JPS63135056A - Interphone system - Google Patents

Abstract

PURPOSE:To attain a smooth calling without causing the sense of disorder by allowing a calling line discrimination circuit provided to both a master set and a submaster set to set the gain of an amplifier circuit at calling between the master set and the submaster set to a value lower than the gain at calling between the master set or the submaster set and the slave set. CONSTITUTION:The gain GA of transmission amplifiers 21, 41 provided corresponding to each of interphone circuits 2, 4 is kept to a prescribed value when the calling line between the master set A (or submaster set B) and a slave set C is closed and lowered when the talking line between the master set A and the submaster set B is closed, while the gain GB of reception amplifiers 22, 24 is kept to a prescribed value at the closing of the talking line to control the received sound volume uniformly. Thus, the reception sound volume at the calling between the master set and the submaster set and between the master set or the submaster set and the slave set is made nearly the same to eliminate the ununiformity at calling of the system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to improvements in intercom systems used in housing information systems and the like.

[Background technology]

This type of intercom system has main unit A, sub unit A, and sub unit A, as shown in Fig. 6. The configuration is such that communication lines can be switched and connected between three parties, 1aB and slave unit C, to communicate with each other, but due to the system configuration, only base unit A has a power supply circuit, and one sub-FF unit has a power supply circuit. B and Magic C receive power supply from the parent iA when the telephone line is closed. Also, main unit A and secondary mirror 8! B includes similar transmitting and receiving amplifiers 100a and 100 in order to amplify the volume during transmitting and receiving to an appropriate level.
Although the amplifier circuits 100, 100 having the same characteristics as those shown in FIG. For example, in the system currently in practical use, the base unit has a DC12V power supply, and this base unit A
When the telephone line between the base unit A or the sub base unit B and the sub base unit B is closed, a voltage of approximately DCIOV is generated in the call line, and a voltage of approximately DCIOV is generated between the base unit A or the sub base unit B and the magic trick C.
When the communication line between the two parties is closed, a voltage of approximately DC6V is generated in the communication line, so the other party of the communication can be identified by the difference in these voltage levels.

However, in such a system, when a communication line is formed between base unit A and magic C, the voltage level AO sent from base unit A to magic C is higher than that of magic C.
Since the voltage level BO output to BO is significantly higher than the voltage level BO outputted to BO, when the communication line between 1A and C is closed, the same voltage level that base unit A was outputting to C is When outputting to the sub-base unit B, the volume of the received voice signal increases significantly, resulting in an unbalanced situation.

FIG. 7 explains this principle. When the call line between base unit A and magic trick C is now closed, base unit A inputs the transmitting volume of S, and uses the transmitting amplifier 100a to perform the magic trick. Considering a system in which a voltage at the AO level is output from the magic trick C, and a voltage at the BO level is output from the magic trick C, which is amplified by the receiving amplifier 100b on the 1uaA side to obtain a listening volume of S, l, as it is, the telephone line As shown in Fig. 8, when the connection is switched between the main unit A and the sub-base unit B, the main unit A, the sub-base unit! If J1 machine B outputs the 1st transmission sound of the same level, at this time the amplifier circuit 100 on the other side will output Ao, Ao'
, the outputs of the sub-base unit B can be considered to be approximately the same, so in this case Ao = Ao'), so the output of the sub-base unit B,
The listening volume of each MimA is determined by each receiving amplifier 10.
It is amplified by 0b and 100b to become S
It can be seen that S□=SRA>>SR), resulting in non-uniformity in system calls.

[Purpose of the invention]

The present invention was developed in view of the above problems, and
An intercom system that eliminates unevenness during system calls by making the listening volume approximately the same during calls between the main unit, sub-base unit, and between the base unit or sub-base unit and magic, thereby making smooth calls possible. is intended to provide.

[Disclosure of the invention]

The present invention proposed to achieve the above object is an intercom system in which mutual communication is possible between a base unit, a sub-base unit, and a magic machine, in which each of the base unit and sub-base unit is provided with a transmitter,
An amplifier circuit consisting of a pair of transmitting and receiving amplifiers provided corresponding to the receiver, a call line discrimination circuit that discriminates the other party based on the voltage level generated in the closed call line during a call, and a discrimination signal from this discrimination circuit. Due to the above amplification circuit (
The intercom circuit includes gain control means for controlling the gain of one or more corresponding amplifiers in two stages, and the call line discriminating circuit closes the call line between the main unit and the sub-base unit. When this is detected, the gain of the amplifier of each of the amplifier circuits is lowered than when the communication line between each of the machine a, the sub-IIIm and the magician is closed.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 to 3 illustrate a first embodiment of the present invention.

Figure 1 is a schematic configuration diagram of the system, where A is the main unit, B
indicates a submaster unit, and C indicates a magic trick. As shown in the figure, the base unit A and the subbase unit B have similar handsets 1°3 with a transmitter T and a receiver R, and an intercom circuit 2.
．． 4, and is configured so that each handset 1, 3 can be picked up to call the other party and talk to each other. Magic trick C is equipped with a microphone M and a speaker SP,
By operating the call button 5, the main unit mA and the sub-main unit B can be called and a conversation can be made.

The intercom circuit 2 (4) provided in both iA and sub 1 [iB includes a transmitting amplifier 21 (41) that amplifies the voice volume input to the transmitter T to a predetermined level, and an output from the other party's side. an amplifier circuit 2 comprising a receiving amplifier 22 (42) that amplifies the transmitting output to a predetermined level according to the transmitted transmitting volume;
0 (40), gain control means 24, 44 for controlling the gain of the transmitting amplifier 21.41 in two stages, a call line discrimination circuit 23.43, and a 4-wire/2-wire converter 25.45 for simultaneous calls. ing.

In this first embodiment, the gain σ■ of the transmitting amplifier 21.41 provided corresponding to each of the intercom circuits 2 and 4 is the gain σ■ of the transmission amplifier 21.41 provided corresponding to each of the intercom circuits 2 and 4. The gain CB of the receiving amplifier 22.42 is maintained at a predetermined value when the communication line is opened, and is controlled to be lowered when the communication line between the base unit A and the sub-base unit B is closed. The configuration is such that the listening volume is maintained at a predetermined value and uniformly controlled.

FIGS. 2a to 2c are circuit diagrams more specifically showing the configuration of main parts on the parent aA side in the first embodiment of the present invention. Although the configuration of the secondary mirror iB is omitted, it goes without saying that the configuration corresponds to the base unit A.

The one in FIG. 2a uses a relay Ry as the gain control means 24, and connects this relay contact r to a comparator CO.
Opening/closing is controlled by the discrimination output of the speech line discrimination circuit 23 composed of MP, and another control resistor R' is connected/disconnected to the 3MM resistor Ro of the negative feedback operational amplifier ○P constituting the transmitting amplifier 21 to determine its gain. is configured to control in two stages, and when the line voltage input to the call line discrimination circuit 23 is lower than its reference voltage V Ref (for example, DC
6V), it is determined that the communication line between base unit A and sign language C is closed (indicated by (A) in Figure 3), and relay R is activated.
Contact r is opened without driving y, and the line voltage is the reference voltage VRe.
If it is higher than f, it is determined that the communication line between the main unit mA and the sub-base unit B is closed (indicated by (b) in the third leap), and the relay Ry is driven to connect the contact r.
is closed to reduce the gain. Figure 2b, 2C
The figure shows a side port in which the gain control means 24 is constructed using FETQ and analog switch SW instead of relay contacts, and FIG. 3 is an explanatory diagram of the discrimination operation in the speech line discrimination circuit.

In the figure, 01 is a coupling capacitor for extracting the audio signal, C2 is a capacitor for integrating the line voltage on which the audio signal is superimposed, and C3 is a capacitor provided to prevent oscillation. The same applies to other embodiments.

FIG. 4 shows a second embodiment of the present invention,
In this embodiment, the gain control means 24 is configured to control the gain σm of the receiving amplifier 22.42 in two stages. The basic operation is different from the first embodiment, when the call line between base unit A and sub-base unit B is closed, it is different from when the call line between base unit A (or sub-base unit B) and sign language C is opened. Also controls to lower the gain GB of the receiving amplifier 22.42.

FIG. 4a is a more specific circuit configuration diagram of this embodiment, and the same reference numerals are given to the parts corresponding to the first embodiment, and the explanation thereof will be omitted.

The gain control means 24 is an analog switch SW.
However, as in the case of the first embodiment, it goes without saying that it may be constructed using relays and FETs.

FIG. 5 shows a third embodiment of the present invention,
In this embodiment, the gain control means 24, 44 are configured to control the gains σ and CB of the transmitting amplifiers 21, 41 and receiving amplifiers 22, 42, respectively.

The basic operation is the main unit A and the sub unit 11. When the communication line between ff1B is closed, the gain of both the transmitter amplifier 21.41 and the receiver amplifier 22.42 is lower than when the communication line between base unit A (or subbase unit B) and sign language C is closed. It is for down control.

Figure 5a shows parent 89. in this third embodiment. This is a circuit diagram showing a specific configuration on the A side, and the gain control means 24 turns on FETQI and Q2.

The gains σ and σ of the transmitting and receiving amplifiers 21 and 22 are controlled in two stages by turning them off.

〔Effect of the invention〕

As can be understood from the above explanation, according to the system of the present invention, the call line discrimination circuit provided in both the base unit and the sub-base unit automatically identifies the other party, and The gain of the amplification circuit during a call between the main unit or sub-base unit and the magician can be controlled to a lower value than the gain during a call between the base unit or sub-base unit, and the listening volume can be maintained at approximately the same level even if the selected call line is different. To enable a smooth call without causing a feeling of discomfort due to non-uniform reception volume every time a call line is switched.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a first embodiment of the present invention, FIGS. 2a to 2C are circuit configuration diagrams showing the first embodiment in more detail, and FIG. 3 is a circuit diagram of a call line discrimination circuit. Discrimination operation explanatory diagram, 4th
The figure shows the configuration of the second embodiment, Figure 4a is a circuit diagram showing the second embodiment more specifically, Figure 5 is the configuration diagram of the third embodiment of the present invention, and Figure 5a is the circuit diagram of the first FIG. 6 is a basic configuration diagram of a conventional intercom system, and FIGS. 7 and 8 are explanatory diagrams of problems in the conventional system. (Explanation of symbols) A...Base unit B...Sub-base unit C...Magic T...Telephone R...Handset 2.4...Intercom circuit 21.41...Transmission Amplifier 22.42...Receiving amplifier 23.43...Talking line discrimination circuit 24.44...Gain control means Fig. 2a Fig. 4a ゛''-23 Fig. 5a Fig. 6 C slave device

Claims (4)

[Claims] (1) In an intercom system configured by combining a base unit with a power supply circuit, and a sub-base unit and slave unit operated by the power supplied from the base unit, each of the base unit and sub-base unit is , an amplifier circuit consisting of a pair of transmitting and receiving amplifiers provided corresponding to a transmitter and a receiver, a call line discrimination circuit that discriminates the other party based on the voltage level generated in the closed call line during a call; The intercom circuit includes gain control means for controlling the gain of at least one or more corresponding amplifiers in the amplifier circuit in two stages according to the discrimination signal of the discrimination circuit, When it is detected that the communication line between the base unit and the sub-base unit is closed, the corresponding amplifier of each of the above amplifier circuits is activated. An intercom system characterized by having a configuration that reduces the gain of the intercom system. (2) The intercom system according to claim (1), wherein the gain control means is configured to control the gain of a transmitting amplifier provided for both a base unit and a sub-base unit. (3) The intercom system according to claim (1), wherein the gain control means is configured to control the gain of a receiving amplifier provided for both the base unit and the sub-base unit. (4) The intercom according to claim (1), wherein the gain control means is configured to control the gains of both transmitting and receiving amplifiers provided corresponding to both the base unit and the sub-base unit. system.