JPS646618Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a button telephone device comprising a main device having a switching function and a plurality of telephones with button switches.

Such button telephone devices are used for mutual communication within relatively small premises, but when transmitting dial pulses to the central office line from a telephone office accommodated in the main device, the main device In the dial pulse sending section inside, the dial pulse is sent out according to the operation on the telephone side, and the circuit on the telephone side is short-circuited while the dial pulse is being sent out in order to prevent the clicking sound caused by the dial pulse from being given to the telephone side. This creates a drawback in that the telephone cannot confirm whether or not a dial pulse is actually sent out in response to a dial operation.

The purpose of the present invention is to eliminate all of the above drawbacks of the conventional technology, and to provide a button telephone device that transmits dial pulses by turning on and off a switching element for transmitting pulses provided in the main device. An extremely effective button that is equipped with a resistor inserted in series with a short-circuit switching element that sometimes shorts the circuit on the telephone side, and that sends a dial pulse signal generated as the terminal voltage of the resistor to the telephone for confirmation. A dial pulse confirmation circuit for a telephone device is provided.

Hereinafter, details of the present invention will be explained with reference to figures showing embodiments.

Figure 1 is a block diagram of the entire configuration, and the main device
Between KSU and each of the multiple telephones TEL ₁ to TEL ₅ ,
A pair of voice lines L _T1 to L _T8 provided for each telephone TEL ₁ to TEL ₈ are connected to a common pair of signal lines L _S and a pair of power lines L _P , and in this example, the total
A 20-core connection cable is applicable.

The main unit KSU also has a switch unit.
A SWU is provided by which each telephone TEL ₁
- Internal exchange connections between TEL ₈ are performed via the trunk unit TKU which supplies communication current, and exchange with central office lines SL ₁ and SL ₂ from the central office via line units SLU ₁ and SLU ₂ . The power supply unit PSU supplies direct current power, which is rectified alternating current power AC, to these connections, while the control unit CTU consisting of memory, processor, transmitter/receiver, etc.
Accordingly, the operation of each part is regulated.

Note that each of the voice lines L _T1 to _{L T8} only transmits voice signals and supplies communication current, and the signal line L _S transmits control signals in the form of encoded signals of various control information. Each of the telephones TEL ₁ to _{TEL 8} is also provided with a control section similar to the control unit CTU, and encoded signals are transmitted and received between them.

In addition, the line units SLU ₁ and SLU ₂ are composed of an incoming call detection section, a dial pulse sending section, etc., and detect a ringing signal that arrives when an incoming call is received, give this information to the control unit CTU, and send it to the control unit CTU. Based on control from the CTU, dialing and line holding operations are performed.

Figure 2 is a circuit diagram of the line unit SLU,
A diode bridge consisting of diodes D ₁ to D ₄ connected between line terminals L ₁ and L ₂ to which the office line SL is connected via contacts di of a dial relay DI,
and the incoming detection part connected via the capacitor C ₁ , the contact psl of the relay PSL and the resistor R ₁
It is composed of RDT, etc., and has line terminals L ₁ and L ₂
Regardless of the polarity of the DC voltage applied from the exchange to the switching unit, the DC voltage is always applied to the switch unit SWU side with the polarity in the same direction.

Also, when sending dial pulses, the telephone
The dial relay operates according to the control of the control unit CTU that follows the dial operation on the TEL ₁ to TEL ₈ side.
As DI repeats operation and recovery, contact di, which is a switching element for sending out dial pulses, turns on and off repeatedly, thereby sending out dial pulses, and during this period, the short-circuit relay
Since the DS operates, the telephones TEL ₁ to _{TEL 8} are short-circuited via the switch unit SWU by turning on the contact ds used as a short-circuit switching element.

However, a resistor _R2 with a relatively low resistance value is inserted in series with the contact ds, and a dial pulse signal corresponding to the dial pulse is generated as the terminal voltage of this resistor, and this is sent to the telephones TEL ₁ to TEL ₈ . Therefore, on the telephone used for dialing,
The transmission of the dial pulse can be confirmed by listening to the dial pulse signal.

Besides this, capacitor C ₂ and resistor R ₃ are
This is for extinguishing the spark at contact di, and when a power outage occurs in the AC power supply AC, the drive output from control unit CTU disappears and relay PSL is restored, so contact psl causes bell BL to connect to the line via capacitor _C1 . Connected between terminals L ₁ and L ₂ , incoming calls will ring during a power outage.
It is supposed to be announced by BL.

Note that the resistance value of resistor R ₂ is the same as that of line terminals L ₁ and L ₂
The value of the loop current passed between the terminals is within the range in which the exchange can respond, and the dial pulse signal generated as the terminal voltage of the dial pulse signal can be determined to be a value that can be properly heard by the receivers of the telephones TEL ₁ to TEL ₈ . .

Furthermore, the contacts di, ds, etc. may be made of semiconductor elements such as transistors or thyristors depending on the conditions, or a resistor _R2 may be inserted between the contacts di and ds. Various modifications are possible. It is free.

As is clear from the above explanation, according to the present invention, it is possible to easily check on the telephone side whether or not the dial pulse sent out from the main device in response to the operation on the telephone side is actually sent out, so that in the event of a failure, If dial pulses are not being sent due to reasons such as this, this can be detected reliably and quickly.
Great effects can be obtained in key telephone devices for various uses.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention; FIG. 1 is a block diagram of the entire configuration, and FIG. 2 is a circuit diagram of the line unit. KSU...Main unit, TEL ₁ to TEL ₈ ...Telephone,
SL, SL ₁ , SL ₂ ...Station line, _L1 , _L2 ...Line terminal, di...Contact (switching element for pulse transmission), ds...Contact (switching element for short circuit),
R ₂ ...Resistor.

Claims (1)

[Scope of utility model registration request] Consisting of a main device and a plurality of telephones, the main device performs exchange connections between the office line and each of the telephones, and sends out dial pulses by turning on and off a pulse sending switching element provided in the main device. In the button telephone device, a resistor is inserted in series with a short-circuiting switching element that shorts the circuit on the telephone side when the dial pulse is sent, and the dial pulse signal generated as a terminal voltage of the resistor is confirmed to the telephone. A dial pulse confirmation circuit for a button telephone device characterized in that it sends out a dial pulse.