JPH0453320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an alarm chord generating device using a low-bit integrated circuit that generates an alarm sound containing a chord component.

[Conventional technology]

For the sound of an automobile horn, a two-tone chord with different fundamental frequency components is preferable to a clear single harmonic tone. In addition, the fundamental frequency component of each of the two sounds is set to approximately 200 to 700Hz, and the
It is desirable to set the sound pressure so that the main component of the sound pressure is a high-order overtone component within a frequency range of about 1 to 3 kHz, which is easy to hear. For example, when attempting to generate such a chord using a sounding device such as a piezoelectric horn that generates sound by being excited by electric vibrations, the following methods can be considered in the prior art.

That is, as shown in FIG. 2, two oscillation circuits 21a with different oscillation frequencies are used to create a chord.
21b, and frequency division modulation circuits 22a, 2 respectively.
2b, etc., to generate a unit pulse train P ₁ that includes the fundamental frequency component and contains many specific high-order harmonic components.
Make it output P ₂ . This technique was devised as a structure based on Japanese Patent Application Laid-Open No. 57-210395.

However, with this structure, two independent oscillation circuits and two modulation circuits must be provided, making the circuit configuration complex. It was difficult.

In order to solve the above problem, it would be possible to use a 4-bit class microcomputer to output two modulated pulse signals with different fundamental frequency components while calculating the timing. It is too sophisticated and expensive to be implemented in equipment.

The present inventors therefore believe that by using a low-bit, low-function, low-cost integrated circuit, the above problems can be solved at once. chords, (2) with a simple circuit configuration,
(3) We thought that it would be possible to generate electricity at a low cost.

[Problem that the invention seeks to solve]

However, 1, which is a typical example of a low-bit integrated circuit,
A bit microprocessor is a processor that processes one bit with one instruction, and is manufactured by Nippondenso Co., Ltd.
The NDP1010 and others are well known, but compared to 4- to 8-bit microprocessors, (1) logical operations can only be performed on a 1-bit basis;
Timing calculations such as executing a JUMP instruction are not possible.

(2) It is not possible to access two or more input/output ports at the same time.

(3) The memory capacity of a 1-bit microprocessor is generally small.

There are functional constraints such as this, and it is possible to output multiple signals with different fundamental frequency components with such a 1-bit microprocessor to essentially generate a chord, and also to fully exhibit the warning sound effect. was unthinkable.

Therefore, despite the above-mentioned limitations, the present invention provides a device that generates an alarm chord with a good tone using a low-bit integrated circuit, thereby creating a compact and low-cost alarm chord generating device that has sufficient performance. This makes it possible to realize the following.

[Means for solving problems]

For this purpose, the first invention uses a low-bit integrated circuit having a plurality of output ports, connects a plurality of semiconductor switching elements to the output port of the integrated circuit, and connects the semiconductor switching element to the output port of the integrated circuit. The apparatus is equipped with a sounding device that generates an alarm sound containing a substantial chord component based on the output of the sound generator.

The integrated circuit includes memory means for outputting a rectangular pulse train consisting of repeating low and high signals to the plurality of output ports based on a program. Moreover, the rectangular pulse train is
It consists of an example of a rectangular pulse including a plurality of fundamental frequency components that mutually form a substantial chord and high-order overtone components that are multiple times the fundamental frequency components.

Furthermore, the integrated circuit repeatedly outputs the information from the memory means to the plurality of output ports so that the ON or OFF inversion operation times of the semiconductor switching elements do not occur simultaneously;
It is programmed so that a substantially integral number of unit periods of each of the plurality of fundamental frequency components in the rectangular pulse train are included in one repetition period, that is, a chord period.

[Effect]

As a result, the following effects are achieved.

(1) The semiconductor switching element has the effect of amplifying the output from the integrated circuit and increasing the sound pressure of the sound generating device.

(2) Even with a rectangular pulse train consisting of repeating low and high signals, any sound can be produced by considering the timing of low and high and changing the pulse period and pulse shape. 1
It is possible to generate two tones and essentially generate a chord with these tones.

In other words, the idea of generating one tone with one rectangular continuous pulse train (also called a unit pulse train) is well known, but in the present invention, a plurality of such continuous pulse trains (unit pulse trains) are combined to generate a substantially chord. This is to ensure that the following occurs.

For example, each continuous pulse train (unit pulse train) that together produces a chord is also a rectangular pulse train, and these continuous pulse trains (unit pulse train)
Even if they are combined, it becomes a rectangular pulse train.
Furthermore, the continuous pulse train (unit pulse train) obtained by decomposing the synthesized rectangular pulse train is a pulse train containing one fundamental frequency component and a higher-order harmonic component, for example, three times or four times the fundamental frequency component. The shape of the pulse train is determined so that

In other words, this continuous pulse train (unit pulse train)
is not a continuous simple pulse (P ₃ in Figure 2), but 2ON, in order to have high-order harmonic components.
A unit pulse train with a pulse missing part in the pulse train, such as 1OFF, 3ON, 1OFF, or
This is a pulse width modulated unit pulse train.

(3) Due to functional limitations of low-bit integrated circuits, information from the memory means is repeatedly output to a plurality of output ports so that the semiconductor switching elements do not turn ON or OFF at the same time.

In other words, for example, out of two output ports, specify a low (also written as LO) or high (also written as HI) potential change to one output port with an odd address, and specify a low (also written as HI) potential change to the other output port with an even address. Alternatively, high is specified so that the semiconductor switching elements do not start operating at the same time.

(4) Since there is a limit to the capacity of the memory means in the integrated circuit, attention is paid to the chord period in order to continuously generate alarm sounds containing continuous chord components within this limit.

For example, the unit period of a continuous pulse train (unit pulse train) containing a fundamental frequency component of 400Hz is 1/400
= 0.0025sec or 2.5msec, and this 400
The unit period of a continuous pulse train (unit pulse train) containing a fundamental frequency component of 500 Hz that forms a chord with the Hz note is 1/500 = 0.002 sec, or 2 msec. Therefore, a period (for example, 2.5 x 4.2 x 5) that includes a substantial integer number of both unit periods (2.5 and 2)
is 10 msec, and the integers are 4 and 5. Of course, you can also set the integers to 8 and 10 and set it to 20msec),
Assuming that one cycle (chord cycle) is taken to access the output port from the memory means, a continuous alarm can be generated for an arbitrary long period of time by repeatedly accessing the output port.

If the unit period does not include a substantially integer number and becomes a completely indivisible number, no chord will be produced during some periods of repeated access, resulting in a deterioration in sound quality.

〔Effect of the invention〕

Due to the above-described configuration and operation, according to the first aspect of the present invention, it is possible to obtain a separately excited alarm chord generating device that generates a pleasant alarm sound that is substantially a chord, while having a small number of parts and being inexpensive. .

Low-bit integrated circuits are inexpensive, have stable quality compared to hard logic circuits, and have excellent features such as being easy to change specifications to change to any sound. It is possible to generate chords using a circuit, and it is possible to continuously generate pleasant sounds while minimizing the capacity of the memory means.

In addition, this sound contains high-order harmonic components that contribute to the sound pressure as frequency components that create a substantial chord with each other, so it has a powerful effect as an alarm sound, making it ideal for calling attention. There is.

Further, in the second aspect of the present invention, an alarm chord can be generated using an existing easily available low-bit microprocessor, and there is no need to use a dedicated integrated circuit.

Furthermore, both the first and second inventions have the advantage that tone settings can be easily set and changed by changing software.

〔Example〕

(First Embodiment) The output ports 2a and 2b of the 1-bit microprocessor 1, whose circuit diagram is shown in FIG. 1, are semiconductor switching devices such as transistors 3a and 3.
It is connected to the base of b. 1m is the memory means within a 1-bit microprocessor. The collector side of each of the transistors 3a, 3b is connected to the + side (13 [V], the terminal is indicated by the symbol B) of the power source via the primary side of the step-up transformer 4a, 4b. The step-up ratio of step-up transformers 4a and 4b is approximately 1:10, and piezoelectric sounding elements 5a and 5b are provided on the secondary side.
are connected. Although known piezoelectric sounding bodies 5a and 5b are used, it is also possible to use the piezoelectric sounding bodies 5a and 5b shown in FIG. 8 or 10, which will be described later.

The oscillation resistor 6 constituting the clock signal generator has a resistance of 1MΩ, and the resistance of the clock signal (frequency
fc=24KHz). The resistor 7, capacitor 8, and Zener diode 9 constitute a 5V power supply circuit for the 1-bit microprocessor 1. 5ab surrounded by a dashed line is a sounding device.

The program for the 1-bit microprocessor 1 is as shown in FIG.
It consists of instructions that specify LO and HI for a and 2b, and is set to repeat 240 instructions in one cycle. Also, since it can only process one bit at a time,
Consideration is given to specifying LO and HI to one output port 2a with an odd address and to the other output port 2b with an even address. One instruction is executed in one clock, and the execution time is 1/fc = 1/24kHz≒
It is 41.7 μsec, and the time for one round is 240×1/fc=
It is 10msec.

The details of the rectangular pulse train 50, which is the output signal from both output ports 2a and 2b, will be explained with reference to FIG. From the output port 2a, as shown in FIG.
1) A 2.5 msec pattern, that is, a continuous pulse train (unit pulse train) 501 is set to repeat four times. The unit period 511 is composed of three pulse trains having different HI times (pulse width modulated). From the output port 2b, a continuous pulse train (unit pulse train) 502 as shown in FIG.
12) is set so that a 2 msec pattern is repeated five times.

The broken line part in Figure 4 is shown in detail in Figure 5.
LO, HI timing (transistors 3a, 3b
OFF and ON timing) are shifted so that they do not occur at the same time. In Figure 5, 53
is the shift amount and is usually set to one clock period.

First, it will be explained that the first embodiment produces chords with good tone. The fundamental frequency ratio of the horn is 4:
It is known that it is desirable to set the ratio to 5 or 5:6. In addition to horn chords, chords with good tone are those whose fundamental frequency ratio is a simple natural number (1,
It is well known that the ratio is 2, 3, 4...). For example, "Domiso", which is known in the music field,
The fundamental frequency ratio of chords such as ``huarado'' and ``socire'' is 4:5:6.

The inventors believe that such a chord is
We focused on the fact that each has an apparent periodicity comparable to the least common multiple of unit periods. In other words, the unit period (reciprocal of the fundamental frequency) is 2.5msec (400Hz)
In the 4:5 chord of 2 msec (500 Hz), the relative relationships of each chord match every 10 msec, with the former being an integer 4 times and the latter being an integer 5 times, respectively. Hereinafter, this will be referred to as the "chord period" (numeral 52 in FIG. 4).

The relative relationship between the output signals from the output ports 2a and 2b can be set so that they repeat at the cycle of this chord, so it is not necessary to set the relative relationship between the output signals from the output ports 2a and 2b so that they repeat at the cycle of this chord. However, by programmatically storing the LO and HI patterns for the chord period and outputting them repeatedly, it is possible to produce chords continuously.

Therefore, in the first embodiment of the present invention, a rectangular pulse train (50 in FIG. 4) consisting of repeating low and high signals is output to a plurality of output ports of a 1-bit microprocessor based on a program. The rectangular pulse train 50 has a memory means (1 m in FIG. 1), and the rectangular pulse train 50 is made up of a rectangular pulse train including a plurality of fundamental frequency components that mutually form a substantial chord and high-order harmonic components that are multiple times the fundamental frequency components. The pulse width is modulated.

The 1-bit microprocessor then operates the semiconductor switching elements (3a, 3 in FIG. 1).
b) The information from the memory means 1m is repeatedly output to a plurality of output ports 2a, 2b so that the ON or OFF reversal operation timings do not occur at the same time, and this one repetition period, that is, the chord period (fourth
The unit period 51 of each of the plurality of fundamental frequency components in the rectangular pulse train 50 is shown in the reference numeral 52) in the figure.
1,512 is actually programmed to be included as an integer number.

In this case, the memory means is the least likely to cause a cycle corresponding to the least common multiple of the unit cycles 511 and 512 of the plurality of fundamental frequency components of the rectangular pulse train 50 to match the chord cycle 52.
It is clear that it becomes possible to implement the invention with a memory capacity of 1m.

Note that here, the semiconductor switching elements 3a, 3
The reason why the data from the memory means 1m is repeatedly outputted to the output ports 2a and 2b so that the reversal operation timings of ON and OFF of b do not occur at the same time will be explained. In this first embodiment, as shown in FIG. 3, the output port 2a is connected to an odd address, and the output port 2b is connected to an even address for LO and HI.
By setting the state to be switched, the OFF and ON timings of the transistors 3a and 3b are set so as not to occur at the same time.

In this way, even a low-function device such as a 1-bit microprocessor in which only one input/output port can be accessed with one instruction can process multiple continuous pulse trains (unit pulse trains) 501 and 501 with different fundamental frequency components. 502 can be output substantially simultaneously. In other words, the above-mentioned reason is that two continuous pulse trains (unit pulse trains) 501 and 502 can be output by one 1-bit microprocessor.

In this way, it is possible to generate a substantial chord with a 1-bit microprocessor,
Any LO and HI patterns may be set within each basic cycle, but the patterns shown in Figure 4a,
As in the first embodiment shown in FIG.
It is possible to generate a signal that contains the largest amount of third-order harmonic components among high-order harmonic components, and it is possible to generate an alarm sound with a particularly high sound pressure.

The frequency characteristics of the signals in FIG. 4b, ie, FIG. 5b, are shown in FIGS. 6a and 6d. Figure 6 shows the pulse waveform on the left and the frequency characteristics on the right, with a and b, b and e,
c and f correspond to each other. With the signal pattern shown in FIG. 6a, it is possible to adjust the timbre and sound pressure (in other words, adjust the frequency characteristics) by changing the width of each pulse.

This becomes clear when comparing the second and third embodiments described below with FIGS. 6a and 6d, which are the first embodiment.

(Second Embodiment) This second embodiment is the same as the first embodiment except that only the shape of the continuous pulse train (unit pulse train) is changed. In this second embodiment, as shown in FIG. 6b, the pulse width modulation is made smaller than in the first embodiment, so as shown in FIG.
It is possible to produce a sound with a higher sound pressure and containing more next harmonic components. Note that in FIG. 6, a is the pulse height value.

(Third Embodiment) Similarly to the second embodiment, the third embodiment differs only in the shape of the unit pulse train. In the third embodiment, the pulse width modulation is increased as shown in Figure 6c, so
A soft sound with a large fundamental frequency component I can be produced as shown in FIG. 6f.

(Fourth Example) The fourth example is a rectangular pulse train 50 as shown in FIG.
The rest is the same as the first embodiment. The one in Fig. 7 has a unit period of 511,5
Only the number of constant width pulses between 12 and 12 is manipulated, and in this case, it is particularly 2ON and 1OFF, and 5011 and 5021 are pulse missing parts. Also, in this figure 7, in addition to the fundamental frequency component, higher harmonic components (especially the 3rd harmonic component)
Contains a lot of.

Next, fifth and sixth embodiments in which only the piezoelectric horn of the first embodiment is changed will be described.

(Fifth Embodiment) In the first embodiment, a well-known piezoelectric sounding body was used, but the piezoelectric sounding body 5b of this fifth embodiment has a structure as shown in FIG. 8, for example, and has a resonance frequency of 500.
Hz, approx. 1.5KHz, the shape and material of each part,
The dimension O is set appropriately (an example of frequency characteristics is shown in FIG. 9). With such a frequency characteristic, the frequency component of the signal (unit pulse train) from the output port 2b in FIG. 1 matches the resonance frequency of the piezoelectric sounding body, so that sound can be generated efficiently. In FIG. 8, the sounding body 11 is made rigid by pasting a thin plate-shaped piezoelectric element 13 onto a diaphragm 12, and this sounding body 11 is set opposite to the opening of the housing 14. A housing 15 serving as a lid is attached to the opening of the housing 14, and the sounding plate 11 is fixedly held therein. In this case, the housing 15 has a large number of openings 16a, 16b...
The openings 16a, 16b, . . . function to release the sound generated in the sounding plate 11 to the outside, and an air layer 17 is formed corresponding to the housing 15. For example, in the bottom plate portion of the housing 14, a lead wire 1 is connected from a drive circuit 18 in which a step-up transformer 4b, a transistor 3b, etc. shown in FIG.
A sound generation drive signal is supplied via terminals 9 and 20.

Note that the other piezoelectric sounding body (corresponding to 5a in FIG. 1) of this fifth embodiment has the same structure as that in FIG. be.

(Sixth Example) Next, a pair of piezoelectric sounding bodies (5a, 5 in FIG.
If b) is integrated into the structure shown in Figure 10, for example, a single horn can generate a chord similar to the sound of two horns sounded simultaneously, and it can be installed in a vehicle. It is possible to save space and reduce weight. In addition, in Fig. 10, the first
The second sounding bodies 31 and 32 are set to face each other so as to be parallel to each other. This first
The second sounding plates 31 and 32 correspond to the piezoelectric sounding bodies 5a and 5b shown in FIG. It is constructed by laminating thin disk-shaped piezoelectric elements 35 and 36 on the substrate. Here, the dimensions of the piezoelectric elements 35 and 36 are 42φ×0.3
The diaphragm 33 is made of Kovar (product name: high nickel alloy manufactured by Nippon Mining Co., Ltd.), and the diaphragm 34 is made of brass, and their dimensions are 90φ x 0.2mm. Set.

The first and second sound boards 3 set opposite each other
The outer peripheries of each of 1 and 32 are adhesively fixed to a ring 37 made of synthetic resin. Air chamber 38
The first and second sounding plates 31 and 32 including this air chamber 38
Accordingly, the sound generating member 39 is constructed.

Lead wires 40 supply driving current to the first and second sounding boards 31 and 32.
a, 40b and 41a, 41b are each independently connected to the drive circuit 42. In this case, the lead wires 40a, 40b of the first sounding board 31 are formed on the ring 37, although not particularly shown in the figure. It is guided to the drive circuit 42 portion through the groove formed by the groove.

The ring 37 constituting the sound generating member 39 includes:
A plurality of, for example, four recesses 37a (only one is visible in the figure) are formed, and a support member 43a made of rubber is fitted into each recess 37a. Be sure to install it against the inside wall. Then, the sounding member 39 is connected to the housing 4
4, so that it can be elastically held and set inside. Here, the housing 44 is composed of a main body part 44a and a lid part 44b that is adhesively fixed to the opening part of the main body part 44a, and the support member 43
a are fitted into recesses formed around the opening of the main body part 44a, and these are fitted into the recesses formed on the periphery of the opening of the main body part 44a.
4b is used to set the pressing force.

Here, the ring 3 constituting the sounding member 39 is
By setting the outer diameter of the ring 37 to 93 mm and the inner diameter of the housing 44 to 100 mm, a ring-shaped acoustic passage 45 having a length h and a width y extending all the way around the outer circumference of the ring 37 is formed. It's becoming like that.
Further, the first sounding plate 31 of the sounding member 39,
A front air layer 46 with a thickness ha=11 mm is formed between the front plate of the lid part 44b of the housing 44, and further between the second sounding plate 32 and the bottom plate of the main body part 44a of the housing 44. , a rear air layer 47 having a thickness R=5 mm is formed.

The front plate portion of the lid portion 44b of the housing 44 has a diameter of 4.8 mm distributed toward the outside.
For example, 48 openings 48a, 48b...
It forms.

It is known that in order to provide resonance in the low frequency range in such a sound generating device, the diameter of the vibrating portion may be set large, the plate thickness thereof may be made thin, and the outer peripheral portion may be fixed. In the sound generating device shown in the above embodiment, by setting each dimension value as described above, the primary resonance frequencies of the sound plates 31 and 32 are set to approximately 400 Hz and approximately 500 Hz, respectively. be able to.

(Seventh Embodiment) In the first and second embodiments, the output signals from the output ports 2a and 2b in FIG.
Other overtone components may be maximized depending on the frequency characteristics of b. For example, FIGS. 11a and 11b show an example of a rectangular pulse train when the fourth harmonic component is set to the maximum. As in this example, output port 2a,
The pattern of the output signal (unit pulse train) from each of 2b may be made different.

(Eighth Example) In each of the above examples, a chord consisting of two notes was used, but
A triple chord may also be created using the three output ports of a 1-bit microprocessor. For example, the unit period is 2.5msec (400Hz), 2msec (500Hz),
Even if it is an actual 4:5:6 chord of 1.67 msec (600 Hz), the chord period is actually 10 msec.

(Ninth Embodiment) In the above embodiment, each output port 2a, 2
The output signals from b were unit pulse trains each having independent fundamental frequency components. That is, each 2 of the output ports of a 1-bit microprocessor 1
a, 2b have different fundamental frequency components for each output port, for example, in FIGS. 4 and 7.
As shown in FIG. 11, unit pulse trains 501, 50
A rectangular pulse train 50 is output after being separated into 2 pulses.
The fundamental frequency components of the respective unit pulse trains (501 and 502) were different between one output port 2a and the other output port 2b.

However, in this ninth embodiment, a rectangular pulse train obtained by adding and subtracting two unit pulse trains is devised, and the plus side and minus side of this rectangular pulse train are outputted from two output ports 2a and 2b (FIG. 13). Two transistors are switched and driven using the PUSH and PULL method. (According to the theory of Fourier series, the frequency component does not change even if addition or subtraction is performed.) The output signal from the output port in this case, that is, the rectangular pulse train is shown in FIGS. 12a and 12b. In this example, from the unit pulse train 501 in FIG. 7a, FIG.
The 12th pulse train obtained by subtracting the unit pulse train 502 of
The plus side of the pulse waveform in FIG. 13 is outputted from the output port 2a in FIG. 13, and the minus side is outputted from the output port 2b in FIG.

In this case, the memory means of the 1-bit microprocessor is programmed with unit pulse trains 501 and 502 having different fundamental frequency components subtracted from each other, that is, combined. Note that it is also possible to perform composition by addition instead of subtraction.

Furthermore, in this case, as shown in FIG. 13, in the drive circuit, the step-up transformer 4 may be a transformer with an intermediate tap, and the neutral point 4c on the primary side may be used as a common terminal (intermediate tap). Also, in this case, the chord period of 100Hz (=
10msec) harmonic distortion occurs and the tone deteriorates, but the intermediate tap 4c on the primary side of the transformer 4
and the primary input terminal has a diode 10 between 4a and 4b.
This can be prevented by inserting parts a and 10b.

(Tenth Embodiment) Furthermore, in the ninth embodiment, the two piezoelectric diaphragms 5a, 5b are connected to the secondary terminals 4a2, 4b of the transformer.
2 are connected in parallel, but if a piezoelectric diaphragm with a wide resonance bandwidth or a well-known speaker driven by electromagnetic force is used, it is also possible to use a single sounding body.

(Other Examples) In the example described above, the fundamental frequency components of the chord are 400Hz and 500Hz, but the frequency can be changed arbitrarily by changing the value of the oscillation resistor 6 shown in FIGS. 2 and 13. Can be set to Also, the fundamental frequency ratio is not only 4:5 or 5:6 but also 3:4 or 6:7.
Alternatively, the ratio may be 5:7, etc., as long as it is a substantially natural number ratio.

Further, the sounding device can be implemented without a step-up transformer, and instead of using a piezoelectric sounding body, for example, a speaker having a voice coil can be used.

Furthermore, although the eighth embodiment is not shown, the 1-bit microprocessor has three output ports, one transistor is connected to each output port, and a transistor is connected between the collector of the transistor and ground. It has a normal transformer without an intermediate tap connected to each, and a total of three piezoelectric sounding bodies connected to each of the transformers.

[Brief explanation of drawings]

FIG. 1 is an alarm chord generation circuit diagram in a first embodiment of the device of the present invention, FIG. 2 is a block diagram illustrating an alarm chord generation circuit based on the prior art, and FIG. 3 is a 1-bit microcomputer circuit diagram in the first embodiment. 4 is a waveform diagram of an example of a rectangular pulse serving as a drive signal in the first embodiment; FIG. 5 is a detailed waveform diagram showing the timing of the drive signal in the first embodiment; FIG. 6a, b, c, d, e, f are the first
The waveform diagram of the drive signal and the frequency characteristic diagram of the waveform in the embodiment to the third embodiment, FIG.
A drive signal waveform diagram in the embodiment, FIG. 8 is a sectional view showing the structural side of the piezoelectric sounding body in the fifth embodiment,
FIG. 9 is a frequency characteristic diagram of the piezoelectric sounding body of the fifth embodiment, FIG. 10 is a sectional view showing a structural example of the piezoelectric sounding body of the sixth embodiment, and FIG. 11 is a drive signal waveform diagram of the seventh embodiment. , FIG. 12 is a drive signal waveform diagram in the ninth embodiment, and FIG. 13 is an alarm chord generation circuit diagram in the ninth embodiment. 2a, 2b...Output port, 1...1-bit microprocessor, 3a, 3b...Semiconductor switching element, 5ab...Sound generating device, 1m...Memory means, 50...Rectangular pulse train, I...Fundamental frequency Component,...Third harmonic component which becomes a high order harmonic component, 52...Chord period, 511,512...Unit period, 4a, 4b...Step-up transformer, 5a, 5b
... Piezoelectric sounding body, 4a ... Middle tap, 4a1,
4b1...Primary input terminal, 4a2, 4b2...2
Next terminal, 44...A housing with an integrated piezoelectric sounding body, 10a, 10b...Diode.

Claims (1)

[Scope of Claims] 1. A low-bit integrated circuit having a plurality of output ports, a plurality of semiconductor switching devices connected to the output ports of the integrated circuit, and and a sounding device that generates a warning sound including a chord component, the integrated circuit having a plurality of output ports,
It has a memory means for outputting a rectangular pulse train consisting of repeating low and high signals based on a program, and the rectangular pulse train includes a plurality of fundamental frequency components that mutually form a substantial chord and a high frequency component that is multiple times the fundamental frequency component. consisting of a rectangular pulse train including a next harmonic component, and the integrated circuit repeatedly outputs information from the memory means to the plurality of output ports so that the switching operation timings of the semiconductor switching elements to ON or OFF do not occur at the same time. and the alarm chord is programmed so that each unit period of each of the plurality of fundamental frequency components in the rectangular pulse train is substantially rectified in one repetition period, that is, one chord period. Generator. 2. The alarm chord generating device according to claim 1, wherein a period corresponding to the least common multiple of the unit period of the plurality of fundamental frequency components of the rectangular pulse train matches the chord period. 3. The alarm chord generating device according to claim 1, wherein the sounding device includes a step-up transformer connected to the semiconductor switching element and a piezoelectric sounding body connected to the step-up transformer. Device. 4. The step-up transformer consists of one pair, each connected to the semiconductor switching element, and the piezoelectric sounding body also has a different resonance frequency.
4. The alarm chord generating device according to claim 3, wherein the alarm chord generating device comprises a pair and is connected to each step-up transformer. 5. The step-up transformer consists of one transformer with an intermediate tap, has an intermediate tap on the primary side of the transformer, has primary input terminals on both sides of the intermediate tap, and connects each of the pair of semiconductor switching elements. 4. The alarm chord generating device according to claim 3, wherein the piezoelectric sounding body is connected to the primary input terminal, and the piezoelectric sounding body is connected to both ends of the secondary terminal of the transformer. 6. The alarm chord generating device according to claim 5, wherein the piezoelectric sounding body is constructed by connecting a pair of piezoelectric sounding bodies in parallel, each having a different resonance frequency. 7. The alarm chord generating device according to claim 6, wherein the pair of piezoelectric sounding bodies are integrally housed in a single housing. 8. The alarm according to claim 5, wherein diodes for absorbing kickback voltage are connected between the intermediate tap on the primary side of the intermediate tap-equipped transformer and the pair of primary input terminals, respectively. Chord generator. 9. Each of the output ports of the integrated circuit includes:
The rectangular pulse train is output after being separated into unit pulse trains having different fundamental frequency components for each output port, and the fundamental frequency components of the unit pulse trains are different between one output port and the other output port. The alarm chord generating device according to claim 1, which is different from the above. 10. Claim 1, characterized in that the memory means of the integrated circuit is programmed with unit pulse trains having different fundamental frequency components added or subtracted from each other, that is, synthesized.
The alarm chord generator described in Section 1. 11. An alarm chord generator comprising an integrated circuit having memory means for storing programmed data, the integrated circuit comprising: a clock signal generator for providing a plurality of clock signals of predetermined frequencies;
microprocessor means for executing said program; at least two output ports for outputting low and high signals forming a rectangular pulse train; and a plurality of addresses, one of said addresses having said low and high signals. said memory means in which one of said data is stored which is used as an instruction to generate a signal at one of said output ports, said memory means being controlled by said rectangular pulse train from said output port of said integrated circuit; ,plural
It has a semiconductor switching element that generates ON and OFF signals, and the ON and OFF signals from the semiconductor switching element
a sound generating device comprising at least first and second tone generating elements driven by an OFF signal to generate chords; An alarm chord generating device characterized in that it determines whether to generate the high signal or to generate the high signal.