JPH02183658A - Two-way simultaneous talking interphone set - Google Patents

Abstract

PURPOSE:To attain the 2-wire one line two-way simultaneous talking not requiring any high voltage power supply by providing 4 series capacitors to A and B sides, connecting a pure resistor for impedance matching, providing two amplifiers to the both and mounting a microphone and a speaker. CONSTITUTION:A voice current of an A side microphone 1 is divided into three by series capacitors C1-C4, one flows to the B side, the other is directed toward an impedance matching pure resistor 7 and the rest is amplified via transformer 4 to activate the A side speaker 6. Then the voice current going to the B side is summed with a DC from a power supply 8, separated by a B side choke coil 10, the DC is smoothed by a capacitor 11 and led to amplifiers 2, 5 at the B side to operate them. The separated voice current is divided into two while being completely isolated from the DC by the action of the choke coil 10 and the series capacitors C1-C4, the part is amplified by the transformer 4 to activate the B side speaker 6 and the other flows to ground via the matching pure resistor 7. Thus, the 2-wire one line two-way simultaneous talking interphone set not requiring any high voltage power supply is obtained.

Description

Detailed Description of the Invention B. Purpose of the Invention [Field of Industrial Application] This invention relates to an intercom for simultaneous two-way communication between side A and side B, and more specifically, two-way simultaneous communication using two lines in one line. Concerning an intercom that made it possible to make calls.

[Conventional technology]

Three-wire and four-wire intercoms allow simultaneous two-way communication, but the devices are complicated and expensive.

Therefore, we used two microphones that also function as IIU speakers and an amplifier, and used a switch to alternately switch between the caller's call and the caller's call.
A wired type is known.

However, after speaking to one microphone, you must immediately switch to the other microphone using a switch, which can be quite inconvenient for complicated calls or long calls, and you have to consider the timing of the other party's call. There are major drawbacks such as not being able to do so.

The applicant has filed patent number 1337414 (publication number 1986-5).
No. 7249) Proposed a two-line, one-line intercom that could be used like a telephone and made use of a semiconductor bidirectional amplifier to allow simultaneous two-way calls without using a changeover switch, and continued to meet demand for several years. I came.

[Problem that the invention seeks to solve]

However, since the semiconductor bidirectional amplifier uses the effect after the phenomenon (punch Lrough) for punching the semiconductor, the punching requires a high voltage to cause the phenomenon. In addition, in the semiconductor method, since the junction circuit for transmitting and receiving voice currents is an R-C only circuit, self-oscillation is likely to occur, and there are problems in combining and separating the feeder and direct lri and voice current. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to obtain a two-wire single-line bidirectional simultaneous call intercom which solves the above-mentioned problems.

Summary: Structure of the Invention [Means for Solving Problems] The present invention amplifies the output of the microphone 1 on the A side with the audio amplifier 2, and the output audio current is transferred to four series capacitors C1, C2, and C.
1 and C4 to the center point 3, connect the primary side of the transformer 4 to the capacitors C2 and C3 on both sides of the connection point, and amplify the output of the secondary side with the amplifier 5 to output the speaker 6. make it work,
One terminal of the series capacitors C3 to C4 is connected to a resistor 7 for impedance matching and grounded, and the other terminal of the series capacitors C1 to C4 connects the outgoing audio current and the direct current from the power supply 8 placed on the A side. The mixture is mixed and transmitted to the B side, which has the same circuit configuration as the A side, through the transmission line 9. On the B side, the audio current is separated from the mixed current sent from the A side by a low frequency choke coil 10, and the direct current is separated by a capacitor 11. The audio current is smoothed and applied to the amplifier 25 on the B side to operate them, and the audio current is transmitted to one terminal of the series capacitors NC1 to C1 on the B side, and is then applied to the transformer 4.
This is a two-way simultaneous call intercom characterized in that the signal is introduced into the amplifier 5 via the amplifier 5 and amplified, the B-side speaker 6 is operated, and the call from the B-side to the A-side is performed by the reverse route to the above.

[For production]

First, when you speak into the microphone l on the A side, the weak voice current is amplified by the amplifier 2 and the series capacitor '11
It is divided into three by c l-ca. One part flows toward the B side, the other part goes to the self-side impedance matching pure resistor 7, and the remaining part passes through the self-A side transformer 4 and is amplified by the amplifier 5. side speaker 6
make it work.

Here, it is necessary to completely match the impedances of the capacitor C4 including the transmission line 9 and the resistor 7, and if there is a mismatch, oscillation will occur. If the matching is perfect, no oscillation will occur and the audio current to the speaker 6 will be small.

The audio current leaving the series capacitor Ic, ~C4 and proceeding toward the B side is A
It merges with the direct dt coming from the tYA8 located on the side,
The audio current is blocked from flowing toward the power source by the A-side choke coil 10. The audio current thus merged with the direct current is transmitted by the transmission line 9 to the B side, which has the same circuit configuration as the A side (components that are the same as those on the A side are indicated by the same symbols), and the audio current is first separated by the choke coil 10 on the B side. , the direct current is smoothed by the capacitor 11 and passes through the line 20 to the amplifier 2 on the B side.
5 to operate them. The separated audio current is passed through the choke coil 10 on the B side and four series capacitors C8.
~ Completely separated from direct current by the action of C4, its series capacity 1c,
-c, is divided into two by the action of its series capacitance, and one part is amplified by amplifier 5 via transformer 4.
Operate the side speaker 6. The other part is grounded through a pure resistor 7 for matching. In this way, the call from the A side reaches the B side and is output from the speaker 6.

When talking from the B side to the A side, when speaking into the B side microphone 1, the voice is emitted from the A side speaker 6 through the same route and action as described above. In this way, simultaneous two-way communication between side A and side B became possible.

〔Example〕

FIG. 1 shows the principle of an example in which a dry battery is used as the DC power source 8.

When making a call from the A side to the B side, power is directly supplied to the A side amplifiers 2 and 5 from the power supply 8 via the line 20, and the series capacitors C3 to C
Since only the audio current is sent to 4, the smoothing capacitor 11
It doesn't have to be there.

As mentioned above, series capacitors 01 to C1 are provided on the A side and B side,
By connecting a pure resistor 7 for impedance matching to one terminal of each, it is possible to balance the A side and the B side and stabilize the operation. In addition, two sets of amplifiers 2 and 5 are provided on both the A side and the B side, and the positions and directions of the microphone and speaker 6 are designed to prevent howling, so that stable operation can be achieved. .

FIG. 2 illustrates an actual wiring diagram using an AC power source, and since the B side has the same configuration as the A side, the wiring is omitted. In FIG. 2, the same reference numerals as in the first part indicate the same parts.

12 is a plug connected to a commercial AC power supply, 13 is a voltage doubler rectifier circuit, and part of its output operates the A-side amplifiers 2 and 5. The other part is mixed with the audio current from the A side and B
side, and thereby operate the amplifiers 2 and 5 on the B side.The following configuration and operation are the same as in FIG.

16 indicates a buzzer for calling the A side from the B side, and on the A side, the changeover switch 17 is the normally closed contact 1 on the buzzer side.
7+, and when the call switch is switched to 1 day on the B side and contact 1B is closed, power is supplied from the battery 19 and the buzzer 16 sounds. On the A side, set the changeover switch 17 to contact 17□
When the switch 18 is released on the B side, the normally closed contact 18□
is closed, and two-way simultaneous calls can be made as described above. After the end of the call, the changeover switch 17 is switched to the buzzer side on the A side, thereby eliminating power consumption. Note that from the A side, the selector switch 17 is switched to the power supply side 17□, and the B side is called directly by voice.

C. Effects of the Invention As described above, the present invention amplifies the output of the microphone 1 on the A side with the audio amplifier 2, and the output audio current is passed through the four series capacitors C.
Connect to point 3 in the center of I 'Cz ・C3 and C4, connect the primary side of transformer 4 to the capacitors C2 and C1 on both sides of that connection point, and connect the output j of the secondary side to amplifier 5. The amplification is performed to operate the speaker 6. One terminal of the series capacitors 01 to C4 is connected to a resistor 7 for impedance matching and grounded, and the other terminal of the series capacitors 01 to C4 is connected to the outgoing audio current and the power supply 8. The configuration is such that the mixed current and direct current are sent to the other party having the same configuration through the transmission line 9, thereby preventing self-oscillation and howling. Also, on the B side receiving the mixed current audio current, there are four series capacitors C and -C.

The voice current and the direct current are separated by the choke coil 10 and separated by the direct current to operate the amplifier in the self-circuit, so that the synthesis and separation of the voice current and the direct current are skillfully performed.

Therefore, high voltage is not required, unlike the above-mentioned two-way, one-line, two-way simultaneous call intercom that uses a semiconductor two-way simultaneous amplifier. Since the power consumption is small (1 to 2 W), if the power is always turned on, both the A side and the B side can talk immediately when desired. Furthermore, it is not possible to replace the 2 wires and 1 line 2 currently used in 3-wire and 4-wire 2 systems. Furthermore, the combination and separation of the audio current and the direct current are reliably performed, and there are also effects such as no self-oscillation occurring.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the principle and embodiment of the present invention, Figure 2
The figure shows an example of an actual wiring diagram using an AC power source. 8...DC type! (dry battery), 13... Voltage doubler rectifier circuit, 16... Buzzer, 18... Buzzer changeover switch.

Claims (1)

[Claims] (1) Amplify the output of microphone 1 on the A side with audio amplifier 2,
The output audio current is connected to four series capacitors C_1・C_2・C
Connect to point 3 in the center of _3 and C_4, connect the primary side of transformer 4 to the capacitors C_2 and C_3 on both sides of that connection point,
The output of the secondary side is amplified by the amplifier 5 to operate the speaker 6, one terminal of the series capacitors C_1 to C_4 is connected to the resistor 7 for impedance matching and grounded, and the other terminal of the series capacitors C_1 to C_4 is connected to the ground. mixes the outgoing audio current with the direct current from the power supply 8 placed on the A side, and transmits the mixture via the transmission line 9 to one terminal of the series capacitors C_1 to C_4 on the B side, which have the same circuit configuration as the A side, and On the B side, the audio current is separated from the mixed current sent from the A side by a low frequency choke coil 10, and the direct current is separated by a capacitor 11.
The audio current is smoothed and added to amplifiers 2 and 5 on the B side to operate them, and the audio current is transmitted to one terminal of the series capacitors C_1 to C_4 on the B side, and is introduced into the amplifier 5 via the transformer 4 and amplified. The two-way simultaneous call intercom is characterized in that the B-side speaker 6 is operated, and the call from the B-side to the A-side is performed through a route reverse to that described above.