JP2007206749A - Signal monitor circuit and signal monitor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact, lightweight and portable signal monitor circuit of simple circuit constitution that can easily specify a signal input to an electric circuit and the frequency thereof when needed and also to provide a signal monitor device which has the signal monitor circuit inside, without an external power source. <P>SOLUTION: Disclosed are the signal monitor circuit including a detecting circuit which detects an object to be monitor having voltage variation in such a case, an output circuit, and a self-holding circuit which enters a self-holding state on receiving a detection result from the detecting circuit to continuously supply electric power to the output circuit and also resets the self-holding state on receiving a reset signal to restore it; and the signal monitor device in which the circuit is incorporated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a signal monitoring circuit capable of monitoring the presence or absence of a signal input in a monitoring target such as a contact point of an electric circuit and the number of times when necessary, and a small, light and simple portable signal incorporating the circuit. It relates to a monitoring device.

  Automatic devices and automatic systems installed in various plants and the like are operated by control circuits incorporated therein. If an operation error occurs in an automatic device, etc., if the operation error continues, it is easy to investigate the cause. It cannot be determined whether or not the error occurred.

  In the latter case, the troubled part is usually searched by connecting a measuring instrument such as an oscilloscope to the control circuit and monitoring the voltage. However, for example, when an oscilloscope is used, the oscilloscope itself is a considerably large heavy object, and the place where the oscilloscope can be installed is limited, and it is heavy labor to carry a small place in the factory. Also, depending on the malfunctioning location, it may be necessary to install these measuring instruments, which are precision instruments, outdoors for a long time. Further, such a measuring instrument needs to secure a separate power source, and since the number of signal input channels is limited, the number of measurement points must be determined within the range of the number of channels. If it is necessary to monitor beyond the number of channels, a similar measuring instrument must be prepared and installed separately.

  In view of the above circumstances, an object of the present invention is to provide a signal monitoring circuit having a simple circuit configuration capable of easily specifying the presence / absence of a signal input in an electric circuit and the number of times when necessary. In addition, the present invention incorporates the signal monitoring circuit described above, is small and lightweight, and therefore is easy to carry, and secures a power supply directly from two connection points to which voltage is constantly applied during signal monitoring, such as a control circuit. An object of the present invention is to provide a signal monitoring device that can be used and does not require an external power supply.

  As a result of intensive studies in view of the above circumstances, the present inventor can easily monitor the presence or absence of a signal to be monitored (particularly voltage change) included in the electric circuit by using a self-holding circuit, thereby The present inventors have found that a simple signal monitoring circuit and a signal monitoring device using the circuit that can confirm the operating state of an electric circuit to be continuously monitored can be obtained, and the present invention has been completed.

  According to one aspect of the present invention, the above object is continued in a self-holding state in response to a detection circuit that detects a voltage change in the monitoring target, an output circuit, and a detection result of the detection circuit. This is achieved by a signal monitoring circuit including a self-holding circuit that supplies power to the output circuit and receives a reset signal to release the self-holding state and return to the original state.

  According to another aspect of the present invention, the object includes a signal input line connectable to a monitoring target, a power input line, and a casing from which these are drawn, and the casing includes the monitoring target. When there is a voltage change, a detection circuit that detects the change through the signal input line, an output circuit, and a detection result of the detection circuit is set to a self-holding state, and continues from the power input line to the output circuit. And a self-holding circuit that releases the self-holding state in response to the input of a reset signal.

  According to the signal monitoring circuit of the present invention, it is possible to easily monitor the presence / absence of a signal input (voltage change) to a monitoring target included in the electric circuit, and thereby it is possible to specify a malfunctioning portion in the electric circuit to be monitored. In addition, since the circuit configuration is simple, the construction, installation location, and number of installations are not limited.

  In addition, since the signal monitoring device of the present invention incorporates the signal monitoring circuit, it is possible to identify a malfunctioning portion in the electric circuit to be monitored, as well as the above, and it is small, light and excellent in portability. In addition, since there is no need to prepare a separate power source and complicated wiring is not required for installation, the installation location and the number of installations are not limited. Therefore, unlike conventional oscilloscopes, the number of signal monitoring targets is not limited.

  The signal monitoring circuit of the present invention can be constructed as a ladder circuit written in a relay contact circuit or a programmable controller. In the former case, a device such as a relay of each circuit can be integrally incorporated on a predetermined substrate on which a predetermined wiring pattern is formed in advance by means such as printing or etching. A device such as a relay may be arranged and fixed on the device mounting bracket, and a wire between them may be connected using a known signal line or the like. In the latter case, only this ladder circuit may be written in the controller, or it may be incorporated in another ladder circuit. Such a signal monitoring circuit can be installed in a publicly known method, for example, in an empty space such as in a control panel or in the vicinity of a device to be monitored.

  Hereinafter, the signal monitoring circuit of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is a circuit diagram showing an example of an embodiment of a signal monitoring circuit of the present invention. In this figure, the circuit of this embodiment includes a detection circuit (C), a self-holding circuit (A), an output circuit (B), and a reset circuit (D), and there is an abnormal voltage change in the monitoring target. In addition, the output circuit (B) is adapted to light the lamp.

  The detection circuit (C) includes signal input lines 11 and 12 and a timer 4 and an operation relay (coil) 5 connected in parallel therebetween. A known signal line or the like is used as the signal input lines 11 and 12, but when the signal monitoring circuit of the present invention is constructed on a substrate, a part of the substrate pattern is used as a signal input line, or A signal input line can be formed by connecting a part of the substrate pattern and a signal line through a socket or the like provided at a predetermined position on the substrate.

  In the self-holding circuit (A), 1 is a keep relay, 1S is its set coil, and 1R is a reset coil. Once the set coil 1S is energized, the keep relay 1 is continuously held even when the energization is stopped. In this state, when the reset coil 1R is energized, the self-holding is released and the original state is restored.

  The output circuit (B) includes a timer 6 and a lamp 21, which are connected in series to the contact output 1a of the keep relay 1 in the self-holding circuit (A). Power is supplied from the input lines 13 and 14. The reset circuit (D) includes a reset relay coil 9 and an a-contact pushbutton switch 10, which are connected in series between the power input lines 13 and 14.

  The power input lines 13 and 14 can be connected to two connection points in a circuit around the installation position of the signal monitoring circuit of the present invention. A circuit having two connection points may have either a DC power supply or an AC power supply, and the power supply voltage is not particularly limited within the range used for normal control. Further, it may be a circuit that includes a monitoring target or a circuit that does not include a monitoring target. Devices such as relays used in the signal monitoring circuit of the present invention can be appropriately selected and used according to the type and voltage of the power source. Since the power source can be appropriately selected as described above, the selection of the monitoring target is not limited by the power source. The power input lines 13 and 14 are provided with fuses 131 and 141 for protection of the signal monitoring circuit of the present invention.

  Next, the operation of the signal monitoring circuit of the present invention shown in FIG. 1 will be described. When a voltage change occurs between the signal input lines 11 and 12 and energization is performed, the coil 4 of the operation relay is excited together with the timer 4 in the detection circuit (C). When the coil 5 is excited, the self-contact (a contact) 5a of the relay 5 is closed in the self-holding circuit (A), and the set coil 1S of the keep relay 1 is excited. The time during which the coil 5 is excited is regulated by the timer 4. That is, the timer 4 starts counting a preset time at the same time as energization between the signal input lines 11 and 12, and when the set time comes, the timer 4 is connected in series to the operation relay 5 between the signal input lines 11 and 12. The self-contact b 4b is opened, the coil 5 is demagnetized, and the contact output to the keep relay 1 is not performed. When the coil 5 is consumed, the a contact 5a is opened. As described above, the set coil 1S is self-held even when the contact a 5a is opened.

  When the set coil 1S is excited, the self-holding contact (a contact) 1a connected between the power input lines 13 and 14 is closed in the output circuit (B), the lamp 21 is turned on, and the timer 6 is energized. Is done. When the timer 6 is energized, the b contact 6b, which is the contact output of the timer 6, is opened in the self-holding circuit (A), but the set coil 1S remains in the self-holding state and the contact 1a is continuously closed. Maintained.

  When the reset push button 10 of the reset circuit (D) is pressed in the above state, the coil 9 of the reset relay is excited and the a contact 9a of the self-holding circuit (A) is closed and connected in series with this. The reset coil 1R is excited. As a result, the self-holding state of the keep relay 1 is released, and the relay returns to the original state.

  Thus, there is a voltage change between the signal input lines 11 and 12, and once the set coil 1S of the keep relay 1 is energized, the lamp 21 is kept lit regardless of the subsequent voltage change. In the circuit of the present invention, when the reset push button 10 is pressed, the lamp is turned off for the first time, and if there is a voltage change between the signal input lines 11 and 12 again, this is notified again by turning on the lamp 21. Will be able to.

  FIG. 2 is a circuit configuration diagram in which three self-holding circuits (A) and three output circuits (B) are connected in parallel in the circuit shown in FIG. In the following, for convenience of explanation, the self-holding circuit (A) and the output circuit (B) are indicated by reference numerals A1, A2, A3 and reference numerals B1, B2, B3, respectively, in the order of operation. In addition, the same code | symbol is used about the same or common part as FIG. In particular, the detection circuit (C) detects the voltage change to be monitored and the self-holding circuit (A1) and the output circuit (B1) operate in the same configuration and operation as in FIG. A duplicate description is omitted.

  When the self-holding circuit and the output circuit are added, the number of these extendable circuits depends on the number of contacts of the operation relay 5. Accordingly, when it is desired to further increase the self-holding circuit and the output circuit, it is necessary to connect a similar operation relay separately in parallel with the operation relay 5 and use the contact output of the newly connected operation relay. By adding additional operation relays in this way, it becomes possible to monitor a larger number of monitoring targets. In the present embodiment, the number of contact output points of the relay 5 is assumed to be 3, and each circuit is added.

  The self-holding circuit (A2) is connected to the set coil 2S of the keep relay 2 in series with the time limit a contact 6a of the timer 6, and the self-holding circuit (A3) of the timer 7 in series with the set coil 3S of the keep relay 3 is connected. There is no difference from the self-holding circuit (A1) except that the time-a contact 7a is connected. Since the time limit contacts 6a and 7a are connected, the self-holding circuits (A2) and (A3) can be operated after the set time has elapsed after the timers 6 and 7 are energized.

  Next, the operation of the signal monitoring circuit shown in FIG. 2 will be described. As in the case described above, the power input lines 13 and 14 are connected to two connection points in a circuit including a monitoring target to which a voltage is constantly applied during monitoring, respectively. .

  When a voltage change occurs between the signal input lines 11 and 12, the coil 5 of the operation relay is excited together with the timer 4 in the detection circuit (C). When the coil 5 of the operation relay is excited, the a contacts 5a-1, 5a-2 and 5a-3 which are the self contacts of the operation relay 5 in the self-holding circuits (A1), (A2) and (A3). Each is closed. In this state, in the self-holding circuits (A2) and (A3), the timing contacts 6a and 7a connected in series to the keep relays 2 and 3 are open, respectively. Neither 2S nor 3S is excited, and only the set coil 1S of the keep relay 1 is excited. The time that the coil 5 is excited is regulated by the timer 4 and the point that the set coil 1S is held by itself even when the contact a 5a-1 is opened is the embodiment shown in FIG. It is the same.

  When the set coil 1S of the self-holding circuit (A1) is excited, the self-contact (a contact) 1a of the keep relay 1 is closed in the output circuit (B1), the lamp 21 is turned on and the timer 6 is operated. In the self-holding circuit (A1), the b-contact 6b, which is the contact output of the timer 6, is instantaneously opened, and after the set time of the timer 6, the a-contact 6a of the self-holding circuit (A2) is closed. Since the contact a 6a is connected, the self-holding circuit (A1) and the self-holding circuit (A2) are not operated simultaneously even when the signal input lines 11 and 12 are energized. The holding circuit (A2) operates separately under the condition that the self-holding circuit (A1) operates.

  Next, when a voltage change occurs again between the signal input lines 11 and 12, the operation relay 5 is energized for the set time of the timer 4 in the detection circuit (C), and the coil 5 is excited as described above. When the coil 5 is excited, the three self-contacts 5a-1, 5a-2 and 5a-3 included in the three self-holding circuits are closed. However, since the self-holding circuit (A1) is in a state in which the b contact 6b is opened, the set coil 1S of the keep relay 1 is not excited, and the timer 7 is not operating in the self-holding circuit (A3). Since the time limit contact 7a is not closed, the set coil 3S of the keep relay 3 is not excited similarly. Therefore, only the set coil 2S of the keep relay 2 of the self-holding circuit (A2) is excited.

  When the set coil 2S is excited, the a contact 2a of the output circuit (B2) is closed, and the lamp 22 and the timer 7 are respectively excited by energization. When the timer 7 is excited, the instantaneous b contact 7b of the self-holding circuit (A2) is opened, and the time limit a contact 7a of the self-holding circuit (A3) is closed after a predetermined set time. By closing the time-a contact 7a, when the voltage further changes between the signal input lines 11, 12, the self-holding circuit A3 operates this time. The function of the instantaneous contact 7b is the same as that of the contact 6b, and the keep relay 2 is maintained in the self-holding state as described above even when the instantaneous b contact 7b is opened.

  Further, when there is a voltage change between the signal input lines 11 and 12, the operation relay 5 is energized for a predetermined time by the timer 4 in the detection circuit (C), and the coil 5 is excited. When the coil 5 is excited, the three self-contacts 5a-1, 5a-2, and 5a-3 included in the coil 5 in the three self-holding circuits are closed, respectively, but the self-holding circuit (A1) and the self-holding circuit are closed. In the circuit (A2), since the instantaneous b-contacts in the circuit are in the open state as described above, the keep relays 1 and 2 do not operate. Therefore, only the self-holding circuit (A3) has its set coil 3S. Will be excited.

  When the set coil 3S is excited, the a contact 3a of the keep relay 3 provided in the output circuit (B3) is closed. As a result, the lamp 23 and the timer 8 are energized and excited. Simultaneously with the excitation of the timer 8, the instantaneous b contact 8b of the self-holding circuit (A3) is opened.

  Further, when adding one self-holding circuit and one output circuit, if the time limit contact 8a of the timer 8 is connected in series with the set coil in the same manner as the self-holding circuits (A1), (A2), (A3). Good. Further, when these circuits are added, they can be sequentially connected in series with a set relay of a self-holding circuit that adds a timer a contact of the timer of the output circuit.

  As described above, when the signal input lines 11 and 12 are energized irregularly three times by voltage change, the lamps are sequentially turned on one by one with energization for each time. Therefore, the operator can know how many times the voltage change has occurred in the monitoring target (the number of malfunctions) by checking the lighting state of the lamp of the circuit. In FIG. 2, a display lamp is used, but other indicators can also be used.

  In the present embodiment, each of the three self-holding circuits and output circuits is provided side by side. However, when all the lamps of these output circuits are lit, the operator presses the manual a-contact pushbutton switch, The reset relay coil 9 is excited, and the a contact outputs 9a-1, 9a-2, 9a-3 of the reset relays provided in the self-holding circuits (A1) to (A3) are closed, respectively. And the reset coils 1R, 2R, 3R connected in series are respectively excited. As a result, the self-holding states of the self-holding circuits (A1) to (A3) are released, and the keep relays 1 to 3 each return to the original state.

  Next, the signal monitoring apparatus of the present invention will be described. The signal monitoring device of the present invention incorporates the circuit shown in FIG. 2 in one housing, and the signal input lines 11 and 12 and the power input lines 13 and 14 are drawn out from the housing. An alligator clip is connected and fixed to the tips of the signal input lines 11 and 12 and the power supply input lines 13 and 14, and this is an electric circuit including a monitoring target and a circuit different from the electric circuit, and is always at a voltage during monitoring. Can be connected to the connection point to which is applied. Also, various crimp terminals can be crimped to the ends of these input lines, and these can be fixed by screwing or the like to the same connection points as described above.

  Moreover, the signal monitoring apparatus of the present invention can be used by incorporating the above detection circuit, self-holding circuit, output circuit, and reset circuit in each unit and combining these units as appropriate. In this case, among the above circuits, for example, two circuits such as a detection circuit and a reset circuit, a self-holding circuit and an output circuit are combined and incorporated in one unit. Three may be arbitrarily selected and incorporated in one unit. Preferably, at least the self-holding circuit and the output circuit are built in one unit.

  FIG. 3 is a diagram showing an example of an embodiment of the signal monitoring apparatus of the present invention that is unitized as described above. For convenience of explanation, it is assumed that the apparatus according to the present embodiment includes the signal monitoring circuit shown in FIG. 2, and description of the configuration and operation of the circuit itself is omitted. In the drawing, thin line frames indicate the respective units. Further, each contact point in the frame indicated by the dotted line actually indicates that it is included in the unit indicated on the right shoulder. Therefore, a connection line is required between each unit for drawing out the contact output of the unit with the built-in relay to other units.

  In FIG. 3, the apparatus of the present invention has a multi-layer structure in which five units (101) to (105) are configured to be stacked. Among these, the unit (101) has a built-in detection circuit (C), and the power input lines 13 and 14 and the signal input lines 11 and 12 are drawn out from the unit. The unit (102) includes a reset circuit (D), and the units (103) to (105) include self-holding circuits (A1), (A2), (A3) and output circuits (B1), (B2). ) And (B3) are incorporated. Further, in a unit having a built-in self-holding circuit and an output circuit, it is preferable to fix a lamp or the like on a surface other than the surface of each casing so that the lighting state of the lamp can be confirmed from the outside. .

  When connecting the contact output of each relay in series in the middle of the wiring of another unit, mutual communication between the units can be performed by a conventionally known method. For example, when the units are stacked, they are brought into contact with each other. Contact points of each connection line may be provided on the surface, so that each contact output may be connected to a predetermined unit from a unit with a relay through a connection line, or a terminal block or the like may be provided separately, Communication between the units may be performed via terminals.

  As described above, the signal monitoring apparatus according to the present invention is not only capable of specifying an accident point by the above-described configuration, but particularly in a circuit in which an operation failure occurs when an instantaneous operation failure occurs irregularly. By connecting a plurality of devices and checking the number of operations of the device of the present invention after a malfunction occurs due to the elapse of a predetermined period, it is possible to identify a defect location.

  Also, by configuring the signal monitoring device of the present invention as a unit, it is easy to combine and add signal monitoring circuits, and take an appropriate circuit configuration according to the status of the electric circuit including the monitoring target. be able to. In addition, by unitization, the number of units that can be shared can be reduced, and the manufacturing cost can be reduced accordingly. Furthermore, since the signal monitoring device of the present invention is not limited by the power supply, it can be easily combined with a new circuit.

  As shown in FIG. 3, the output circuit can use not only a display lamp but also other indicators. For example, a time meter is connected to display the time when there is a voltage change in the monitoring target. It is also possible to connect various communication means and display the same time on the outside. In the above-described embodiments, the relay contact circuit is shown, but an equivalent circuit can be configured using, for example, a non-contact relay or a programmable controller. In that case, if necessary, a device such as a DC / AC converter can be used in combination.

  The signal monitoring circuit and the signal monitoring device according to the present invention are connected to a monitoring target in an electric circuit such as a control circuit, such as a control circuit. It is particularly useful for identifying malfunctioning parts that cause contact failure due to disconnection, contact failure due to disconnection of resistors and other accessories, relay contact failure, and the like.

It is a circuit diagram showing an example of an embodiment of a signal monitoring circuit of the present invention. FIG. 2 is a circuit configuration diagram in which three self-holding circuits (A) and three output circuits (B) shown in FIG. 1 are connected in parallel. It is a figure which shows an example of embodiment of the signal monitoring apparatus of this invention unitized.

Explanation of symbols

A Self-holding circuit B Output circuit C Detection circuit D Reset circuit 1, 2, 3 Keep relay 1S, 2S, 3S Set coil 1R, 2R, 3R Reset coil 4, 6 Timer 5 Operation relay (coil)
9 Reset relay (coil)
10 Switch 11, 12 Signal input line 13, 14 Power input line 21, 22, 23 Lamp 111, 121, 131, 141 Fuse (101), (102), (103), (104), (105) Unit (enclosure )

Claims (15)

  A detection circuit for detecting a voltage change in the monitoring target, an output circuit, a detection result of the detection circuit, a self-holding state, and continuously supplying power to the output circuit, and a reset signal And a self-holding circuit that releases the self-holding state and returns to the original state in response to the input of the signal.   The signal monitoring circuit according to claim 1, wherein a timer is connected to the detection circuit, and the detection result is sent to the self-holding circuit.   The signal monitoring circuit according to claim 1, wherein the self-holding circuit includes a keep relay.   The signal monitoring circuit according to claim 1, wherein the reset signal is generated by a switch operation.   5. The signal monitoring circuit according to claim 1, wherein the self-holding circuit and the output circuit are plural and the same number are connected in parallel.   6. The signal monitoring circuit according to claim 1, wherein the signal monitoring circuit is used for detecting a contact failure and a relay operation / contact failure in an electric circuit to be monitored.   It consists of a signal input line that can be connected to the monitoring target, a power supply input line, and a chassis from which these are drawn, and when the voltage changes in the monitoring target, it is detected via the signal input line. The detection circuit, the output circuit, and the detection result of the detection circuit are in a self-holding state, the power is continuously supplied from the power supply input line to the output circuit, and the reset signal is input to be self-holding. A signal monitoring device including a self-holding circuit for releasing the state.   The signal monitoring device according to claim 7, wherein a timer is connected to the detection circuit, and the detection result of the detection circuit is sent to the self-holding circuit for the set time.   The signal monitoring apparatus according to claim 7, wherein the self-holding circuit includes a keep relay.   The power source of the output circuit is a circuit different from the circuit including the monitoring target, and is supplied from two connection points to which a voltage is constantly applied during monitoring. The signal monitoring device described in 1.   The signal monitoring device according to claim 7, wherein the reset signal is generated by a switch operation.   12. The device according to claim 7, wherein the housing includes a plurality of and the same number of the self-holding circuits and the output circuits, and both the circuits are connected in parallel to the voltage input line and the signal input line, respectively. The signal monitoring apparatus described.   The said housing is comprised from the multilayer structure which can stack and connect a some unit, and combined with at least the said self-holding circuit and the said output circuit, and was accommodated in one unit. The signal monitoring device according to item.   The signal monitoring apparatus according to any one of claims 7 to 13, wherein the casing has a plate magnet fixed to either one or both of outer surfaces orthogonal to the stacking direction of the respective layered portions. The signal monitoring device according to claim 7, which is used for detecting a contact failure and a relay operation / contact failure in an electric circuit to be monitored.

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