JPH0779491B2 - End signal transmission circuit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end signal transmission circuit having a relatively simple structure applied to a telephone exchange device such as a button telephone device or an exchange which connects an analog terminal.

2. Description of the Related Art Conventionally, some analog terminals have a function of automatically ending the operation of its own communication / communication circuit by a signal sent from the line when the other party who communicates or talks through the line ends the call. . A DC loop momentary disconnection signal is used as a notification signal of the other party's end call sent from this line (hereinafter referred to as an end call signal).

FIG. 3 shows the configuration of a conventional end signal transmitting circuit.

In FIG. 3, reference numeral 1 denotes an analog terminal, which is connected through a terminal 3 to a common contact 4a of a relay 4 having one circuit and two contacts, and also connected through a terminal 5 to one end of a capacitor 6 and a DC supply circuit 7. . Reference numeral 4b is a contact, which is connected to the DC supply circuit 7 and one end of the capacitor 8. The negative terminal of the DC supply circuit 7 is grounded through the relay 9. The other ends of the capacitors 6 and 8 are connected to the speech transformer 10. Reference numeral 11 is a ringer oscillator, which receives an incoming signal from the contact 4c of the relay 4 and the contact 12 of the relay 12.
to supply to c.

Reference numeral 2 denotes an analog terminal, which is connected to the common contact 12a of the relay 12 having two contacts in one circuit through the terminal 15 and the terminal 1
6 through one end of capacitor 17 and DC supply circuit 18
It is connected to the. A contact 12b is connected to the DC supply circuit 18 and one end of the capacitor 19. The negative terminal of the DC supply circuit 18 is grounded through the relay 20.
The other ends of the capacitors 17 and 19 are the call transformer 21.
It is connected to the.

Next, the operation of the above conventional example will be described based on the timing chart shown in FIG.

As can be seen from FIG. 4 (a), the ringer oscillator 11
Continuously sends incoming signals to the contacts 4c and 12c of the relays 4 and 12. When an incoming call is detected, the common contact 4a and the contact 4c of the relay 4 are connected (see FIG. 4 (b)), the incoming signal is supplied to the analog terminal 1, and the display (not shown) of the analog terminal 1 is supplied. Displayed) (see FIG. 4 (d)). Then, at time t1, when the analog terminal 1 responds to the incoming call, a direct current is supplied from the direct current supply circuit 7 to the relay 4 contact 4b.
And a common contact 4a. When the call ends at time point t2, the relay 9 momentarily cuts off for a certain period of time (the time between time t2 and time t3) based on a specific control signal, so that the call end signal is supplied to the analog terminal 1 (FIG. 4). (See (c)).

The analog terminal 2 also supplies the call-end signal by the same operation (see FIGS. 4 (e) to 4 (g)).

In this way, the above-mentioned conventional call end signal sending circuit can also send the call end signal.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned conventional call end signal sending circuit, in order to send a call end signal to one analog terminal 1 or analog terminal 2, an independent relay 9 or relay other than relay 4 and relay 12 is provided. There is a problem that the circuit configuration becomes complicated because 20 and an independent control signal for controlling this are required.

The present invention solves such a conventional problem and is excellent in that it is possible to generate an end signal by utilizing one control signal and an original relay for transmitting an incoming signal. Another object of the present invention is to provide an end signal transmission circuit.

Means for Solving the Problems In order to achieve the above object, the present invention provides a first switch for connecting / disconnecting an output signal of a ringer oscillator, and a common contact connected to a first analog terminal. A second switch that connects the telephone line terminal and the first switch terminal by switching, and a common contact is connected to a second analog terminal, and a second telephone line terminal and the first switch terminal. And a third switch which is connected by switching
A DC supply circuit for supplying a DC voltage to the second telephone line,
When there is an incoming call to the first and second telephone lines, the second and third switches are connected to the terminals of the first switch for that period, and the first and second analog terminals respond. In this case, the second and third switches are connected to the terminals of the first and second telephone lines, and when the first and second analog terminals are terminated, the second and third switches are connected during the period. And a control means for switching the third switch to the terminal side of the first switch and turning off the first switch.

With the above-described configuration, the present invention switches the second and third switches to the terminal side of the first switch during the period when the control means completes the first and second analog terminals. Since the switch No. 1 is turned off, even if the number of analog terminals increases, the supply of DC voltage can be controlled by one first switch, and the circuit configuration can be simplified.

Embodiment FIG. 1 shows the structure of an embodiment of the present invention. In FIG. 1, 31 is a first analog terminal, and terminal 33
Is connected to a common contact 34a of a relay 34 (second switch) having one circuit and two contacts, and is also connected to one end of a capacitor 36 and a DC supply circuit 37 through a terminal 35. 34b is a contact, which is a DC supply circuit 37 and a capacitor 3
Connected to one end of 8. The other ends of the capacitors 36 and 38 are connected to the speech transformer 40. Reference numeral 41 is a ringer oscillator, which sends an incoming signal. Reference numeral 60 denotes a relay (first switch) having one circuit and one contact, which allows an incoming signal sent from the ringer oscillator 41 to pass or be blocked through the movable contact 60a. The smoke saving 60b of the relay 60 is caused by the contact 34c of the relay 34 and the contact 42c of the relay 42 (third switch) having one circuit and two contacts.
It is connected to the.

32 is a second analog terminal and relays through terminal 45
It is connected to the common contact 42a of 42 and is also connected to one end of the capacitor 47 and the DC supply circuit 48 through the terminal 46. 42b is a contact, which is connected to one end of the DC supply circuit 48 and the capacitor 49. The other ends of the capacitors 47 and 49 are connected to the call transformer 51.

Next, the operation of the above embodiment will be described based on the timing chart shown in FIG.

As can be seen from FIG. 2 (a), the ringer oscillator 41
Continuously supplies an incoming signal to the movable contact 60a of the relay 60. When an incoming call is detected, the common contact 34a and the contact 34 of the relay 34 are connected (see FIG. 2 (c)), and the analog terminal
An incoming signal is supplied to 31 and a display (not shown) of the analog terminal 31 displays based on the incoming signal (second
See FIG. (D)). When the analog terminal 31 responds to the incoming call at time t11 (see FIG. 2 (d)),
The common contact 34a of the relay 34 is switched to the contact 34b side, and a DC current is supplied from the DC supply circuit 37 to the analog terminal 31 through the relay 34. When the call ends at time t12, the common contact 34a of the relay 34 is switched to the contact 34c side for a certain time (the time between time t12 and time t13, see FIG. 2C) based on a specific control signal, and the relay When 60 is interrupted for a certain period of time (time between time t12 and time t13, see FIG. 2 (b)), an end signal (see FIG. 2 (d)), which is a signal for a certain period of time, is not supplied with direct current. ) Is supplied to the analog terminal 31 (see FIG. 2 (d)).

The analog terminal 32 also supplies the end signal by the same operation (see FIGS. 2 (e) and 2 (f)).

As described above, according to the above-described embodiment, a so-called end signal, which interrupts the direct current instantaneously with a smaller number of relays than the conventional example, can be supplied to the analog terminal, so that the circuit configuration becomes relatively simple. . Also, the number of control signals is reduced.

In the present embodiment, at the time of sending the end signal (for example, at time t12 point), the relay 60 is first opened by the control signal, and then the common contact 34a of the relay 34.
Switches to the contact 34c side, while at the end of the end signal (time t13 point), the common contact 34a of the relay 34 first switches to the connection point 34b side by the control signal, and then the relay
Relays 60 and 34 should be selected so that 60 is connected.

EFFECTS OF THE INVENTION As is apparent from the above-described embodiment, the present invention, when the control means terminates the call of the first and second analog terminals,
Since the second and third switches are switched to the terminal side of the first switch and the first switch is turned off, even if the number of analog terminals increases, the DC voltage supply control can be performed with only one first switch. In addition, it has an effect that the circuit configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of an end signal transmitting circuit according to an embodiment of the present invention, FIG. 2 is a timing chart used to explain the operation of the end signal transmitting circuit shown in FIG. 1, and FIG. FIG. 4 is a timing chart used for explaining the operation of the end signal sending circuit shown in FIG. 3, and FIG. 4 is a schematic circuit diagram of the end signal sending circuit. 31,32 …… Analog terminal, 34,42 …… Second switch, 3
7,48 …… DC supply circuit, 41 …… Ringa oscillator, 60…
... the first switch.

Claims (1)

[Claims] 1. A first switch for connecting / disconnecting an output signal of a ring oscillator, a common contact is connected to a first analog terminal, and a terminal of a first telephone line and a terminal of the first switch are connected. A second switch which is switched and connected; a third contact whose common contact is connected to the second analog terminal and which switches and connects the terminal of the second telephone line and the terminal of the first switch; When there is an incoming call on the DC supply circuit for supplying a DC voltage to the first and second telephone lines and the first and second telephone lines, the second and third switches are set to the first and second periods, respectively. And the second and third analog terminals are connected to the terminals of the first and second telephone lines when the first and second analog terminals respond, and the first and second analog terminals are connected. , The period when the second analog terminal ends A termination signal sending circuit, comprising: a control means for switching the second and third switches to the terminal side of the first switch and disconnecting the first switch.