JPH048662Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] The present invention relates to a loudness circuit.

In order to compensate for the lack of low and high frequencies when the volume is turned down, the loudness circuit is designed so that the low and high ranges have a larger output than the midrange only when the volume is turned down using the volume adjuster. It is for the purpose of

[Prior art and its problems]

Conventionally, there has been a device of this type as shown in FIG.

In the figure, 1 is an input terminal into which an audio signal is input, 2 is a ground terminal, 3 is an output terminal that outputs an audio signal that has passed through a loudness circuit,
Reference numeral 4 denotes a volume for adjusting the volume, which has an input end 4a, a ground terminal 4b, and a slider end 4c.
are connected to input terminal 1, ground terminal 2, and output terminal 3, respectively. Input terminal 1, ground terminal 2
A series circuit of compensation elements including capacitors 5a and 5b and a resistor 6 is connected between the capacitor 5 and the capacitor 5.
An intermediate tap 4d of the volume 4 is connected to the connection point between a and 5b.

In the above configuration, when the slider of the volume 4 is at the intermediate tap 4d, the loudness characteristic of the circuit becomes as shown by curve _A1 in Fig. 6, and the slider moves toward the input end 4a. Accordingly, the characteristic curve changes from A ₂ , A _{3 .} . . A ₅ , and the amount of compensation changes. However, on the ground end side, as shown by A' ₁ in FIG. 6, the characteristic curve A ₁ is simply shifted, and true loudness characteristics cannot be obtained.

Generally, a volume is in its normal operating range when its slider is between the intermediate tap and the ground end, and the effect of the loudness circuit is most expected in this range. Nevertheless, in the above-mentioned loudness circuit, only a fixed amount of compensation can be obtained in this region, which is almost far from the generally known loudness curve.

[Purpose of invention]

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional circuit, and its object is to provide a loudness circuit that exhibits characteristics approximated by a loudness curve.

[Embodiment] Hereinafter, an embodiment of the present invention will be described based on the drawings, in which the same parts as those in FIG. 5 are given the same reference numerals.

FIG. 1 is a circuit diagram showing an embodiment of the loudness circuit according to the present invention.
Three intermediate taps 4 between a and the ground end 4b
d ₁ , 4d ₂ , 4d ₃ are provided, and capacitors 5a ₁ , 5b ₁ ,
First series circuit consisting of resistor 6 ₁ , capacitor 5
a ₂ , 5b ₂ and a resistor 6 ₂ and a third series circuit consisting of capacitors 5a ₃ , 5b ₃ and a resistor 6 ₃ are connected in parallel, and the capacitor 5
A connection point between a ₁ and 5b ₁ , a connection point between capacitors 5a ₂ and 5b ₂ , and a connection point between capacitors 5a ₃ and 5b ₃ are connected to intermediate taps 4d ₁ , 4d ₂ and 4d ₃ , respectively. The capacitors 5a ₁ to 5a ₃ above each have a capacity of
High-frequency compensation elements C ₅ , C ₃ , and C ₁ , capacitors 5b ₁ to 5b ₂ are low-frequency compensation elements whose capacitances are C ₆ , C ₄ , and C ₂ , and resistors 6 ₁ to 6 ₃ are resistors R ₃ , _R2 , and _R1 , and the capacitances _C1 to _C6 are set so that the following relationship holds between them: _C1 < _C2 , _C3 < _C4 , _C5 < _C6. Ru.

In the above configuration, when the slider of the volume 4 is located between the input end 4a and the intermediate tap _4d1 , the compensation element does not work and the frequency characteristic becomes flat as shown in FIG. 2a.

Next, reduce the volume 4 a little and when the slider is between the intermediate taps 4d ₁ and 4d ₂ , the compensation element 5
a ₁ , 5b ₁ , and 6 ₁ act to raise the low and high frequencies above the midrange as shown in Figure 2b.

When the volume 4 is further reduced and the slider is located between the intermediate taps 4d ₂ and 4d ₃ , the compensation elements 5a ₁ and
5b ₁ , 6 ₁ and compensating elements 5b ₁ , 5b ₁ , 6 ₂ work to further raise the low and high frequencies as shown in FIG. 2c.

Then, when the volume 4 is turned down and the slider is between the intermediate tap 4d ₃ and the ground end 4b, compensation elements 5 ₃ , 5b ₃ , and 6 ₃ are added,
As shown in FIG. 2(d), improved characteristics in the low and high frequencies can be obtained.

Figure 3 shows the circuit shown _in Figure ₁ with specific _constants .
C ₂ , C ₄ , C ₆ are 0.1μF, R ₁ to _{R 3} are 3KΩ, r ₁ to _{r 8} are
When the resistance is set to 2.5KΩ and the characteristics when the slider is at points a to d are calculated, the frequency characteristics a to d as shown in FIG. 4 are obtained.

In the above embodiment, three intermediate taps are provided, but any number may be used as long as there are two or more, and the larger the number of taps, the more accurate the auditory correction can be performed.

Further, in the illustrated embodiment, a resistor and a capacitor are used as compensation elements, but a similar circuit can be constructed by further using an inductance, or by using an inductance instead of a capacitor.

Further, the position of the intermediate tap may be set anywhere depending on the constant of the compensation element, but for example, let the number of taps be n, and the resistance values between each tap be r _{o +1} , r _o ,
When r _o-1 ,..., r ₁ , the ratio of each resistance value is
2 ^n-1 : 2 ^n-2 ...2 ¹ : 2 ⁰ : 2 ⁰ or so.

[Effect of idea]

As explained above, according to the present invention, a plurality of intermediate taps are provided on the volume adjustment volume, and the sliding effect is achieved by both the low frequency compensation element and the high frequency compensation element connected to each of the intermediate taps. Since the optimal amount of compensation for the low and high frequencies can be obtained depending on the position of the speaker, even in the commonly used volume range, the amount of compensation for the high and low ranges can be obtained according to the volume, and the loudness Characteristics that approximate a curve can be obtained.

Therefore, it is possible to obtain the effect that the frequency characteristics are audibly flat at any volume.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a graph showing the loudness characteristics at each volume position of the circuit in Figure 1, Figure 3 is an equivalent circuit diagram with specific constants added to the circuit in Figure 1, and Figure 4 is the output terminal in Figure 3. FIG. 5 is a circuit diagram showing a conventional circuit example, and FIG. 6 is a graph showing characteristics of the circuit shown in FIG. 5. 4...Volume for volume adjustment, 4d ₁ to 4d ₃ ...
Intermediate tap, 5a ₁ ~ 5a ₃ , 5b ₁ ~ 5b ₃ , 6 ₁ ~ 6 ₃
...Compensation element.

Claims (1)

[Claims for Utility Model Registration] A loudness circuit having a volume for volume adjustment and a compensation element connected to an intermediate tap of the volume, wherein the volume for volume adjustment is provided with a plurality of intermediate taps, and each of the intermediate taps is provided with a plurality of intermediate taps. A loudness circuit characterized in that both a low-frequency compensation element and a high-frequency compensation element are connected to the loudness circuit.