JPS58142659A - Dial signal originating circuit - Google Patents

Abstract

PURPOSE:To realize a telephone set which also works for pulse dial (DP) signals and two frequencies mixing (MF) signals, by installing a DP/MF signals sending- out circuit which operates even with an office power source by a dial signal oscillating circuit, an sending either one of the two signals by a key pad. CONSTITUTION:When a handset 10 is lifted up, a hook-switch 2 is tilted from a bell circuit 3 to a channel side, and a circuit consists of a main wire terminal 1 the hook-switch 2 a DP/MF signals sending-out circuit 14 is formed. Under the DP signal sending-out mode, a power source is applied to a key pad 12 and a D signal oscillating circuit by the DP/MF changeover switch in the DP/MF signals sending-out circuit 14. When the key pad 12 is depressed, a DP signal is sent out from the oscillating circuit. On the other hand, the power source is applied to the key pad and an MF signal oscillating circuit by the changeover switch under the MF signal sending-out mode. When the key pad 12 is depressed, an MF signal is outputted from the MF signal oscillating circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dial signal transmitting circuit capable of transmitting both a pulse dial signal and a two-frequency mixed dial signal.

Conventionally, two types of telephones are known: one that transmits a pulse dial signal and one that transmits a two-frequency mixed dial signal. These will be explained using FIGS. 1 and 2.

Figure 1 shows the pulse dial signal (hereinafter referred to as DP signal).
FIG. 2 is a block diagram of an example of a telephone that sends out a message. The calling operation of this telephone will be explained.

First, when the handset 10 is lifted, the hook switch 2 falls down from the bell circuit 3 to the communication path side, and a circuit of office line terminal 1 - hook switch 2 - DP signal sending circuit 4 is formed. Therefore, when the rotary dial 5 is turned, a DP signal is sent out from the DP signal sending circuit 4 via the hook switch 2 and the office line terminal 1. 6 is a hybrid circuit, 7 is a balanced circuit, 8 is a receiver, and 9 is a transmitter.

FIG. 2 is a block diagram of a two-frequency mixing (hereinafter referred to as MF) telephone. The same reference numerals as in FIG. 1 indicate the same components. In this example, the switch 13 is the hybrid circuit 6
and the transmitter 9 or the hybrid circuit 6 and the MF signal sending circuit 11 are switched to be connected. Therefore, when the handset 10 is lifted, the hook switch 2 falls from the bell circuit 3 toward the communication path side, and a circuit of office line terminal 1 - hook switch 2 - hybrid circuit 6 is formed. So, when you press keypad 12, switch 13 almost simultaneously
falls toward the MF signal sending circuit 11 side. Thus, the MF signal is transmitted from the MF signal sending circuit 11 to the hybrid circuit 6.
It is sent to the station via the hook switch 2 and the station line terminal 1. When the keypad 12 is released, the switch 13 falls toward the transmitter 9 side.

In this way, conventional telephones use DP signals, MF
There are independent systems that use signals.

However, considering the ease of installation and maintenance of the telephone, and the improvement of outgoing call services, there was a desire to create a telephone that could send out dial signals in two ways with one telephone. .

The present invention was made based on such a demand.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a dial signal generating circuit for a DP/MF switching type telephone that operates on the office power supplied from a telephone line.

The dial signal sending circuit of the present invention is a dial signal sending circuit in which a first dial signal sending circuit that sends out a pulse dial signal and a second dial signal sending circuit that sends out a two-frequency mixed dial signal are connected in series. circuit, and when making a call, connect the telephone line to the telephone circuit network side.
When transmitting a dial signal, switching connection means switches and connects the telephone line to the dial signal transmitting circuit, respectively; a constant current circuit extracts power from the line power supply from the telephone line; A circuit for extracting electric power, an oscillation circuit for a first dial signal, an oscillation circuit for a second dial signal, a selection means for selecting one of these two oscillation circuits, and a control section for controlling each of the aforementioned elements. If the selection means selects so that power is supplied from the constant current circuit to the first dial signal oscillation circuit, the power of the constant current circuit is always supplied to the first dial signal oscillation circuit and the first dial signal oscillation circuit. , is supplied to the control unit and controlled so as not to be supplied to the second dial signal oscillation circuit, and power is supplied to the second dial signal oscillation circuit from a circuit that extracts power from the telephone line via a resistor. When selected by the selection means, the electric power of the constant current circuit is supplied to the control section, and the electric power of the constant current circuit is controlled not to be supplied to the oscillation circuit of the first dial signal.

Embodiments of the present invention will be described below with reference to the drawings. Third
The figure is a conceptual diagram of an embodiment of the present invention. As shown, DP
/MF signal sending circuit 14 is provided, and the keypad 12 sends out any of the signals.

Next, a detailed block diagram of the DP/MF signal sending circuit 14 is shown in FIG.

In Figure 4, 20.21 is the input terminal on the central line side, 22
．． 23 is an input terminal on the telephone circuit network side. These input terminals 20 to 23 are connected to a diode bridge 24, and the diode bridge 24 rectifies the DC power supplied from an exchanger (not shown) to provide a power source for each circuit. That is, a surge absorbing Zener diode 49, a resistor 43, a constant current circuit 25. When the latching relay Ds switch 36, which is normally pushed to the latching relay 34 and further to the input terminal 23 side, is pushed to the dial signal sending circuit side contact 37, the DP signal sending switch 38, the MF signal amplification sending circuit 47, and the DP signal sending Power is supplied to the make load 40 at this time.

Of these circuits, the DP signal sending switch 38
The MF signal amplification sending circuit 47 is a first dial signal sending switch that sends out a P signal, and the MF signal amplification sending circuit 47 is a second dial signal sending switch that sends out an MF signal.These two are connected in series and combined to produce a dial signal. It constitutes a sending circuit.

In addition, the latching relay circuit 34 and the latching relay D
The s switch 36 is a switching connection means that switches and connects the telephone line to the telephone circuit network side when making a call, and switches and connects the telephone line to the dial signal sending circuit side when sending out a dial signal.

On the other hand, from the constant current circuit 25, a power supply line 26 and a resistor 43 are connected.
From there, a power supply line 41 extends to two other contacts in the DP/MF changeover switch 27, which is the selection means.

Then, from the other two contacts of the DP/MF changeover switch 27, the DP which is the oscillation circuit of the first dial signal is connected.
A current supply line 28 extends to the signal oscillation circuit 29, and a power supply line 42 extends to the MF signal oscillation circuit 44, which is an oscillation circuit for the second dial signal. This allows the operator to use DP/M
When the F changeover switch 27 is switched, one of the oscillation circuits is selected. Further, a line extends from the DP/MF changeover switch 27 to the keypad 12, and a key input line 30 extends from the keypad 12 to the DP signal oscillation circuit 29, M
It extends to the F signal oscillation circuit 44. Therefore, if the DP/MF selector switch 27 selects the constant current circuit 25 side,
Current is supplied to the keypad 12 from a constant current circuit 25, and when the keypad is pressed, a key signal is sent to the DP signal oscillation circuit 29. Further, when the DP/MF signal selector switch 27 selects the resistor 43, power is supplied to the keypad 12 from the resistor 43, and when the keypad 12 is pressed, the key signal is sent to the MF signal oscillation circuit 44. Ru. In this way, the DP/MF changeover switch 27 serves as a selection means for selecting one of the two oscillation circuits.

33 is a control unit that controls each element of this circuit. The constant current circuit 2 is connected to the control unit 33 via a power supply line 26.
Voltage is applied from 5. In addition, the DP signal oscillation circuit 29
A Ds signal line 31 extends from the MF signal oscillation circuit 44, a MUTE signal 45 extends from the MF signal oscillation circuit 44, and a signal obtained from the Konera signal line and a current supply line 28 from the DP/MF changeover switch 27.
Based on the current obtained through the latching relay Ds signal line 35, the control unit 33 controls the latching relay 34 via the latching relay Ds signal line 35, and controls the latching relay 34 and meter load 40 via the Dp break signal line 39. conduct.

For example, the details of the constant power supply circuit 25, control section 33, DP and MF signal oscillation circuits 29 and 44 are as shown in FIG.

The constant current circuit 25 includes two diodes 66, a PnP transistor 69, a capacitor 71, and a Zener diode 7.
0. Consisting of resistors 67 and 68, resistor 67 is connected to the emitter of transistor 69 from A connected to input terminal 22, and diode 66 is connected to the pace of transistor 69 in parallel with resistor 67. From this base there is a resistance of 68
extends to line B that connects to input terminal 23.

In addition, a capacitor 71 is connected from the collector of the transistor 69.
and Zener diode 70 are connected to line B in parallel. Further, a current supply line 26 extends from the collector to a DP/MF changeover switch 27.

Two oscillation circuits 29 and 44 are composed of a level shift circuit 60 and 61, a DP oscillator 62, an MF oscillator 63, and a Zener diode 65. Level shift circuit 60.61
Power is applied to the DP/MF changeover switch 27 from the middle point of the DP/MF changeover switch 27, and by switching the DP/MF changeover switch 27, power is switched and applied from each of the output side contacts of the DP/MF changeover switch 27. It is composed of Similarly, the same power source as the level shift circuit 60 is supplied to the DP signal oscillator 62 from the output side of the DP/MF changeover switch 27, and the level shift circuit 60 is connected to the MF signal oscillator 63 from the output side of the DP/MF changeover switch 27. It is configured to be supplied with the same power as the shift circuit 61.

On the other hand, output signals from the keypad 12 are input to a DP oscillator 62 and an MF oscillator 66 via level shift circuits 60 and 61, respectively.

However, the level shift circuits 60 and 61 do not operate unless two power supplies are simultaneously applied from the middle point and output side of the DP/MF switch. Therefore, when the DP/MF changeover switch 27 is as shown by the solid line in the figure, the level shift circuit 60 is operable, and when it is as the broken line, the level shift circuit 61 is operable. The Zener diode 65 also prevents excessive voltage from being applied between the A line and the B line via the resistor 43 and the DP/MF changeover switch 27.

Also, level shift circuits 60 and 61, DP signal oscillator 62,
The MF signal oscillator 63 and the control section 33 are connected to the B line.

With this configuration, in the DP signal transmission mode, the DP/MF changeover switch 27 is turned down as shown by the solid line in FIG. 4. As a result, power is supplied from the constant current circuit 25 to the DP signal oscillation circuit 29. On the other hand, power is similarly applied to the keypad 12, and when the keypad 12 is pressed, the DP
The signal oscillation circuit 29 outputs a Ds signal and a DP signal. The Ds signal is given to the control unit 36 via the DS signal line 31, and based on this, the control unit 33 operates the latching relay 34 and moves the latching relay Ds contact 36 to the dial circuit side contact line 37 side. . On the other hand, the DP signal line 32
The DP signal is input to the DP signal sending switch 38 via the DP signal, and as a result, the DP signal switch 38 is opened and closed in synchronization with the DP signal. Therefore, it means that the DP signal has been sent out.

At the same time, the DP signal and the power from the constant current circuit 25 are input to the control section 33. As a result, the control unit 33 knows that it is in the Dp signal sending mode, and synchronizes with the Dp signal.
The make load 40 and the latching relay circuit 34 are controlled. In other words, the latching relay Ds contact 36 is connected to the dial circuit side contact line 37 by the latching relay circuit 34.
When tilted to the side, a make load 40 is applied.

As a result, the power supplied from the exchange is input terminal 20 → diode bridge 24 → Dp signal sending switch 38 → make load 40 → latching relay Ds connection 36
There are cases where the current flows through the circuit → diode bridge 24 → input terminal 21, and cases where the DP signal sending switch 38 is open and no current flows. In other words, the current is turned on and off before reaching the exchange, and a DP signal is sent.

On the other hand, when the MF signal transmission mode is selected by the DP/MF changeover switch 27, this switch 27 is turned down as shown by the broken line in the figure. Therefore, a voltage is applied to the keypad 12 and the MF signal oscillation circuit 44 from the A line via the resistor 43. Therefore, when the keypad 12 is pressed, the MF signal oscillation circuit 44 outputs a MUTE signal and an MF signal.

The MUTE signal is input to the control section 33, and the control section 33 causes the latching relay circuit 34 to move the latching relay Ds contact 36 toward the dial circuit side contact line 37 side. moreover,
The MF signal is input to the MF signal amplification and transmission circuit 47, and output from there to the exchange. At this time, the make load 40 is configured to be in an open state.

Also, at this time, while the latching relay Ds contact 36 is pushed down to the dial circuit side contact wire 37, the MF signal confirmation sound circuit 48 works as a bypass circuit between the input terminal 23 and the diode matrix 24, and at the receiver,
A confirmation sound is audible.

FIG. 6 shows a circuit diagram of an embodiment of the latching relay circuit 34 that operates as described above.

The break signal is supplied from the break signal supply line 39 to the base of the npn transistor 81 via the resistor 93 when the DP signal is sent.

Further, a resistor 92 is arranged between the pace of the transistor 81 and the B line connected to the input terminal 23. Resistors 90 and 91 are connected in series between the collector of transistor 81 and the A line connected to input terminal 22. Further, the emitter of the transistor 81 is connected to the B line.

Further, between the resistors 90 and 91, the conductor of the pnp transistor 80 is connected.

In this circuit, when a break signal is input, current is no longer supplied from the break signal supply line 39 to the pace of the transistor 81, the transistor 81 is turned off, and the current flowing into the pace of the transistor 80 is reduced.
Transistor 80 is in an off state, and transistor 80
The latching relay circuit 34 has the function of stopping the supply of

A resistor 94 and diodes 104 and 105 extend in parallel from the collector of transistor 80. Resistor 94 is pnp
Connected to the emitter of transistor 84 and connected to diode 1
05 is connected to the emitter of the pnp transistor 82 and the pace of the transistor 84. transistor 84
The collector of the transistor 83 is connected to the base of the transistor 83 via a resistor 95, and serves as a power supply point 83.

The collector of transistor 82 and the B line are connected.

This circuit operates as follows unless a signal for operating the latching relay circuit 34 is input via the latching relay Ds signal line 35.

The power supplied from the collector of the transistor 80 passes through the resistor 94, the transistor 84, and the capacitor 10.
7. When the capacitor 107 is charged and the charging current stops flowing, the potential difference between the collector potential of the transistor 84 and the pace potential decreases, and the transistor 82
is turned off, and as a result, transistor 84 is turned off.

Therefore, in terms of AC, the latching relay circuit 34 is made to have a high impedance to eliminate the influence of this circuit on sidetone and speech.

From the power supply point 83, Pnp transistors 86, 88 extend with their emitters connected, a resistor 96 extends to the pace of transistor 86, and a resistor 100 extends to the pace of transistor 88.

On the other hand, npn transistors 89 and 87 extend from the B line with their emitters connected, a resistor 102 extends to the base of transistor 89, and a resistor 98 extends to the base of transistor 87.

The respective collectors of transistors 86 and 89 are connected and extend through a single winding latching relay 85 to the common connection point of the collectors of transistors 88 and 87.

A latching relay Ds signal is applied to each of the transistors 86, 87, 88, and 89 through resistors 97, 99, 101, and 103, respectively.

There are two modes of this signal: transistor 86;
The set mode in which transistor 87 is turned on, and the transistor 88,
There is a reset mode in which 89 is turned on.

In this set mode, the latching relay contact is pushed toward the dial circuit side connection dotted line 37, and returned in the reset mode.

Further, a Zener diode 106 is connected in parallel with the capacitor 107 to ensure a constant voltage.

The latching relay Ds contact 36 is moved by such a latching relay circuit 34, and the DP signal or MF
A signal is sent out, but the DP signal sending switch 38 and the make load 40 . MF signal amplification sending circuit 4
An embodiment of the circuit No. 7 is shown in FIG.

Transistors 110, 111 and resistors 120 to 122 are D
A p signal sending switch 38 is configured. transistor 11
0 is connected to the A line at the emitter, and is also connected to a resistor 121 extending from the A line at a pace. This transistor 11
The pace of 0 and the collector of transistor 111 are 122
connected via. The emitter of the transistor 111 becomes the contact line 37 on the dial circuit side, and the emitter of the transistor 111 becomes the contact line 37 on the dial circuit side.
The base of is connected to the A line through the resistor 120, and at the same time the D
This is a P signal line 32. In addition, the transistor 110
The collector of is resistor 114, 124 and transistor 1
It is connected to 15 emitters.

Therefore, in the DP signal sending mode, the latching relay Ds contact 36 is turned down as shown by the line ■ in the figure, and every time the DP multiplier turns on and off the transistor 111, a Dp signal appears at the latching relay Ds contact 36, and this sent to the exchange.

- On the other hand, the resistor 114 and the emitter of the transistor 112 are connected, and the base of the transistor 112 and the collector of the transistor are connected. The collector of the transistor 112 and the emitter of the transistor 113 are commonly connected and connected to the emitter of the transistor 111. Further, the resistor 124 and the emitter of the transistor 111 are connected through diodes 128 and 129. A break signal when the DP signal is sent is supplied to the base of the transistor 113 via the break signal line 69.

When the break signal is activated, the transistors 112 and 113 are turned off, and when the break signal is not active, the transistors 112 and 113 are turned on.

Then, when turning on (making) the DP double signal transistors 111 and 110, since the break signal is not active, the transistors 112 and 113 are turned on.
A resistor 114 is connected in series with the transistor 110, and a resistor 114 is connected in series with the transistor 110.
14, the load becomes heavier. Conversely, when the brake signal is active, the resistor 114 does not serve as a load.

Transistors 115 and 116 are MF signal amplification transistors, and the base of transistor 115 and transistor 1
The collector of transistor 16, the collector of transistor 115, and the emitter of transistor 116 are connected.

A resistor 123 extends from the collector of transistor 115 to latching relay Ds contact 36. Also, the transistor 11
A resistor 125 is connected to resistor 124 from a pace of 6.

It is connected to the base of the transistor 116 via a transformer 117 and a capacitor 127, and the MF signal is obtained from the MF signal line. A resistor 126 is arranged in parallel with the secondary coil of the transformer 117.

This transformer reverses the phase of the MF signal to the transistor 1.
15.116 for amplification.

In the MF signal transmission mode, the MF signal is transmitted from the MF signal line 46 to the transistor 115.11 via the transformer 117.
6 and sent to the exchange via the latching relay Ds contact 36. .

In order to confirm this MF signal, a confirmation sound circuit 48, which is a bypass circuit, is provided between the latching relay Ds contact 36 and the input terminal, and is arranged in series with a resistor 118 and a capacitor 119. Since this confirmation sound circuit 48 becomes a load at the time of a break when transmitting a DP signal, it needs to be sufficiently larger than the load included in the receiver 8 and the transmitter 9 of the handset 10.

Because of the above configuration, effective power is supplied by the DP/MF changeover switch 27 via the resistor 43 or the constant current circuit 25.

For example, in the DP signal sending mode, the voltage via the resistor 43 is cut off by the DP/MF signal changeover switch 27, so that an excessive voltage is not applied to the MF signal oscillation circuit 44, thereby protecting the circuit.

Furthermore, as is clear from FIG. 6, by sending the break signal, current consumption can be limited without flowing current to the circuit side including the single-winding latching relay 85, and the break operation can be guaranteed.

Furthermore, as shown in FIG. 7, a make load 114 is added during make to ensure an appropriate make current.

Further, during a call, the constant current circuit 25 has high impedance in terms of alternating current, and does not affect the communication path. During a call, the MF signal oscillation circuit 44 also stops operating, so it hardly becomes a load.

Since the circuit can transmit the DP signal and the MF signal from almost the same position on the circuit, the system configuration of the entire dial signal transmitting circuit is easy.

Furthermore, since a latching relay is used to switch the dial signal between the sending circuit and the calling circuit, this relay consumes no current except when switching, and the voltage drop at the switch contact is extremely small. Therefore, both the dial signal sending circuit and the confirmation circuit operate effectively with the station power supply.

Furthermore, the MF signal confirmation circuit can confirm the transmission of the MF signal, and since the MF signal confirmation circuit can have a sufficiently high impedance in the break operation when the DP signal is transmitted, a break can be guaranteed.

As explained above, by using the dial signal oscillation circuit of the present invention, it is possible to configure a DP/MF signal dual-purpose telephone that operates even with a local power source. In addition, as a result of switching between the confirmation circuit and the dial signal sending circuit using a latching relay, there is no current consumption while switching to the sending circuit side, so the station current can be used effectively. It can also be applied to the configuration of

As a result of the above, it is possible to handle the junctions connected to either the DP or MF circuits with one electric wire.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a DP type telephone, Fig. 2 is a block diagram of an MF type city telephone, Fig. 3 is a block diagram of a telephone based on the circuit of the present invention, and Fig. 4 is a block diagram of a dial signal transmitting circuit of the present invention. The block diagrams and FIGS. 5 to 7 are circuit diagrams of embodiments of essential parts of the present invention. 38...First dial signal sending circuit 47...Second
Dial signal sending circuit (34, 36)...Switching connection means 25...Constant current power supply circuit 43...Circuit for extracting power 29...First dial signal oscillation circuit 44...Second Dial signal oscillation circuit 27...selection means 33...control unit Patent applicant, 1゜Japanese Army 46 Telephone Public Corporation Tokyo Shibaura Electric Co., Ltd. Patent attorney Hon 1) Takashi-26 = Fig. 1 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 6

Claims (1)

[Claims] A first dial signal sending circuit that sends out a pulse dial signal, and a second dial signal sending circuit that sends out a two-frequency mixing type dial signal.
When making a call with the dialing signal sending circuit connected in series with the dialing signal sending circuit, the telephone line is connected to the telephone circuit network side.
When transmitting a dial signal, switching connection means switches and connects the telephone line to the dial signal transmitting circuit, respectively; a constant current circuit extracts power from the line power supply from the telephone line; A circuit for extracting electric power, an oscillation circuit for a first dial signal, an oscillation circuit for a second dial signal, a selection means for selecting one of these two oscillation circuits, and a control unit for controlling each of the aforementioned elements. and when the selection means selects so that power is supplied from the constant current circuit to the first dial signal oscillation circuit, the power of the constant current circuit is always supplied to the first dial signal oscillation circuit, and a control unit, and controls not to supply it to the second dial signal oscillation circuit, and power is supplied to the second dial signal oscillation circuit from a circuit that extracts power from the telephone line via a resistor. A dial signal transmitting circuit characterized in that, when selected by the selection means, the power of the constant current circuit is controlled to be co-supplied to the control section and not supplied to the oscillation circuit of the first dial signal.