JPH0421106Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to a testing device for a relay matrix circuit that is constructed by connecting a large number of relay contacts in a matrix, and specifically aims to provide a testing device for a relay matrix circuit that can detect defects and identify defective locations. It is something to do. <Background of the invention> For example, when the type of IC to be tested in an IC tester changes, the various signals applied to the IC under test must be changed to conform to the standards of the IC under test. A relay matrix circuit is used as a device for selecting and extracting various signals generated from a signal source. A relay matrix circuit is constructed by mounting a large number of relays on a single printed circuit board, and connecting the contacts of the large number of relays in a matrix.
Since such a relay matrix circuit has a large number of relay contacts, an operation test is performed after assembly and wiring work is completed. <Conventional Testing Apparatus> FIG. 1 shows a conventional testing apparatus for a relay matrix circuit. In the figure, 1 indicates a relay matrix circuit. A relay matrix circuit 1 has a plurality of row lines 2
a, 2b, 2c and column lines 3a, 3b, 3c, and these row lines 2a, 2b, 2c and column lines 3a,
Relay contacts K ₁₁ , K ₁₂ , at each intersection with 3b and 3c
It is constructed by connecting K ₁₃ , K ₂₁ , K ₂₂ , K ₂₃ , K ₃₁ , K ₃₂ , and K ₃₃ . The figure shows each relay contact _K11 to _K33.
The drive coil is not shown. A first switching circuit 4 and a second switching circuit 5 are connected to the outside of the relay matrix circuit 1. The first switching circuit 4 is a switching circuit for selectively applying a DC voltage to each of the column lines 2a to 2c. The second switching circuit 5 selects the column lines 3a, 3b, and 3c to
This is a switching circuit that connects voltage measuring means 6 to voltage measuring means 6. According to this test device, for example, relay contacts K _C1 and K _S1 are turned on, and relay contacts K ₁₁ , K ₁₂ , and K ₁₃ in relay matrix circuit 1 are turned on in sequence. At this time, when the relay contact K ₁₁ is on, the voltage of the DC power supply 7 is obtained in the voltage measuring means 6, and K ₁₂ ,
When K ₁₃ is on, the voltage is zero, and switch K _C1
When switch K _C2 is turned off and switch K C2 is turned on, voltage is generated only when relay contact K ₁₂ is turned on, and voltage is generated only when switch K _C3 is turned on and relay contact K ₁₃ is turned on. This shows that the wiring for relay contacts K ₁₁ , K ₁₂ , and K ₁₃ is done correctly. Here, for example, if no voltage is generated when relay contact K _C1 is turned on while relay contact K _C1 is energized, it is determined to be defective. This defect may be caused by, for example, relay contact K ₁₂ or K ₁₃ remaining on. However, in order to identify the defective part, it is necessary to search for the defective part using a tester outside the testing device or visually. FIG. 2 shows another example of the prior art. In this example, the row lines 2a, 2b, 2c are connected to the driver group 8,
Each row line 2a, 2b, 2c is connected to a driver 8a, 8b,
8c. Each column line 3
A comparator group 9 is connected to a, 3b, and 3c,
Each voltage comparator 9a, 9 of the comparator group 9
The logic level output to each column line 3a, 3b, 3c is detected by signals b and 9c. Furthermore, in this example, comparators 9a, 9b, 9c
The computer 11 inputs each output to the computer 11, and the computer 11 supplies the drive signal to the register 12, and the driver 8a, 8
A case is shown in which a drive signal is applied to terminals b and 8c. In this configuration, data is written in the register 12 so that the row line 2a is given H logic and the row lines 2b and 2c are made L logic. When the relay contact _K11 is turned on, the computer 11 receives the logic signal output from the comparator 9a. If the output of the comparator 9a is L, it is determined to be normal. At this time, if H logic is output from the comparator 9a, it is abnormal. This abnormality can be considered to be due to the influence of either or both relay contacts _K12 and _K13 being turned on. <Disadvantages of the Prior Art> As described above, the conventional relay matrix circuit testing device can detect abnormalities in the relay matrix circuit, but has the disadvantage that the abnormal location cannot be specified. <Purpose of the invention> This invention aims to provide a testing device that can identify defective locations in a relay matrix circuit. <Summary of the invention> In this invention, a resistor with a weighted resistance value is connected to the column line, and a voltage dividing circuit is formed by this resistor and one voltage dividing resistor, and the relay contact is switched on. The voltage dividing ratio of the voltage dividing circuit is changed each time the relay contact is turned on, and a different voltage is generated each time each relay contact is turned on.The structure is configured so that the defective location can be identified by the difference in the divided voltage. It is something. <Example of the invention> Fig. 3 shows an example of the invention. In this invention, resistors 13a, 13b, 13c having weighted resistance values are connected to the row lines 2a, 2b, 2c. These resistors 13a, 13b, 13c
The other ends of each are commonly connected and connected to one potential pole 15 of the DC power supply 14. Column lines 3a, 3b, 3c are selection switches K _P1 ,
A common connection is made through K _P2 and K _P3 , and a voltage measuring means 16 is connected between the common connection point and one potential pole 15 of the DC power supply 14. A voltage dividing resistor 18 is connected between the other potential pole 17 of the DC power supply 14 and the common connection point of the selection switches K _P1 , K _P2 , K _P3 . In this configuration, when the resistance value of the voltage dividing resistor 18 is R, the resistance values of the resistors 13a to 13c are selected to be, for example, 1/9R, 1/4R, and 3/7R. <Operation of the device> According to the configuration of this device described above, the selection switch
When K _P1 is turned on and relay contact K ₁₁ is turned on, voltage measuring means 16 measures the voltage generated across resistor 13a. Since the resistance value of the resistor 13a and the resistance value of the voltage dividing resistor 18 are 1/9:1, the resistance value of the resistor 13a is 1/9:1.
The voltage E _a generated at a is E _a =E/10. (E is the voltage of the DC power supply 14) If the voltage E of the DC power supply 14 is 10 volts, then E _a =1 volt. Then turn relay contact K ₁₁ back off and relay contact
Turn on _K12 . At this time, the DC voltage measuring means 1
6 is applied with the voltage E _b generated in the resistor 13b. E _b = 1/5E, and E _b = 2 volts. Turn off relay contacts K ₁₁ and K ₁₂ and turn on K ₁₃ . In this state, the DC voltage measuring means 16 measures the voltage E _c generated across the resistor 13c. Since the resistor 13c is selected to be 3/7R, E _C =3/10E. In other words, E _C =3 volts. By sequentially turning on the relay contacts K ₁₁ , K ₁₂ , and K ₁₃ in this manner, the voltage measuring means 16 indicates 1 volt, 2 volts, and 3 volts, respectively.
If the voltage measuring means 16 does not indicate 1 volt when the relay contact _K11 is turned on, it is abnormal. This abnormality can be identified by its indicated value. In other words, the voltage applied to the voltage measuring means 16 changes as shown in the following table depending on the combinations in which relay contacts K ₁₁ , K ₁₂ , and K ₁₃ are turned on. In the table, 0 is off, 1 is on, E _io is voltage measurement means 16
Indicates the voltage applied to

[Table] In this way, the voltage E _io given to the voltage measuring means has different values in all combinations in which the relay contacts K ₁₁ , K ₁₂ , and K ₁₃ are turned on, so the voltage measured by the voltage measuring means 16 Normality and abnormality can be determined by However, in the event of an abnormality, it is possible to identify which relay contact is defective, whether it remains on or off, based on the measured voltage value. In addition, it is possible to detect not only the relay contacts themselves but also the fact that solder has fallen between printed wirings, resulting in a short circuit. Relay contacts K ₁₁ , K ₁₂ , connected to one row line 3a,
After inspecting K ₁₃ , turn off the changeover switch K _P1 and
Turn on K _P2 and turn on relay contacts K ₂₁ , K ₂₂ , and K ₂₃ in this order. In this case as well, the voltage measuring means 16
If the display shows 1, 2, and 3 volts in sequence, the relay contact
K ₂₁ , K ₂₂ , and K ₂₃ can be determined to be normal. In this way all relay contacts can be tested. Although the case where there are three row lines 2a, 2b, and 2c has been described above, there is no limitation on the number of row lines. For example, if there are 8 row lines, the weighted resistors R _a ,
Each resistance value of R _b , R _c ... is 1/9R, 1/4R, 3/7R,
Select like 2/3R, R, 3/2R, 7/3R, 4R,
If the voltage of the DC power supply 14 is 10 volts, the voltages given to the voltage measuring means 16 are 1, 2, 3, 4,
It is possible to obtain divided voltages of 5, 6, 7, and 8 in steps of 1 volt each. Therefore, if the 8 relay contacts connected to one column line are turned on in sequence and the divided voltage changes to 8 volts in 1 volt steps, all the relay contacts connected to that column line are normal. It can be determined that there is. <Effects of the invention> As explained above, according to this invention, the wiring condition of each relay contact of the relay matrix circuit 1 can be inspected. In particular, since the abnormal location can be identified in a state where an abnormality is detected, the defective location can be determined in a short time. Therefore, the effect is extremely great in practical use. <Another embodiment of the invention> Fig. 4 shows another embodiment of the invention. In this example, a configuration is shown in which the microcomputer 41 controls each part and determines whether the parts are good or bad. That is, the divided voltage taken out by the changeover switch group 5 is converted into a digital signal by the A-D converter 42, and the digital signal is input into the microcomputer 41. The microcomputer 41 instructs the relay contact drive circuit of the relay matrix circuit 1 which relay contact is to be turned on. Therefore, the microcomputer 41 can predict in advance the divided voltage generated through the relay contacts based on the command, and compares the measured value input from the A-D converter 42 with the reference value and determines whether they match. If so, display 4
3 is displayed as good. The display 43 can be configured to have, for example, an array of light emitting elements corresponding to each relay contact, and to display a defect by causing the light emitting element corresponding to the defective relay contact to emit light. In the above description, the DC power supply 14 and the voltage dividing resistor 18 are connected in series, and the series circuit is connected between the common potential point and the selection switch 5. However, the DC power supply 14 is connected between the common potential point and the resistors 13a, 13b, 13c, and the voltage dividing resistor 18 is connected between the selection switch 5 and the common potential, similar effects can be obtained.

[Brief explanation of the drawing]

1 and 2 are connection diagrams for explaining a conventional relay matrix circuit testing device, FIG. 3 is a connection diagram for explaining an embodiment of this invention, and FIG. 4 is a connection diagram for explaining an embodiment of this invention. FIG. 2 is a block diagram for explaining an embodiment of the present invention. 1...Relay matrix circuit, 2a, 2b,
2c...row line, 3a, 3b, 3c...column line, 5...
...Selection switch, 6...Voltage measuring means, 13
a, 13b, 13c...Resistor with weighted resistance value, 14...DC power supply, 18...Resistor for voltage division.

Claims (1)

[Scope of Claim for Utility Model Registration] A. From a plurality of relays in which a plurality of row lines and a plurality of column lines are arranged to intersect, and a relay contact is connected to each intersection point of each row line and column line. A relay matrix circuit consisting of: B A plurality of resistors having one end connected to the row line of this relay matrix circuit, the other ends commonly connected to a common potential point, and having mutually weighted resistance values, C a plurality of selection switches, one end of which is connected to the column line of the relay matrix circuit and the other end of which is commonly connected; A voltage dividing resistor that is connected in series with each of the plurality of resistors via a switch to constitute a voltage dividing circuit; a DC power supply connected to the other end and applying a DC voltage to a series circuit of the voltage dividing resistor and the plurality of resistors; A relay matrix circuit testing device comprising: voltage measuring means for measuring the voltage generated in each of the resistors;