage value corresponding to each switching element is detected to determine the closed switching element, the voltage value applied to the input terminal of the microcomputer when a plurality of switching elements are closed simultaneously is There is a case where the voltage applied to the input terminal when any one of the switching elements is closed is duplicated. For this reason, the closed switching element cannot be detected properly.

  Accordingly, an object of the present invention is to add a switching element without causing an increase in manufacturing cost, and to properly detect a closed switching element when a plurality of switching elements are simultaneously closed. It is to provide a switching device that can be used.

  In order to solve the above problem, the invention according to claim 1 includes a plurality of switching elements, an output terminal and an input terminal, and the switching elements are parallel to each other between the input terminal and the output terminal. And a signal processing unit for identifying which one of the switching elements is closed at the contact, and each switching element is inserted in series between the output terminal and the input terminal, A plurality of filters having signal pass bands that do not overlap with each other, and the signal processing unit has different frequencies corresponding to the respective pass bands of the respective filters provided corresponding to the respective switching elements. Signals are periodically output to the output terminal without overlapping each other, and the input is made through the filter connected to the switching element with the contact closed. Based on the signal fed back to the terminal, one of said switching elements and judging whether the closed.

  According to a second aspect of the present invention, in the first aspect of the present invention, the signal processing unit is indicated by a fundamental frequency and a multiple of the fundamental frequency, and each frequency corresponds to a signal passband of each filter. The frequency of the signal fed back to the input terminal from the output timing of the signal of each frequency output from the output terminal and the output portion that periodically outputs to the output terminal without overlapping each other signal, And a determination part for detecting the switching element closed from the determination result.

  The invention according to claim 3 is the invention according to claim 2, wherein the output portion includes a PWM circuit that outputs an output signal composed of pulses corresponding to each frequency at a predetermined period. To do.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, each of the filters is an analog filter, and each output signal is pulsed between the filter and the output terminal of the signal processing unit. A waveform shaping circuit for converting a square wave shown in FIG. 4 into a sine wave corresponding to each frequency is inserted.

  According to a fifth aspect of the present invention, in the second aspect of the present invention, the determination unit determines the frequency of the signal fed back to the input terminal from the output timing of the signal of each frequency output from the output terminal. Therefore, it has a timer circuit for measuring the feedback time of the signal from the output timing to the input terminal.

  According to the configuration of the first aspect, the signals of the respective frequencies periodically output from the output terminals of the signal processing unit without overlapping each other have passbands corresponding to the respective frequencies, and are closed. Feedback to the input terminal through a filter provided corresponding to each switching element, so that even when a plurality of switching elements are closed at the same time, each of the filters passing through each filter corresponding to each closed switching element The frequency signals are sequentially fed back to the input terminals without overlapping each other. Therefore, even when a plurality of switching elements are closed at the same time, it is possible to properly detect each closed switching element without causing misunderstanding as in the prior art in determining which switching element is closed. it can.

  In addition, since the plurality of switching elements are connected in parallel between the output terminal and the input terminal of the signal processing unit, in order to add a switching element, a filter is newly connected to the switching element to be added, It is sufficient to output a signal having a frequency corresponding to the pass band of the filter from the signal processing unit, and it is not necessary to newly add an input terminal and an output terminal of the signal processing unit. Therefore, a switching element can be easily added without increasing the manufacturing cost as in the conventional case by newly providing an input / output terminal in the signal processing unit.

  According to the configuration of the second aspect, each frequency output from the output portion is indicated by a fundamental frequency and a multiple of the fundamental frequency. Therefore, the frequency corresponding to the passband of each filter can be easily distinguished by each filter. can do. Moreover, since the frequency of the signal fed back to the input terminal is determined by the determination part from the output timing of the signal of each frequency output from the output terminal, it is possible to easily detect which switching element is closed. it can.

  According to the configuration of the third aspect, since an output signal composed of pulses corresponding to each frequency is output from the PWM circuit at a predetermined period, the pass band of each filter connected to each switching element is set. Corresponding signals having different frequencies can be periodically output to the output terminal without overlapping each other.

  According to the configuration of the fourth aspect, by converting the square wave into a sine wave by the waveform shaping circuit, the frequency corresponding to the pass band of each filter configured by the analog filter is surely discriminated by each filter. Can do.

  According to the configuration of the fifth aspect, since the feedback time of the signal from the output timing to the input terminal is timed by the timing circuit of the determination part, the feedback to the input terminal is detected in order to detect the closed switching element. It is possible to more easily determine the frequency of the processed signal from the output timing of the signal of each frequency output from the output terminal.

  The present invention will be described with reference to the illustrated embodiments.

  The present embodiment shows an example in which the present invention is applied to a remote controller for controlling the operation of an air conditioner.

  In the example shown in FIG. 1, the switching device 10 according to the present invention includes a plurality of switching elements SW1, SW2, SW3,..., SWx, an output terminal 12 to which each switching element is connected, and two inputs. A signal processing unit 14 that includes terminals 13a and 13b and that identifies which switching elements SW1 to SWx are closed and a plurality of filters 15 is provided.

  Each of the switching elements SW1 to SWx includes a pair of contacts 16 that are spaced apart from each other, and a contactor 17 that can contact each of the contacts in order to close the contacts. The switching elements SW1 to SWx are connected in parallel between the output terminal 12 of the signal processing unit 14 and the input terminals 13a and 13b, respectively. As is well known in the art, the contacts 16 of the switching elements SW1 to SWx are opened and closed by manual operation of an operation unit (not shown) for operating the contacts. Each of the switching elements SW1 to SWx is used for, for example, operation switching, temperature and wind direction adjustment of the air conditioner.

  In the illustrated example, each filter 15 is configured by a conventionally well-known analog filter 15, and is connected in series with each switching element between the output terminal 12 of the signal processing unit 14 and each switching element SW <b> 1 to SWx. Has been inserted. Each filter 15 has a signal pass band that does not overlap with each other, and allows a signal of a frequency corresponding to each pass band to pass when the corresponding switching elements SW1 to SWx are closed. .

  In the illustrated example, the signal processing unit 14 includes a CPU, and includes an output portion 19 connected to the output terminal 12 and a determination portion 20 connected to both the first and second input terminals 13a and 13b. Both the first and second input terminals 13a and 13b are used as interrupt terminals for the CPU in the illustrated example. The first input terminal 13 a is an input terminal for receiving a signal processed by the signal processing unit 14, and the second input terminal 13 b is a control terminal for receiving a control signal for controlling the operation of the output portion 19. is there. The first input terminal 13a reads an input signal when a control signal is input to the second input terminal 13b. A pull-up resistor 18 for adjusting a voltage applied to each input terminal is connected to both the first and second input terminals 13a and 13b.

  In the illustrated example, the output portion 19 has a PWM circuit 21 that is well known in the art. The PWM circuit 21 has a rectangular pulse shape composed of a pulse group of a fundamental frequency n (Hz) and frequencies n2 (Hz), n3 (Hz),..., Nx (Hz) that are integer multiples of the fundamental frequency. Signals are sequentially output to the output terminal 12 in accordance with the number of switching elements. As shown in FIG. 2A, the signals of the respective frequencies n1 to nx (Hz) are repeated so as to be spaced apart from each other by a certain time interval from the lower frequency to the higher frequency and to repeat each with a constant period. A pattern is output to the output terminal 12. As will be described later, the operation of the PWM circuit 21 is controlled by a control signal that is input to the second input terminal 13 b and sent through the determination portion 20. Thereby, unnecessary radiation noise can be reduced, and current consumption can be reduced. The signal pass band of each filter 15 is set corresponding to each of the frequencies n1 to nx (Hz) of the signal output from the PWM circuit 21, respectively.

  In the example shown in FIG. 1, between the output terminal 12 and each filter 15, the waveform of the output signal output from the output portion 19 is changed from a square wave indicated by a pulse to a sine wave corresponding to the pass band of each filter 15. A waveform shaping circuit 22 is inserted for conversion into

  Of the signals of the respective frequencies n1 to nx (Hz) that are output to the output terminal 12 and converted into sine waves by the waveform shaping circuit 22, they pass into the pass band of the filter 15 connected to the switching elements SW1 to SWx that are closed. The corresponding frequency signal is fed back to the first input terminal 13a through the filter.

  In the illustrated example, the determination portion 20 connected to each of the input terminals 13a and 13b has a feedback time from the output timing of the signals having the respective frequencies n1 to nx (Hz) from the output terminal 12 to the first input terminal 13a. It has a clock circuit 23 for clocking. In the time measuring circuit 23, the time when the signals of the respective frequencies n1 to nx (Hz) output to the output terminal 12 pass through the corresponding filter 15 of the pass band and are fed back to the first input terminal 13a. Stored in advance.

  When the determination part 20 detects that the control signal is received at the second input terminal 13b, it sends the control signal to the PWM circuit 21 of the output part 19 as described above. As a result, the PWM circuit 21 sequentially outputs signals of frequencies n1 to nx (Hz) to the output terminal 12. Note that the PWM circuit 21 outputs LO when none of the switching elements SW1 to SWx are closed. Thus, when any of the switching elements SW1 to SWx is closed, the first input terminal 13a can be applied with an L edge from H, and the first input terminal 13a becomes LO. Further, when the determination part 20 detects that the control signal is received at the second input terminal 13b, the determination part 20 starts reading the signal input to the first input terminal 13a. In addition, the determination unit 20 sequentially compares the feedback time of the input signal to the first input terminal 13a measured by the timer circuit 23 and the feedback times of the frequencies n1 to nx (Hz) stored in the timer circuit 23 in advance. Then, it is determined which frequency n1 to nx (Hz) corresponds to the frequency of each signal fed back from the comparison result. Further, the determination portion 20 detects the filter 15 through which the feedback signal has passed, that is, the closed switching elements SW1 to SWx, from the determination result of the frequency of the feedback signal.

  The detection operation of the switching element closed in the signal processing unit 14 will be described with reference to the flowchart shown in FIG.

  The signal processing unit 14 determines whether or not a control signal is input to the second input terminal 13b in the determination part 20 (step S1).

  When it is determined by the determination portion 20 that no control signal is input to the second input terminal 13b, that is, when all the switching elements SW1 to SWx are open, the second input terminal is repeated by repeating step S1. Wait for input of signal to 13b.

  On the other hand, when the determination part 20 determines that a signal is input to the second input terminal 13b, that is, when any of the switching elements SW1 to SWx is closed, the control input to the second input terminal 13b. The signal is sent from the determination part 20 to the PWM circuit 21 of the output part 19. The PWM circuit 21 receives the control signal from the determination part 20 and sequentially outputs signals of the frequencies n1 to nx (Hz) to the output terminal 12 (step S2).

  Further, when the determination part 20 detects that a control signal is input to the second input terminal 13b, the determination part 20 starts reading a signal input to the first input terminal 13a. The feedback time of the signal input to the first input terminal 13a is measured by the timer circuit 23 of the determination part 20. The determination part 20 compares the feedback time of the input signal timed by the timekeeping circuit 23 with the feedback time of the signals n1 to nx (Hz) stored in advance in the timekeeping circuit 23, whereby the frequency of the input signal is determined. It is determined which of n1 to nx (Hz) corresponds (step S3).

  For example, as shown in FIG. 2B, the first input is performed in a time equal to the feedback time of the signal of the frequency n2 (Hz) stored in advance in the timing circuit 23 as the feedback time of the input signal timed by the timing circuit 23. When the signal is continuously input to the terminal 13a periodically, it is determined that the frequency of the input signal is n2 (Hz).

  From the determination result of the frequency of the input signal, the closed switching element is determined (step S4). If the determination portion 20 determines that the frequency of the input signal corresponds to, for example, n2 (Hz), it is determined that the switching element SW2 to which the filter 15 in the passband corresponding to the frequency n2 (Hz) is connected is closed. Determined in portion 20.

  By transmitting the determination result to the air conditioner from a transmitter (not shown) of the remote controller, for example, the air direction of the air conditioner can be adjusted to the wind direction according to the operation of the operator of the remote controller.

  According to the present embodiment, as described above, signals of the frequencies n1 to nx (Hz) periodically output from the output terminal 12 of the signal processing unit 14 without overlapping each other correspond to the respective frequencies. Since the signal is returned to the first input terminal 13a through the filter 15 provided corresponding to the closed switching elements SW1 to SWx, the plurality of switching elements SW1 to SWx are simultaneously closed. Even in this case, the signals of the respective frequencies that have passed through the respective filters 15 corresponding to the respective closed switching elements SW1 to SWx are sequentially fed back to the first input terminal 13a without overlapping each other. Therefore, even when a plurality of switching elements SW1 to SWx are closed at the same time, it is possible to properly detect each closed switching element without causing misunderstanding as in the past in determining which switching element is closed. can do.

  In addition, as described above, since the plurality of switching elements SW1 to SWx are connected in parallel between the output terminal 12 of the signal processing unit 14 and the input terminals 13a and 13b, a switching element is newly added. It is sufficient that the filter 15 is newly connected to the switching element to be added, and a signal having a frequency corresponding to the pass band of the filter is output from the signal processing unit 14, and the input terminals 13a, 13b of the signal processing unit 14 and There is no need to add a new output terminal 12. Therefore, a switching element can be easily added without causing an increase in manufacturing cost as in the prior art by newly providing the input / output terminals 12, 13a, 13b in the signal processing unit 14.

  Further, as described above, each frequency of the pulse signal output from the PWM circuit 21 of the output portion 19 is indicated by the fundamental frequency n and an integer multiple of the fundamental frequency. Corresponding frequencies can be easily distinguished by the respective filters 15.

  Further, as described above, since the feedback time of the signal from the output timing to the first input terminal 13a is timed by the timing circuit 23 of the determination part 20, the first switching circuit is detected in order to detect the closed switching element. The frequency of the signal fed back to the input terminal 13a can be more easily determined from the output timing of the signals of the frequencies n1 to nx (Hz) output from the output terminal 12.

  In the present embodiment, an example in which each filter 15 is configured by an analog filter has been described, but each filter 15 may be configured by a digital filter instead. In this case, the waveform shaping circuit 22 for converting the waveform of the pulse signal output from the PWM circuit 21 into a sine wave can be eliminated. Moreover, although each filter 15 showed the example inserted between each switching element SW1-SWx and the output terminal 12, it replaced with this and each filter 15 was replaced with each switching element SW1-SWx and each input terminal 13a. , 13b.

  Furthermore, although the example which used the switching apparatus 10 which concerns on this invention for the remote controller of an air conditioner was shown, it replaced with this, for example, remote controllers other than an air conditioner, or a remote controller provided with several switching elements The present invention can be applied to these devices.

1 is a block diagram schematically showing a switching device according to the present invention. (A) shows the waveform of the signal output from the PWM circuit of the output portion, and (b) shows the waveform of the signal input to the first input terminal. It is a flowchart until the detection of the closed switching element in the determination part.

Explanation of symbols

SW1, SW2, SW3,..., SWx switching element 12 output terminal 13a, 13b input terminal 16 contact 14 signal processing unit 15 filter 10 switching device 19 output part 20 determination part 21 PWM circuit 22 waveform shaping circuit 23 timing circuit

Claims (5)

  A plurality of switching elements, and an output terminal and an input terminal, and the switching elements are connected in parallel to each other between the input terminal and the output terminal, and any of the switching elements is closed. And a plurality of filters having signal pass bands that are inserted in series between the output terminals and the switching elements and do not overlap each other. The signal processing unit periodically outputs signals of different frequencies corresponding to the respective pass bands of the respective filters provided corresponding to the respective switching elements to the output terminal without overlapping each other. Any of the switches is based on a signal fed back to the input terminal through the filter connected to the switching element with the contact closed. Switching apparatus characterized by ring element to determine whether the closed.   The signal processing unit is indicated by a fundamental frequency and a multiple of the fundamental frequency, and each outputs a signal of each frequency corresponding to the signal pass band of each filter to the output terminal periodically without overlapping each other. An output portion, and a determination portion for determining the frequency of the signal fed back to the input terminal from the output timing of the signal of each frequency output from the output terminal, and detecting the closed switching element from the determination result. The switching device according to claim 1, further comprising:   The switching device according to claim 2, wherein the output portion includes a PWM circuit that outputs an output signal composed of pulses corresponding to each frequency at a predetermined period.   Each filter is an analog filter, and between each filter and the output terminal of the signal processing unit, for converting each output signal from a square wave indicated by a pulse to a sine wave corresponding to each frequency. The switching device according to claim 3, wherein a waveform shaping circuit is inserted.   The determination part counts the time of signal feedback from the output timing to the input terminal to determine the frequency of the signal fed back to the input terminal from the output timing of each frequency signal output from the output terminal. The switching device according to claim 2, further comprising a circuit.

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