JPS6058424B2 - Cable inspection adapter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable testing adapter, and more particularly to a cable testing adapter that can easily test for disconnections and short circuits in a cable consisting of a plurality of signal lines.

In electronic equipment, multiple types of signals are usually required to achieve a desired function, and in order to receive and receive these signals,
Multiple signal lines are required.

For convenience of handling, these signal lines are each covered with an insulating layer and bundled into one cable to electrically connect predetermined parts of the electronic device. If such a cable malfunction occurs, that is, a break in each signal line that makes up the cable, or a short circuit between signal lines due to damage to the insulating layer covering these signal lines,
It takes a lot of effort and time to identify a signal line that is disconnected or short-circuited, especially when a failure occurs in a cable that is mounted on a device.

The present invention has been made in view of the above, and an object of the present invention is to provide a cable inspection adapter that can easily inspect a cable consisting of a plurality of signal lines. and a cable inspection adapter for inspecting short circuits, including a potential generation circuit that applies a test potential to each of the plurality of signal lines, a plurality of display means provided corresponding to the plurality of signal lines, and a disconnection or short circuit. In order to convert the logic condition of the output of the signal line to which the inspection potential is applied according to the instruction means for instructing the inspection and the disconnection and short circuit instruction output of the instruction means and to apply it to the display means, for each signal line. It is characterized in that it includes a logic circuit provided therein.

Preferred embodiments of the present invention will be described in detail below.

The drawing is a configuration diagram of an embodiment of the present invention, and C is a cable to be inspected for disconnections and short circuits between signal lines, and is provided with connectors N2 and No at both ends. No. is a connector that can be freely attached to and detached from one end of the cable, and when the connector is attached to the cable, the predetermined signal lines of the cable are connected within the connector so that they are connected to each other by the connector. has been done. Signal line C of the cable
l, c2, Cs,...cn are selector switches 5
, ~5n and a resistor R to a power supply P1 that outputs a potential of logic "1".

Further, these signal lines c1 to Cn are connected to the switches S1 to Sn.
and is grounded via a power supply P1,
Switches s1 to Sn and resistors R and R'' constitute a potential generation circuit. I, ll to In, Kl to Kn are inverters, and N
1~Nn, Ml~Mn, Ql~Qn are NAND gates,
F1 to Fn are flip-flop circuits, L1 to Ln are light emitting diodes, and each anode terminal is a resistor R''
A power supply P2 having an output of a logic one level potential via
connected to. A changeover switch ST is provided as an instruction means for instructing a disconnection (disconnection) or short circuit inspection. SF is a switch for resetting the flip-flops F1 to Fn, and by closing the switch SF and setting the reset terminal of the flip-flop to a ground level potential, these flip-flops F1 to Fn are placed in a reset state. The output will be at a logic 0 potential level. P3 is a power supply having an output at a logic 1 potential level, and applies a logic 1 potential to the inverters I, Ml to Mn flip-flops F1 to Fn via resistors RT and RF.

Next, the operation of this device will be explained. First, when checking for disconnection of the signal line in the cable, check connector N.

Attach it to one end of cable C. It is assumed that internal wiring is provided within the connector so that all the signal lines c1 to Cn are connected to each other by this connector. Switch ST is opened as shown in the figure. Furthermore, the switches for providing logic levels to the signal lines in the cable connect all switches S2 to Sn other than switch S1 to power supply P1.
Only the switch S1 is set to the ground side, and only the signal line C1 is grounded via the resistor R''.

The signal lines C2 to Cn are connected through resistors R. Connected to the output terminal of power supply P1. In such a state, only the light emitting diodes provided corresponding to the disconnected signal line emit light, and the light emitting diodes provided corresponding to the unbroken signal line do not emit light, as will be explained below. .

Assume that only the signal line C2 is disconnected, and no other signal lines are disconnected.

At this time, the potential of 5V applied to the signal line C2 from the power supply P1 is not electrically connected to the signal line C1, which is held at 0, because the signal line C2 is disconnected, and the potential of this signal line is is held at 5V.

By the way, since the changeover switch S is in the open state, the input of the inverter I is a logic 1, and its output is a logic 0. Therefore, since a logic 0 level is applied to the input terminal of the NAND gate N2 connected to the inverter I, the output of the NAND gate N2 is a logic 1.

On the other hand, since the logic 1 level signal of the signal line C2 is applied to the inverter K2, the output of the inverter K2 is logic "0", and the output of the NAND gate connected to the output terminal of the inverter K2 is Since a logic 0 signal is applied to one input terminal, the output of the NAND gate becomes logic 1, and in the end, a logic 1 signal is applied to both input terminals of the NAND gate Q2. The output of Q2 becomes a logic 0. When a signal with a logic 0 level is applied to the flip-flop F2, the output of the flip-flop becomes a logic 1, and the inverter 1
A light emitting diode that is inverted in 2! The cathode side of is logic 0
level, the light emitting diode emits light, and the signal line C
2 clearly indicates that a disconnection has occurred. Next, it will be explained that the light emitting diodes provided corresponding to the signal lines with no disconnection do not emit light.

For example, since there is no disconnection in the signal line C3, the potential of 5V applied to the signal line C3 from the power supply P1 is applied to the connector N.

Since the signal line C1 is connected to the signal line C1 which is at a potential of 0V through the terminal, the potential of the signal line C1 becomes 0V. Therefore, signal line C
The input of the inverter K3 connected to the N.
, is applied to one input terminal of AND gate M3. On the other hand, since the switch ST is in the open state, the signal level applied to the other input terminal of the NAND gate M3 becomes logic 1, so a logic 1 signal is applied to both input terminals of the NAND gate M3. The NAND gate M3
The output of is logic 0, and this signal is the output of N,AND gate O
is applied to one input terminal of the N. The output of the AND gate Q3 becomes logic 1 and is input to the flip-flop F3 connected to the NAND gate Q3. Therefore, the output of the flip-flop F3 becomes a logic 0 level, and this output level is inverted by the inverter 13 to become a logic 1 level, which is applied to the cathode side of the light emitting diode L3; Since a high potential of logic 1 is applied to both sides,
The light emitting diode L3 does not emit light, which indicates that there is no disconnection in the signal line C3 corresponding to the light emitting diode L3. Connector N. Therefore, it is possible to easily know whether any other signal line connected to the signal line C1 is disconnected or not by checking whether a light emitting diode provided corresponding to the signal line emits light. In this way, whether or not the signal line of the cable is disconnected can be determined by whether or not the light emitting diode emits light.

Next, a test to determine whether the signal lines in the cable are short-circuited to each other is performed as follows.

First, from the cable to connector N. is disconnected, one end of the cable is opened, and the switch ST is closed to set the input terminal side of the inverter I to the ground level. Then, one of the two signal lines for testing whether or not there is a short circuit is connected to the switch s1 through the Sn resistor R''.
It is grounded, and the other side is connected to the output terminal of the power source P1 via the switches s1 to Snl and the resistor R.

For example, when inspecting the presence or absence of a short circuit between signal lines C1 and C2, the signal line C1 is grounded through the switch S1 resistor R'', and the other signal line C2 is connected to the power source through the switch S2 and the resistor R''. Connect to the output terminal of P1.At this time, if the two signal lines C1 and C2 are short-circuited, the signal line C2
has a potential level of logic 0, and the signal applied to the input terminal of inverter K2 and one input terminal of NAND gate N2 is at logic 0 level.
The outputs of ND gate N2 are both logic 1, and these outputs are each applied to one input terminal of NAND gates M2 and Q2. Since the other input terminal of the NAND gate M2 is grounded via the switch ST, the potential of the other input terminal is at the logic 0 level, and therefore the NAND
The output of gate M2 is at a logic 1 potential level, and this output is applied to the input terminal of NAND gate Q2. That is, a logic 1 potential level is applied to both input terminals of the NAND gate Q2, and as a result, the output of the NAND gate Q2 becomes a logic 0 potential level, and this output is input to the flip-flop F2. As aforementioned,
When a logic 0 potential level is applied to the flip-flop, the output of the flip-flop becomes a logic 1 potential level, and this output level is inverted by the inverter 12 and applied as a logic 0 potential level to the cathode side of the light emitting diode L2. As a result, it is found that the light emitting diode L emits light and the signal line C2 provided corresponding to the light emitting diode L2 is short-circuited with the signal line C1. However, if the signal lines C1 and C2 are not short-circuited, the light emitting diode provided corresponding to the signal line C2! The reason why the light does not emit light will be explained next.

If the signal line C2 is not short-circuited with the signal line C1, the signal line C2 is connected to the output terminal of the power supply P1 via the switch S2 and the resistor R, so the potential of the signal line C2 is at the logic 1 level. This potential is input to inverter K2 and one input terminal of NAND gate N2. The potential level of logic 1, which is the output of inverter 1, is applied to the other input terminal of NAND gate N2.

Therefore, the outputs of inverter K2 and NAND gate N2 both have a logic 0 potential level. This NAND gate N
The logic 0 potential level of 2 is input to the NAND gate Q2, and as a result, the output of the NAND gate Q2 becomes a logic 1 potential level, which is input to the lower flip-flop 2. In this case, the output of the flip-flop F2 is at a logic 0 potential level and is inverted by the inverter 12.
Light emitting diode! A logic 1 potential level is applied to the cathode side of the light emitting diode B, but since a logic 1 potential level is also applied to the anode side of the light emitting diode b, the light emitting diode does not emit light and corresponds to the light emitting diode L2. It can be seen that the signal line C2 provided as above is not short-circuited with the signal line C1.

In this way, whether or not there is a short circuit between the signal lines of the cable can be determined based on whether the light emitting diode emits light or not.

In the above-described embodiment, the connector N is used to check whether or not the signal line of the cable is disconnected.

Although all the signal lines of the cable are connected to each other by the above method, it is of course possible to wire the connector so as to selectively connect only the signal lines to be inspected. As is clear from the above description, the cable inspection adapter according to the present invention has the advantage of being able to very easily inspect the presence or absence of breaks in each signal line of a cable consisting of a plurality of signal lines and the presence or absence of short circuits between signal lines. .

[Brief explanation of drawings]

The drawing is a circuit configuration diagram for explaining one embodiment of the present invention. NO-N3: Connector, C: Cable, c1~Cn: Signal line, I, Kl~Kn, ll~In: Inverter, M1
~Mn, Ql~Qn: NAND gate, L1~Ln: light emitting diode, P1~P3: power supply.

Claims (1)

[Claims] 1. In a cable inspection adapter for inspecting disconnections and short circuits in a cable including a plurality of signal lines, a potential generation circuit that applies a test potential to each of the plurality of signal lines, and a potential generating circuit provided corresponding to the plurality of signal lines. a plurality of display means, an instruction means for instructing disconnection or short-circuit inspection, and a logic condition of the output of the signal line to which the test potential is applied according to the output of the instruction means for disconnection or short-circuit, and the logic condition of the output of the signal line is converted and applied to the display means; A cable inspection adapter characterized in that it includes a logic circuit provided for each signal.