JPH0658992A - Electric circuit inspection equipment - Google Patents

Abstract

PURPOSE:To provide an electric circuit inspection equipment for determining the electric resistance of an electric circuit to be inspected while avoiding the effect of the volume of an electronic buzzer and suppressing consumption of DC power supply. CONSTITUTION:A NAND gate NAND monitors the potential difference between a DC power supply E and the joint of a fixed resistor R2 and a resistor R11 thus detecting whether an electric circuit M to be inspected is connected between inspection terminals T11, T12 provided, respectively, at the DC power supply E and one end of a series circuit of the fixed resistor R2 and the resistor R11. When the NAND gate NAND detects connection of the electric circuit M with the inspection terminals T11, T12, a comparing circuit COMP actuates an electronic buzzer BZ to produce an alarm based on the potential difference between the joint of a fixed resistor R3 and a variable resistor R5 and the joint of the fixed resistor R2 and the resistor R11.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric circuit inspecting apparatus in which an inspection terminal is connected to a connection terminal of an electric circuit to be inspected to inspect its quality, and more particularly, a positive electrode of a DC power source and a first fixed resistor. The potential difference between the resistor and the connection point of the resistor with a NAND gate, and connect the electrical circuit to be inspected to the inspection terminals formed at both ends of the series circuit of the DC power supply and the first fixed resistor and the resistor. When the NAND gate detects that the connection terminal of the electric circuit to be inspected is connected to the inspection terminal by detecting whether or not the terminal is connected, The alarm sound of the electronic buzzer is sent out by moving the slider of the variable resistor based on the potential difference between the connection point of the fixed resistor and the variable resistor of 2 and the connection point of the first fixed resistor and the resistor. Or stop it Accordingly the present invention relates to an electrical circuit inspection system comprising to determine the electrical resistance of the inspected electrical circuit.

[0003]

2. Description of the Related Art Conventionally, an electric circuit inspecting device of this type is one in which a series circuit of a DC power source and an electronic buzzer is connected between inspection terminals connected to connection terminals of an electric circuit to be inspected. Was proposed.

[0004]

[Problems to be solved] However, in the conventional electric circuit inspection apparatus, since the series circuit of the DC power supply and the electronic buzzer is simply connected between the inspection terminals,
(i) There is a drawback that the value of the current given to the electronic buzzer decreases as the electric resistance of the electric circuit to be inspected connected between the inspection terminals increases, and (ii) the inspection connected between the inspection terminals. As the electrical resistance of the target electrical circuit increases, the volume of the alarm sound of the electronic buzzer decreases, and as a result (iii) it is possible to detect whether the electrical circuit to be tested is connected between the test terminals. There is a drawback that it becomes difficult as the electric resistance of the electric circuit to be inspected increases, and at the same time (iv) even if it is possible to detect whether or not the electric circuit to be inspected is connected, the magnitude of the electric resistance cannot be determined. There were some drawbacks.

Therefore, in order to eliminate these drawbacks, the present invention monitors the potential difference between the positive electrode of the DC power supply and the connection point of the first fixed resistor and the resistor with a NAND gate to detect the DC power supply and the first. It detects whether the connection terminals of the electric circuit to be inspected are connected to the inspection terminals formed at both ends of the fixed resistor of 1 and the series circuit with the resistor, and the NAND gate is connected to the inspection terminal of the electric circuit to be inspected. When it is detected that the connection terminal is connected, the comparison circuit corresponds to the electric resistance of the electric circuit to be inspected, and the connection point of the second fixed resistor and the variable resistor and the first fixed resistor and the resistor. An electric circuit inspection device that determines the electric resistance of an electric circuit to be inspected by moving an electronic buzzer alarm sound based on the potential difference between the connection point of Proposal One in which cents to.

[0006]

[Constitution of the invention]

[0007]

[Means for Solving the Problems] The means for solving the problems provided by the present invention is, "In an electric circuit inspecting apparatus in which an inspection terminal is connected to a connection terminal of an electric circuit to be inspected to inspect ) It is connected in series to the inspection terminal via the DC power source E and the first fixed resistor R _2, and the electrical resistance of the inspection target electric circuit to which the connection terminal is connected to the inspection terminal is small. and R _12, (b) a first fixed resistor R ₂ and the resistor R _11;; resistor R ₁₁ to compensate for Nau adverse first input terminal connected to a connection point of the R ₁₂ and the The input terminal of 2 is connected to the positive electrode of the DC power source E to detect whether or not the connection terminal of the inspection target electric circuit is connected to the inspection terminal, and the connection terminal of the inspection target electric circuit is connected to the inspection terminal. NAND gate NAND for sending high level output when Is connected to the negative pole of the (c) NAND gate of one of the terminal via a second fixed resistor R ₃ is connected to the output terminal and the other terminal is a DC power source E, the connecting terminal is connected to the test terminal The variable resistor R ₅ for setting or _obtaining the discriminant value R _X0 of the electric resistance of the tested electric circuit, and (d) the second fixed resistor R ₃ and the variable resistor R ₅ are not connected to each other. The inverting input is connected and the inverting input has a first fixed resistor R ₂ and a resistor R ₁₁ ; R.
Is connected to the connection point of _12, the second fixed resistor R ₃ and a variable resistor the potential at the connection point of the R ₅ and the first fixed resistor R ₂ and the resistor R _11; at the connection point of R ₁₂ The potential of the connection point of the second fixed resistor R ₃ and the variable resistor R ₅ is compared with the potential, and the potential of the first fixed resistor R ₂ and the resistor R ₁₁ ;
A comparator circuit COMP for sending a positive output from the output terminal when the potential becomes higher than the potential of the connection point of ₁₂ and (e) a third fixed resistor R ₄ to the output terminal of the comparator circuit COMP. And one terminal is connected and the other terminal is a DC power source E
Is connected to the negative electrode of the comparator circuit COMP, and an alarm sound is generated or stopped according to the output sent from the comparison circuit COMP to determine the electric resistance of the inspection target electric circuit whose connection terminal is connected to the inspection terminal. An electronic circuit inspection device characterized by comprising an electronic buzzer BZ ".

[0008]

The electric circuit inspecting apparatus according to the present invention is an electric circuit inspecting apparatus in which an inspection terminal is connected to a connection terminal of an inspection target electric circuit to inspect whether or not it is good. [Solution]], and the potential difference between the positive electrode of the DC power source and the connection point of the first fixed resistor and the resistor is monitored by a NAND gate to detect the DC power source and the first fixed resistor. Detects whether or not the connection terminal of the electric circuit to be inspected is connected to the inspection terminals formed at both ends of the series circuit with the resistor and the resistor, and the NAND gate connects the connection terminal of the electric circuit to be inspected to the inspection terminal. When it is detected that the comparison circuit corresponds to the electric resistance of the electric circuit to be inspected, the connection point of the second fixed resistor and the variable resistor and the connection point of the first fixed resistor and the resistor. Based on the potential difference between Since it determines the electrical resistance of the test object electric circuit by allowed to delivery or stop the alarm sound of the child buzzer moves slider of the variable resistor,
(i) The volume of the alarm sound of the electronic buzzer does not affect the influence of the electric resistance of the electric circuit to be inspected, and (ii) the electric resistance of the electric circuit to be inspected can be determined. And (iii) a function to suppress the consumption of the DC power supply by supplying a current to the series circuit of the second fixed resistor and the variable resistor only when the electric circuit to be inspected is connected to the inspection terminal. Make up.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an electric circuit inspecting apparatus according to the present invention will be specifically described with reference to the accompanying drawings with reference to its preferred embodiments.

However, the embodiment described below
It is described to facilitate or facilitate understanding of the present invention, and is not described to limit the present invention.

In other words, each element disclosed in the embodiments described below includes all design changes and equivalent replacements within the spirit and technical scope of the present invention.

(Description of the accompanying drawings)

FIG. 1 is a circuit diagram showing a first embodiment of an electric circuit inspecting apparatus according to the present invention. In particular, fixed resistors R ₁₁ and R ₂ are provided for inspection terminals T ₁₁ and T _12. And the DC power source E are connected in series, and the fixed resistor R ₆ is inserted between the non-inverting input terminal and the output terminal of the comparison circuit COMP.

FIG. 2 is a circuit diagram showing a second embodiment of the electric circuit inspection apparatus according to the present invention. In particular, a variable resistor R ₁₂ and a fixed resistor are provided for the inspection terminals T ₁₁ and T _12. Bowl R
₂ and DC power source E are connected in series, and comparison circuit C
Fixed resistor R between non-inverting input and output of OMP
_It shows the case where ₆ is inserted.

FIG. 3 is a circuit diagram showing a third embodiment of the electric circuit inspecting device according to the present invention. In particular, fixed resistors R ₁₁ and R ₂ are provided for inspection terminals T ₁₁ and T _12. And the DC power source E are connected in series, and the fixed resistor R ₆ is not inserted between the non-inverting input terminal and the output terminal of the comparison circuit COMP.

FIG. 4 is a circuit diagram showing a fourth embodiment of the electric circuit inspecting device according to the present invention. In particular, a variable resistor R ₁₂ and a fixed resistor are provided for the inspection terminals T ₁₁ and T _12. Bowl R
₂ and DC power source E are connected in series, and comparison circuit C
Fixed resistor R between non-inverting input and output of OMP
_It shows the case where ₆ is not inserted.

(Configuration of First Embodiment)

First, with reference to FIG. 1, the configuration of a first embodiment of an electric circuit inspection apparatus according to the present invention will be described in detail.

Reference numeral 10 denotes an electric circuit inspecting apparatus according to the present invention, which is a set of inspection terminals T ₁₁ and T ₁₁ for connecting to the connection terminals T ₂₁ and T _{22 of} the inspection target electric circuit M, respectively. T ₁₂ is inserted between the DC power source E whose positive and negative electrodes are connected to the test terminals T ₁₁ and T ₁₂ , respectively, and the positive terminal of the test terminal T ₁₁ and DC power source E, and they are connected in series with each other. Fixed resistors R ₁₁ and R ₂ are provided. Here, the fixed resistor R ₂ has inspection terminals T ₁₁ and T ₁₂
Inspected electrical circuit M of the connection terminals T _21, T ₂₂ and when connected, respectively, the fixed resistors R ₂ from the positive electrode of the DC power source E, the fixed resistors R _11, test terminal T ₁₁ with respect to the connection terminals T ₂₁ ，
Inspection target electric circuit M, connection terminal T ₂₂ and inspection terminal T ₁₂
It is inserted in order to limit the magnitude of the current flowing to the negative electrode of the DC power source E via the. Fixed resistor R
₁₁ is inserted in order to compensate for the adverse effect that the electric resistance R _X of the electric circuit M to be inspected is small, and (i) the electric resistance R _X of the electric circuit M to be inspected is relatively small. When it is small, in order to determine the value of the electric resistance R _X , the slider of the variable resistor R ₅ described later is moved to make the electric resistance value equal to the electric resistance R _X of the inspection target electric circuit M. The need to move the slider to near the end of the movable range when adjusting so as to avoid the unstable electric resistance value, and (ii) the electric resistance of the electric circuit M to be inspected R
_{When X} is relatively small, the positive offset voltage applied to the comparison circuit COMP, which will be described later, causes a voltage drop between the connection terminals T _{21 and} T _{22 of the} electric circuit M to be inspected (that is, a voltage drop due to the electric resistance R _X ). ), The alarm sound of the electronic buzzer BZ, which will be described later, can be stopped only by moving the slider of the variable resistor R ₅ and adjusting the electric resistance value thereof. It is inserted in order to make it possible to reliably determine the value of the electric resistance R _x .

In the electric circuit inspection apparatus 10 according to the present invention, the first input terminal is connected to the connection point of the fixed resistors R ₁₁ and R ₂ and the second input terminal is the DC power source E and the fixed resistor. Whether or not the connection terminals T ₂₁ and T ₂₂ of the electric circuit M to be inspected are connected to the connection point of R ₂ (that is, the positive electrode of the DC power source E) and the inspection terminals T ₁₁ and T ₁₂ (in other words, (Whether or not the inspection of the inspection target electric circuit M is performed), and the inspection target electric circuit M is inspected for the inspection terminals T ₁₁ and T ₁₂ .
NAND gate NAND for transmitting a high-level output as shown below when the connection terminals T ₂₁ and T _{22 of} are connected.
Is equipped with. The NAND gate NAND has a test terminal T
₁₁ and T ₁₂ , connection terminals T _{21 of} the electric circuit M to be inspected,
When T ₂₂ is connected, the potential of the first input end (that is, the potential of the connection point of the fixed resistors R ₁₁ and R ₂ ) is the potential of the second input end (that is, the potential of the positive electrode of the DC power supply E). It outputs a high level output because it is lower than
₁₁ and T ₁₂ , connection terminals T _{21 of} the electric circuit M to be inspected,
When T ₂₂ is not connected, the potential of the first input terminal (that is, the potential of the connection point of the fixed resistors R ₁₁ and R ₂ ) is the potential of the second input terminal (that is, the positive potential of the DC power source E). As it is high, it sends out low level output. By the way,
If the NAND gate NAND is made of, for example, a CMOS integrated circuit, the power consumption can be reduced, and the consumption of the DC power supply E can be suppressed, which is preferable. The holding power supply end of the NAND gate NAND is directly connected to the positive electrode and the negative electrode of the DC power source E.

In the electric circuit inspection device 10 according to the present invention, one terminal is further connected to the output terminal of the NAND gate NAND via the fixed resistor R ₃ and the other terminal is the DC power source E and the inspection terminal T ₁₂ . It is connected to the connection point (that is, the negative electrode of the DC power supply E) and adjusts the slider to determine the judgment value R _X0 of the electric resistance R _X of the electric circuit M to be inspected (that is, the electronic buzzer BZ starts to output an alarm sound or A variable resistor R ₅ for setting or detecting (the value of the electric resistance R _X of the electric circuit M to be inspected at the end of sending), and a non-inverting input terminal of the fixed resistor R ₃ and the variable resistor R ₅ . The fixed resistor R is connected to the connection point, the inverting input terminal is connected to the connection point of the fixed resistors R ₁₁ and R ₂ , and the holding power supply terminal is connected to the output terminal of the NAND gate NAND and the negative electrode of the DC power source E. ₃ and a variable resistor The potential of the _fifth connection point and the fixed resistors R _11, R ₂ in the connection point and a comparing circuit COMP for comparing the potential comprises. The output of the comparison circuit COMP becomes positive when the potential at the connection point between the fixed resistor R ₃ and the variable resistor R ₅ is higher than the potential at the connection point between the fixed resistors R ₁₁ and R ₂ , and the fixed resistor R 5 It becomes zero when the potential of the connection point of ₃ and the variable resistor R ₅ is lower than the potential of the connection point of the fixed resistors R ₁₁ and R ₂ . Incidentally, the variable resistor R ₅ compensates for the negative offset voltage applied to the comparison circuit COMP. In addition, the comparison circuit COMP
Since the holding power is not supplied from the DC power source E unless a high-level output is sent from the NAND gate NAND, the DC power source E may be consumed in a standby state where the inspection of the electric circuit M to be inspected is not executed. Absent.

The electrical circuit inspection apparatus 10 according to the present invention additionally includes a fixed resistor R ₄ for the output terminal of the comparison circuit COMP.
One terminal is connected through the other terminal and the other terminal is connected to the connection point of the DC power source E and the inspection terminal T ₁₂ (that is, the negative electrode of the DC power source E), and a voltage of a predetermined value or more starts to be applied between both terminals. The electronic buzzer BZ for stopping the alarm sound when the alarm sound starts to be output or the voltage lower than the predetermined value starts to be applied, the connection point of the comparison circuit COMP and the fixed resistor R ₄ and the fixed resistor. R ₃ and a variable resistor fixed resistor is inserted between the connection point of the R ₅ R ₃ and a variable resistor the potential of the connection point fixed resistor R ₅ R _11,
Electronic buzzer B when it becomes higher than the potential of the connection point of R ₂
The operation and fixing of the electronic buzzer BZ when the operation of Z is accelerated and the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ becomes higher than the potential of the connection point of the fixed resistors R ₁₁ and R _2. In order to maintain hysteresis between the operation of the electronic buzzer BZ when the potential of the connection point of the resistor R ₃ and the variable resistor R ₅ becomes lower than the potential of the connection point of the fixed resistors R ₁₁ and R ₂ . a fixed resistor R _6, and includes. Incidentally, the fixed resistor R ₄ is arranged to limit the current given to the electronic buzzer BZ to a suitable range. The electronic buzzer BZ is preferable because it has a longer life than the mechanical buzzer.

(Operation of First Embodiment)

The operation of the first embodiment of the electric circuit inspection apparatus according to the present invention will be described in detail with reference to FIG.

Electricity to be inspected for the inspection terminals T ₁₁ and T ₁₂
When circuit M is not connected

[0026] When the connection terminals T _21, T ₂₂ of the inspected electrical circuit M the inspection terminals T _11, T ₁₂ is not connected, since during the test terminals T _11, T ₁₂ are blocked , A current does not flow from the positive electrode of the DC power supply E to the negative electrode through the fixed resistors R ₂ and R _11, and the potential of the first input terminal of the NAND gate NAND (that is, the connection point of the fixed resistors R ₁₁ and R ₂ ). Potential becomes equal to the potential of the second input terminal (that is, the potential of the positive electrode of the DC power source E). Therefore, the NAND gate NAN
The potential at the output end of D is at low level.

Since the potential at the output terminal of the NAND gate NAND is at a low level, the holding power is not given to the comparison circuit COMP from the DC power source E via the NAND gate NAND, and the potential at the non-inverting input terminal of the comparison circuit COMP. Is low and the potential of the inverting input terminal is high (that is, equal to the potential of the positive electrode of the DC power supply E). Therefore, the output of the comparison circuit COMP is zero.

Since the output of the comparison circuit COMP is zero,
The electronic buzzer BZ has no voltage applied across its terminals,
No alarm sound is sent out.

Electricity to be inspected for the inspection terminals T ₁₁ and T ₁₂ .
When circuit M is connected

When the connection terminals T ₂₁ and T _{22 of the} electric circuit M to be inspected are connected to the inspection terminals T ₁₁ and T ₁₂ , respectively, the fixed resistors R ₂ and R ₁₁ are connected from the positive electrode of the DC power source E. A current flows to the negative electrode of the DC power supply E via the inspection terminal T ₁₁ , the connection terminal T ₂₁ , the inspection target electric circuit M, the connection terminal T _22, and the inspection terminal T ₁₂ . The magnitude of the current at this time is
It is determined by the magnitudes of the fixed resistors R ₂ and R ₁₁ and the electric resistance R _X of the electric circuit M to be inspected.

Since the potential of the first input terminal of the NAND gate NAND is the potential of the connection point of the fixed resistors R ₁₁ and R ₂ , the potential of the second input terminal (that is, the potential of the positive electrode of the DC power source E) is Compared to the low level. Therefore, the potential at the output end of the NAND gate NAND becomes high level.

Since the potential at the output end of the NAND gate NAND becomes high level, holding power is applied from the DC power source E to the comparison circuit COMP through the NAND gate NAND. The comparison circuit COMP is determined by the potential of the non-inverting input terminal set by the fixed resistor R ₃ and the variable resistor R ₅ , the fixed resistors R ₂ , R ₁₁ and the electric resistance R _X of the electric circuit M to be inspected. Begin comparing with the potential at the inverting input.

Depending on the position of the slider of the variable resistor R ₅ , the potential at the non-inverting input terminal of the comparison circuit COMP is compared with the potential at its inverting input terminal (that is, the potential at the connection point of the fixed resistors R ₁₁ and R ₂ ). When it is high, the output of the comparison circuit COMP becomes positive. When the output of the comparison circuit COMP becomes positive, the electronic buzzer BZ applies a sufficient voltage between both terminals, and outputs an alarm sound.

When the slider of the variable resistor R ₅ is moved, the potential of the non-inverting input terminal of the comparison circuit COMP becomes the potential of its inverting input terminal (that is, the potential of the connection point of the fixed resistors R ₁₁ and R ₂ ). It becomes equal and further smaller, the comparison circuit COMP
Output becomes zero. When the output of the comparator circuit COMP becomes zero, the electronic buzzer BZ does not apply a voltage between both terminals and does not output an alarm sound.

On the other hand, depending on the position of the slider of the variable resistor R ₅ , the potential of the non-inverting input terminal of the comparison circuit COMP becomes the potential of its inverting input terminal (that is, the connection point of the fixed resistors R ₁₁ and R ₂ ). Potential) is lower than or equal to
The output of MP becomes zero. When the output of the comparison circuit COMP becomes zero, the electronic buzzer BZ does not apply a voltage between both terminals and does not send an alarm sound.

When the slider of the variable resistor R ₅ is moved, the potential of the non-inverting input terminal of the comparison circuit COMP becomes the potential of its inverting input terminal (that is, the potential of the connection point of the fixed resistors R ₁₁ and R ₂ ). Equalize and further increase, comparing circuit COMP
The output of becomes positive from zero. When the output of the comparison circuit COMP becomes positive from zero, the electronic buzzer BZ starts to send a warning sound because a sufficient voltage is applied between both terminals.

In summary, according to the present invention, the NAND gate NAND is set to the high level only when the connection terminals T ₂₁ and T _{22 of the} electric circuit M to be inspected are connected to the inspection terminals T ₁₁ and T ₁₂ . Since the output is sent, the inspection terminal T ₁₁ ,
Connection terminals T ₂₁ and T _{22 of the} electric circuit M to be inspected with respect to T ₁₂ .
Unless the holding power is applied from the DC power supply E to the NAND gate NAND, the comparator circuit COMP and the circuits such as the electronic buzzer BZ are not supplied with power from the DC power supply E, and the DC power is supplied in the standby state. The power source E is not consumed.

Further, according to the present invention, by moving the slider of the variable resistor R ₅ to send or stop the alarm sound of the electronic buzzer BZ, the electric resistance R _X of the electric circuit M to be inspected is reduced. Can be determined.

Further, according to the present invention, it is possible to prevent the volume of the alarm sound of the electronic buzzer BZ from being influenced by the magnitude of the electric resistance R _X of the electric circuit M to be inspected.

(Second Embodiment)

Further, the configuration and operation of the second embodiment of the electric circuit inspection apparatus according to the present invention will be described in detail with reference to FIG.

The second embodiment has substantially the same construction as the first embodiment except that the fixed resistor R ₁₁ is replaced by the variable resistor R ₁₂ .

Therefore, in the second embodiment, by adjusting the variable resistor R ₁₂ , the variations in the offset voltage of the comparison circuit COMP and the adverse effects due to the variations in the variable resistor R ₅ are eliminated. It has substantially the same operation as that of the embodiment.

Therefore, for the sake of simplicity of explanation, the same reference numerals as those included in the first embodiment are used for the respective members corresponding to the members included in the first embodiment. By giving the reference numerals, other detailed description will be omitted.

(Third Embodiment)

In addition, the configuration and operation of the third embodiment of the electric circuit inspection apparatus according to the present invention will be described in detail with reference to FIG.

The third embodiment has substantially the same structure as the first embodiment except that the fixed resistor R ₆ is removed.

Therefore, the third embodiment is an electronic buzzer when the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ is higher than the potential of the connection point of the fixed resistors R ₁₁ and R _2. The operation of BZ cannot be accelerated, and the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ is fixed resistors R ₁₁ and R 5.
Electronic buzzer BZ when it becomes higher than the potential of the connection point of ₂
And the operation of the electronic buzzer BZ when the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ becomes lower than the potential of the connection point of the fixed resistors R ₁₁ and R _2. It has substantially the same operation as that of the first embodiment except that it cannot be held.

Therefore, for the sake of simplicity of explanation, the same reference numerals as those included in the first embodiment are used for the respective members corresponding to the members included in the first embodiment. By giving the reference numerals, other detailed description will be omitted.

(Fourth Embodiment)

In addition, with reference to FIG. 4, the configuration and operation of the fourth embodiment of the electric circuit inspection apparatus according to the present invention will be described in detail.

The fourth embodiment has substantially the same construction as the second embodiment except that the fixed resistor R ₆ is removed.

Therefore, the fourth embodiment is an electronic buzzer when the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ is higher than the potential of the connection point of the fixed resistors R ₁₁ and R _2. The operation of BZ cannot be accelerated, and the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ is fixed resistors R ₁₁ and R 5.
Electronic buzzer BZ when it becomes higher than the potential of the connection point of ₂
And the operation of the electronic buzzer BZ when the potential of the connection point of the fixed resistor R ₃ and the variable resistor R ₅ becomes lower than the potential of the connection point of the fixed resistors R ₁₁ and R _2. It has substantially the same operation as that of the second embodiment except that it cannot be held.

Therefore, for the sake of simplicity of explanation, the same reference numerals as those included in the second embodiment are used for the respective members corresponding to the members included in the second embodiment. By giving the reference numerals, other detailed description will be omitted.

(Modification)

In the above description, only the case where the holding power supply end of the comparison circuit COMP is connected to the output end of the NAND gate NAND and the output end of the DC power supply E for the purpose of suppressing the consumption of the DC power supply E has been described. , The present invention is
The present invention is not limited to this, and includes the case where the holding power supply terminal of the comparison circuit is connected to the positive electrode and the negative electrode of the DC power supply.

[0057]

As is apparent from the above, the electric circuit inspecting apparatus according to the present invention is an electric circuit inspecting apparatus in which the inspection terminal is connected to the connection terminal of the electric circuit to be inspected and the quality of the electric circuit is inspected. In particular, the configuration is as described in the section of [Solution for problem], and the potential difference between the positive electrode of the DC power supply and the connection point of the first fixed resistor and the resistor is monitored by the NAND gate, Detects whether the connection terminals of the electric circuit to be inspected are connected to the inspection terminals formed at both ends of the series circuit of the power supply, the first fixed resistor and the resistor, and the NAND gate inspects the inspection terminals. When it is detected that the connection terminals of the electric circuit are connected, the comparison circuit corresponds to the electric resistance of the electric circuit to be inspected and the connection point between the second fixed resistor and the variable resistor and the first fixed resistor. And resistor connection The electric resistance of the electronic circuit to be inspected is determined by moving the slider of the variable resistance to send or stop the alarm sound of the electronic buzzer based on the potential difference between the It has the effect that the volume of the alarm sound can be prevented from being influenced by the magnitude of the electric resistance of the electric circuit to be inspected, and (ii) the effect that the magnitude of the electric resistance of the electric circuit to be inspected can be determined. Then
Further, (iii) an electric current can be caused to flow in the series circuit of the second fixed resistor and the variable resistor only when the electric circuit to be inspected is connected to the inspection terminal, which has the effect of suppressing the consumption of the DC power supply.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of an electric circuit inspection device according to the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of the electric circuit inspection device according to the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the electric circuit inspection device according to the present invention.

FIG. 4 is a circuit diagram showing a fourth embodiment of the electric circuit inspection device according to the present invention.

[Explanation of symbols] 10 ................................... Electrical circuit inspection device BZ ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Electronic buzzer COMP ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Comparison circuit E ・ ・ ・ ・DC power supply M ..Electrical circuit to be inspected NAND ..... Nand gate R ₁₁ , R ₂ , R ₃ , R ₄ , R ₆・ ・ Fixed resistors R ₁₂ , R ₅・ ・ ・ ・ ・ ・ ・ Variable resistors T ₁₁ , T ₁₂・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Inspection terminals T ₂₁ , T ₂₂・ ・ ・ ・ ・ ・ ・ ・ Connection terminals

Claims (5)

[Claims] 1. An electric circuit inspecting apparatus in which an inspection terminal is connected to a connection terminal of an electric circuit to be inspected and inspected for its quality, comprising: (a) a DC power source E and a first fixed resistor R for the inspection terminal. A resistor R ₁₁ that is connected in series via ₂ and that compensates for the adverse effect that the electrical resistance of the electrical circuit to be inspected to which the connection terminal is connected to the inspection terminal is small;
R ₁₂ and (b) the first fixed resistor R ₂ and the resistor R ₁₁ ;
It is detected whether or not the first input end is connected to the connection point of R ₁₂ and the second input end is connected to the positive electrode of the DC power source E, and the connection terminal of the electric circuit to be inspected is connected to the inspection terminal. And a second fixed resistor R ₃ is provided at the output terminal of the NAND gate NAND for outputting a high level output when the connection terminal of the inspection target electric circuit is connected to the inspection terminal, and (c) the output terminal of the NAND gate NAND. One terminal is connected through and the other terminal is connected to the negative electrode of the DC power source E, and the determination value R _X0 of the electric resistance of the electric circuit to be inspected in which the connection terminal is connected to the inspection terminal is set or obtained. And a non-inverting input end is connected to a connection point of the variable resistor R ₅ for (d) the second fixed resistor R ₃ and the variable resistor R ₅ and the inverting input end is the first fixed resistor R ₂ And resistor R ₁₁ ; connected to the connection point of R ₁₂ , The potential of the second connection point of the fixed resistor R ₃ and a variable resistor R ₅ and the first fixed resistor R ₂ and the resistor R _11; compare the potential at the connection point of the R _12, the second fixed resistor a positive output from the output terminal when it becomes higher than the potential at the connection point of R _12; potential of the connection point of the vessel R ₃ and a variable resistor R ₅ is first fixed resistor R ₂ and the resistor R ₁₁ A comparison circuit COMP for sending, and (e) a comparison circuit COM
One terminal is connected to the output terminal of P through the third fixed resistor R ₄ and the other terminal is connected to the negative electrode of the DC power source E, and the output is sent from the comparison circuit COMP. An electric circuit inspecting device, comprising: an electronic buzzer BZ for determining an electric resistance of an electric circuit to be inspected having a connecting terminal connected to an inspection terminal by generating or stopping an alarm sound. 2. The electric circuit inspection apparatus according to claim 1, wherein the holding power supply terminal of the comparison circuit COMP is connected to the output terminal of the NAND gate NAND and the negative electrode of the DC power source E. 3. The electric circuit inspection apparatus according to claim 1, wherein the resistors R _{11 and} R ₁₂ are fixed resistors. 4. The electric circuit inspection apparatus according to claim 1, wherein the resistors R _{11 and} R ₁₂ are variable resistors. 5. A fourth fixed resistor R ₆ is inserted between the non-inverting input terminal and the output terminal of the comparison circuit COMP, and any one of claims 1 to 4 is characterized in that. The electric circuit inspection device described.