JPS6342256A - Key telephone system - Google Patents

Abstract

PURPOSE:To exactly send out both a touch tone signal and a pulse dial signal, by forming a DC loop for allowing a DC to flow to a call transformer at the time of sending out a dial signal. CONSTITUTION:In case of sending out a pulse dial signal, a transistor Q3 is turned on by a controlling circuit 11 and the first ds1 contact 8 and the second ds2 contact 14 are turned on, by which a speech path 9 is switched by the first ds1 contact 8 and grounded, and also, a DC loop circuit of a resistance Rs-the second ds2 contact 14-a call transformer T is formed by the second ds2 contact 14, and connected in parallel to a DC loop forming circuit 7. Accordingly, in case the pulse dial signal is sent out by ON and OFF of a (di) contact 4, even if the time when a transistor Q1 is turned on by a charge time of a time constant circuit of a resistance R1 and a capacitor C1 is delayed, a make rate and a waveform can be obtaines normally by the DC loop circuit by the resistance Rs-the second ds2 constant 14-the call transformer T.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a button telephone device capable of transmitting both pulse dialing and touch tone dialing signals.

2. Description of the Related Art An example of a conventional key telephone device will be explained based on the block diagram of FIG. In FIG. 2, 1 is the main device;
This main device 1 is connected to the switching center 2 through a station 11Aa, and is also connected to an extension telephone @3 through an extension line.

The main device 1 is composed of 4 to 13 parts described below. That is, reference numeral 4 denotes a central office line contact (di contact) which is turned on during a call involving a dial signal and also opens and closes when a pulse dial signal is sent, and is connected to an input/output terminal S to the exchange 2. 6 is a diode bridge connected to the diode contact 4, and the DC side terminal of this diode bridge 6 is connected to a resistor R1, a capacitor C, and a transistor Q1.
A DC loop forming circuit 7 consisting of the following is connected, and a series circuit consisting of a capacitor C2 for preventing direct current from flowing and a winding on the exchange side of the telephone transformer T is connected in parallel to this DC loop forming circuit 7. . The winding on the extension telephone side of the telephone transformer T is equipped with a mirror shunt contact (which operates when sending pulse dial signals and touch tone dial signals and prevents f from being overheard) which is sent to the extension telephone 3. (
1., contact) 8, communication path 9 connects to contact 1, 7,! 5, extension '4i, telephone 3 i; Tasojitonei,
Connect the touch 1-on oscillator 10tJ that oscillates the 1st wave,
1t, -'(', 11 is the control circuit, 1-
・DI-contact 4 glue 1. via transistor Q. /-1
2) - The ds contact 8 is connected to the ds contact L via the transistor Q, and the touch 1-1 oscillator lO is controlled via the transistor Q, etc.), and the DC loop forming circuit 7 is an AC - The constants of L5, capacitor C8, and resistor R1 are set to 1 and 1.1 to have a sufficiently high impedance and no loss. When the control circuit 11 sends a signal to turn on the transistor Q2, the di contact 4 turns on and the DC loop passes through the diode bridge 6 and the DC loop forming circuit 7. The circuit is formed, 2 9 On the other hand,
Voice number 44 is condenser C7 - call 1... Lance '1'' - call path 9 - extension 1! It is transmitted through the route of handset 3.

10 (jl,: right to the call letter protection ", da de one \・" raw signal -j,'(hang l! Go no Wani II work 1. (: next th street 5, touch 1・,]・The six circuits that send out the dial signal are the control circuit 11.J, and the transistor QJ.
By turning on the ds contact 8 and turning on the ds contact 8, the communication line 9 is grounded through the tJJ change τ resistance 1<2 and the oscillator 10 to 9 is grounded.
Nda, Lee V Louis A ~ Hair item 1 - Lance T through 1. ．． ．．
．． -1':'Send exchange 2\. Pulse dial (
When transmitting the signal M', the control circuit 11 connects the transistor Q to A to turn on the ds contact 8. Turns Q on and off. -Toyo 1
The 1di contact 4 is turned on and off to send a pulse dial signal to the exchange 2.

2) Press the conventional button 7' to send out a 4-notch touch signal and a pulse dial signal.

Problems to be Solved by the InventionHowever, there is no problem when the conventional button telephone device sends a touch tone dial signal, but when it sends a pulse dial signal, the following problem occurs. There was a problem that when DI contact 4 was turned off to send out a pulse dial signal, the charge in capacitor C1 of 7 DC loop forming circuit 7 was discharged, and DI contact 4
When the transistor Q turns on due to the time constants of the resistor R1 and capacitor C1, a delay time occurs when the transistor Q turns on, causing the notor rate to fluctuate and the waveform to be significantly disturbed.
This can lead to incorrect dialing.

The present invention solves the problems mentioned in 1-4).The object of the present invention is to provide a button telephone device that can accurately transmit both the touch +=-tone signal and the pulse dial signal. That is.

In order to solve the above-mentioned problems, the present invention has a central office line contact that is turned on during a call including a dial signal and opens and closes when a pulse dial signal is sent, and a central office line contact that is connected to the central office line contact. Diode bridge 41.

A shield connected to the diode bridge, a no-DC loop forming circuit, and a DC loop-forming circuit connected in parallel;
Condenser and communication I-lance, pH, etc.) Series circuit separate λ, i'ii J-note condenser (parallel to 3, pulse dial I-signal is sent out and touch 1--Fern, dial signal is turned on when sent out. Connect the series circuit consisting of the current limiter 1-contact and the current-limiting resistor,
Operation According to the above configuration L,-, when the office line contact is turned on to send a signal, the signal is turned on to send a direct current to the telephone transformer through the contact.
Even if the current loop loops and the DC loop forming circuit turns on with a delay, it will still turn on.

You can revise the waveform, pulse dial signal and touch 1-
An explanation will be given below based on the direction of both of the dial signals (if number can be sent from April to April).

FIG. 14 is a block diagram showing the configuration of a key telephone device according to an embodiment of the present invention. Figure 1 is delicious.

The parts that are the same and have the same functions as the conventional example (1, the same and the explanation will be omitted). In FIG. 1, the second shunt contact of the relay 12 (
ds2 contact) 14 and a current limiting resistor Rs.

Next, the operation will be explained. In FIG.

In order to make a call, the control circuit 11 connects the transistor Q.
2 is sent, the di contact 4 is turned on, and a DC loop circuit is formed through the diode bridge 6 and the DC loop forming circuit 7.

On the other hand, the voice signal is transmitted along the path from capacitor C2 to communication transknee communication path 9 to extension telephone 3.

At this time, the DC loop forming circuit 7 has a sufficiently high AC impedance as in the conventional example, and the time constants of the capacitor C0 and the resistor R1 are set so as not to cause a loss at the communication level.

The operation when transmitting a dial signal in the above-mentioned talking state is as follows. When transmitting a touch tone dial signal, the control circuit 11 turns on the transistor Q3 to turn on the first DS, contact 8, second DS, and contact 14, and transmits the touch tone dial signal from the touch tone oscillator 10. 1 through Lance T to the exchange 2. At this time, by turning on the second ds2 contact 14, a direct current is superimposed on the communication transformer T through the resistor Rs. Although the communication transformer T causes a slight level loss when a direct current flows through it, there is no problem as long as the touch tone oscillator 10 has sufficient output capability. Further, the first ds□ contact 8 switches the communication path 9 to earth, thereby preventing the inner Rs telephone 3 from hearing sound. When sending a pulse dial signal, the control circuit 11 turns on the transistor Q3 to turn on the first DS1 contact 8, the second DS, and the contact 14, thereby switching the communication path 9 at the first DS1 contact 8. At the same time, the second ds2 contact 14 connects the resistor Rs to the second ds, and the contact 14 to the telephone transformer T.
forms a DC loop circuit, and is connected in parallel to the DC loop forming circuit 7. Therefore, when a pulse dial signal is sent by turning on and off the di contact 4, even if the timing at which the transistor Q8 turns on is delayed due to the charging time of the time constant circuit of the resistor R1 and the capacitor C, the resistor Rs - the second
A normal make rate and waveform can be realized by the DC loop circuit consisting of the ds and the contact 14 and the communication transformer T.

In this way, when sending out a dial signal, the resistor R3-second ds2 contact 14 is connected in parallel to the DC loop forming circuit 7.
- By connecting a DC loop circuit using a telephone transformer T, pulse dial signals can be sent out accurately.

Effects of the Invention According to the present invention, a DC loop is formed in which DC is passed through the telephone transformer when sending a dial signal, and even if the DC loop forming circuit is turned on with a delay, the make rate of the pulse dial signal can be improved. , the waveform can be improved, and both touch tone signals and pulse dial signals can be accurately transmitted.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a button telephone device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of an example of a conventional button telephone device. DESCRIPTION OF SYMBOLS 1... Main device, 2... Switching office, 3... Extension telephone, 4... Office line contact (di), 5... Input/output terminal, 6
... Diode bridge, 7... DC loop forming circuit, 8, 14... Shunt contact (DS), 9... Communication path, 10... Touch tone oscillator, 11... Control circuit, 12 ...Relay (DI), 13...Relay (
O3).

Claims (1)

[Claims] 1. A central office line contact that is turned on during a call that includes a dial signal and opens and closes when a pulse dial signal is sent, a diode bridge connected to the central line contact, and a DC loop forming circuit connected to the diode bridge;
A series circuit consisting of a capacitor and a communication transformer is connected in parallel with the DC loop forming circuit, and a shunt contact that is turned on when a pulse dial signal and a touch tone dial signal are transmitted and a current limiting circuit are connected in parallel to the capacitor. A button telephone device that connects a series circuit consisting of resistors.