JPH1155798A - Check device for input line in broadcast equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To check a voice input line with a comparatively simple configuration. SOLUTION: A level VM at a point M and a level VS at a point S are detected respectively by voltage detection circuits 36, 37. Then the levels VM, VS detected by the voltage detection circuits 36, 37 are different when input lines a-d are normal or when a break or a short circuit takes place in the input lines a-d. Thus, a break or a short circuit in the input lines a-d can be detected by catching a chance in the levels VM, VS.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for inspecting an input line to which a sound input device such as a microphone is connected for a disconnection or a short circuit in a broadcasting device. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input line inspection device suitable for application to a microphone or the like where emphasis is placed on an input line.

[0002]

2. Description of the Related Art As the above-mentioned broadcasting equipment, for example, the one shown in FIG. This is used for the premises broadcasting equipment of a building, etc., and as shown in the figure, a generally known PTT ("Press To Talk")
Or, a hand microphone (hereinafter, simply referred to as a microphone) 1 having a “Push To Talk”) switch (hereinafter, simply referred to as a talk switch) 10 is provided.
The microphone 1 is connected to a microphone terminal 21 provided on a front panel 20 of the device main body 2 via a curl cord 11 dedicated to the microphone 1.
As shown in FIG. 3B, the input board (substrate) 3 in the device main body 2 is connected to an input terminal 30 via an input cable 31. FIG. 3B shows the device body 2
FIG. 3 is a diagram showing a state in which a front panel 20 is removed from FIG.
Normally, when using this broadcasting equipment, the front panel 20 is attached to the front of the equipment main body 2.

The input board 3 includes, for example, an amplifier circuit 32 for amplifying an audio signal input from the microphone 1 via the curl cord 11 and the input cable 31, and whether or not the microphone 1 is in use. That is, a switch circuit 33 for detecting the ON / OFF state of the talk switch 10 is provided. Also, the device body 2
In addition to the input board 3, for example, it controls which one of a plurality of speakers (not shown) provided at an appropriate position in the building premises outputs the audio signal amplified by the amplifier circuit 32, for example. A control board or the like (not shown) is also provided.

In FIG. 3A, the front panel 2
Are operation keys for giving various instructions to a CPU (Central Processing Unit) provided on the control board. Also,
.. Are provided above these operation keys 22, 22,...
For example, it is a display unit having, for example, a liquid crystal panel configuration for displaying a broadcast state or the like by the broadcast device. Further, the device main body 2 is configured to be housed in a large cabinet rack (not shown), and therefore, fixing holes 24, 24,... For fixing the device main body 2 to the cabinet rack. Are provided at approximately four corners of the front panel 20.

By the way, the connection relationship between the microphone 1 and the input board 3 is represented by an electric circuit as shown in FIG. As shown in FIG.
1 and the input cable 31 each have four signal lines. These signal lines are connected to each other one by one via a microphone terminal 21 provided on the front panel 2, whereby four input lines a to d from the microphone 1 to the input board 3 are connected. Are formed.

[0006] The microphone 1 has therein a dynamic type converter 1 for converting collected sound into an electric signal.
2 and the talk switch 10 described above. Of these, one end of each of the input lines a to d and the b line is connected to the converter 12 (specifically, both ends of a coil (not shown) constituting the converter 12). One end of the remaining c-line and one end of the d-line are connected to the talk switch 10. The talk switch 10 is provided to short-circuit one end of the c-line and d-line when it is turned on, and to short-circuit one end of the a-line and one end of the d-line when it is in the OFF state. Have been.

On the other hand, on the input board 3 side, of the input lines a to d, the other end of the line a is connected to the input side of the amplifier circuit 32 via a DC cut capacitor 34. The other end of the a-line and the input side of the capacitor 34 (the left side in the figure)
The input resistor 35 for impedance matching is connected to the ground (GN
D) It is provided in series with the potential. Also, this a
The other end of the b line, which is connected to the converter 12 of the microphone 1 in a pair with the line, is grounded in the input board 3. The other end of the c line is directly connected to the switch circuit 33, and the d line, which is paired with the c line and connected to the talk switch 10 of the microphone 1, is grounded in the input board 3. ing.

According to the circuit configuration of FIG. 4, when the talk switch 10 is in the OFF state, the line a connected to the amplifier circuit 32 is grounded via the talk switch 10 and the line d. No audio signal is output from the device 12, that is, the microphone 1 itself is in an unusable state. Then, when the talk switch 10 is turned on, the connection between the a-line and the ground potential is released, and thus the audio signal is output from the converter 12 for the first time. When the talk switch 10 is turned on, the input side of the switch circuit 33 is connected to the c line and the talk switch 1.
Grounded via the 0 and d lines, whereby the switch circuit 33 detects that the microphone 1 is in use. When the switch circuit 33 detects that the microphone 1 has been used, the CPU supplies the audio signal amplified by the amplifier circuit 32 to each speaker. The sound input to the (converter 12) is broadcast from each speaker.

Here, for example, it is assumed that the a-line or the b-line among the input lines a and b is disconnected.
In this case, no audio signal is output from converter 12 irrespective of the ON / OFF state of talk switch 10. Also, it is clear from the figure that the audio signal is not output from the converter 12 even when the a-line and the b-line are short-circuited to each other. On the other hand, when the c-line or the b-line is disconnected, the input side of the switch circuit 33 is not grounded even if the talk switch 10 is turned on, so that the switch circuit 33 detects that the microphone 1 is in use. Can't do it, so microphone 1
The sound input to the (converter 12) is not broadcast from the speaker. On the contrary, when the c-line and the d-line are short-circuited with each other, the ON / OFF of the talk switch 10 is performed.
Regardless of the state, the switch circuit 33 (CPU) continues to recognize that the microphone 1 is in use.

If the input lines a to d are disconnected or short-circuited as described above, inconveniences such as the inability to broadcast can occur. In order to prevent such inconveniences, the input lines a to d may be disconnected or short-circuited. Must always be checked for In particular, the microphone (hand microphone) 1 as described above is often used as an emergency microphone. In this case, the disadvantage of being unable to broadcast as described above is a fatal trouble. The inspection of lines a through d is very important. Also,
In this broadcasting device, for example, in order to perform maintenance and inspection of the broadcasting device, as described above,
May be removed. At this time, the connection between the microphone terminal 21 provided on the front panel 20 and the input cable 31 and the connection between the input cable 3 and the input terminal 30 on the input board 3 are mechanically twisted or the like. Since a heavy load is applied, the above-described disconnection, short circuit, and the like are likely to occur.

Therefore, as a method for checking whether or not each of the input lines a to d has a disconnection or a short circuit,
Conventionally, for example, a high-frequency oscillation circuit (not shown) that oscillates a high-frequency signal of an inaudible frequency is provided on the microphone 1 side, and this high-frequency signal is transmitted to the device
There is a method of inspecting each of the input lines a to d by detecting on the (input board 3) side.

[0012]

However, according to the above-described conventional inspection method, a relatively complicated circuit called a high-frequency oscillation circuit must be provided on the microphone 1 side.
There is a problem that the circuit configuration in the microphone 1 becomes complicated. Therefore, the above-mentioned prior art is not suitable for a microphone that places importance on miniaturization, such as the hand microphone 1 shown in FIG.

Therefore, the present invention compares the input line connecting the voice input device such as the microphone 1 and the device main body 2 (input board 3) with a disconnection or a short circuit as compared with the prior art. It is an object of the present invention to provide an inspection apparatus capable of performing an inspection with a simple configuration. In addition, by making simple modifications to existing broadcasting equipment,
It is a feature of the present invention to provide an inspection device capable of detecting disconnection or short circuit of the input line.

[0014]

Means for Solving the Problems To achieve the above-mentioned object, of the present invention, the first aspect of the present invention is directed to the first aspect.
And an audio signal input line having an audio input device connected between one end of each of the first and second lines.
A first DC power supply means for supplying a DC power supply for inspection between the other ends of the second and second lines, and a connection between the one ends of the first and second lines in parallel with the audio input device; And a first voltage drop means for preventing the first and second lines from being short-circuited in a direct current manner between the one ends.
A first detecting means for detecting one or both of a voltage between the other ends and a current flowing through each of the lines at the other end of the first and second lines;
It is provided with.

The first voltage drop means can be constituted by, for example, a resistor. Further, the first short-circuit preventing means can be constituted by providing a capacitor or a resistor in series between one end of one or both of the first and second lines and the audio input device, for example.

According to the first aspect of the present invention, when both the first and second lines are normal, the current of the DC power supplied from the first DC power supply means is equal to the first and second currents. It flows in the order of one of the second lines, the first voltage drop means, and the other of the first and second lines. Therefore, for example, the first
The input impedance (resistance value) of the circuit to which the audio signal is input from the audio input device via the second line is substantially infinite, and the impedance (resistance value) of the first and second lines is Assuming that the impedance (resistance value) between one end of the first and second lines via the first short-circuit preventing means is substantially infinite, the first detecting means detects the direct current. A voltage value corresponding to a voltage drop caused by the current of the power supply flowing through the first voltage drop means, or
A current value is detected by dividing the voltage value of the voltage drop by the impedance (resistance value) of the first voltage drop means.

On the other hand, when a disconnection occurs in any of the first and second lines, the current of the DC power supply does not flow through the first and second lines. Therefore, in this case, the first detecting means detects the voltage value of the DC power supply itself, or detects a current value of substantially zero (0).

When the first and second lines are short-circuited to each other, a state equivalent to short-circuiting both ends of the first voltage drop means is obtained. Therefore, the first detecting means detects a voltage value of substantially zero (0), or detects a current value larger than a current value detected when the first and second lines are normal.

That is, when a disconnection or short circuit occurs in the first and second lines, the first detecting means detects a voltage value or a current value different from those when these lines are normal. In order to achieve such an effect, the audio input device connected between one ends of the first and second lines must be provided with, for example, a resistor for constituting the first voltage drop means. And a capacitor and a resistor, for example, for constituting the first short-circuit prevention means.

According to a second aspect of the present invention, in the apparatus for inspecting an input line in a broadcasting device according to the first aspect of the present invention, a status signal indicating whether or not the audio input device itself is in use. And a state signal input line having third and fourth lines connected to one end of each of the lines, and the third and fourth lines being connected to the state signal generation unit. A second DC power supply for supplying a DC power supply for inspection between the other ends of the first and second lines, and a second DC power supply connected between one end of the third and fourth lines in parallel with the state signal generator. A voltage drop means, a second short-circuit prevention means for preventing the third and fourth lines from short-circuiting DC between the one ends, and a third and fourth line comprising the first and fourth lines. DC current between the second line and the one end A third short-circuit preventing means for preventing short-circuit, and a second detecting means for detecting one or both of a voltage between the other ends and a current flowing through each of the lines at the other end of the third and fourth lines. And detection means.

The second voltage drop means can be constituted by, for example, a resistor. Further, the second short-circuit prevention means can be constituted, for example, by providing a capacitor or a resistor in series between one or both ends of the third and fourth lines and the state signal generating means. The third short-circuit preventing means is required to electrically insulate the first and second lines from the third and fourth lines, or to electrically connect one end between these lines. In some cases, the connection can be realized by realizing the connection via a capacitor or a resistor.

According to the second aspect of the present invention, when both the third and fourth lines are normal, the current of the DC power supplied from the second DC power supply means becomes the third and fourth currents. It flows in the order of one of the fourth lines, the second voltage drop means, and the other of the third and fourth lines. Therefore, for example, the third
And the input impedance (resistance value) of the circuit to which the status signal from the status signal generating means is input via the fourth line
Is substantially infinite, and the impedance (resistance value) of the third and fourth lines is substantially zero, and furthermore, one end between the third and fourth lines via the second short-circuit prevention means. Assuming that the impedance (resistance value) is substantially infinite, the second
Detecting means for detecting the voltage value of the voltage drop caused by the current of the DC power supply flowing through the second voltage drop means, or the voltage value of the voltage drop corresponding to the impedance (resistance value) of the second voltage drop means. ) Is detected as the current value corresponding to the value obtained by dividing the current value.

On the other hand, when a disconnection occurs in any of the third and fourth lines, the current of the DC power supply does not flow through the third and fourth lines. Therefore, in this case, the second detection means detects the voltage value of the DC power supply itself, or detects a current value of substantially zero.

When the third and fourth lines are short-circuited to each other, a state equivalent to a short-circuit at both ends of the second voltage drop means is obtained. Therefore, the second detection means detects a voltage value of substantially zero, or detects a current value larger than a current value detected when the third and fourth lines are normal.

That is, when a disconnection or a short circuit occurs in the third and fourth lines, the second detecting means detects a voltage value or a current value different from those when these lines are normal.

Further, when the first and second lines and the third and fourth lines are short-circuited with each other, the first and second lines are supplied from the first DC power supply means to the first and second lines. The current of the DC power supply flows to the third and fourth lines, and the current of the DC power supply supplied to the third and fourth lines from the second DC power supply means changes to the first and second lines.
Flows to the side of the line. Therefore, also in this case, both the first and second detecting means detect a voltage value or a current value different from the case where all of the first to fourth lines are normal.

In order to achieve the above-described operation, the audio input device having the state signal generating means connected between one ends of the third and fourth lines must be provided on the second side. For example, only a resistor for constituting the voltage drop means and only a capacitor and a resistor for constituting the second and third short-circuit preventing means are provided.

According to a third aspect of the present invention, in the input line inspection apparatus for a broadcast device according to the first or second aspect of the present invention, the audio input device is a dynamic microphone. It is.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the case where the input line inspection apparatus according to the present invention is applied to, for example, the above-described broadcasting equipment shown in FIG. 3 will be described with reference to FIGS. I do.

FIG. 1 shows the microphone 1 shown in FIG.
FIG. 3 is a circuit diagram electrically showing a connection relationship between the input board 3 and the input board 3. As shown in the figure, this circuit is the same as that shown in FIG.
The circuit arrangement shown in, five resistors R ₁ through R
_5, is provided with a three capacitors C ₁ through C _3.

That is, on the input board 3 side, the DC voltage V _CC which is the driving power source of each of the amplifier circuit 32 and the switch circuit 33 described above, and the input side of the capacitor 34 on the other end side of the line a (Left side of the figure)
The resistor R ₁ are connected in series. Then, between the input resistor 35 and a line, and a capacitor C ₁ connected in series. Further, a resistor R ₃ is provided in series between the DC voltage V _CC and the other end of the c-line and the input side of the switch circuit 33.

On the other hand, in the microphone 1, the converter 1 is connected in series between one ends of the a-line and the b-line.
2 and forms a parallel and a resistor R ₂ provided. And
In a line, and the position of the resistor R ₂ is connected, between a position where the OFF terminal of the talk switch 10 is connected, is provided with a capacitor C ₂ in series. Furthermore,
a position where the resistor R ₂ is connected in the b-line;
Between the transducer 12 is provided with a capacitor C _3. Also, between each end of the c-line and d-line, in series, i.e. forms a parallel to the talk switch 10, and the resistor R ₅ is provided. Then, a series second resistor R ₄ is provided between the position where the resistor R ₅ is connected on the c-line and the ON terminal of the talk switch 10.

Therefore, according to the above configuration, when each of the input lines a to d is normal (when there is no disconnection or short circuit in each of the lines a to d), the DC voltage V is applied to the lines a and b. _The DC current supplied by _CC is the resistor R
₁ , a line, resistor R ₂ , b line, and ground (G
ND). Thus, to represent the distribution channels of the DC current in the electrical circuit, is as in FIG. 2 (a), i.e., between the ground and the DC voltage V _CC, comprised of resistors R ₁ and the resistor R ₂ Metropolitan This is a circuit equivalent to connecting a series circuit. Accordingly, the voltage between the other ends of the a-line and the b-line, that is, the potential VM at the point _M in FIG.

[0034]

(Equation 1)

On the other hand, regarding the c-line and the d-line,
When the talk switch 10 is in the OFF state, the DC current supplied from the DC voltage V _CC is supplied to the resistor R ₃ , the c line,
The current flows in the order of the resistor R ₅ , the d line, and the ground (GND). Therefore, when this DC current flow path is represented by an electric circuit, it becomes as shown in FIG. 2B, that is, the DC voltage V _CC
And between the ground, the resistor R ₃ and the resistor was connected a series circuit consisting of R ₅ Metropolitan equivalent circuit. Therefore, the voltage between the other ends of the c-line and the d-line, that is, S in FIG.
The potential V _{SOFF at the} point is expressed by the following _{equation (} 2).

[0036]

(Equation 2)

When the talk switch 10 is in the ON state, the DC current supplied from the DC voltage V _CC is supplied to a parallel circuit including resistors R ₃ and c, resistors R ₄ and R ₅ , a d line, Then, they flow in the order of the ground (GND).
Accordingly, the flow path of this DC current is represented by an electric circuit as shown in FIG. 2C, that is, between the DC voltage V _CC and the ground, a resistor R ₃ and resistors R ₄ and R ₄ are connected. _This is a circuit equivalent to connecting a parallel circuit consisting of _five in series. Therefore, the potential V _{SON at the} point S is expressed by the following _{equation (} 3).

[0038]

(Equation 3)

Here, for example, it is assumed that the line a or the line b is disconnected. In this case, since the DC current supplied from the DC power supply V _CC does not flow through the a-line and the b-line,
The potential V _M of the M points, it is needless to say that the above-mentioned DC voltage V _CC and substantially equivalent.

When the c-line or the d-line is broken, no DC current from the DC power supply V _CC flows through the c-line and the d-line regardless of the ON / OFF state of the talk switch 10. Therefore, the potential V _{S at the} point _{S is obtained.}
Is substantially equivalent to the DC voltage V _CC .

For example, assume that the a-line and the b-line are short-circuited to each other. In this case, the state is equivalent to the state where the point _M is grounded. Therefore, the potential VM at the point _M becomes the ground potential, that is, zero (0 [V]).

When the a-line and the c-line are short-circuited to each other, a state equivalent to the short-circuit between the points M and S is obtained. Therefore, when the talk switch 10 is in the OFF state, this can be represented by a circuit as shown in FIG.
That is, a parallel circuit composed of resistors R ₁ and R ₃ and a parallel circuit composed of resistors R ₂ and R ₅ are connected in series between the DC voltage V _CC and the ground. Becomes a circuit equivalent to The potential VM at the point _M and the potential _{VSOFF at the} point S are equivalent, that is, expressed by the following _{equation (} 4). Incidentally, the potential V _M and V _SOFF of this time, the V _A (i.e., the _{V M = V SOFF = V A} ).

[0043]

(Equation 4)

On the other hand, when the talk switch 10 is turned on in a state where the a-line and the c-line are short-circuited with each other, as shown in FIG.
A circuit equivalent to connecting a parallel circuit composed of resistors R ₁ and R ₃ and a parallel circuit composed of resistors R ₂ , R ₄ and R ₅ in series between _CC and ground is provided. Therefore, the potential V _M at the point _M and the potential V _{SON at the} point S are expressed by the following _{equation (} 4). Note that the potentials V _M and V at this time are
_{Let SOFF} be V _B (that is, _let V _M = V _SON = V _B ).

[0045]

(Equation 5)

Further, when the a-line and the d-line are short-circuited to each other, the state is equivalent to the case where the point M is grounded, as in the case where the a-line and the b-line are short-circuited to each other. Therefore, in this case, the potential VM at the point _M becomes the ground potential, that is, zero (0 [V]).

When the b-line and the c-line are short-circuited to each other, the state is equivalent to the point S being grounded. Therefore, in this case, the talk switch 10 is turned on.
Regardless of the / OFF state, the potential V _{S at the} point _S is equal to the ground potential,
That is, it becomes zero (0 [V]).

When the c-line and the d-line are short-circuited to each other, as in the case where the b-line and the c-line are short-circuited to each other, a state equivalent to that the point S is grounded is obtained. Therefore, also in this case, the potential V S at the point _S is the ground potential, that is, zero (0 [V]).

Even if the b-line and the d-line are short-circuited to each other, since both are connected to the ground potential in the input board 3, the potentials V _M and S
It does not affect the potential V _S of the point. Of course, in this case,
There is no effect on the operation of the broadcast equipment itself.

As described above, the potential V _{M at the} point _M and the potential V at the point S when disconnection or short circuit occurs in each of the input lines a to d.
Table 1 shows the changes in _{S in} a list.

[0051]

[Table 1]

As is apparent from Table 1, when a disconnection or a short circuit occurs in each of the input lines a to d, the potential V _{M at the} point _M and the potential V _{S at the} point _S become normal. It is different from the value when Accordingly, by the potential V _S of the potential V _M and S point of the point M, it is detected by the voltage detecting circuit 36 and 37 as shown in FIG. 1, respectively, catch the change of the voltage V _M and V _SN, It is possible to inspect whether the input lines a to d are disconnected or short-circuited.

Each of the voltage detection circuits 36 and 37
, For example, it can be constituted by a comparator circuit to the reference potential the potentials V _M and V _S when the respective lines a to d is all normal. Further, the potentials V _M and V _S are set to, for example, A / D (analog /
After the digital conversion by the (digital) converter, the digital values can be analyzed by the above-mentioned CPU to check for disconnection and short circuit of each of the lines a to d. When a disconnection or a short circuit occurs in each of the lines a to d, for example, by displaying a message indicating the fact on the display unit 23, the occurrence of the disconnection or the short circuit can be intuitively recognized.

[0054] As described above, according to this embodiment, checks whether by capturing the change in the potentials V _M and V _SN, no disconnection or short-circuit in the respective input lines a to d are generated can do.

In order to realize this inspection, it is necessary to add new parts and the like to the microphone 1 and the input board 3 (the apparatus main body 2). The only new addition to the side is the passive components of _three resistors R ₂ , R ₄ and R ₅ and two capacitors C ₂ and C ₃ . Therefore, for example, even if this embodiment is applied to the microphone 1 shown in FIG. 4 described above, the microphone 1 itself does not increase in size, and is extremely inexpensive and easily remodeled (design change). An inspection device for each of the input lines a to d can be realized.

For example, the circuit configuration in the microphone 1 is generally often formed by a printed wiring board. In this case, the three resistors R ₂ , R ₄ and R
₅ and if only adding only two capacitors C ₂ and C _3, the size and shape of the printed wiring board is almost be said that there is no need to change. Further, if only the _three resistors R ₂ , R ₄ and R ₅ and the two capacitors C ₂ and C ₃ are used, even if these are added by aerial wiring, a large work load is not applied. Therefore, the present embodiment is suitable for a voice input device such as a microphone (hand microphone) 1 and the like, in which miniaturization is important.
Very effective.

Also on the input board 3 (device main body 2) side, two resistors R ₁ and R ₃ , one capacitor C ₁ , and two voltage detection circuits 36 and 37 are provided.
(Or the change of the program for controlling the A / D converter and the CPU described above) only.
No significant design changes are required. Further, the curl code 11 and the input cable 31 constituting each of the input lines a to d are the same as those shown in FIG. 4 and need not be changed at all.

Each of the input lines a to d in this embodiment corresponds to the first to fourth lines described in the claims. Applying the DC voltage V _CC to the point M on the a-line via the resistor R ₁ corresponds to the first DC power supply means described in the claims. The resistor R ₂ corresponds to a first voltage drop means described in the appended claims, the capacitor C ₂ and C ₃ corresponds to the first short prevention means. The capacitor C ₂ also functions as a third short prevention means described in the appended claims. Also, the capacitor C _3, without providing this does not particularly affect the operation of the broadcasting equipment. Then, the voltage detection circuit 36 that detects the potential VM at the point _M corresponds to the first detection means described in the claims.

The talk switch 10 corresponds to the state signal generating means described in the claims. And c
Applying the DC voltage V _CC to the point S on the line via the resistor R ₃ corresponds to the second DC power supply means described in the claims. And the resistor R ₅ is
Corresponding to the second voltage drop means described in the claims,
Resistor R ₄ corresponds to the second short prevention means. Then, the voltage detection circuit 37 for detecting the potential V _S at the point _S corresponds to the second detection means described in the claims.

Although the present embodiment has been described with reference to the cabinet / rack-type broadcast equipment as shown in FIG. 3, the present embodiment can be applied to broadcast equipment of other forms. .

The present embodiment can be applied not only to the hand microphone 1 as shown in FIG. 3 but also to other types of microphones. Of course, the present embodiment is applicable not only to the microphone but also to other audio input devices such as a tape recorder.

Further, in the present embodiment, the potential V _M at the point _M and the potential V _{S at the} point _S are detected, but these potentials (voltage values) V _M and V _S are detected. Instead, for example, a current flowing through each of the input lines a to d may be detected, and a disconnection or a short circuit of each of the input lines a to d may be detected from the detected current value.

[0063]

As described above, according to the input line inspection apparatus of the broadcast equipment according to the first aspect of the present invention, disconnection or short circuit occurs in the first and second lines to which the audio input equipment is connected. Then, the detected value of the voltage or current by the first detecting means becomes a value different from that when each line is normal. Therefore, from this detection value, it can be inspected whether the first and second lines are disconnected or short-circuited.
In order to realize this test, the audio input device must be provided with, for example, a resistor for constituting the first voltage drop means, and a resistor for constituting the first short-circuit preventing means, for example. Only capacitors and resistors. Therefore, as compared with the above-described conventional technology that requires a relatively complicated circuit such as a high-frequency oscillation circuit, there is an effect that the inspection of each line (audio signal input line) can be realized with a very simple circuit configuration. . This effect is obtained in a voice input device that places importance on miniaturization, such as the microphone (hand microphone) 1 shown in FIG.
Very effective. Also, for example, when the invention according to claim 1 is applied to an existing broadcasting device that is not provided with an input line inspection device, the above-described capacitor or resistor is provided for an audio input device. Therefore, it is not necessary to make a large-scale design change on the voice input device side.

According to the second aspect of the present invention, the audio input device has a status signal generating means for generating a status signal indicating whether or not the audio input device itself is in use. In a broadcasting device provided with a status signal input line (third and fourth lines) for transmitting the status signal, the status signal is detected by a voltage or current detected by the second detection means. It is possible to inspect whether the input line is disconnected or short-circuited. Further, according to detection values of the first and second detection means,
It can also be checked whether the status signal input line and the audio signal input line are short-circuited to each other. In order to realize this test, the audio input device must be provided with, for example, a resistor for constituting the second voltage drop means, and second and third short-circuit preventing means. For example, only capacitors and resistors are used. Therefore,
Even in a broadcasting device having the above status signal input line,
The same effect as the first aspect is obtained.

According to the third aspect of the present invention, there is provided an apparatus for inspecting an input line in a broadcasting device, wherein the broadcasting device provided with a dynamic microphone is used as the audio input device. The same effect as the invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating an electrical schematic configuration of an embodiment of an inspection apparatus according to the present invention.

FIG. 2 is an equivalent circuit of each of input lines a to d in the embodiment.

FIG. 3 is an external view of a generally known broadcasting device.
(A) is a front view, (b) is a side view which shows the state which removed the front panel from the apparatus main body.

FIG. 4 is a circuit diagram showing an electrical schematic configuration of an audio input portion in the broadcasting device of FIG. 3;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 microphone 2 device main body 3 input board 10 PTT switch 11 curl cord 12 converter 31 input cable 36, 37 voltage detection circuit R ₁ , R ₂ , R ₃ , R ₄ , R ₅ resistor C ₁ , C ₂ , C ₃ Capacitor V _CC DC voltage a, b, c, d Input line

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryuichi Yamamoto 7-2-1, Minatojima-Nakamachi, Chuo-ku, Kobe City, Hyogo Prefecture Inside TOA Co., Ltd. No.2-1 Inside TOA Co., Ltd. (72) Inventor Shogo Harui 7-2-1, Minatojima-Nakamachi, Chuo-ku, Kobe-shi, Hyogo Pref.

Claims (3)

[Claims] 1. An audio signal input line having first and second lines and an audio input device connected between one end of each of these lines, and an inspection between the other ends of the first and second lines. First DC power supply means for supplying a DC power supply, first voltage drop means connected in parallel with the audio input device between one ends of the first and second lines, First short-circuit preventing means for preventing the first and second lines from being short-circuited in a DC manner between the one ends; and at the other end of the first and second lines, between the other ends. An input line inspection apparatus for a broadcast device, comprising: first detection means for detecting one or both of a voltage and a current flowing through each of these lines. 2. The voice input device according to claim 1, further comprising: a status signal generating unit configured to generate a status signal indicating whether or not the voice input device itself is in use. The voice input device has third and fourth lines. A state signal input line connected between the one end to the state signal generating unit, a second DC power supply unit for supplying a DC power supply for inspection between the other ends of the third and fourth lines, A second voltage drop means connected between one end of a third and a fourth line in parallel with the state signal generating means; and the third and fourth lines are mutually DC-connected between the one ends. A second short-circuit preventing means for preventing short-circuiting; and a third short-circuit preventing means for preventing the third and fourth lines from being short-circuited with the first and second lines at the one end side. Means for preventing short-circuit of the third and fourth lines. 2. The apparatus according to claim 1, further comprising a second detection unit configured to detect one or both of a voltage between the other ends and a current flowing through each of the lines. 3. The apparatus according to claim 1, wherein the audio input device is a dynamic microphone.