JP2000162343A - Time signal sound formation circuit of clock body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a time signal sound in a clock body that can generate a smooth attenuation sound while driving a compact speaker with less power consumption. SOLUTION: A time signal sound formation circuit 30 is provided with an integral circuit part 61 for forming a time constant adjustment signal E where a voltage changes successively by integrating an attenuation control signal D that is set to a constant voltage, an electric charge accumulation circuit part 31 and a discharge time constant adjustment circuit part 41 for forming a correction sound source signal B by differentiating a sound source signal A that is a constant voltage pulse signal group, waveform-shaping circuit part 51 for forming a sound generation control signal C where the correction sound source signal B is shaped into a rectangular pulse signal, and an amplification circuit part 65 for driving a speaker 81 by amplifying the sound generation control signal C. The discharge time constant adjustment circuit part 41 successively reduces the differential time constant when differentiating a sound source signal according to the voltage change in the time constant adjustment signal E.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clock body for producing an alarm sound and a time signal, and more particularly to a circuit for producing a time signal from a speaker.

[0002]

2. Description of the Related Art Today, a clock body that divides a high frequency signal formed by a crystal oscillator, forms an accurate reference pulse of 1 Hz or 0.5 Hz, and drives a pointer by a step motor to display an accurate time. Is often used. Furthermore, in forming a reference pulse from a high-frequency signal formed by a crystal oscillator, a reference pulse which is a hand movement control signal is formed using a timer counter or the like of a microcomputer without being limited to the case of using a frequency dividing circuit, and an alarm is generated. The sound signal and the time signal sound signal are also formed using a microcomputer, and the hands are moved according to the hand movement control signal to display the time, and at the set time, an electronic sound is emitted as an alarm sound. There is also a clock body that sounds. The alarm sound is generated not only when an alarm sound signal for generating an electronic sound is generated by a microcomputer but also by using a melody IC or the like to output an alarm sounding control signal from the microcomputer to activate the melody IC. Then, the melody IC may output an alarm sound signal.

As described above, in a timepiece having a sound-producing function, a melody IC or the like is used for a sound source circuit when music or voice is sounded as an alarm sound from a speaker, and a frequency of 1 kHz or less is used when an electronic sound is sounded from a speaker. An audio frequency forming circuit that forms a sound source signal of about 3 kHz is used, and a small cone speaker, an electromagnetic speaker, a piezoelectric buzzer, or the like is used as a sounding body.

When a small cone speaker is used to adjust the volume for generating an alarm sound or a time signal sound, a voltage is applied to the speaker using a variable resistor or a voltage dividing resistor. The voltage to be adjusted. or,
When using an electromagnetic speaker or piezoelectric buzzer, adjust the pulse width of the sound source signal formed by the audible frequency formation circuit,
The volume is adjusted by adjusting the average power supplied to a speaker or the like.

In a timepiece having such a volume adjusting function, when an alarm sound is generated, the volume is increased stepwise. In addition, the time signal sounds three times before the hour, two seconds before, and one second before the hour in order to produce a sound similar to the time signal sound conventionally used in television, radio or telephone. Attempts have been made to generate a sound source signal for generating an hour sound that indicates the hour.

[0006] Then, the time signal signal forms a sound source signal of about 1 kilohertz as a notice sound for about 0.3 seconds,
A sound source signal of about 2 kilohertz is sustained for about one second as the hourly sound, and a sound source signal is attenuated so that the volume of the hourly sound is gradually reduced.

[0007]

When sounding a time signal, the volume of the conventional sound, which has been familiar from the past, is gradually reduced. In a timepiece using an electromagnetic speaker or a piezoelectric buzzer, a combination of a frequency dividing circuit is used. To change the pulse width by controlling the pulse width, or by controlling the change in the pulse width by dividing using a program timer. A disadvantage that was not suitable for a watch body fit.

In a timepiece using a small cone speaker, it is relatively easy to lower the volume smoothly, but the power consumption is large, and the life of a timepiece using a battery as a power source is shortened. There was a drawback that it was difficult to make a small watch body. The present invention eliminates such disadvantages, and provides a timepiece sound forming circuit for a watch body that uses a relatively simple circuit configuration and can drive a speaker with low power consumption and generate a smooth decay sound. Is what you do.

[0009]

According to the present invention, there is provided an integrating circuit section for forming a time constant adjusting signal in which a voltage is sequentially changed by integrating a constant voltage attenuation control signal, and a pulse signal group having a constant voltage. A charge accumulation circuit section and a discharge time constant adjustment circuit section for forming a modified sound source signal by differentiating a certain sound source signal; a waveform shaping circuit section for forming a sound emission control signal obtained by shaping the modified sound source signal into a rectangular wave pulse signal; An amplifying circuit unit that drives a speaker by amplifying a signal, and a time signal sound forming circuit, wherein the discharge time constant adjusting circuit unit sequentially changes a resistance value according to a voltage change of the time constant adjusting signal, This is a discharge time constant adjusting circuit for sequentially reducing the differential time constant when forming the modified sound source signal.

As described above, the time signal generating circuit according to the present invention includes the charge storage circuit section for differentiating the pulse voltage of the sound source signal and the discharge time constant adjusting circuit section. The adjustment circuit unit forms a modified sound source signal by differentiating the sound source signal, and has a waveform shaping circuit unit that shapes the waveform into a rectangular wave based on the corrected sound source signal.
By changing the differential time constant by the charge accumulation circuit unit and the discharge time constant adjustment circuit unit, the pulse width of the sounding control signal output by the waveform shaping circuit unit can be easily changed.

Since the integration circuit section forms the time constant adjustment signal by integrating the constant voltage attenuation control signal, it is possible to form a signal for smoothly increasing the voltage as the time constant adjustment signal. By inputting the constant control signal to the discharge time constant adjusting circuit and changing the resistance value of the discharge time constant adjusting circuit, the differential time constant of the differentiating circuit by the charge storage circuit and the discharge time constant adjusting circuit can be smoothed. Can be changed to

Therefore, it is possible to smoothly change the pulse width of the tone generation control signal and smoothly reduce the volume from the speaker.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A time signal sound forming circuit according to the present invention comprises:
As shown in FIG. 1, the microcomputer 11 controls the driving of the second hand motor 17 and the hour / minute hand motor 18 by using a speaker.
A time signal sound forming circuit 30 incorporated in a clock circuit capable of generating an alarm sound and a time signal sound from 81.

The circuit of this clock body drives a second hand motor 17 and an hour / minute hand motor 18 by outputting a predetermined hand operation control signal to a motor buffer 15 based on an accurate clock signal from a crystal oscillator. The hour and minute hands are moved to display the time. Also, switch box
By a signal from each switch provided in 13, the microcomputer 11 performs a predetermined operation, performs on / off control of an alarm, fast-forward or fast-return control of a pointer, and generates an alarm sound at a predetermined time. The microcomputer 11 outputs the sound source signal A of the electronic sound and the sound source signal A of the electronic sound as the time signal.

In this clock circuit, the detection resistor 22
And a brightness detection circuit 21 including a photoelectric conversion element 23 such as a CdS cell, and detects the brightness of a place where a clock body is installed, such as a room. When the surroundings of the clock become dark, a light / dark signal is input to the microcomputer 11 so that the sound source signal A for generating a time signal every hour is not output from the sound source signal output port 27.

The sound source signal A is obtained by dividing a high-frequency clock signal formed by using a crystal oscillator to form a rectangular wave pulse signal in an audible frequency band by the microcomputer 11 so as to generate a sound source signal output port. Output from 27. As shown in FIG. 1, the sound source signal output port 27 of the microcomputer 11 for outputting the sound source signal A is connected to the charge storage circuit section 31 of the time signal generating circuit 30, and the AND circuit 71 and the inverter 73 are connected to the time signal generating circuit 30. This is connected to the amplification circuit section 65 of the hourly sound generation circuit 30 via the power supply.

The other input terminal of the AND circuit 71 is connected to the control signal output port 25 of the microcomputer 11. The time signal generating circuit 30 is formed by a charge storage circuit section 31, a discharge time constant adjusting circuit section 41, a waveform shaping circuit section 51, an amplifier circuit section 65, and an integrating circuit section 61. .

The charge storage circuit section 31 is composed of a plurality of capacitors and a changeover switch, and a first capacitor 32 and a second capacitor 33 having different capacities are arranged in parallel to each terminal of the changeover switch 35 and the sound source signal output port 27. Provided between
Discharge time constant adjustment circuit section for common terminal of changeover switch 35
Connected to 41. Therefore, the sound source signal output port 27 can be connected to the discharge time constant adjusting circuit 41 via any one of the capacitors. The changeover switch 35 is operated by operating the changeover switch 35.
When transmitting the sound source signal A output from the sound source signal output port 27 to the discharge time constant adjusting circuit unit 41, the capacity of the capacitors 32 and 33 inserted into the transmission path can be switched.

The discharge time constant adjusting circuit 41 is a circuit for connecting the charge storage circuit 31 and the waveform shaping circuit 51 and for inserting a resistor between the charge storage circuit 31 and the ground point. I have. A resistor inserted between the charge storage circuit section 31 and the ground point is provided between the ground point with the transistor 43, which is an active element, as a variable resistor and the transistor 43 and the fixed resistor 42 in parallel. Is what it is.
Note that a protection resistor 45 is inserted in the collector of the transistor 43. A diode 47 having an anode grounded is also provided in parallel with the transistor 43 and the fixed resistor 42.

Therefore, a differentiating circuit is formed by the charge storage circuit section 31 and the discharge time constant adjusting circuit section 41. By controlling the conductivity of the transistor 43, the differentiating time constant of the differentiating circuit can be changed. Can be. Therefore, the modified sound source signal B obtained by differentiating the sound source signal A while changing the differentiation time constant can be input to the waveform shaping circuit 51. Further, the waveform shaping circuit section 51 is a circuit for connecting the discharge time constant adjusting circuit section 41 and the amplifier circuit section 65 via the inverter 52, and a pull-up resistor for supplying the sound generation control signal C to the amplifier circuit section 65. 55, and a diode 53 for a diode-OR circuit that has a diode 53 facing the inverter 52 and that can also supply the sound source signal A passing through the AND circuit 71 to the amplifier circuit section 65. Circuit.

The amplifying circuit section 65 has a transistor 67 as an amplifying element. The base of the transistor 67 is connected to the waveform shaping circuit section 51 via a protection resistor 66. Is connected to a ground point via a speaker 81. In addition, the integrating circuit section 61 includes a resistor
Connect the resistor 62 to the attenuation signal output port 29 of the microcomputer 11 by connecting the capacitor 62 and the capacitor 63 in series, connect the capacitor 63 to the ground point, and adjust the middle point of the resistor 62 and the capacitor 63 to discharge time constant. This is connected to the base of the transistor 43 in the circuit section 41 via the limiting resistor 44.

Accordingly, since the time signal generating circuit 30 forms a differentiating circuit by the charge accumulating circuit section 31 and the discharging time constant adjusting circuit section 41, as shown in FIG. When the signal A is output from the microcomputer 11, a modified sound source signal B obtained by differentiating the sound source signal A
Can be input to the waveform shaping circuit unit 51. And
When the attenuation control signal D of a constant voltage is output from the attenuation signal output port 29 of the microcomputer 11, the integration circuit section
61 forms a time constant control signal for sequentially increasing the voltage by integrating the attenuation control signal D, and supplies the time constant control signal to the transistor 43 of the discharge time constant adjusting circuit 41.

For this reason, in the discharge time constant adjusting circuit 41,
The conductivity of the transistor 43 is gradually increased, and the charge and discharge time of the charge storage circuit unit 31 is changed to be shorter. Accordingly, the differential time constant in the differentiating circuit formed by the charge storage circuit unit 31 and the discharge time constant adjusting circuit unit 41 is shortened, and the pulse width of the modified sound source signal B input to the waveform shaping circuit unit 51 is gradually changed.

The discharge time constant adjusting circuit 41 includes a resistor 41
And a diode 47 having an anode connected to the ground point in parallel with the transistor 43 to prevent generation of a reverse pulse in the corrected sound source signal B when the sound source signal A falls.
As described above, the pulse width of the modified sound source signal B input to the waveform shaping circuit unit 51 is reduced, and the waveform shaping circuit unit 51 outputs the pulse width in accordance with the pulse width exceeding the threshold value of the inverter 52 as the waveform shaping circuit unit 51. The width of the L level pulse of the tone generation control signal C also gradually decreases.

Therefore, the speaker 81 is connected to the speaker 81 via the amplifier circuit 65.
, The current supplied to the speaker 81 sequentially decreases, and the volume of sound generated from the speaker 81 also decreases sequentially. And this decrease in volume
The time constant adjustment signal E output from the integration circuit unit 61 can be smoothly reduced in accordance with the voltage rise. The integration time constant of the integration circuit section 61 is the voltage of the time constant adjustment signal E for operating the transistor 43 of the discharge time constant adjustment circuit section 41 in the unsaturated region in about one second, which is the sounding time of the positive sound. And the differential time constant of the differentiating circuit formed by the charge storage circuit unit 31 and the discharge time constant adjusting circuit unit 41 is a square wave pulse of about 2 to 3 kHz which is a positive tone. Is set to the maximum time constant, which is a differential time constant that causes the signal to attenuate and disappear within about one pulse time.

The time signal generating circuit 30 shown in FIG.
Since the capacitance of the charge storage circuit unit 31 is made variable by the changeover switch 35, when the capacitance of the charge storage circuit unit 31 is switched to a smaller value, the differential time constant can be further shortened, as shown in FIG. As described above, the pulse width of the modified sound source signal B is reduced, the pulse width of the sound control signal C is always smaller than the pulse width of the sound source signal A, and the sound volume from the speaker 81 is set to be small. This makes it possible to smoothly change the volume to a small value.

In this embodiment, the sound source signal output port
When outputting sound source signal A from 27, control signal output port 25
, The sound source signal A of the alarm sound output from the microcomputer 11 can be passed through the AND circuit 71 and input to the amplifier circuit section 65. When a passage control signal is output from the microcomputer 11, the AND circuit 71 is opened by the passage control signal, and the sound source signal A passing through the AND circuit 71 is passed through the inverter 73 and the diode 75 in the same manner as the modified sound source signal B. It can be input to the amplifier circuit section 65.

Then, the phase of the sound source signal A passing through the AND circuit 71 and the tone generation control signal C output by the waveform shaping circuit section 51 are made to coincide with each other through the inverter 73, The sound source signal A, which is generated at a constant volume such as an alarm sound, has a wider L-level pulse than the sound generation control signal C because it is synthesized with the sound generation control signal C output from the waveform shaping circuit 51.
Speaker 81 without reducing the volume to sound from 81
Can be sounded.

When the sound is generated without decreasing the volume, as in the case of the announcement sound in the time signal, the pass control signal is set to the L level, the AND circuit 71 is closed, and only the sound control signal C output by the waveform shaping circuit 51 is output. The sound is supplied to the amplifier circuit 65, and the speaker 81 is sounded at a volume determined by the capacitance of the capacitor of the charge storage circuit 31. When the hourly sound is emitted, the attenuation control signal D is applied to the integrating circuit 61 to generate the hourly sound. The sound volume can be smoothly reduced.

The time signal generating circuit 30 is used not only when the volume is set stepwise by switching the capacitance of the capacitor of the charge storage circuit 31, but also as shown in FIG. In some cases, the maximum differential time constant may be changed by connecting the fixed resistor 42 and the variable resistor 49 in series so that the resistance value of a resistor provided in parallel with the transistor 43 in the transistor 41 can be adjusted.

As described above, by continuously adjusting the resistance value of the resistor, even when the capacity of the charge storage circuit unit 31 is fixed, the volume of the time signal generated from the speaker 81 is continuously adjusted. Adjustment settings can be made. Note that a variable capacitor such as a variable capacitor or a trimmer capacitor may be used for the charge storage circuit unit 31 so that the maximum volume of the time signal can be continuously adjusted and set.

The time signal generating circuit 30 is incorporated into a clock body by combining a sound source signal A via an AND circuit 71 and a tone generation control signal C via a differentiating circuit and a waveform shaping circuit 51 into an amplifying circuit 65. Although it is connected to the signal output port of the microcomputer 11 so that it can be input to the microcomputer 11, a sound source signal forming circuit for forming a sound source signal of the time signal is provided separately from the microcomputer 11, and the time signal sound forming circuit 30 The sound source signal of the time signal and the attenuation control signal D may be input at a predetermined timing controlled by the microcomputer 11. That is, it is sufficient that the time signal generation circuit 30 forms the sound control signal C for smoothly changing the duty ratio of the sound source signal for generating the hourly sound. The sound control signal C causes the speaker 81 to sound and the alarm sound to be generated. Is a speaker independently of the time signal generating circuit 30 which amplifies the sound source signal A output from the melody IC or the like controlled by the microcomputer 11 as appropriate.
In some cases, the sound is supplied to the speaker 81, and a time signal or an alarm sound is generated from the speaker 81.

[0033]

According to the present invention, an integrating circuit for forming a time constant adjusting signal for sequentially changing a voltage, a charge accumulating circuit and a discharging time constant adjusting circuit for differentiating a sound source signal, and a tone control signal are formed. A time signal generating circuit having a waveform shaping circuit section and an amplifier circuit section for driving a speaker, wherein the discharge time constant adjusting circuit section is configured to differentiate a sound source signal according to a voltage change of the time constant adjusting signal. This is a timepiece sound forming circuit of a clock body serving as a discharge time constant adjusting circuit section for sequentially decreasing the differential time constant.

Therefore, the tone control signal which changes the pulse width by the differentiating circuit, the integrating circuit, and the waveform shaping circuit and generates a smooth average current change corresponding to the voltage change for integrating the constant voltage by the integrating circuit is formed. Can be. For this reason, a sound source signal that smoothly attenuates the volume as the hourly sound in the time signal can be formed by a relatively simple circuit, and a circuit capable of forming a small and low power consumption time signal can be formed. Is what you can do.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a time signal generating circuit for a timepiece according to the present invention.

FIG. 2 is a time chart showing signals in a time signal generating circuit for a timepiece according to the present invention.

FIG. 3 is a time chart showing signals in a time signal generating circuit for a timepiece according to the present invention.

FIG. 4 is a diagram showing another example of a time signal generating circuit for a timepiece according to the present invention.

[Explanation of symbols]

Reference Signs List 11 microcomputer 13 switch box 15 motor buffer 17 second hand motor 18 hour and minute hand motor 21 brightness detection circuit 25 control signal output port 27 sound source signal output port 29 attenuation signal output port 30 time signal generation circuit 31 charge storage circuit section 41 discharge Time constant adjusting circuit section 51 Waveform shaping circuit section 61 Integrating circuit section 65 Amplifying circuit section 81 Speaker

Claims (1)

[Claims] 1. An integrating circuit section for forming a time constant adjusting signal in which a voltage changes sequentially by integrating a constant voltage attenuation control signal, and a modified sound source which differentiates a sound source signal which is a pulse signal group of a constant voltage. A charge storage circuit section and a discharge time constant adjustment circuit section for forming a signal, a waveform shaping circuit section for forming a sound control signal obtained by shaping a modified sound source signal into a rectangular wave pulse signal, and a speaker for driving the speaker by amplifying the sound control signal A sound signal is input to the charge storage circuit portion, and the corrected sound source signal differentiated by the charge storage circuit portion and the discharge time constant adjustment circuit portion is supplied to the waveform shaping circuit portion. Each circuit unit is connected so that the sound generation control signal shaped by the waveform shaping circuit unit is input to the amplifier circuit unit, and the time constant adjustment signal output by the integration circuit unit is further input to the discharge time constant adjustment circuit unit. The discharge time constant adjusting circuit section includes:
A time signal generating circuit for a clock body, wherein a differential time constant for differentiating a sound source signal in accordance with a voltage change of a time constant adjusting signal is sequentially reduced.