JPS6244575Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a volume control device that automatically operates an electronic device from a set state when the power is turned on, thereby preventing, for example, loud impact sounds from being output from a speaker. . BACKGROUND ART In various electronic devices, a volume control volume and a power switch are provided separately. In this case, adjusting the volume and turning on or off the power can be done manually, or even remotely using a remote controller. By the way, when the power switch is turned off, the volume adjustment volume remains fixed at the setting position when the power was turned off, so when the power switch is turned on again, the sound corresponding to this setting position suddenly changes from the speaker. Therefore, in some cases, an extremely large output may be obtained and it is unavoidable that it will adversely affect the circuit system, speakers, etc. In particular, turn on the power to the remote controller,
This remote control only has buttons for controlling shutoff and volume increase/decrease, and there is no scale for the volume setting position that can be used as a guide to the volume level (actually, there is no scale). This makes it difficult to tell how much volume will be produced when the power is turned on. Also, when the power to an electronic device is shut off, the power to the motor that controls the volume adjustment volume inside the device according to instructions from the remote controller is also cut off, so the volume adjustment volume's setting position when the power is turned off is the same as the setting position when the power is turned on. Therefore, there is a risk that a loud impact sound will be output from the speaker when the power is turned on.

In view of the above, the present invention proposes a volume control device which has a simple structure and which prevents a loud impact sound from being output from a speaker when the power is turned on.

An example of the device according to the present invention will be explained below with reference to the drawings. 1 is a low frequency signal source, 2 is a volume control volume, and 3 is an amplifier for low frequency signals, which is normally used. The output is supplied directly to the speaker 4. 5a and 5b are DC power supplies whose connection points are grounded. A circuit passing through the collector-emitter of the NPN transistor 6a, the emitter-collector of the resistor 7a, 7b, and the emitter-collector of the PNP transistor 6b is connected to the series circuit of the power supplies 5a and 5b, and the connection point of the resistors 7a and 7b is connected to the motor 8. This motor 8 drives the above-mentioned sound volume adjustment volume 2.
A series circuit consisting of normally open switches 9a and 9b is connected to the series circuit of the power supplies 5a and 5b described above, and the connection point of these switches 9a and 9b is normally connected to the bases of the transistors 6a and 6b described above. It is something that This switch 9a, 9b
may be operated manually or by remote control. Therefore, if the connection point between the switches 9a and 9b is connected to the bases of the transistors 6a and 6b, turning on the switch 9a turns on the NPN transistor 6a, which connects its collector, emitter, resistor 7a, and motor 8. A current is supplied from the power supply 5a in the direction of the arrow a through the power supply 5a, and the volume 2 is thereby rotated, for example, counterclockwise, thereby reducing the volume. Also, by turning on switch 9b
PNP transistor 6b turns on and its collector
Power supply 5 through emitter resistor 7b-motor 8
Assume that a current is supplied from b in the direction of arrow b, thereby rotating the volume 2 in the opposite direction to that described above to increase the volume.

In the present invention, a preset resistor 10 and a main volume (volume adjustment volume 2 in this example) are used.
The detection volume 11 detects the operating position of the main volume 2 which is linked to the main volume 2, and the detection obtained by the detection volume ₁₁ with respect to the preset potential V1 obtained in the preset resistor 10 mentioned above. The difference between the potential V ₃ and the potential V 2 ₍ both V ₁ and V ₂ include negative potentials in this example) and its height (V ₁
When V ₂ is at a high potential, it is +, and when it is at a low potential, it is -.
A determination circuit 12 that determines whether V ₃ is within a preset potential range of -V ₀ to +V ₀ , a switching control circuit 19 , and a switch device 20 that is switched by the switching control circuit 19 is provided. When there is an output from the discrimination circuit 12 when the power is turned on, that is, the potential ±
When V ₃ is outside the set potential -V ₀ to +V ₀ ,
The detection volume 11 is operated by the output from the discrimination circuit 12 so that the potential ±V ₃ falls within the range of the set potential.

As the preset resistor 10, a plurality of fixed resistors may be connected in series and the preset potential _V1 may be obtained from the connection point, but a volume may be used as shown in the figure, so the following will be explained. It is explained as a volume.

In order to obtain the above-mentioned potentials _V1 and _V2 , in this example, the volumes 10 and 11 are connected to the power supplies 5a and 5.
They are connected to the series circuit of b, respectively, and the discrimination circuit 1
2, window comparators 15a and 15b are configured by pairing the output terminals of the voltage comparator (amplifier) 13 to which the above-mentioned potentials _V1 and _V2 are applied via resistors 14a and 14b, respectively. Resistors 16a, 17a, 17 are connected to one input terminal of each, and connected to the series circuit of power supplies 5a and 5b.
b, 16b are connected in series, the connection point between resistors 17a and 17b is grounded, and the connection point between resistors 16a and 17b is connected.
The connection point with a and the connection point with 16b and 17b are respectively connected to the other input terminals of window comparators 15a and 15b, and the respective output terminals of both comparators 15a and 15b are connected to each other through resistors 18a and 18b. The figure shows a case in which it is configured by connecting to. and resistor 1
The voltages (the above-mentioned set potentials) +V ₀ and -V ₀ applied to the other input terminals of the window comparators 15a and 15b are determined by the resistance values of 7a and 17b.

Also, the switching control circuit 19 is an NPN transistor 21
and the emitter of the NPN transistor 22 are connected together, and the collectors of both transistors are connected together and connected to the positive side of the power supply 5a through the resistor 25, and the emitters of each of the PNP transistors 23 and 24 are connected to the power supply 5a. The base of transistor 23 is connected to the positive electrode side of transistors 21 and 2.
The collector of the transistor 24 is connected to the base of the transistor 24 and grounded through the resistor 26. The collector of the transistor 24 is grounded through the coil 27 of the relay 20 which becomes the switch device 20.
This figure shows a configuration in which the bases of each are grounded.

In this case, the switch device, that is, the relay 20 has three relay contacts 28, 29, and 30, and the movable contact 28a of the contact 28 is connected to the transistor 6.
a and 6b, fixed contact 28b is connected to the connection point of switches 9a and 9b, fixed contact 28c is connected to the connection point of resistors 18a and 18b as output terminals of the discrimination circuit 12, and the movable relay contact 29 Resistors 18a and 18 with contact 29a mentioned above
The fixed contacts 29c are connected to the bases of the transistors 21 (and therefore the emitters of the transistors 22) of the switching control circuit 19 to the connection points b, and the movable contacts 30a of the relay contacts 30 are connected to the output terminals of the amplifier 3. , the fixed contact 30b is connected to one end of the speaker 4. It is assumed that these relay contacts 28, 29, and 30 are in the state shown by solid lines when the relay 20 is in a non-energized state (no current flows through the relay coil 27).

To explain the operation of the above-mentioned configuration, before the power is turned on (the power is supplied to the amplifier 3 and the discrimination circuit 12 and the switching control circuit 19), each relay contact 28, 29, and 30 is in the state shown by the solid line. be. When the power is turned on in this state, potentials V ₁ and V ₂ are obtained from the volumes 10 and 11, and these are compared by the comparator 13. Now temporarily V ₁ <
Assume that V ₂ and +V ₃ is obtained from the comparator 13, and that V ₃ >V ₀ .

At that time, the positive potential obtained from the output terminal of the window comparator 15a is applied to the bases of the transistors 6a and 6b through the contacts 28c and 28a of the relay contact 28. Therefore, in this case, the transistor 6a is turned on, and a current is supplied from the power supply 5a to the motor 8 in the direction of the arrow a through the transistor 6a, which drives the motor 8. As a result, the main volume 2 and the detection volume 11 move counterclockwise, for example. ie, the potential V ₂ is operated so as to approach V ₁ . In this case, transistor 6a
A voltage (current) such that switching is controlled is obtained from the comparator 15a.

In this state, the voltage obtained at the connection point of the resistors 18a and 18b is applied to the base of the transistor 21 and the emitter of the transistor 22 of the switching control circuit 19.
is turned on, thereby turning on transistor 23, which turns off transistor 24, that is, relay 20 is in a non-energized state, so that each relay contact 28, 29, and 30 continues to be in the state shown by the solid line, respectively. However, the above-described operation continues.

In this way, when the potential V ₂ approaches the preset potential V ₁ and the potential +V ₃ falls within the range of the set potential -V ₀ to +V ₀ , no output can be obtained from the window comparator 15a, and as a result, the transistor 21
and 23 are turned off, and the transistor 24 is turned on. Therefore, the relay 20 is energized, the relay contacts 28, 29 and 30 are respectively switched to the states shown by the dotted lines, and the output from the amplifier 3 is supplied to the speaker 4. Therefore, by operating the switch 9a or 9b, the motor 8 can be rotated in any direction, that is, the volume can be adjusted freely. Even if the potential V ₂ is greatly different from the preset potential V ₁ again during this adjustment, since the relay contact 29 has been switched to the state shown by the dotted line, the switching control circuit 19 is controlled by the output from the discrimination circuit 12. is not controlled.

The above is about the case where V ₂ is higher than the preset potential V ₁ , but if V ₁ > V ₂ , the transistor 6b is turned on by the output from the window comparator 15b, and the motor 8 is supplied with a voltage from the power supply 5b. A current is supplied in the direction of arrow b, thereby rotating the main volume 2 and the detection volume 11 clockwise, and operating the potential _V2 in a direction closer to the preset potential _V1 . In this case, the switching control circuit 19
In this case, transistors 22 and 23 are turned on,
24 turns off.

In this way, the potential -V ₃ changes from the set potential -V ₀ to +
When it falls within the range of V ₀ , relay 20
is energized, the relay contacts 28, 29 and 30 are switched to the state shown by the dotted lines, and thereafter the volume can be adjusted arbitrarily by operating the switches 9a and 9b, as described above.

Furthermore, when the power is turned on, the potential _V2 is already close to the reference potential _V1 , that is, the potential ± _V3 is the set potential _-V0 to +
When it is within the range of V ₀ , neither of the transistors 21 and 22 of the switching control circuit 19 is turned on, so the transistor 23 is also not turned on, and therefore the transistor 24 is immediately turned on and energizes the relay 20. Since each relay contact 28, 29 and 30 is switched to the state shown by the dotted line, the switches 9a and 9b are immediately used to operate the motor 8, that is, to control the main volume 2.
operations can be performed.

As described above, the main volume 2 can be operated by operating the switch 9a or 9b, but the next time the power to the electronic device is cut off, the relay 20 will be in the de-energized state, and will therefore switch to the state shown by the solid line. In other words, it can handle power-on again.

In this example, in addition to the above configuration, a second
A comparator 35 is provided. That is, 35 is a second comparator that compares the voltage detected by the operating position detecting resistor 11 interlocked with the main volume 2 and the reference voltage _V4 , and one input terminal is connected to the operating position detecting resistor 11. The other input terminal is connected to the middle point of the reference voltage setting resistors 36 and 37 connected in series between the positive power source 5a and the ground. The output terminal of the comparator 35 is an inverting circuit 38
and the base of a transistor 40 via a resistor 39, the collector of the transistor 40 is connected to the positive electrode of a power source 5a via a relay 41, and its emitter is grounded. On the other hand, the output terminal of the amplifier 3 described above is connected to a power display element drive circuit 45 via an attenuator 44.
The output terminals of are respectively connected to the terminals of a plurality of light emitting diodes (LEDs) 54 as power display elements. The attenuator 44 is composed of resistors 46 and 47 connected in series between the output terminal of the amplifier 3 that provides 1/10 attenuation and the ground, and is switched in parallel with the resistor 46 by a relay 41. A switch 48 is connected to cancel the attenuation.

49 and 50 are scale plates of the power meter 45, as shown in the plan view of FIG. 52. Further, 53 is a switch that is switched by the relay 41, and when the relay 41 is not energized, it switches as shown by the solid line, and the voltage from the power source 5a is supplied to the lamp 52 via the terminal 53a and the contact 53c. , when the relay 41 is energized, it switches as shown by the broken line and the voltage from the power source 5a is applied to the terminal 53.
a, is supplied to the lamp 51 via contact 53b. Therefore, in the low range where the volume is low, the lamp 5
1 is lit and the scale plate 49 is illuminated, and in the high range where the volume is large, the lamp 52 is lit and the scale plate 50 is illuminated.
is illuminated, and the audio output is reliably read with high precision by scale plates 49 and 50, which differ depending on the size of the audio output.

Next, the operation of the present invention will be explained. Main volume 1 is set at a certain angle θ (for example, 10 o'clock on a clock)
The output voltage E ₀ of the operating position detection resistor 11 is below the reference voltage Er given by the resistors 36 and 37 up to the angle corresponding to the 30 minute position. As a result, the output of the comparator 35 is a low voltage and the output of the inverting circuit 38 is a high voltage, turning on the transistor 40, energizing the relay 41, and switching the switch 48 on one side and the switch 53 on the other side as shown in broken lines. It can be switched to the state of Therefore, the output amplification circuit 3
The output is not attenuated by the attenuator 44 and is directly supplied to the drive circuit 45 in a low range, and the drive circuit 45 drives the display element 54. Further, the lamp 51 is turned on and the power is read with high precision by the scale plate 49.

Furthermore, when the rotation angle of the main volume 1 is made greater than θ, the output voltage E ₀ of the operating position detection resistor 11 becomes greater than the reference voltage Er, so the output voltage of the comparator 35 becomes a high voltage, and the output voltage of the inverting circuit 38 becomes high. Since the output becomes a low voltage, the transistor 40 is turned off, the relay 41 is deenergized, and one of the switches 4 is turned off.
8 and the other switch 53 are switched to the state shown by the solid line. Therefore, the output of the output amplification circuit 3 is attenuated to 1/10 by the attenuator 44, and the output of the drive circuit 4 is
5 and is supplied to the display element 54 by the drive circuit 45.
is driven. Further, the lamp 52 is turned on and the power is read with high precision by the scale plate 50.

The main volume 2, the detection volume 11 for detecting its operating position, and the presetting resistor 10 are arranged on one axis as a resistance device as shown in FIG. 3, and the presetting resistor 10 is connected to the operating knob. 31, the preset value is set, and the main volume 2 and detection volume 11 are manually operated knob 3.
2 and is also adjusted by the motor 8 via a transmission means (gear).

According to the present invention described above, when power is turned on to the electronic device, the main volume 2 is automatically operated to the state set in advance by the preset volume 10, and then the switching control circuit 19 is operated to cause the speaker 4 to emit the sound. Since the preset volume 10 is set appropriately, a sound louder than the speaker 4 will be suddenly emitted when the power is turned on, which may disturb the surroundings or have a negative impact on the circuit system, speakers, etc. This can be avoided in advance.

By the way, when trying to digitally display the output by configuring a power meter for electronic equipment with multiple display elements such as LEDs, it is possible to compare the output by arranging a small number of display elements from low output level to high output level. In an amplifier with a large target, when the volume is low, the number of display elements is small and the output display content is unclear, and when the volume is high, the level difference between the display elements is large and the output display content is also unclear. Therefore, the display accuracy deteriorates, and the display function is often not fulfilled. However, if an attempt is made to improve this point by increasing the number of display elements, there is a drawback that the price of the device inevitably increases.

In contrast, in the example shown in the figure, the range of the meter is switched and displayed when the output is small and when the output is large, depending on the operating position of the main volume, so there is no need to arrange many display elements. By effectively using all the display elements, it is possible to display the output clearly and reliably, regardless of the magnitude of the output. Therefore, the power meter can be adjusted from low output level to high output level using a small number of multiple LEDs.
When displaying digitally using display elements such as, if the output volume is low, use the lower range if the output volume is low, and if the output volume is high, use the higher range. By using this range, all display elements can be used effectively to display clearly.

Furthermore, in the above-described embodiment, the loudness may be turned on and off when the volume is low by a relay, and the power meter may be a moving coil type or a moving iron piece type meter, and its scale plate may be set to a high range or a low range. It may be possible to switch by using .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an example of a volume control device according to the present invention, FIG. 2 is a plan view of its scale plate, and FIG. 3 is a side view of a resistance device. 2 is a main volume, 10 is a preset resistor, 11 is an operation position detection volume, 35 is a comparator, and 60 is a control means.

Claims (1)

[Scope of Claim for Utility Model Registration] A main volume, a volume for detecting the operation position of the main volume whose both ends are connected to a DC power supply and which operates in conjunction with the main volume, and a preset resistor whose both ends are connected to a DC power supply; a determination circuit for determining whether a difference in voltage obtained from a predetermined voltage dividing point of the slider of the operation position detection volume and the preset resistor is within a predetermined range; a drive means for driving a slider of the main volume and a slider of the operation position detection volume; and a drive means for controlling the drive means according to the output of the discrimination circuit to move the slider of the main volume and the operation position detection volume within a predetermined range. and a switching control circuit that operates the drive means by turning on and off a switch circuit when the voltage difference in the discrimination circuit falls within the predetermined range, A switch circuit is a volume control device that can be turned on and off manually or by remote control signals.