JPH04128407U - voltage divider circuit - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to achieve impedance matching between the amplifier output and voltage divider input via a fader adjuster, and to perform stable fader operation by isolating the input and output of the voltage divider. It is something. [Configuration] A configuration in which an impedance matching device is provided at the input of the voltage divider circuit of the fader adjuster connected to the output of the audio equipment to perform impedance matching, and a transformer circuit is further provided to isolate the input/output section in the voltage divider circuit. This is what I did.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea is related to the voltage divider circuit that forms the fader function of audio equipment. It is especially suitable for adjusting faders in car stereos, etc. Regarding the binder circuit.

0002

[Prior art]

Traditionally, audio equipment with fader functions, such as car stereo voltage Many divider circuits have been provided with circuit diagrams shown in FIGS. 3 and 4. In the figure 1 is a car stereo amplifier section with a series fader adjuster, 1a to 1d is the output terminal of amplifier section 1, 2 is the final stage amplifier of amplifier section 1, and 3 is the terminal of multi-amplifier 1. Series fader adjuster provided, 9 connected to voltage divider output, example For example, front power amplifier, 10 connected to voltage divider output, e.g. Rear power amplifier, 20 is parallel fader (hereinafter referred to as parafader) adjuster 20a to 20d are the output terminals of the amplifier section 20, 21 is the amplifier section of the car stereo with This is a parafader adjuster provided in the amplifier section 20.

0003 Figure 3 shows a voltage device connected to the output of the amplifier section 1 equipped with a series fader adjuster 3. Figure 4 shows the output of the amplifier section 20 equipped with the parafader adjuster 21. For example, by connecting the same voltage divider 30 as described above, The sound signal level is adjusted to supply the output from voltage divider 30 to power amplifiers 9 and 10. This fades the color.

0004 Above, the voltage divider 30 is compared to the output impedance of the amplifier sections 1 and 20. form a high input impedance circuit, and each input signal is passed through capacitor C1. It is divided by a resistance divider circuit of relatively high resistors R5 and R6 and output.

[0005]

[Problem that the idea aims to solve] However, the fader circuit of multi-amplifier 1 and 20 configured in this way (the above voltage divider circuit 30) by the respective series or parafader adjusters 3, 21. Adjust the fader arbitrarily to adjust the acoustic output signal to the front and rear power amplifiers 9 and 10. The disadvantage was that it was not possible to do enough.

[0006] In other words, voltage divider 30 is a high input impedance circuit. Therefore, even if you adjust fader adjusters 3 and 21, the acoustic output signal that should be faded cannot be narrowed down. In addition, there were drawbacks such as the acoustic output signal being output with phase inversion.

[0007] For example, set the series fader adjuster 3 in Figure 3 to the maximum on the front side (the maximum on the lower side in Figure 3). (Large position), the acoustic output signal of rear power amplifier 10 is faded. There is no aperture, and the output is phase inverted. Also, in the parafader circuit of Figure 4, For example, set the parafader adjuster 21 to the maximum position on the rear side (the maximum position on the upper side in Figure 4). When set, the acoustic output signal of the front power amplifier 9 will not be able to restrict the sound. There was a problem.

[0008] In addition, many of the amplifier sections 1 and 20 described above form a BTL output circuit, but for example, Even if the amplifier output circuit is not a BTL output circuit but a single output amplifier, the series or When parafader adjusters 3 and 21 are set to the front maximum position or rear maximum position , the sound output signal becomes zero output and no sound can be produced, or the fader function does not produce sound. This had the disadvantage of causing problems such as the inability to aperture the aperture.

[0009] Therefore, the input and output of the voltage divider circuit is adjusted using an isolation amplifier. Isolation is possible, but isolation amplifiers require a power supply. Moreover, since there is a power supply circuit, fuses and line filters are also required. The drawback was that the circuit configuration was complicated.

0010 This idea was made in view of the above points, and its purpose is to Eliminating the drawbacks of the conventional example, an impedance matching filter is installed at the input of the voltage divider. In addition, the input and output of the voltage divider is isolated for accurate fade. Provides a voltage divider circuit that can perform the voltage divider function. Ru.

[0011]

[Means to solve the problem]

The voltage divider circuit of this invention has a fader adjuster installed at the output of the audio equipment. Then, connect a voltage divider circuit to this fader adjuster to fade the output signal. In the voltage divider circuit to be coded, the above voltage divider circuit The impedance matching device installed at the input and the input/output of the voltage divider circuit are adjusted. It is equipped with a transformer circuit for isolation.

0012

[Effect]

According to this invention, a voltage device is connected to the output of an amplifier section that has a fader adjuster. You can connect a fader to fade the output signal.

[0013] In the above, an impedance matching box is installed at the input of the voltage divider, and the amplifier section By matching the output impedance of the amplifier section, the positive output terminal and and the negative side output terminal, the hot side input terminal of the voltage divider, and the ground A series installed inside the amplifier section that can be connected to the side input terminals in parallel. Or adjust the output signal fader accurately by adjusting the parafader adjuster. can be done.

[0014] Furthermore, a transformer is installed inside the voltage divider, and the voltage Since the input and output sections of the input/output section of the input/output divider can be isolated, the voltage Ground the output terminal of the voltage divider, and then connect the voltage divider - output constant can be set by resistor attenuator, voltage divider The output can be accurately connected to the connected device.

[0015] In this way, voltage divider impedance matching and input/output isolation With this option, the unstable fader function operation of the conventional example can be eliminated.

[0016]

【Example】

An embodiment of the voltage divider circuit according to this invention is shown in FIGS. 1 and 2. explain. Note that the same parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted. figure , 4 is the voltage divider circuit of this invention, and 5 and 6 are the voltage divider circuits of this invention. Impedance matching device provided at the input of binder 4, 7 and 8 are voltage devices This is a transformer that isolates the input and output of the driver 4.

[0017] Figure 1 is composed of a series fader adjuster 3, and Figure 2 is composed of a parafader adjuster 21. This is a fader circuit in which a voltage divider 4 is connected to the The amplifier sections 1 and 20 are output via series or parafader adjusters 3 and 21 as in the conventional example. The acoustic output signal is supplied from the power terminals 1a to 1d, 20a to 20d to the voltage divider 4. .

[0018] The input circuit of voltage divider 4 has impedance matching between input terminals 4a and 4b. An impedance matching device 6 is provided between the input terminals 4c and 4d, and the amplifier sections 1 and 20 are connected to each other. The above impedance matching filter is configured to match the output impedance of For example, high wattage resistors can be used for 5 and 6, and the above amplifier section The output terminals 1a to 1d of voltage divider 4 correspond to the input terminals 4a to 4d of voltage divider 4. can be connected.

[0019] The acoustic signal input to this voltage divider 4 and impedance matched is It is supplied to transformers 7 and 8 through a resistance divider circuit of resistors R1 and R2, and this transformer 7, The secondary side output of 8 is isolated from the above input circuit. This transformer 7,8 The output signal from the secondary side is adjusted by the output level and output impedance of resistors R5 and R6. It is supplied to the front and rear power amplifiers 9 and 10 via the circuit.

[0020] The voltage divider 4 configured in this way serves as a voltage divider for the speaker outputs of the amplifier sections 1 and 20. The positive output terminals 1a, 1c and the negative output terminals 1b, 1d and the voltage divider 4 Hot side input terminals 4a, 4c and ground side input terminals 4b, 4d are matched and connected to input/output signals. It also forms the speaker output low impedance and voltage circuit of amplifier sections 1 and 20. The impedance of the impedance matching device 5, 6 of the 4-input divider is matched. It can be formed by

[0021] In addition, the input part of the voltage divider 4 and the output part forming a resistance attenuation circuit are connected to each other. Completely isolated with transformers 7 and 8, voltage divider The output characteristics such as the output level and output impedance of 4 are determined by the constants of resistors R5 and R6. In particular, the ground side output terminals 4f and 4h can be grounded, and voltage connection to the front and rear power amplifiers 9 and 10 connected to the output of the power divider 4. Connection loss and performance problems due to connection mismatching can be prevented.

[0022] In this way, the output and input of the amplifier sections 1 and 20 and the voltage divider 4 can be matched and connected. Depending on the series fader adjuster 3 or para fader adjuster 21, the fader The function is to impedance match the speakers directly to the output terminals 1a to 1d of amplifier sections 1 and 20. In the same way as when connecting the same speaker and performing fader operation for this speaker output, Fader adjustment can be performed via the stage divider 4.

[0023] In addition, the isolation circuit between the input section and the output section by the transformers 7 and 8 is Unlike isolation amplifiers, it does not require a power supply, which simplifies the circuit configuration. , and provides stable isolation operation without being affected by power supply noise. can do.

[0024]

[Effect of the idea]

As mentioned above, the voltage divider of the fader circuit according to this invention is An impedance matching device is installed in the circuit, and the input/output section of the voltage divider is Isolation with a lance allows accurate and stable fader adjustment. It has the effect of being able to

[0025] Furthermore, the impedance matching device and isolated output are shaped as described above. Therefore, it can be applied to any type of fader circuit. Since the above isolation circuit does not require a power supply, there are no problems caused by the power supply. This has the advantage of requiring fewer parts, especially for car stereos and other components. It is ideal for fader circuits, and also has the effect of simplifying installation work.

[0026] Moreover, it has a simple structure and can be constructed at low cost. It has excellent features such as being easy to use.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a voltage divider of a fader circuit having a series fader adjuster according to the present invention.

FIG. 2 is a circuit diagram of a voltage divider of a fader circuit having a parafader adjuster according to the present invention;

FIG. 3 is a circuit diagram of a voltage divider of a fader circuit having a conventional series fader adjuster.

FIG. 4 is a circuit diagram of a voltage divider of a fader circuit having a conventional parafader adjuster.

[Explanation of symbols]

1 Amplifier section 1a to 1d Amplifier output terminals 2 Final stage amplifier inside the amplifier section 3 Series fader adjuster 4 Voltage divider 4a~4d Voltage divider input terminals 4e~4h Voltage divider output terminal 5,6 Impedance matching box 7,8 transformer 9 Front power amplifier 10 Rear power amplifier 20 Amplifier section 21 Parafader adjuster

Claims (1)

[Scope of utility model registration request] 1. A voltage divider circuit that provides a fader adjuster at the output of an audio device and connects a voltage divider circuit to the fader adjuster to fade the output signal, wherein an impedance matching filter is provided at the input of the voltage divider circuit. and a transformer circuit for isolating input and output of the voltage divider circuit.