JPS5847362A - Channel switching system - Google Patents

Abstract

PURPOSE:To prevent the catching of another wrong talking circuit, by delaying the recovery of a relay in a main device which performs the switching between an outside line and an extension in case the feed is cut off to the main device while said relay is working and as a result giving a time margin of ring-off operation to the speaker when a service interruption, etc. arises. CONSTITUTION:The switching is carried out between an outside line CO and a private talking circuit PRV via contacts l1 and l2 of a switch relay L of a main device M, and a connection is given to a key telephone TEL and other key telephones. A switch control a power supply part PW is also connected to the circuit PRV. While a delaying circuit containing a transistors TRQ1 and Q2, a capacitor C, etc. is connected between parts CNT and PW. When the feed is cut to the device M while the relay L is working, the working of the relay L is held by the discharge of the capacitor C. Then a time margin of ring-off operation is given to the telephone TEL, and the catching of a wrong line CO is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for switching communication paths in an IT telephone device, and more particularly to a method for switching operation of a communication path switching circuit during a power outage.
It is.

In a small telephone device, which has one line each for a talk port II (hereinafter referred to as an outside line) to an outside line and a talk port II (hereinafter referred to as an extension line) between two telephones, it is not possible to make a call using a butane telephone. Many telephones use this type of call path switching system, in which the telephone line and extension housed in the main unit are switched by the operation of a relay in the main unit by a selection operation. In the device, when the power supply to the main device is cut off due to a power outage etc. during a call to the line connected to the line connected by the operation of the switching relay of the communication path, the switching relay is restored and the communication circuit of the I-tan telephone is switched off. When the switching relay is restored, it is immediately switched to the line i+ui to be connected, and especially when the restoration side of the switching relay is an outside line, it has the disadvantage that it results in invalid capture of the roaring outside line, which is undesirable.

The present invention has been made to eliminate these drawbacks.

Embodiments of the present invention will be described below with reference to the drawings.

The drawing is a circuit diagram of an embodiment of HOMEKI, where M is the main device and C is the main device.
o is an outside line port (m<for example, a central office line) and a telephone set at the outside line.

In the main device M, PRv is an extension call circuit, L is a switching relay between an outside line and an extension, tX to t3 are contacts of switching relay L,
Is CNT time II? ) switching control unit, Ql is a transistor for controlling the operation of the switching relay L, Q2 is a transistor for controlling the slow and slow recovery of the switching relay L, C is a capacitor for slow and slow recovery of the switching relay L, PW is connected to the power supply unit 1R1, R3 is a resistor, D1～
D3 public safety diode, C01゜CO2 is foreign bank telephone line, Pl
, P2 is an extension telephone line, TI.

T2 is an outside line to the telephone TILL, a communication line common to the extension, and C is a control line.

In the embodiment, the operation side of the switching relay O is for internal calls, and the recovery side is for external calls. It is configured so that it is possible to make phone calls.

In a state where power is being supplied to each part from the power supply section pw of the main device M and neither outside line calls nor internal calls are occurring, the operation instruction of the switching relay B is sent to the output OUT of the switching control section CNT when the power is turned on. Signal (+ polarity signal)
is sent out, the transistor Q1 becomes conductive (hereinafter referred to as on), and the switching relay L changes to FW(+V)-D2-L-Q1 (=rvlid-
Emitter) - operates on the earth path and switches the relay L
After the O operation, the switching control unit CNT is activated by its self-contact t3.
The input IN2K ground is input and the output OUTK is sent out.The operation instruction signal is maintained and the switching relay L continues to operate. In other words, the switching relay L
q, 9% configured to be a constantly operating relay
The contact point t1.12 is switched to the dotted line side and the call is made.
〒2 is connected to the extension communication circuit PRY.

First, a case where the outside line CO is a telephone placed horizontally will be explained. The outside line selection information is inputted from the Ittan Denzumekicho KL that responded to the outside line call or the incoming call from the foreign bank via the control line C to the input INI of the switching control unit CNT in the main device M, thereby making it possible to select the The switching relay L recovery instruction signal (earth potential signal) is output from the output OUT of the switching control unit CN.
is output and the transistor q1 becomes non-conductive (hereinafter referred to as OFF), so the operating path for the switching relay L is cut off, the switching relay Llj is restored, and its contact t
1. t2 switches to the solid line side and the next route rCO-CO
I-L1 (recovery)-1-1-, -Oki-1-2-t2 (recovery)
-CO2-COJ creates a communication path between the outside@CO and the Gatan telephone T)iL, making it possible to make calls outside the Datan Dentsuki TeKL company.

In the above operation, the switching relay is restored without any delay time unlike when the power supply is stopped, which will be described later.
When the restoration instruction signal is sent to the NT 10 output OUT, restoration occurs immediately (according to the normal restoration time of the switching relay L), so there is no delay in the line switching operation.

Next, although it is omitted in Figure 6 to explain the case of an extension call, when a common-law call is made, it is determined that the call is not received due to the extension capture information from the horizontal phone, the extension ringing information, or the response information of the called phone placed horizontally. Various control circuits within the device M carry out known operations from calling the extension to the extension call state. When the extension call state is reached, the switching control unit CNT
An operation instruction signal (+ polarity signal) for the switching relay L is outputted from the output OUT of the transistor Qla, and the transistor Qla is turned on. When the transistor Q1 is turned on, the switching relay L operates on the operating path of the switching relay L, and its contacts t1. L2. t3 is switched to the dotted line side, and the communication line τ1 of the methane telephone horizontally installed. ! 2 is extension call 41
P1. It is connected to the extension communication circuit PRY K via P2, and the switching control unit CNT K has a ground input to its input IN2 through contact A3 as the operation information of the switching relay L, and the output OUT K is sent out. The above-mentioned operation instruction signal is maintained, and the switching relay L maintains its operation. In this way, both the horizontally placed telephones of the calling side and the called party are supplied with communication current from the extension communication circuit PRY, and internal calls are made between the horizontally placed telephones.

Now, in the above-mentioned extension call state, if the power supply from the power supply section PW is cut off due to a power outage, for example, the +V voltage supplied to the output terminal of the power supply section PW will suddenly drop,
Becomes earth potential. In addition, the output 00 of the switching control unit CN〒
Q1 also becomes the ground potential, and the transistor Q1 is turned off. Since the output terminal of the power supply unit PW is at ground potential, the voltage generated by the charges accumulated in the capacitor CK causes the diode D2 to be reverse biased and turned off, and as a result, the charges accumulated in the capacitor CK are C-L
-Q2 (Kopottuta Pace) -R3-Earth Jri! At first, the operating state of the switching relay L is maintained on the route ``trector) - 03-13 (operation) - ground''. This operating state is maintained as long as the discharge current of the capacitor C is greater than or equal to the holding current of the switching relay L. In other words, switching relay L
If the power supply is cut off, the IK will perform a slow recovery operation. on the other hand,
Due to the interruption of the power supply, even during the slow and slow recovery of the switching relay L, the visible display (not shown) indicating that an extension call is in progress on the horizontally placed phone goes out, making it impossible to make an extension call. As a result, if a person who is making an extension call using the methane telephone TFL notices an abnormality (such as a power outage) and stops the extension call while the switching relay L maintains the operating state lIM, the methane telephone τKL Since the current loop of the communication path is cut off before the outside line CO is captured, the inconvenience of erroneously capturing the outside line CO is eliminated. In addition, if the power supply from the power supply unit FW is cut off instantaneously due to a power outage, etc., the input IN of the switching control unit CNT
Information via contact t3 of switching relay L input to 2 (
Since the extension call state is immediately regenerated by the ground potential signal), the extension call state is maintained before and after the momentary power supply interruption.

As explained in detail above, in the present invention, the switching relay that switches the communication path is configured to perform a delayed recovery when the power supply is cut off, so that when a power outage occurs, the person making the call is required to perform the call termination operation. The present invention has an extremely large effect as it provides time margin and prevents erroneous capture of other call lines.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of the present invention. M: Main device placed Nitan telephone CO: Outside! i
PRY: Extension manCNT: Switching control section P%V: Power supply section L: Switching relay Ql
, Q2: ) Lanzosta C; Continued from page 1 of Capacitor 0 Inventor: Shingo Tanaka, 3-9-23 Nishigotanda, Tokyo Parts District, Hasegawa Electric Manufacturing Co., Ltd. ■Applicant: Nippon Telegraph and Telephone Public Corporation ■Applicant: Iwasaki Tsushinki Co., Ltd. 1-7-41 Kugayama, Suginami-ku, Tokyo ■Applicant Nippon Tsushin Kogyo Co., Ltd. 260 Kitamimi, Takatsu-ku, Kawasaki City ■Applicant Nakayo Tsushinki Co., Ltd. 2-chome Daisawa, Setagaya-ku, Tokyo No. 40-2 ■Applicant Hasegawa Electric Manufacturing Co., Ltd. 3-9-23 Nishigotanda, Hobongiwa-ku, Tokyo

Claims (1)

[Claims] The Tan telephone device has a system in which external lines and internal lines are switched by a relay in the main device, and is characterized in that when the power supply to the main device is cut off while the relay is operating, recovery of the relay is delayed. A communication path switching method.