JPH0570350B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intercom calling circuit, and more particularly to an intercom calling circuit that outputs a chime sound composed of electronic sounds.

[Prior Art] Conventionally, the calling circuit of an intercom is a chime sound generating circuit shown in Fig. 4 (Japanese Patent Publication No. 56-49359).
It is known to use a chime tone composed of as a ring tone. The chime sound generation circuit shown in FIG. 4 includes a basic oscillation circuit 1 that creates a pseudo chime sound;
Monostable multivibrator circuit 2, attenuation circuit 3,
It is composed of a power supply time limit circuit 4.

When the ring activation switch S is operated, the power supply time limit circuit 4 is activated and the chime sound transmission time is determined.
When the power supply time limit circuit 4 is activated, power is supplied to the basic oscillation circuit 1, the monostable multivibrator circuit 2, and the amplifier A, which generate a pseudo chime sound.
Turning on transistors Q ₂ and Q ₃ with a time constant including capacitor C ₅ of this monostable multivibrator circuit 2,
The off operation is determined, the bias circuit of diodes D ₅ and D ₆ is formed or cut off, the resistor R ₁ that constitutes the oscillation constant is shorted or opened, and the oscillation frequency is switched from the first sound to the second sound. It will be done. The two-frequency oscillation frequency receives a predetermined attenuation in the attenuation circuit 3,
A chime sound is sent from speaker SP. In addition,
In FIG. 4, symbols R ₁ to R ₂₃ are resistors, C ₁ to _{C 11} are capacitors, Q ₁ to _{Q 6} are transistors, and D ₁ to _{D 9} are diodes.

[Problems to be Solved by the Invention] This chime sound generation circuit oscillates and organizes the first and second sounds in an analog manner using wiring logic, so it is susceptible to variations in the characteristics of circuit elements. Furthermore, there are other drawbacks such as the large number of parts and the inability to obtain a stable chime sound.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and provides an intercom that can send out a chime sound with excellent pitch by generating and attenuating a chime sound consisting of first and second sounds using a digital variable resistor. The purpose is to provide a calling circuit for.

[Means for Solving the Problems] In order to achieve this object, the intercom calling circuit according to the present invention includes a calling button and a chime sound that generates a chime sound consisting of a first sound and a second sound in response to the operation of the call button. In an intercom calling circuit that includes a sound generation circuit and a speaker into which a chime sound is input, the chime sound generation circuit includes a microcomputer that starts control in response to operation of a call button, and a plurality of control terminals of the microcomputer. and a digital variable resistor consisting of multiple resistors connected between each speaker, and a digital variable resistor that is built into a microcomputer and attenuates by opening and closing multiple control terminals according to a preset order. The attenuation amount increases in order from the minimum attenuation value to the maximum attenuation value, the first attenuation value, the second attenuation value, the third attenuation value, ... n-th attenuation value.
1 attenuation value, an n-th attenuation value, the first attenuation value and the n-th attenuation value, the second attenuation value and the n-th attenuation value..., the (n-1)th attenuation value and the n-th attenuation value. Each of the attenuation values is alternately repeated, and the attenuation value alternately repeated with the n-th attenuation value is changed from the first attenuation value to the second attenuation value...n-th attenuation value.
The apparatus includes a switching means that generates a chime sound by sequentially switching so that the amount of attenuation increases sequentially to an attenuation value of -1.

[Embodiment of the Invention] Hereinafter, an embodiment of a calling circuit for an intercom according to the present invention will be described in detail with reference to the drawings.

In Fig. 1, the intercom calling circuit is as follows:
It is equipped with a call button SW, a chime sound generation circuit to be described later that generates a chime sound consisting of a first sound and a second sound in response to the operation of the call button SW, and a speaker 16 into which this chime sound is input. .

This chime sound generation circuit is connected between a microcomputer 10 that starts control in response to the operation of a call button SW, and a plurality of control terminals L ₁ , L ₂ , L ₄ , L ₈ of the microcomputer and a speaker 16. It has a digital variable resistor 11.

The digital variable resistor 11 has a plurality of resistors 1
1a, 11b, 11c, and 11d are connected to a plurality of control terminals _L1 , _L2 , _L4 , and _L8 of the microcomputer 10, a resistor 12 is connected to the power supply B side, and a resistor 13 is connected to the reference potential side. A plurality of resistors 11a, 1
The connection points of 1b, 11c, 11d, 12, and 13 are connected to the input side of an amplifier 15 via a capacitor 19. The power supply of amplifier 15 is transistor 1
The voltage is supplied via the emitter and collector by turning on and off 4. Transistor 14 is controlled from control port 04 of microcomputer 10.
The microcomputer 10 has power terminals 01 and 0.
Power supply B is supplied from 2. This power supply is stabilized by a Zener diode 23. Clock terminal x ₁ ,
A clock from capacitors 20, 21 and an oscillator 22 is applied from _X2 , and an input port resistor 18 is connected to the input port 03, so that a call signal is sent out when the call button SW is pressed.

Further, the chime sound generating circuit is built in the microcomputer 10 and is connected to a plurality of control terminals L ₁ ,
The resistances 11a, 11b, 11c, and 11d of the digital variable resistor 11 are changed by opening and closing L ₂ , L ₄ , and L ₈ .
As shown in FIG. 3, the first attenuation value CSW ₀ , the second attenuation value CSW ₁ , and the third
, a 15th attenuation value CSW ₁₄ , _and a 16th attenuation value CSW ₁₅ .

Furthermore, this chime sound generation circuit has a first attenuation value CSW ₀ , a sixteenth attenuation value CSW ₁₅ , and a second attenuation value CSW 15.
CSW ₁ and the 16th attenuation value CSW ₁₅ ..., the 15th attenuation value
CSW ₁₄ and the 16th attenuation value CSW ₁₅ are alternately repeated, and the attenuation values alternately repeated with the 16th attenuation value CSW ₁₅ are changed from the first attenuation value CSW ₁ to the second attenuation value CSW ₂ . It has a switching means that generates a chime sound by sequentially switching the attenuation amount to increase in order to the attenuation value _CSW14 of 15.

When the microcomputer 10 operates the call button SW, a signal is input to the input port 03 and control starts. The microcomputer 10 incorporates a chime sound sending program 25 shown in FIG. 2 as a chime sound sending means.

When the call button SW is operated, the chime sound sending program 25 is executed, and in process 26, a plurality of control terminals L ₁ , L ₂ , L ₄ , and L ₈ are controlled to open and close, and the resistors 11a and 11b of the digital variable resistor 11 are controlled to open and close. ,11
A chime sound of 650Hz corresponding to the first sound is generated by opening and closing (switching) c and 11d.
At the same time, the chime sound of 650Hz is output from 0 to 750mS in accordance with the preset order of resistors 11a, 11b, 11c, 11
d is controlled by a first damping control subroutine 28.
Judgment box 27 determines whether 750mS has elapsed, and when 750mS has elapsed, multiple control terminals are
L ₁ , L ₂ , L ₄ , L ₈ are controlled to open and close, and resistors 11a, 11b, 11c of the digital variable resistor 11,
By opening and closing (switching) 11d, a 512Hz chime sound corresponding to the second sound is generated. At the same time, the digital variable resistor 1 is
1 resistors 11a, 11b, 11c, and 11d.

[Operation of the Invention] In the intercom call circuit configured as described above, when the call button SW is pressed, a signal is sent to the input port 03 of the microcomputer 10. This makes the control port 04 active and supplies power to the amplifier 15. At the same time, the chime sound sending program 25 is executed, and the chime sound of 650Hz is transmitted to the resistor 11 of the digital variable resistor 11.
a, 11b, 11c, and 11d, and a chiming sound of 512 Hz is generated from the digital variable resistor 11.
It is generated from the resistors 11a, 11b, 11c, and 11d. Note that the resistors 11a to 11d are the resistors 11a
is the lowest, and increases in the order of resistance 11b and resistance 11c, and resistance 11d is the highest. As shown in Figure 3, the transmission time of the first sound τ ₁ is 750 mS, and the transmission time of the second sound is 750 mS.
The sound transmission time τ ₂ is 1860 mS.

The microcomputer 10 is replaced with a switch, and the microcomputer 10 connects the control terminals L ₁ , L ₂ ,
To explain the execution of the first attenuation control subroutine 28 and the second attenuation control subroutine 31 as those that switch L ₄ and L ₈ , the attenuation value CSW ₀ is set at all of the plurality of control terminals L ₁ , L ₂ , L ₄ , L ₈ is in the open state and the amount of attenuation is the minimum. Attenuation value CSW ₁ is a state in which the control terminal L ₁ is closed and the other control terminals L ₂ , L ₄ , and L ₈ are open.

Hereinafter, the opening and closing of the plurality of control terminals L ₁ , L ₂ , L ₄ , and L ₈ are combined so that the attenuation increases in order,
Attenuation value CSW ₁₄ is a state in which control terminals L ₂ , L ₄ , and L ₈ are closed and only control terminal L ₁ is open. The attenuation value CSW ₁₅ has a maximum attenuation amount when the control terminals L ₁ , L ₂ , L ₄ , and L ₈ are closed. As shown in FIG. 3, for example, when the second attenuation control subroutine 31 of the chime sound sending program 25 is executed,
Attenuation values CSW ₀ and CSW ₁₅ are alternately repeated at the frequency of the second sound of 512Hz, and a chime sound of 512Hz is created from the resistances 11a, 11b, 11c, and 11d of the digital variable resistor 11, and the first chime sound of the second sound is Attenuation control is performed. Next, the attenuation values CSW ₁ and CSW ₁₅ are repeated alternately at the frequency of the second sound, 512 Hz.
A chime sound of Hz is created, and the second attenuation control is executed. In this way, the program is executed sequentially, and in the last run the damping value CSW ₁₄ and
CSW ₁₅ is executed alternately and repeatedly at the second sound frequency of 512Hz, creating a chime sound also at 512Hz,
The amount of attenuation is maximum. For the sake of explanation, the second chime sound
Although the generation and attenuation of sound have been explained, the first sound is also generated and attenuated in the same way as the second sound, but the attenuation value is alternately repeated at a frequency of 650 Hz. In addition, in the above example, the resistance 11 of the digital variable resistor 11
a, 11b, 11c, 11d are a plurality of control terminals L ₁ , L ₂ , L ₄ ,
The explanation has been made assuming that the combination of _L8 switching has values from the minimum attenuation value CSW ₀ to the maximum attenuation value CSW ₁₅ in which the attenuation amount increases in order, but the first attenuation value, the second attenuation value , a third attenuation value, an (n-1)th attenuation value, and an n-th attenuation value (n is a positive integer).

[Effects of the Invention] As is clear from the above description, the intercom calling circuit according to the present invention can open and close a plurality of control terminals in accordance with a preset order to generate a digital variable resistor consisting of a plurality of resistors. is the first attenuation value, the second attenuation value, and the third attenuation value from the attenuation value with the minimum attenuation amount to the maximum attenuation value of the attenuation amount in which the attenuation amount increases in order.
, an n-1th attenuation value, an n-th attenuation value, a first attenuation value, an n-th attenuation value, a second attenuation value and an n-th attenuation value..., an n-1th attenuation value. and the n-th attenuation value alternately, and the attenuation value alternately repeated with the n-th attenuation value is changed from the first attenuation value to the second attenuation value.
Attenuation value...The number of time constant components such as capacitors and resistors is reduced by providing a switching means that generates a chime sound by sequentially switching the attenuation amount to increase sequentially to the n-1th attenuation value. Moreover, it is not necessary to provide adjustment members corresponding to changes in temperature and manufacturing characteristics of capacitors, resistors, etc., and a stable chime sound can be generated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an intercom calling circuit according to the present invention, FIG. 2 is a flowchart of a chime sound transmission program related to FIG. 1, and FIG. 3 is a chime sound waveform diagram of FIG. FIG. 4 is a circuit diagram of a conventional intercom calling device. 11...Digital variable resistor, 11a, 11b,
11c, 11d...Multiple resistors, SW...Call button, SP...Speaker, 10...Microcomputer, _L1 , _L2 , _L4 , _L8 ...Multiple control terminals, CSW ₀ ...
First attenuation value (minimum attenuation value), CSW ₁ ...
Second attenuation value, CSW ₂ ...Third attenuation value, ...CSW ₁₄
... n-1th attenuation value, CSW ₁₅ ... nth attenuation value (attenuation value with maximum attenuation amount).

Claims (1)

[Claims] 1. Calling of an intercom comprising a call button SW, a chime sound generation circuit that generates a chime sound consisting of a first sound and a second sound in response to the operation of the call button, and a speaker 16 into which the chime sound is input. In the circuit, the chime sound generating circuit includes:
A plurality of resistors 11a each connected between a microcomputer 10 that starts control in response to the operation of the call button, a plurality of control terminals L ₁ , L ₂ , L ₄ , L ₈ of the microcomputer, and the speaker. , 11b, 11c, and 11d, and the plurality of control terminals L ₁ , L ₂ , L ₄ , and L ₈ are opened and closed in accordance with a preset order built into the microcomputer. The digital variable resistor has a first attenuation value CSW _{0 , a second attenuation value CSW 1 from} the attenuation value with the minimum attenuation amount to the attenuation value with the maximum attenuation amount in which the amount of attenuation increases in order.
Third attenuation value CSW ₂ ,...n-1st attenuation value
CSW ₁₄ has an n-th attenuation value CSW ₁₅ , and the first
the attenuation value CSW ₀ and the nth attenuation value CSW ₁₅ , the second
the attenuation value CSW ₁ and the n-th attenuation value CSW ₁₅ ..., the n-1 attenuation value CSW ₁₄ and the n-th attenuation value CSW ₁₅ are alternately repeated, and the n-th attenuation value
CSW ₁₅ and the attenuation values alternately repeated from the first attenuation value CSW ₁ to the second attenuation value CSW ₂ ... n-1th
and switching means for generating the chime sound by sequentially switching so that the attenuation amount increases sequentially to an attenuation value CSW ₁₄ .