JPS58127193A - Electronic bell sound generation circuit for time piece - Google Patents

Abstract

PURPOSE:To obtain an electronic bell sound generation circuit which can be integrally assembled into an IC enabling damping variation of the intensity of emission cyclically by controlling a synthesized ON resistance with the selection of parallel MOS transistors in damping modulation circuits. CONSTITUTION:Damping modulation circuits enabled as a bell sound selection signal 200 goes to a high level are each provided with groups 120 and 122 of parallel MOS transistors to control audible frequency signals f4 and f5. Transistors 120-1, 120-2..., 122-1, 122-2..., of these groups 120 and 122 are ON controlled through gates with NAND gates 124-1, 124-2..., 126-1, 126-2..., where a emission period selection signal S and the signals 200, f4, f5 and the like are applied to a damping control signals. Thus, a continuous electronic bell sound whose intensity of emission is varied cyclically by a synthesized ON resistance of transistors freely selected is generated from a circuit integrally assemblable into an IC circuit. Likewise, as other damping modulation circuits are enabled, desired continuous electronic bell sounds are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic bell sound generation circuit for a timepiece, and more particularly to an improvement in an electronic bell sound generation circuit whose sound intensity is attenuated and changed periodically.

In recent years, with the electronicization of clocks, electronic bells have also been used for wake-up alarms, and in order to vary the sound of such electronic bells or to obtain an alarm sound that approximates the sound of a conventional bell striking mechanism, it is necessary to There is a need for a bell sound generating circuit that periodically changes its attenuation.

Conventionally, in order to obtain these various periodic attenuation-changing sounds, a charging/discharging circuit consisting of a resistor and a capacitor was usually incorporated into the sounding circuit, and the sounding intensity was changed using the charging/discharging action of the charging/discharging circuit. However, with this conventional device, the magnitude of the attenuation change in the resistive acid varies depending on the characteristics of the capacitor, and due to the dispersion of the characteristics, it is difficult to obtain a constant periodic fishing force attenuation change characteristic. . Furthermore, the resistor or capacitor must be connected externally to the IC-based bell sound generating circuit, which has the drawback of increasing the size and cost of the device.

Furthermore, as another conventional device, a device that changes the pulse duty ratio of the sounding signal has been proposed, but this conventional device requires an extremely complicated circuit configuration in order to control changes in the sounding intensity in fine steps. It had the disadvantage of being called necessary. In addition, in conventional devices, the sound intensity, which attenuates and changes, is changed as the alarm operation progresses from the alarm time, and as a result, a relatively quiet operation is performed at the beginning of the alarm activation, and this is gradually changed. There has been a problem in that it has not been possible to obtain a device that can provide a reliable wake-up effect by increasing the sound intensity.

Furthermore, in the conventional device, the sounding intensity and period of the electronic bell sound are predetermined, and this cannot be arbitrarily selected depending on the state of use.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide an electronic bell sound generation circuit that periodically attenuates and changes the sounding intensity, and to provide an electronic bell sound generation circuit that
In addition to providing a circuit that can be integrated into the C circuit, it also automatically adjusts the sound intensity and duration of this electronic bell sound.
To provide an electronic bell sound generation circuit for a watch that can switch between a case where the sound intensity of the electronic bell sound is changed and a case where a user can arbitrarily select the sounding intensity of the electronic bell sound.

In order to achieve the above object, the present invention provides first and second gate circuits each having a group of at least two parallel-connected MOS transistors and a gate circuit for supplying an audio frequency signal to the gate input of each MO transistor. an attenuation modulation circuit, each MO8) of the two attenuation modulation circuits, a sound generation circuit that produces sound at a sound intensity corresponding to the combined on-resistance of the transistor, and a gate circuit of one of the two attenuation modulation circuits, each MO8). an attenuation control circuit that supplies an attenuation control signal to turn off the transistors periodically and sequentially; and a MOS transistor in the first attenuation modulation circuit to which the attenuation control signal from the attenuation control circuit is supplied. A sounding period selection circuit that selects the sounding period and sounding intensity of the signal supplied to the sounding circuit by switching and selecting, and a sounding period selection circuit that sequentially changes the sounding intensity by changing the attenuation period and sounding period step by step from the alarm time. a sounding intensity switching circuit that supplies a switching control signal to the attenuation control circuit and the sounding period selection circuit so that the attenuation control circuit and the sounding period selection circuit select one of the attenuation modulation circuits; When the first attenuation modulation circuit is selected by the bell sound selection switch, the sounding intensity is periodically attenuated and the sounding intensity is changed by changing the attenuation cycle and the sounding period every predetermined time period. The present invention is characterized in that a pseudo bell sound is generated, and when the second attenuation modulation circuit is selected by the bell sound selection switch, a pseudo bell sound whose sound intensity is attenuated and changed periodically is generated.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a preferred embodiment of the electronic bell sound generation circuit according to the present invention, and the circuit of the present invention is incorporated in an electronic alarm clock, and the electronic alarm clock uses a reference signal generator such as a crystal oscillator. A frequency dividing circuit 12 that divides a reference signal into pulses of a desired frequency; a waveform shaping circuit 14 that shapes drive pulses of 1 to 2 Hz; a drive circuit 16 including an amplifier; a synchronous motor 18 for a watch; The driving force is transmitted to the wheel train 20 to which the time indicator hand is fixed.

Further, the clock device is provided with a reference contact 22, and when the indicated time corresponds to a desired set time, the reference contact 22 is turned on, and the electronic bell sound generation function of the present invention is performed. The signal of this reference contact 22 is supplied to a snooze control circuit 28 via a chattering prevention circuit 24 and a one-shot circuit 26, respectively.

Further, the snooze control circuit 28 is supplied with signals from a manually operated snooze switch 36 and a snooze counter 38 that counts the number of snoozes, and performs a snooze operation according to each of these input signals.

Further, the snooze control circuit 28 receives a signal from a bell sound selection switch 30, which is manually operated to select the bell sound, to prevent chattering times! 32 and a one-shot circuit 34. The output signal from the snooze control circuit 28 is input to the time signal control circuit 37. The time signal control circuit 37 is connected to the snooze control circuit 2.
This is a circuit that controls the gibber sound generation effect based on the signal from 8.

In the present invention, in order to obtain a bell sound in which the sounding intensity changes attenuated periodically, the audible frequency signal (f4, f,) output from the frequency dividing circuit 12 is periodically attenuated and modulated to produce the sounding effect. , this sound generation action is performed by the sound generation circuit 40,
The sound generation circuit 40 in the embodiment includes a speaker 42 and a drive transistor 44 that supplies a drive current to the speaker 42.

In the present invention, in order to separately supply the sound generation circuit 40 with two types of drive signals whose sound sound intensity is attenuated and changed at a predetermined period and whose sound sound intensity changes such that the sound sound intensity increases as the alarm activation progresses, First attenuation modulation circuit 46
and a second attenuation modulation circuit 48, and in the embodiment, two different audio frequency signals f4, f are supplied to both attenuation modulation circuits 46, 48, respectively.

An attenuation control circuit 50 is provided to control the attenuation effect of both attenuation modulation circuits 46, 48, and the attenuation modulation is controlled by a periodic attenuation control signal K, and the period of this periodic attenuation control signal K is controlled by a periodic attenuation control signal K. The attenuation control circuit 50 receives pulse signals f, , ft, f3, f4 having different periods from the frequency dividing circuit 12 in order to change the f, , ft, f3, f4 according to the progress of alarm activation.
is supplied.

In the present invention, as described above, two attenuation modulation circuits 46 and 48 are provided, and each of these attenuation modulation circuits supplies different electronic bell sound drive signals to the sound generation circuit 40. By arbitrarily selecting the attenuation modulation circuits 46 and 48, the user can produce a sound with a desired electronic bell sound. In the embodiment, the first attenuation modulation circuit 46 includes a control circuit that sequentially changes the attenuation cycle and sounding period in stages according to the progress of alarm activation, and the second attenuation modulation circuit 48 changes the sounding intensity of the electronic bell sound. consists of an arbitrarily user-adjustable control circuit, for this purpose,
On the output side of the second attenuation modulation circuit 48 is a sound intensity adjustment resistor 5.
A variable resistor is connected at 2, and these different electronic bell sound drive signals are supplied to the transistor 44 of the sounding circuit 40 via a wired OR gate 54.

Then, a sound generation circuit 40 based on the first attenuation modulation circuit 46
A sounding period selection circuit 56 is provided to change the sounding period stepwise as the alarm operation progresses.
A short-term selection signal is supplied to the first attenuation modulation circuit 46 at the beginning of the alarm activation, and a selection signal S whose duration is increased sequentially as the alarm activation progresses.

In this embodiment, when controlling the first attenuation modulation circuit 46, a sounding intensity switching circuit is used to change the attenuation change period of the attenuation control circuit 5o and the sounding period of the sounding period selection circuit 56 as the alarm operation progresses. 58, and in the embodiment, three levels of different sounding intensity signals H, I, and J are sent to both circuits 50 every 8 seconds from the start of alarm activation.
. control to shorten it step by step,
The effect of sequentially increasing the sounding period of the trench sounding period selection circuit 56 is performed. To switch the sound intensity, the sound intensity switching circuit 58 supplies a signal C to the first attenuation modulation circuit 46, and the attenuation control circuit 50 supplies an inverted signal K to the attenuation control signal to the sound period selection circuit 56. suppliedb
Ru.

Then, from the frequency dividing circuit 12 to the sound intensity switching circuit 58, the IH
z pulse signal is supplied, and the time report start signal A from the time report control circuit 37 is also supplied to the switching circuit 58, and the selection blocking signal B, which is an inverted signal, is sent to the switching circuit 58 and the sound generation period selection circuit 56. is being supplied to.

FIG. 2 shows a specific circuit configuration of the above-described sounding intensity switching circuit 58 that changes the sounding intensity step by step.
The timing chart for automatically changing the electronic bell sound, that is, the sounding intensity by the first attenuation modulation circuit 46, is shown in the third timing chart.
FIG. 4 is a timing chart for the case where the second electronic bell sound, that is, the second attenuation modulation circuit 48 produces a sound effect at the sound intensity set by the user.

The switching circuit 58 includes six stages of cascade-connected FFs 50-1 to 6.
0-6 and an AND gate 62, 64, 66 that combines the outputs of these FFs 60, an inverter 68, 70, 72, an inverter 74 controlled by the bell selection signal 200 of the bell selection switch 30, and an OR gate 76. . An IHz pulse signal is supplied from the frequency dividing circuit 12 to the clock input of the first stage FF 60-1, and the IHz pulse is sequentially controlled to be frequency divided and inverted by the FF group 60.

First, the operation of switching the first electronic bell tone shown in FIG. 3 will be explained. At alarm time t1, the pre-bell selection control circuit 280
The sound generation control signal B is rLJ), thereby FF6
The zero reset is released and the frequency division and inversion operations are started. The output C of the first stage FF5Q-1 is supplied to the first attenuation modulation circuit 46, which has a pulse period of 2 seconds, so that the first attenuation modulation circuit 46 has a period of 1 second during which sound can be produced, as will be described later. This can be followed by a 1 second pause period.

The output frequency divided by FF60-2 and FF'60-3 is OFF'60-4.6o-5, 60-6 in the next stage.
This forms a clock input from each FF, and the signal E becomes "■(" at time t, o, that is, 8 seconds after the alarm time t1, and then at time tto, 8 seconds after the alarm time t1.) At time t, 8 seconds after the signal F which becomes IN(J), the signal G which becomes rHJ is outputted.

At this time, the bell sound selection signal 200 is rLJ, and the inverted signal 202 by the inverter 74 is rHJ, so the signal E is inverted by the inverter 68 and becomes the signal H, and the signal F is inverted by the inverter 68. After being inverted by 7 degrees, the signal E is combined with the AND gate 64 to form the signal 2, and the signal G is further combined with the signal F through the OR gate 76 and the inverter 72 and the AND gate 66. is output as signal J, which causes
As shown by diagonal lines in FIG. 3, the switching signals H, I, and J are divided into three stages every 8 seconds from the alarm time t1, and the time ts.

Thereafter, it is output as the switching signal G to the attenuation control circuit 50 and the sound generation period selection circuit 56 described above. Therefore, in this embodiment, three different switching signals H1, J are output every 8 seconds from alarm time t, and signal G is output as a switching signal from tso 24 seconds after alarm time t1. These switching signals enable stepwise switching control of the sound sound intensity.

Next, the operation of switching the second electronic bell sound shown in FIG. 4 will be explained.

The selection of the second bell sound is performed by the user turning on the bell sound selection switch 30 manually, thereby causing the bell sound selection signal 2 of the chattering prevention circuit 32 to be turned on.
00 is rHJ, and as a result, its inverted signal 202 is rHJ.
Becomes LJ. Therefore, the AND gate 62.64 in FIG.
．． 66 are all gated off, and signals H, I, and J are not output. When the second bell tone is selected, the bell tone selection signal 200 is output from the OR gate 76, and the constant signal G becomes l'-Hj.

As described above, the sound intensity switching circuit 58 outputs different sound intensity switching signals selected by the bell sound selection switch 30 when the alarm is activated, and the attenuation control circuit 50 performs attenuation control according to these switching signals. . Then, the sounding period selection circuit 56 selects the sounding period according to the output of the sounding intensity switching circuit 58, and the sounding period selection circuit 56 is shown in FIG.
6 circuit configurations are shown. The selection circuit 56 is composed of AND gates 78, 80, 82 and NOR gates 84, 86, and after the alarm time, inverts the attenuation control signal K and the attenuation control signal obtained from the attenuation control circuit 50, which will be described later, for each of the four stages. The signal q is sequentially output, and in the figure, in the first stage of 8 seconds, the signal is inverted, and in the next 8 seconds, the signal q is output, and in the next 8 seconds, the dog is activated again at time ts.

Thereafter, the signal G is output as the sound generation period selection signal S to both attenuation modulation circuits 46 and 48.

FIG. 6 shows a preferred embodiment of the time signal control circuit 37 and the attenuation control circuit 70, and a timing chart thereof is shown in FIG. The time signal control circuit 37 is composed of the FF 51, and its clock input φ receives the I from the frequency dividing circuit 12.
A Hz signal is supplied, and a sound generation control signal r from a snooze control circuit 28 is supplied to the reset input. The signal at the output Q of the FF 51 is output as the time reporting start signal A, and the signal at the output Q of the F'F 51 is output as the selection blocking signal B.

The attenuation control circuit 50 includes eight stages of FFs 88 connected in series, the first stage FF 88-1 is supplied with the time signal start signal A from the time signal control circuit 37, and the FFs 88 sequentially start the inversion action from the alarm time t1. Row j1 This inversion timing is controlled by a pulse signal supplied to the clock input of each FF 88, and in this embodiment, four types of pulse signals f supplied from the frequency dividing circuit 12 are used as this pulse signal.

(16H2), f2 (32, Hz), f3 (64H2)
, f4 (128Hz) are selectively supplied, and in order to select these pulse signals
4.96 and an OR gate 98 are provided.

Each of the AND gates 9o to 9G is supplied with a signal from the aforementioned sound intensity switching circuit 58.
The inversion period of the FF group 88 is switched and controlled at 8 second intervals, thereby making it possible to change the period of attenuation change. The Q output of the final stage FF5s-s is supplied to one gate input of the bistable multivibrator 100, the output M of the multivibrator 100 is supplied to the reset input of each FF88, and the other gate input of the multivibrator 100. The output of the OR gate 98 is connected to the inverter 10.
2 as signal N. Therefore, F.F.
Group 88 is reset every eight clock inputs, and this reset period forms the period of attenuation change. Then, the output of the FF group 88 is the inverter group +
04, and its timing is based on the periodic attenuation control signal that sequentially switches to rLJ in response to the clock input as shown in FIG. 7, and the inverted signal K (K, ,
to form K6).

FIG. 8 shows a specific circuit configuration of the first attenuation modulation circuit 46. In this embodiment, two different audio frequency signals f4, f are used as attenuation control signals of the attenuation control circuit 50. The Ryokawa force signal subjected to the attenuation modulation is periodically modulated by the Ryokawa force signal, and the superimposed and supplied Ryokawa force signals are supplied to the sound generation circuit 40. Thereby, it is possible to obtain a pseudo electronic bell sound that approximates a conventional bell striking mechanism. By changing the period of the attenuation control signal described above as the alarm is activated, and further changing the sounding period using the selection signal S of the selection circuit 56, it is possible to increase the sounding intensity as the alarm is activated.

The first attenuation modulation circuit has a set of MOS transistors connected in parallel, but as in this embodiment, two types of audio frequency signals f4. As is clear from FIG. 8, this embodiment uses two M2S) transistor groups 10 to attenuate and modulate f.
6.108, MOS) transistor 106 of the embodiment
．． 108 each consists of a P-channel open drain connection, and the current value of the output signal changes depending on the combination of its on-operation resistance.

Nant gate sets 110 and 112 are connected to the gate inputs of each of the eight MOS) transistor sets 106 and 108, respectively, and audio frequency signals f4 and f! are connected to the inputs of each Nant gate 110 and 112, respectively. 1 is supplied,
Further, as control signals for attenuation modulation of this, the attenuation control signal of the attenuation control circuit 50 is supplied with the one sound generation period selection signal S1, the inverted signal 202 of the Pell tone selection signal 200, and the signal U that determines the auxiliary sound generation period. In the embodiment, the first audio frequency signal f4 is set to a frequency of 2 KHz, and the second audio frequency signal f is set to a frequency of 4 KHz.

In the embodiment, the signal U that determines the auxiliary sound generation period is set such that the first two stages from alarm activation are a 1-second intermittent sound followed by a 1-second pause period, and the third and fourth stages are set as follows: In this case, the sound generation period is controlled so as to remove the pause period and produce continuous sound, and for this purpose, the NOR gate 1 is supplied with the switching signals H and I of the sound intensity switching circuit 58.
14 and its output T with a switching signal C) 1
16, and its sound generation period control signal U is supplied to the four gates disposed on the downstream side of each Nantes gate 110, 112.

The output of each of the MOS transistor sets 106.1.08 is caused by the gate power V and W changing periodically, which turns off the transistors one after another.
The combined resistance of the transistor sets 106 and 108 is sequentially and periodically controlled to increase, and as a result, the current value of the output signal of the MOS transistor set gradually decreases. Therefore, by mixing this Ryokawa power signal in the wired or game (wired or game) 118 and supplying it to the sound generation circuit 40 as the drive control signal It is possible to perform a control action that changes sequentially as the process progresses.

9, 10, 11, and 12 respectively show the first electronic bell tone, that is, the drive signal to the sound generation circuit 4o that sequentially changes over four stages from the alarm time when the sound intensity is automatically changed according to this embodiment. The changing state of X is shown. At the time of selection, the inverted signal 202 is rHJ.
The attenuation modulation circuit 46 depends on its operating state.

FIG. 9 shows a first stage of 8 seconds from the alarm time, during which the switching signal c (2 second period) from the sound intensity switching circuit 58 is applied to the gate input U of the first damping modulation circuit 46.
During these 8 seconds, the basic sounding action is to repeat a 1-second intermittent sound followed by a 1-second pause.

Furthermore, the actual sounding period of this one second intermittent sounding period is further suppressed by the selection signal S of the sounding period selection circuit 56, and the time t3 further determined by the selection signal S from the intermittent sounding period t. ~t, and t6~t8
Intermittent pronunciation is possible only during a short period of time. During this short sounding period, the first attenuation modulation circuit 4
6 is a MOS) transistor group 106.108 whose synthesized sound resistance is in a high state, that is, two MOS) transistors 106-7, 106-8 and 108-7.108- in the final stage.
8 is in the ON state, the current value of the control signal be understood. Therefore, in the first stage immediately after the alarm time, the sound generation operation is performed quietly.

FIG. 1O shows the sounding operation in the second stage of 8 seconds after 8 seconds have elapsed from the alarm time; at this time, the auxiliary sounding period is still controlled by the signal U, so that A one-second intermittent sound followed by a one-second pause is repeated. Then, the actual sound generation period at this time is from time tit to t13, t, which is further determined by the sound generation period selection signal S during the one second sound generation period.
The sound generation operation is performed only during 14~tli, tlfi~t1□, and t18~tlO, and the attenuation control circuit 50 at this time
Since the cycle of the attenuation control is controlled by the pulse signal f of 32 Hz, the attenuation control is performed at half the cycle of the first stage. Since the four transistors in the latter stage contribute to the ON operation, the sound intensity also increases.

Therefore, in the second stage, it is possible to perform a sounding operation with a short cycle and a slightly reduced drive current and an increased sounding intensity during the sounding period every second.

FIG. 11 shows the sound generation operation in the third stage of 8 seconds after 6 seconds have elapsed from the alarm time, and at this time, the first attenuation modulation circuit 46 invalidates the signal C that determines the auxiliary sound generation period. , the sound generation period is an intermittent sound lasting 8 seconds, and the pause periods in the first and second stages have disappeared. The sound generation period is controlled only by the selection signal S, and the period of attenuation modulation at this time is also controlled by the 64Hz pulse f3, so the period of attenuation modulation is also short. Since the on-operation resistance of the six transistors in the latter stage is also used in 108, the driving current thereof is also increased, making it possible to obtain a sounding effect with even stronger sounding strength.

Furthermore, 24 seconds after the alarm time, as shown in FIG. 12, the auxiliary sound period control signal C and the sound period selection signal S both become 4, and the alarm operation continues until the alarm action is stopped. Continuous intermittent sound generation will be performed, and at this time, MOS) transistor group 106.108
Since the on-state resistance of all the transistors is used, the sound drive current increases significantly, and since the period of attenuation modulation at this time is controlled by the pulse f4 of 128H2, the intermittent period is also extremely short. This makes it possible to produce a sound effect with a large sound intensity and to obtain a reliable wake-up effect.

Although the sounding operation of the first electronic bell is performed as described above, in the present invention, the second N-th child bell can be further sounded by the second attenuation modulation circuit, and this second attenuation modulation circuit 48 A specific circuit configuration is shown in FIG.

As is clear from FIG. 13, the second attenuation modulation circuit 48 also has almost the same circuit configuration as the first attenuation modulation circuit 46, that is, two sets of MOS transistors 1201.
122, and each of these gate inputs is connected to a Nant gate group 124 and 126, respectively. and,
Audio frequency signals f4 and f are supplied to the inputs of each Nant gate set 124 and 126, respectively, and one sound period selection signal S1 is added to the attenuation control signal of the attenuation control circuit 50 as a control signal for attenuation modulating the signals. Sound selection signal 200
is supplied.

Therefore, when the bell sound selection switch 30 performs a second electronic bell, that is, a sounding operation with the sounding intensity set by the user, the bell sound selection signal 200 becomes rHJ, so the second attenuation modulation circuit 48 On the other hand, at this time, the inverted signal 2oz# remains low, so the first' attenuation modulation circuit 46 described above becomes ineffective.

The second attenuation modulation circuit 48 includes the first
Since the signal U that determines the auxiliary sound generation period in the attenuation modulation circuit 46 is not supplied, the second electronic bell tone performs a continuous sounding action without intermittent sounding every second. It is controlled by the period selection signal S to increase and change every 8 seconds. The sound intensity at this time can be further adjusted externally by the user using a sound intensity adjustment resistor 52 connected to the second attenuation modulation circuit 48, thereby selecting a desired electronic bell sound.

FIG. 14 shows a timing chart of the second attenuation modulation circuit 48, and it is understood that a continuous sounding effect can be obtained.

As described above, according to the present invention, two attenuation modulation circuits are provided to drive electronic bells with different sounding characteristics, and the user can arbitrarily select one of them by operating the bell sound selection switch. The advantage is that it is possible to set a desired electronic bell sound, and in the embodiment, the user can also arbitrarily adjust the sound intensity of one of the electronic bell sounds.

In the embodiments described above, since a snooze mechanism is provided, it is possible to perform a snooze effect on any of the electronic bell sounds, making it possible to obtain a multifunctional alarm clock. As explained above, according to the present invention, by attenuating and modulating the audible frequency signal, it is possible to obtain a complex tones that cannot be obtained with conventional electronic alarms, and in particular, it is possible to obtain complex tones that cannot be obtained with conventional electronic alarm sounds. It is possible to produce a sound similar to a bell sound by a bell-striking mechanism, and it is possible to improve the sound quality of an alarm clock.

Further, according to the present invention, the sounding intensity is gradually increased as the alarm operation progresses, so that the sounding intensity is quiet at first and then gradually increases, making it possible to obtain a comfortable and reliable wake-up effect.

Further, according to the present invention, since the attenuation modulation circuit MO8) is configured in multiple layers, the circuit can be integrated into an IC without using conventional resistors or the like, and a small and low-cost sounding circuit can be provided. It has the advantage of

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing a preferred embodiment of the electronic bell sound generation circuit according to the present invention, FIG. 2 is a specific circuit diagram of the sound intensity switching circuit in FIG. 1, and FIG. 2 is a timing chart, FIG. 5 is a specific circuit diagram of the sound generation period selection circuit in FIG. 1, FIG. 6 is a specific circuit diagram of the time signal control circuit and attenuation control circuit in FIG. Figure 7 is the timing chart diagram of Figure 6, Figure 8 is the timing chart of Figure 1.
The specific circuit diagram of the first attenuation modulation circuit in the figure, 9th% 10% 11.12 is the first attenuation modulation circuit in the present invention.
Timing chart showing the sound effect of the attenuation modulation circuit
13 is a specific circuit diagram of the second attenuation modulation circuit in FIG. 1, and FIG. 14 is a timing chart diagram of FIG. 13. 28... Bell sound selection control circuit, 30... Bell sound selection switch, 40... Sound generation circuit, 46... First attenuation modulation circuit, 48... Second attenuation modulation circuit, 50... Attenuation control circuit, 52...Sounding intensity adjustment resistor, 56...Sounding period selection circuit, 58...Sounding intensity switching circuit, 106.108, 20.122...MOS) transistor. De Q so Edoff ψQα2ζgusζri;
s0φN〉〉〉〉 ≧ ≧ 33 yo ta≧hama
-～Tsu? 1ψTo ~ 1S Q Electrician H Hifu ψ'<MM
"MYMM>>>>ψ tntos's -N1 punishment ψto's>>>>33 ≧ ≧≧ ≧ ≧ 3
ψ Gate's>>>>33 33":',";3 X
. Uni 1-: 5 +71 'lgζ base! ? Gutatatatayu! ■ 2545- Tata≧≧≧≧≧≧≧) 8

Claims (1)

[Claims] (1) first and second attenuation modulation circuits each having a group of at least two parallel-connected MOS) transistors and a gate circuit for supplying an audio frequency signal to the gate input of each MO8) transistor; Each MO of modulation circuit
8) A sound generation circuit that produces sound at a sound intensity corresponding to the composite on-resistance of the transistors, and a gate circuit for either one of the two attenuation modulation circuits, each MO8) Attenuation control for turning off the transistors periodically and sequentially. An attenuation control circuit that supplies the signal, and a signal that is supplied to the sound generation circuit by switching and selecting which MOS transistor in the first attenuation modulation circuit is to supply the attenuation control signal from the attenuation control circuit. a sounding period selection circuit that selects a sounding period and sounding intensity, and switching to the attenuation control circuit and the sounding period selection circuit to sequentially change the sounding intensity by changing the attenuation period and sounding period step by step from the alarm time. a sound generation intensity switching circuit that supplies a control signal; and a bell sound selection switch that controls selection of either one of the attenuation modulation circuits by the attenuation control circuit;
When the attenuation modulation circuit is selected, it periodically attenuates and changes the sounding intensity, and also changes the attenuation cycle and sounding period every certain period of time to generate a pseudo-bell sound whose sounding intensity changes, and selects the bell sound. 1. An electronic bell sound generation circuit for a watch, characterized in that when a second attenuation modulation circuit is selected by a switch, a pseudo bell sound whose sounding intensity is attenuated and changed periodically is generated. (2. In claim 1, a variable resistor is inserted between the second attenuation modulation circuit and the sound generation circuit, and the sound intensity is periodically attenuated and changed by varying the resistance value of the variable resistor. An electronic bell sound generation circuit for a watch, characterized in that the sounding intensity of the pseudo bell sound can be varied.