Abstract:
A trouble-shooting circuit arrangement for localizing and identifying the first failure in time in a sequence of failures which has a plurality of monitor circuits including trouble detector circuits for producing direct current outputs in response to the occurence of failure or trouble at various contact points and trouble localization circuits for identifying the trouble which has occurred in any of the monitor circuits, identifying such factors as coolant, pressure, temperature, fuel and the like in an engine. The arrangement locates the first failure or trouble in time, which has occurred in any of the circuits so as to remedy the countermeasures of the equipment against the occurence of trouble or failure therein.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a device for identifying and localizing a fault by means of a multiple position or element monitoring apparatus and, more particularly, to a first in-time failure or trouble localization circuit arrangement for identifying a failure which has occurred initially when circuit troubles are taking place at a plurality of positions or elements in a multipoint monitoring apparatus. 
     When a variety of factors such as coolant, pressure, temperature, fuel and the like are monitored, for example, in an engine, if plural factors malfunction sequentially, it is very important to identify the first failure and the point where this has occurred in order to remedy the cause of the troubles and correct the countermeasure against the troubles. 
     A malfunction alarm lamp therefore blinks ON and OFF and indicates normally the first fault in time which occurs at a point, and the second and later faults are indicted by the continuous energization of corresponding alarm lamps or by varying the period of the blinking of the alarm lamps so that a supervisor can easily identify the faults. 
     The conventional means for identifying such faults however employs a number of complicated circuits in the fault identifying circuit, resulting in an expensive construction and fails to render satisfactory service. 
     OBJECTS OF THE INVENTION 
     Accordingly, an object of this invention is to provide a circuit arrangement which will locate and indentify the first failure which has occurred in a time sequence and which can eliminate the disadvantages of the conventional device and has a simple construction with very reliable members for identifying any trouble therein. 
     It is another object of this invention to provide a trouble location circuit device which can identify the first failure or trouble in time which has occurred therein merely by connecting one wire or line to the circuit. 
     It is yet another object of this invention to provide a circuit arrangement for locating trouble which has storage means for holding information as to trouble even after the fault contact is disconnected. 
     It is further object of this invention is to provide a circuit which can identify the state of an alarm circuit irrespective of the operation of the identifying circuit. 
     It is still another object of this invention to provide a circuit device which does not affect adversely the operation of the stoppage of the alarm circuit or the the fault identifying operation thereof. 
     SUMMARY OF THE INVENTION 
     According to this invention, there is provided a circuit arrangement for locating and identifying the first failure in time which employs circuit groups in which predetermined points of fault identifying circuits are connected in a very simple configuration using silicon controlled rectifiers to identify the first trouble in time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other related objects and features of the invention will be apparent from a reading of the following detailed description and the accompanying drawings, in which: 
     FIG. 1 is a circuit diagram showing one preferred embodiment of the electrical circuit arrangement contemplated herein; 
     FIG. 2 is a block diagram of the trouble localization shooting circuit device shown in FIG. 1 but employing a reciprocating type switch at the failure contact therein; 
     FIG. 3 is a block diagram of the circuit device shown in FIG. 1 but employing a smoothing circuit therein; 
     FIG. 4 is a block diagram of the circuit device shown in FIG. 1 but employing a normally open switch at the failure contact therein; and 
     FIG. 5 is a circuit diagram of another preferred embodiment of the circuit device but connecting an alarm circuit to the electric circuit for identifying the trouble according to this invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, particularly to FIG. 1 showing one preferred embodiment of the circuit device constructed according to this invention, wherein like reference numerals designate the same parts in the following views, trouble detector circuits 2 1 , 2 2 , 2 3 , . . . connected to a common DC power line 1 and trouble localization shooting circuits 3 1 , 3 2 , 3 3  connected to the detector circuits 2 1 , 2 2 , 2 3 , . . . , respectively form monitor circuits 4 1 , 4 2 , 4 3 , . . . , respectively for monitoring temperature, pressure, fuel or the like. The shooting circuits 3 1 , 3 2 , 3 3 , . . . respectively consist of first and second output terminals 5 1 , 5 1  &#39;; 5 2 , 5 2  &#39;; 5 3 , 5 3  &#39;; . . . and lock signal terminals 6 1 , 6 2 , 6 3 , . . . , wherein the lock signal terminals of the respective shooting circuits 3 1 , 3 2 , 3 3 , . . . are connected to each other to form a lock circuit 7 through a lock line 7&#39; as will be described in greater detail. 
     The trouble detector circuits 2 1 , 2 2 , 2 3 , . . . exemplified in FIG. 1 consist respectively of resistors 8 1 , 8 2 , 8 3 , . . . and trouble contacts 9 1 , 9 2 , 9 3 , . . . connected in series with the respective resistors 8 1 , 8 2 , 8 3 , . . . for normally closing and opening upon occurrence of trouble or failure such as temperature rise or the like connected between the DC power line 1 and ground, and produce and apply respectively outputs from between the respective resistors and the trouble contacts to the first output terminals 5 1 , 5 2 , 5 3 , . . . of the shooting circuits 3 1 , 3 2 , 3 3 , . . . . 
     Further, the shooting circuits 3 1 , 3 2 , 3 3 , . . . exemplified in FIG. 1 consist respectively of first resistors 10 1 , 10 2 , 10 3 , . . . , first diodes 11 1 , 11 2 , 11 3 , . . . , and silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , . . . connected in series with each other between the first output terminals 5 1 , 5 2 , 5 3 , . . . and the ground; second resistors 12 1 , 12 2 , 12 3 , . . . connected to the first output terminals 5 1 , 5 2 , 5 3 , . . . and constant-voltage diodes 13 1 , 13 2 , 13 3 , . . . connected at respective one side to the respective resistors 12 1 , 12 2 , 12 3 , . . . and at the other side to the gates of the respective silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , . . . for applying gate voltages thereto; resistors 14 1 , 14.sub. 2, 14 3 , . . . and capacitors 15 1 , 15 2 , 15 3 , . . . connected as delay circuits in parallel with each other connected between the gates of the silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , . . . and the ground; and second and third diodes 16 1 , 16 2 , 16 3 , . . . and 17 1 , 17 2 , 17 3 , . . . connected at respective one ends to the lock signal terminals 6 1 , 6 2 , 6 3 , . . . and connected at the former the other ends to between the respective diodes 11 1 , 11 2 , 11 3 , respectively and the respective silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , respectively and connected at the latter the other ends to between the respective diodes 12 1 , 12 2 , 12 3 , . . . and the respective constant-voltage diodes 13 1 , 13 2 , 13 3 , . . . . 
     Since the trouble contacts 9 1 , 9 2 , 9 3  are not closed unless all the monitoring circuits malfunction so that no outputs are produced from the trouble detector circuits 2 1 , 2 2 , 2 3 , . . . , respectively, no voltage is applied from the DC power line 1 to the trouble-circuits 3 1 , 3 2 , 3 3 , . . . , and both the first and second output terminals 5 1 , 5 1  &#39;; 5 2 , 5 2  &#39;; 5 3 , 5 3  &#39;; . . . and the lock signal terminals 6 1 , 6 2 , 6 3 , . . . retain zero potentials (L level). 
     If trouble or a failure occurs and the trouble contact 9 2  is accordingly opened, an electric current is flows from the DC power line 1 through the resistor 8 2  to the trouble-circuit 3 2 . Therefore, both the output terminals 5 2 , 5 2  &#39; go to H level at this moment. However, after the delay time determined by the second resistor 12 2 , the resistor 14 2  and the capacitor 15 2  has elapsed, the constant-voltage diode 13 2  conducts to allow the DC voltage to be applied to the gate of the silicon controlled rectifier SCR 2  and the rectifier SCR 2  which is triggered and conducts to become ON. Thus, the trigger current flows through the second resistor 12 2  and the constant-voltage diode 13 2  is abosrbed by the second resistor 12 2 , the third diode 17 2 , the second diode 16 2  and the silicon controlled rectifier SCR 2 , but since the current is a direct current, the silicon controller rectifier SCR 2  remains in the ON state as it is. 
     This circuit configuration incorporating the delay element is adopted in this circuit device because, even if the trouble shooting contact 9 2  is instantaneously opened due to certain cause and an input is instantaneously applied to the shooting circuit 3 2  due to disturbance, the silicon controlled rectifier SCR 2  may not be opened in response thereto. 
     When the silicon controlled rectifier SCR 2  is thus conducted to become ON, the first output terminal 5 2  remains at the H level but the second output terminal 5 2  &#39; goes to the L level. A desired predetermined circuit, which will be hereinafter described as one example in greater detail with respect to FIG. 5, not shown in FIG. 1 is connected between both the terminals 5 2  and 5 2  &#39;  to detect the output between the terminals 5 2  and 5 2  &#39; so as to confirm the fact that trouble occurs in this monitor circuit 4 2  as distinguished from the other normal monitor circuits 4 1 , 4 3 , . . . being zero potential or level. 
     If the trouble shooting contact 9 1  is then opened due to occurrence of the trouble or failure, the direct current is flown from the DC power line 1 to the shooting circuit 3 1  in the same manner as the operation of the trouble shooting circuit 3 2  as described previously. Therefore, the first and second output terminals 5 1  and 5 1  &#39; goes to the H level. Since the lock circuit 7 which consists of a circuit by way of the second resistor 12 1 , the third diode 17 1 , the lock signal terminal 6 1  the lock line 7&#39;, the lock signal terminal 6 2 , the second diode 16 2 , the conducting silicon controlled rectifier SCR 2  and the ground is however closed, no trigger is applied to the silicon controlled rectifier SCR 1 , with the result that the silicon controlled rectifier SCR 1  remains OFF. Therefore, both the first and the second output terminals 5 1  and 5 1  &#39; retain the H level as before, and the H and L levels occur only at the output terminals 5 2  and 5 2  &#39; of the trouble shooting circuit 3 2  in which the trouble or failure has initially taken place (i.e., first in time), but both the H levels occur at the output terminals 5 1  and 5 1  &#39; of the trouble shooting circuit 3 1  in which the trouble is has also taken place next in time order. Thus, both the troubles in the monitor circuits can be distinguished according to the sequence of the occurrence of the troubles. Since the output terminals of the trouble shooting circuits 3 3 , . . . go to both H level in the same manner as the second time sequence operation when the third trouble and the later troubles occur in the corresponding monitor circuits after the second sequence trouble, even if a number of monitor circuits are provided, the first trouble in time can be exactly identified. 
     It is noted that although a mechanical switch is exemplified as the trouble contact in the aforementioned embodiment, it is not limited only to this but a contactless output from a transistor or an IC circuit and the like may also be applied to the trouble shooting circuit when trouble occurs. It is also noted that when the trouble contact is not opened due to the occurrence of the trouble but returned to the original position after it is opened, a memory circuit may be applied between the resistor 8 1  and the trouble contact 9 1  as shown in FIG. 2. 
     As shown in FIG. 3, in case that the electric current from the DC power line 1 is not a complete direct current but includes a ripple as is produced from a full-wave rectifier, it is preferable to insert a diode 19 between the trouble detector circuit 2 1  and the trouble shooting circuit 3 1  and to connect a smoothing capacitor 20 between the positive side of the diode 19 and the ground. 
     Further, it is also noted that when the trouble shooting contact is normally opened and closed upon occurrence of trouble, contrary to the situation in the previous embodiment, it is preferred to connect a trouble contact 9 1  and a resistor 8 1  connected in series between the DC power line 1 and the shooting circuit 3 1  as shown in FIG. 4. 
     Referring now to FIG. 5 showing an alarm circuit AR connected between the first and second output terminals 5 1  and 5 2  &#39; as one example, since no input is applied from the DC power line 1 to the trouble shooting circuit 3 1  when no trouble occurs but in normal state, no output is produced from the trouble shooting circuit 3 1 , and the alarm circuit AR is not operated. When trouble occurs in equipment to be monitored such as an engine auxiliary device, an input is applied from the DC power line 1 to the trouble shooting circuit 3 1  as was described previously, the silicon controlled rectifier SCR 1  is conducts to become ON, with the result that a direct current flown from the output terminal 5 1  through a resistor R 1  is partially applied through a diode D 1  to an alarm buzzer (not shown) as a drive output, and amplified through an output amplifier (not shown) and then drives the buzzer. 
     The direct current partially flows through a resistor R 2  and a resistor R 3  to the base of a transistor Tr 1 , and is applied as an input signal through a diode D 2  between the resistors R 2  and R 3  so as to blink. Therefore, the base current of the transistor Tr 1  is bypassed through the diode D 2  according to the on or off of the flicker signal to become on or off, with the result that the transistor Tr 1  is repetitively on or off synchronously with the period of the blinking signal. 
     At this time the direct current which flows through a resistor R 4  is applied to the base of a transistor Tr 12  to render the transistor Tr 1  ON or OFF according to the flicker signal as above. Therefore, the transistor Tr 2  becomes ON or OFF according to the ON or OFF of the flicker signal to intermittently energize an alarm lamp L. 
     Assuming that the circuit shown in FIG. 5 has a failure which is first in time, the alarm lamp L blinks, but if the trouble is the second in time sequence, the silicon controlled rectifier SCR 1  shown remains OFF due to the closure of the lock circuit 7 as in the same manner described. Therefore, a direct current is applied to the base of the transistor Tr 2  by way of the resistor 10 1 , the output terminal 5 1  &#39;, the diode D 3  in the trouble shooting circuit 3 1 . As a result, even if the transistor Tr 1  goes ON or OFF, the transistor Tr 2  does not blink and the alarm lamp L is continuously energized, and the trouble can be identified which is first in time according to the blinking or continuous energization of the alarm lamp in this embodiment. It is noted that the trouble which is second and later in time can also be arbitrarily identified by deenergizing the lamp when the trouble which is second and later in time take place or by varying the frequency of the blinking as compared with the blinking for the first failure in time. 
     It is also noted that when a buzzer stop signal is applied through the diode D 4  externally from an external power source (not shown), a gate voltage is applied to the silicon controlled rectifier SCR to conduct the rectifier SCR which is deenergized so far so as to eliminate the drive output to the alarm buzzer. 
     It should be appreciated from the foregoing description that since the circuit arrangement contemplated herein comprises a plurality of monitor circuits 4 1 , 4 2 , 4 3 , . . . having trouble detector circuits 2 1 , 2 2 , 2 3 , . . . for producing direct current outputs in response to the occurrence of trouble or failures at trouble contacts 9 1 , 9 2 , 9 3 , . . . and localizatin trouble trouble shooting circuits 3 1 , 3 2 , 3 3 , . . . , said shooting circuits 3 1 , 3 2 , 3 3 , . . . consisting of first resistors 10 1 , 10 2 , 10 3 , . . . , first diodes 11 1 , 11 2 , 11 3 , . . . , and silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , . . . connected in series with each other between the first output terminals 5 1 , 5 2 , 5 3 , . . . and ground, second resistors 12 1 , 12 2 , 12 3 , . . . connected to the first output terminals 5 1 , 5 2 , 5 3 , . . . and constant-voltage diodes 13 1 , 13 2 , 13 3 , . . . connected on one side to resistors 12 1 , 12 2 , 12 3  . . . and on the other side to the gates of the silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , . . . , a delay circuit connected between the gates of the respective silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , . . . and the ground, lock signal terminals 6 1 , 6 2 , 6 3 , . . . connected through second diodes 16 1 , 16 2 , 16 3 , . . . between the first diodes 11 1 , 11 2 , 11 3 , . . . and the silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3 , third diodes 17 1 , 17 2 , 17 3  connected between the second resistors 12 1 , 12 2 , 12 3 , . . . and the silicon controlled rectifiers SCR 1 , SCR 2 , SCR 3  to the lock signal terminals 6 1 , 6 2 , 6 3 , . . . wherein the respective lock signal terminals 6 1 , 6 2 , 6 3 , . . . in said trouble shooting circuits 3 1 , 3 2 , 3 3 , . . . are connected with each other, it can consist of a simple construction with very reliable members in the trouble shooting circuits for identiying the trouble therein. Since the circuit contemplated herein can absorb the trigger currents of trouble shooting circuits other than the first trouble shooting circuit by energizing silicon contorlled rectifier in the first failure localization trouble shooting circuit, it can exactly identify the first failure or trouble in time therein merely connecting one wire or line to the trouble shooting circuit and store the signal of the first failure even after the fault contact is recovered upon repair of the trouble because the electric current flows from the lock signal terminal of the trouble shooting circuit for identifying the trouble except the trouble shooting circuit identifying the first failure which flows through the silicon controlled rectifier in the first failure trouble shooting circuit. It is also understood that since the trouble localization signals of the first failure and later failures can be applied to the alarm circuit AR connected to the first failure localization trouble shooting circuit device of this invention and the output signals of the trouble contacts 9 1 , 9 2 , 9 3 , . . . are applied to the first output terminal in this invention, it can identify the state of the alarm circuit AR irrespective of the operation of the identifying circuit and accordingly does not adversely affect the operation of the stoppage of the alarm circuit and the blinking of the fault identifying operation thereof.