JPS6137838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dial signal sending circuit for sending a dial signal from the main unit of a key telephone device to a central office line, for example.

In devices such as button telephones, where the number of central office lines is less than the number of telephones, the dial signal generation circuit originally installed in the telephone, multi-frequency signal (PB signal)
It is more economical to centralize the oscillation circuit or dial pulse generation circuit in the main device, and devices with such a configuration are being considered. However, this conventional configuration had the following drawbacks.

(1) In the case of PB (push button) dialing, the PB signal is mixed with voice signals from the telephone, making it impossible to dial correctly. Also, the confirmation sound level of the PB signal heard by the telephone becomes excessive.

(2) In the case of a pulse dial, there is a large clicking noise when the pulse is sent out, which causes discomfort to the user.

It is also possible to solve the above disadvantages by disconnecting the telephone from the central office line when dialing, but in this case the following disadvantages occur.

(1) No dial confirmation tone is heard on the telephone, and it is unclear whether a dial signal is actually being sent, giving the user a sense of anxiety.

(2) The clicking noise that occurs when switching between disconnecting and reconnecting the telephone is loud and causes discomfort to the operator.

In order to solve these problems, this invention attenuates the dialing signal and supplies it to the telephone, allowing the user to hear an appropriate confirmation sound and suppressing the clicking sound when switching. Therefore, this invention will be explained in detail.

FIG. 1 shows an embodiment in which the present invention is applied to a button telephone device, in which a pair of office lines L1 and L2 are connected to one side of the main device ME, and a telephone TEL is connected to the other side of the main device ME. Connected through SL and control line DL. In the main device ME, the input terminals 1 and 1' of the PB type dial sending circuit SDP are connected to the office lines L1 and L.
2, and the output terminals 2, 2' are connected to the communication line SL through the communication path switch SW. telephone
In TEL, one side of the communication circuit SC is connected to the handset HS, and the other side is connected to the communication line SL. The dial button KEY is connected to a button information detection circuit KC, and the button information detection circuit KC is connected to a control line DL. In the dial sending circuit SDP, high resistances, for example, 500Ω resistors R1 and R1' are connected between input terminals 1 and 1' and output terminals 2 and 2', respectively.
A low resistance, e.g. 100Ω resistor R2, is connected between terminals 2 and 2'.
is connected. Contact ds of dial switching relay DS
1 and ds2 switch and connect the terminals 1 and 1' to the terminals 2 and 2' side and the PB signal oscillation circuit PBO, respectively. The contact dm of the click suppression relay DM is inserted in series with the resistor R2. Each relay contact is shown with a solid line when it is not operating, and a broken line when it is operating. PB signal oscillation circuit PBO, relay DS, DM are PB dial control circuits
Controlled by PC. Control circuit PC is control line DL
For example, it has a built-in microcomputer and receives dialing information from the telephone TEL.
Controlling the PB signal oscillator circuit PBO to generate a corresponding PB dial signal and transmitting it to the office lines L1 and L2 is the same as in conventional devices of this type. In this invention, a relay DM, resistors R1, R1', and R2 are provided,
Make it work as follows.

Relays DM and DS are always inactive, and the telephone
When you raise the handset HS with TEL, the telephone line L1, L2 and the communication circuit SC are connected by the communication path switch SW, and the communication current is directly supplied to the communication circuit SC from the office line L1, L2 via the communication path switch SW. be done.
When the operator operates the dial button KEY in this state, the button information detection circuit KC detects dial information and sends it to the PB dial control circuit PC via the control line DL. The dial control circuit PC first drives relay DM, and then drives relay DS. At this time, the click sound generated by the operation of the relay DS is divided by the resistor R2 and transmitted to the communication circuit SC, so that the click sound heard by the operator is reduced compared to when the resistor R2 is not provided.

Next, the dial control circuit PC drives the PB signal oscillator PBO based on the received dial information to generate a PB signal. This PB signal passes through contacts ds1 and ds2 input terminals 1 and 1' and is sent to the office lines L1 and L2, and is also sent to the telephone TEL via output terminals 2 and 2'.
It is also transmitted to the resistors R1, R1',
Since the voltage is divided by R2, the arriving signal is attenuated, resulting in a confirmation sound with an appropriate volume.

Also, set the DC resistance of the PB signal oscillation circuit PBO to 100Ω.
In general, due to the presence of high resistances R1 and R1', most of the current supplied from the office lines L1 and L2 flows to the PB signal oscillation circuit PBO, and only a small amount of current flows to the communication circuit SC. For this reason, the voice signal, etc. that enters the main device ME from the handset HS when sending a dial signal becomes a very low level signal. Furthermore, this mixed signal is attenuated by the resistors R1, R1', and R2 and reaches the office lines L1 and L2, so the amount of mixed signal mixed into the PB signal is negligibly small, and dialing is performed normally.

When the dial transmission is completed, the dial control circuit
The PC first restores Relay DS and then Relay DM. In this case as well, the click sound generated by the restoration of relay DS is divided by resistor R2 and the communication circuit
The click volume transmitted to the SC is reduced.

Note that if there are multiple office lines, it is also possible to adopt a configuration in which one PB signal oscillation circuit is shared. Furthermore, the control circuit PC has conventionally incorporated a microcomputer to control the relay DS and the PB signal oscillator PBO, and in addition to this, it is not possible to operate the relays DM and DS to perform order control as described above. easily achieved.

FIG. 2 shows another embodiment of the present invention. The symbols are the same as those of the embodiment in FIG. , ds2 is terminal 1,
1' is connected to terminals 2, 2' and both ends of a low resistance, for example, 100Ω terminating resistor R3, and the dial pulse generation relay is activated by the DP dial control circuit DC.
Controls DI, switching relay DS, and click suppression relay DM. A contact di of a dial pulse generation relay DI is inserted in series between the terminal 1 and the office line L1, and spark canceling circuits R4 and C are connected in parallel with this contact di.

Relays DI, DS, and DM are inactive at all times, and the telephone
When the TEL handset HS is raised, the communication circuit SC is connected to the office lines L1 and L2 via the communication path switch SW. At this time, when the operator operates the dial button KEY, dial information is sent from the button information detection circuit KC to the dial control circuit DC. Since the dial control circuit DC drives the relay DM and then the relay DS, the clicking noise caused by the operation of the relay DS is reduced. Further, the loop of the station lines L1 and L2 is mainly held by the resistor R3.

Next, the dial control circuit DC drives the relay DI based on the received dial information, and operates the contact di intermittently to generate a dial pulse. contact di
A clicking sound is generated due to the intermittent connection of the resistor R.
3, R1, R1', and R2 before reaching the communication circuit SC, the volume heard by the operator is low and becomes an appropriate confirmation sound.

When the dial transmission is completed, the dial control circuit
DC first restores Relay DS and then Relay DM. In this case as well, the click sound generated by the restoration of the relay DS is attenuated by the resistor R2, and the click sound level transmitted to the communication circuit SC is reduced.

As explained above, according to the dial signal sending circuit of the present invention, it is possible for the operator to hear the confirmation sound of the dial signal sent out at an appropriate volume.
Does not cause discomfort or anxiety to the user. Furthermore, it is possible to suppress the clicking noise that accompanies the switching operation in the dial signal sending circuit, which also reduces the user's discomfort. Furthermore, in the case of PB type, PB
It is possible to make the voice signal mixed into the signal very small, and to eliminate the adverse effect on dial signal transmission. Furthermore, the circuit of the present invention has a simple configuration, and since both the PB type and the DP type have almost the same configuration, it is possible to share the circuit, and it has a large economic effect.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a PB dial signal sending circuit, and FIG. 2 is a diagram showing an embodiment in which the present invention is applied to a dial pulse signal sending circuit. L1, L2: Office line, ME: Main device, TEL: Telephone, SDP: PB type dial sending circuit, SDD: DP type dial sending circuit, 1, 1': Input terminal, 2,
2': Output terminal, R1, R1': High resistance, R2: Low resistance, PBO: PB oscillation circuit, DS: Dial switching relay, DM: Click suppression relay, DI: Dial pulse generation relay, SL: Communication line, DL : Control line.

Claims (1)

[Claims] 1 A pair of input terminals connected to a central office line in an inactive state and a pair of output terminals are directly connected, a multi-frequency signal oscillation circuit is connected to the input terminals in an active state, and a high resistance a switching circuit that connects the input terminal and the output terminal via the switching circuit, and a low resistance that is provided between the pair of output terminals and has a resistance value smaller than the high resistance between the output terminals in an operating state. , and a click suppression relay circuit that opens the click suppression relay circuit in the non-operating state, and when starting to send out a multi-frequency signal to the office line, the click suppression relay circuit is first set to the operating state, and then the switching circuit is opened. operate,
and a control circuit that restores the click suppression relay circuit after restoring the switching circuit when the transmission of the multi-frequency signal is stopped, and the resistance values of the high resistance and the low resistance are determined by the switching circuit. The dial signal sending circuit is selected so that the volume of a click generated when switching the circuit is sufficiently attenuated at the output terminal, and the multi-frequency signal to be sent out is attenuated to an appropriate volume before reaching the output terminal. 2. Directly connect an input terminal and a pair of output terminals in an inactive state, connect a first low resistance to the input terminal in an active state, and connect the input terminal through a high resistance whose resistance value is larger than that of the first low resistance. a switching circuit that connects the terminal and the output terminal, and a second low resistor that is provided between the pair of output terminals and has a resistance value smaller than the high resistor between the output terminals in the operating state, and is inactive. a click relay suppressing relay circuit that opens the click suppressing relay circuit when the dial pulse is started, and a dial pulse generating circuit provided between the input terminal and the central office line. and a control circuit for restoring the switching circuit and then restoring the click suppression relay circuit after the transmission of dial pulses is completed, and restoring the click suppression relay circuit. The resistance value is such that the volume of the click that occurs when switching the switching circuit is sufficiently attenuated at the output terminal, and the resistance values of the first low resistance, high resistance, and second low resistance are such that the transmitted dial pulse is appropriate. a dial signal sending circuit configured to reach the output terminal with a volume attenuated to a certain level;