JPH029258A - Switch circuit for line closing - Google Patents

Abstract

PURPOSE:To attain line closing and closing release by one-push type switch by providing a semiconductor switch element connected to a line via a diode bridge in parallel and applying line closing via the diode bridge at on-state and one-push type switch giving an on-signal to a semiconductor switch element at on-operation. CONSTITUTION:A switch 10 is one-push type switch and when the switch 10 is depressed for line closing, a transistor(TR) Q1 is turned on to close lines L1, L2. Simultaneously, a TR Q2 is turned on by the on-state and a power is supplied through the lines L1, L2 from the power circuit 7. A voltage at a power terminal in the control circuit 8 rises by the charging of a capacitor C1 and the TR Q2 keeps the on-state. Thus, even if the switch 10 is restored to the off-state, the line closing state is kept remained. When the talking with the opposite side is finished and the state of left unswitched is reached and when the exchange makes the line voltage zero, the TR Q1 is turned off. The line closing is released through the off-state and the lines L1, L2 are released.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a line-closing switch circuit for a communication circuit of a loudspeaker telephone or the like.

[Prior Art] Fig. 12 shows an example of a circuit of a conventional loudspeaker telephone, and this conventional example has a push-in switch 2 that connects lines L, , , L 2 and a speech circuit 1, and a diode that determines the current direction. When the switch 2 is turned on, M voltage is applied to the communication circuit 1, and this application causes the communication circuit 1 to close the line. There is.

FIG. 13 shows another conventional example, in which the times ftQ
A relay drive circuit 4 is connected to L + and L 2 via a diode Pritsuno 3, and a communication circuit 1 is connected via a relay contact 2α5 of the relay driven by the relay drive circuit t.
is connected between the output terminals of a diode bridge 3, and each time a one-push type switch 6 provided in the relay drive circuit 4 is operated, the relay drive circuit 4 reverses the operation of the relay and operates the relay. The contact 5 is turned on and off.

That is, by operating the switch 6, the relay contact 5 is turned on and off, and the line voltage of the communication circuit 1 is turned on and off by the L, and the recorded line is opened and closed by the -.

[Problems to be Solved by the Invention] However, since the former conventional example uses a push-in switch, there is a problem in that it is difficult to automatically disconnect using a timer or the like.

In addition, in the latter conventional example, automatic disconnection using a timer etc. can be easily adopted, but when the other party ends the call, the line L, , L
If connected to an exchange that reduces the voltage of 2 to zero,
If a latching type relay is used, there is a problem in that the relay cannot be reset and the line remains closed.

Historically, when using a single-stair pull type relay, even if the line voltage drops to zero, the relay turns off at that moment.
Although the above problem is eliminated, the single staple type generally consumes a current of several 101 A at all times, so 4#iL,,L
There is a problem in that a telephone operated by power supply from 2 cannot obtain an operating current for the circuit, and a loudspeaker telephone cannot obtain sufficient volume from a speaker.

The present invention was made in view of the above-mentioned problems, and it can easily perform automatic disconnection, has low power consumption, and the current flowing from the line is low, and can be used even with loudspeaker telephones without affecting the volume of the speaker. Furthermore, the purpose is to provide a line closing switch circuit that can automatically disconnect the line even when connected to an exchange that sets the line voltage to zero V at the end of a call, and also provides a one-push type switch. To provide a line closing switch circuit that can close a line with an instantaneous operation, close and unclose the line with a single one-push switch, and send out dial pulses and control signals. The purpose is to

[Means for Solving the Problems r'i1] The present invention comprises a first semiconductor switching element which is connected in parallel to a line via a diode 7) and which closes the line via a diode 7) when turned on; a second semiconductor switch element that is turned on when the semiconductor switch element is turned on; a power supply circuit that is supplied with power from the diode through the second semiconductor switch element; It consists of a control circuit that outputs an on signal to the switch element, and a one-push type switch that applies an on signal to the first semiconductor switch element when it is turned on.

The invention according to claim 2 is the invention according to claim 1, in which the one-push type switch is charged in a short time when the switch is turned on, and the charged charge is discharged over a long period of time from when the switch is turned off. This discharge current is used as the ON signal for the first semiconductor switch element.

The invention according to claim 3 is the invention according to claim 2, further comprising means for detecting the operation of the one-push type switch and inputting a detection signal to the control circuit, and when the one-push switch is operated after the line is closed, the control circuit In this case, the output of the ON signal of the first semiconductor switching element is stopped.

Furthermore, the invention according to claim 4 is the invention according to claim 3, further comprising a dial switch group for instructing the control circuit to send dial pulses, and when the dial switch group is operated, the first semiconductor switch is activated in response to the switch. The control circuit outputs a signal to turn on and off, and sends a dial pulse to the line.

Furthermore, the invention according to claim 5 is the invention according to claim 3 or 4, further comprising a group of control switches for instructing the control circuit to send out a control signal, and when a switch of this control switch group is operated, the above-mentioned switch is activated in response to the switch. A control circuit outputs a signal for turning one semiconductor switch on and off, and a control signal consisting of a pulse train is sent to a line.

[Function] With the above configuration, the first semiconductor switch element can be turned on by operating the switch to close the line, and at the same time, by turning on the first semiconductor switch, f:
The switch semiconductor of tS2 is turned on and power is supplied from the line to the control circuit through the power supply circuit, and after the power supply, the on state of the semiconductor switch element of fjSl can be maintained by the on signal of the control circuit.

When the line voltage becomes zero after the end of the call, the power supply to the control circuit is stopped, the first semiconductor switch element is forcibly turned off, and the line connection is released.

In addition, according to the invention set forth in claim 2, the time for operating the switch can be shortened.

Further, in the invention as set forth in claim 3, if the switch is operated after the line is closed, the control circuit turns off the first semiconductor switch element in response to this operation and releases the line.

Furthermore, in the invention set forth in claim 4, when the line is closed and a switch of the dial switch group is operated, the control circuit activates the PII.
The semiconductor switch element of Jl is turned on and off to disconnect the line and send a dial pulse to the line.

Similarly, in the invention as set forth in claim 5, when the line is closed and the control switch group is operated, the control circuit turns on and off the first semiconductor switch element and sends a control signal consisting of a pulse train to the line.

[Example 1 1 (Δ) and FIG. 1 show the circuit of this embodiment. In this embodiment, a communication circuit 1 is connected to a coupling transformer 9 and a gouio via a bridge 3, and is connected to L2. 1 is obtained from a power supply circuit 7.A line connection circuit is made up of a resistor R1 connected between the output terminals of the diode bridge 3 and a transistor Q, which is a first semiconductor switching element.
It consists of a series circuit with .

The power supply circuit 7 includes a transistor Q, which is a second semiconductor switching element, at the output end of the diode bridge 3.

is connected through #i when transistor Q2 is on.
Power is supplied from L, , L2 through a diode bridge 3 to create a stable power supply voltage necessary for operation of the communication circuit 1 and a control circuit 8 to be described later.

The control circuit 8 is composed of a one-chip microcomputer, etc., and when it receives power supply, it starts operating and sets the output port O1 to H''.

The switch 10 is a one-push type switch, and is connected to the output terminal of the diode bridge 3 and the base of the transistor Q via a resistor R2.

In this embodiment, when the switch 10 is pressed as shown in FIG. 2(a) to close the line, the transitions X y Q
A base current flows through the resistor R2 to the base of the transistor Q, turning on the transistor Q and closing the line L2.

At the same time, this turning on causes current to flow through the emitter base of transistor Q2, resistor R3, and transistor Q, turning on transistor Q2, and power supply circuit 7 is turned on at times ML, , L.
Power is supplied from 2 units. Due to this power supply, the stabilized power supply voltage of the power supply circuit 2 is applied to the telephone communication circuit 1, and the communication becomes possible. On the other hand, in the control circuit 8 whose power supply voltage is the voltage across the capacitor C1 charged through the diode 1'D, the voltage at the power supply terminal is increased by the photoelectric current of the capacitor C5 as shown in FIG.
It rises as in b). When this voltage reaches the operating voltage Vcc of the control circuit 8, the control circuit 8 sets the output port O1 to H'' as shown in FIG. Since the transistor Q1 is connected to the base of the transistor Q through a circuit such as
Even if 0 is turned off again, the line remains closed.

Next, when the call with the other party ends and a so-called forget-to-hang-up state occurs and the exchange sets the line voltage to zero, the power supply to the power supply circuit 7 is stopped and the output voltage of the power supply circuit 7 also becomes zero V.

Therefore, the operation of the control circuit 8 is also stopped, and its output is stopped.
0+ becomes L'', and the transistor Q1 turns off. This turns off the line connection and releases the line, L2.

Even if you forget to turn it off at this point! Voltage 5! If the line is connected to a non-PV exchange, the line can be automatically disconnected by operating the control circuit 8 with a timer and setting the output port o to L'' after a certain period of time.

Of course, the end of the call may be detected by reversing the polarity of the lines L, L2, etc., and the line connection may be canceled after a certain period of time from that point. Even if it is released, the power consumption can be suppressed because the control circuit 8 of the surface microcomputer is used, but in order to further suppress the power consumption, it is preferable to increase the value of the resistor R1.

X1 Note: In the circuit of the first embodiment, it is necessary to keep pressing the switch 10 until the control circuit 8 starts operating, but this embodiment has been improved in this respect.

In other words, in this embodiment, the circuit that causes the base current to flow through the base of the transistor Q1 when the switch 10 is pressed is configured by the resistor R6.
Diode D3, resistor R7, capacitor C2, resistor R2
, a diode D, and another output port o2 of the control circuit 8 is used to control the charge discharging transistor Q3 of the capacitor C2.

When the switch 10 is pressed and operated as shown in FIG. 4(a), the transistors Q, Q2 are turned on in the same way as in the first embodiment. As shown in Figure 4(d), the capacitor C2 is charged with a short time constant R7, C2, and then the charge of the capacitor C2 is discharged to the base of the transistor Q1 with a long time constant R2, C2. In order to allow current to flow, the transistor Q1 remains on for a certain period of time even if the switch 0 is opened immediately after being pressed. If the voltage of the capacitor C1 reaches the operating voltage Vcc of the control circuit 8 as shown in FIG. 4(b) within this certain period of time, the output port 01 of the control circuit 8 will change as shown in FIG. 4(c). Since the level becomes H'', the on state of the transistor Q is continuously maintained. At the same time, the output port 02 is maintained for a certain period of time as shown in Fig. 4(e), so the transistor Q is turned on and the charge in the capacitor C2 is discharged via the resistor R7 and the transistor Q3. Turns on transistor Q1 of
Off control is performed only at the output port 01 of the control circuit 8.

The operation in case of forgetting to turn off is the same in this embodiment as in Embodiment 1 described above, and as a countermeasure against an exchange that does not reduce the line voltage to zero even though the other party's call has ended, the control circuit 8 is provided with a timer function. Good.

X1 Clear - In the above embodiments 1 and 2, in order to forcibly release the line connection at the end of a call, an off switch is provided and the control circuit 8
However, in this embodiment, the switch 10 must be operated.
The circuit #iL, , L2 can be closed and unclosed by the following operations, and is constructed by adding the following circuit to the circuit of the second embodiment. As shown in the diagram, a capacitor C1 is provided to supply power to the control circuit 8.
A series circuit of a resistor R8 and a transistor Q4 is connected in parallel to the input port 1 of the control circuit 8, and the collector of the transistor Q4 is connected to the input port 1 of the control circuit 8.
A capacitor C3 is connected between the base and emitter of the transistor, and a resistor R6 is connected via a resistor R5.

The operation when the line is closed is the same as in the second embodiment, but when the switch 10 is operated as shown in FIG.
The input capo of the control circuit 8 is turned on during the on period of 1. as shown in FIG. 6(b). changes from H'' to L''. The control circuit 8 detecting this change outputs the output port 0.
1 at the falling edge of the switch signal of switch 10, tI
rJ6 As shown in Figure 6(c), the transistor Q1 is inverted from "H" to L to turn off the transistor Q1.In other words, the line connection is released.At the same time, as shown in Figure 6(d), the output capacitor is turned off. 02 from ``L'' to ``H'' for a certain period of time,
The transistor Q3 is turned on, thereby discharging the charge in the capacitor C2 that was charged when the switch 10 was turned on, and returning the capacitor to its initial state.

The operation in case of forgetting to turn off is the same in this embodiment as in Embodiment 1.2 above, and the control circuit 8 also has a timer function as a countermeasure against an exchange that does not reduce the line voltage to zero even though the other party's call has ended. It's fine if you can.

Dog 1"L [The above embodiments 1, 2.3 were specialized in responding to the other party, but in this embodiment, a dial pulse can be sent after the line is closed. A dial switch group 11 for transmitting dial pulses is added to the circuit of Example 3.

In order to send out dial pulses, the line is first closed by operating the switch 10, and then the line shown in FIG.
, ), when a switch in the dial switch group 11 is operated, the control circuit 8 controls the output port 0 according to the dial number of the switch so as to meet the dial pulse standard as shown in FIG. A signal that repeats "H" and "L" is output. This signal causes transistor Q,
Repeatedly turn on and off #il L , , L
2 intermittently and dial pulse times Ml, 1. It can be sent to L2. At this time, the transistor Q2 is also repeatedly turned on and off at the same time. Note that during this dial pulse sending period, the control circuit 8 sets the output port O2 to H'' as shown in FIG. 8(c).
During the period, transistor Q3 is on, and switch 10 is turned on.
operation is not accepted.

In addition, switch 10P is used to release the line after the call ends.
Work A, and even release the line when you forget to turn it off, or control circuit 8
This embodiment is similar to the third embodiment in that it has a timer function.

In K11 foot embodiment 4, it is possible to send a dial pulse, but in addition to the function of this embodiment 4, this embodiment also sends a special control signal to a home telephone exchange etc. through ML, L2. It was made so that it could be done.

In other words, as shown in FIG. 9, a control switch group 12 is added to the circuit of the fourth embodiment, and when sending a control signal, after the line is closed, the control switch group 12 is added as shown in FIG.
If the switch No. 2 is operated, the control circuit 8 will output the output port O1 in the same way as dial pulse transmission according to the switch.
by controlling pIrJ10 as shown in Figure (b).
Outputs a signal that repeats With this signal, the transistor Q can be repeatedly turned on and off to intermittently turn on and off the circuits ML, . . . L2, and send a control signal consisting of a pulse train to the line ML, . . . L2. At this time transistor Q2
will also be turned on and off at the same time. Note that during the sending period of this control signal, the control circuit 8 sets the output port 02 to H'' as shown in FIG. 10(c), so this H''
During the period, transistor Q is turned on and switch 10 is turned on.
operation is not accepted.

The operation of the switch 10 when disconnecting the line after the end of a call, the disconnection of the line when the user forgets to disconnect the line, and the fact that the control circuit 8 is provided with a timer function are similar to the fourth embodiment and the third embodiment.

A system using a home telephone exchange using this embodiment is shown in FIG. 11. In this system, the telephone exchange 13 is connected from the outdoor side! 14 and the telephone line 16 of the door intercom slave unit 15, and on the indoor side, an internal line consisting of an extension line 17 and a signal line 18 is led out from the telephone exchange 13, and a telephone outlet 19 is connected to this internal line. Modular jack 2 installed in telephone outlet 19
1 is connected to a telephone 20 such as a loudspeaker telephone using the switch circuit for a communication circuit of this embodiment. Telephone exchange @13 calls outside #114, extension 17, and inside #! in response to incoming calls or calls. 17, a communication line 16 and an extension line 17 form a communication path, and at the same time, a signal indicating the line status is sent to the telephone outlet 19 through a signal #118, and the telephone outlet 19 is configured to display or notify.

[Effects of the Invention] The present invention provides a semiconductor switch element @1 which is connected in parallel to a line via a diode bridge and closes the line via the diode bridge when turned on, and a semiconductor switch element @1 which is turned on when this semiconductor switch element is turned on. 2 semiconductor switch elements;
A power supply circuit that is supplied with power from the diode Pritsuno through this second semiconductor switching element, a control circuit that operates by receiving power from this power supply circuit and outputs an ON signal to the first semiconductor switching element, and Since it consists of a one-push type switch that gives an ON signal to the first semiconductor switch element, it is possible to maintain the line connection by forming a latching type switch using the semiconductor switch element. The current flowing from the R31 line can be suppressed to a small level, and as a result, even if it is installed in a public address telephone, it will not affect the volume of the speaker, and it can also be connected to a telephone exchange that reduces the line voltage to zero after the end of a call. Even in such a case, when the line voltage becomes zero V, the power supply to the control circuit is stopped and the second semiconductor switch element is automatically forced off to release the line connection. Since it is a latching type switch using an element, it also has the advantage of being easy to automatically disconnect using a timer function, etc.

Further, the invention according to claim 2 is such that the one-push type switch is charged in a short time when the switch is turned on, and the charged charge is released for a long time from when the switch is turned off, and the discharge current caused by this release is transferred to the first semiconductor switch. Since this is an ON signal for the element, it has the effect of reducing the time required to operate the switch.

Furthermore, the invention according to claim 3 is provided with means for detecting the operation of the one-push type switch and inputting a detection signal to the control circuit, and when the switch is operated after the line is closed, the control circuit detects the operation of the first semiconductor switch. Since it is designed to stop the output of the ON signal of the element, if the switch is repeatedly operated after the line is closed, the control circuit will turn off the first semiconductor switch element in response to this operation and release the line. Furthermore, the invention according to claim 4 provides a dial switch group for instructing the control circuit to send out Guyarvals, and when the dial switch group is operated, the semiconductor of PltJ1 is activated in response to the switch. The control circuit outputs a signal to turn on and off the switch and sends a dial pulse to the line, so when the line is closed and a switch in the dial switch group is operated, the control circuit switches to the first semiconductor. It is possible to turn on and off the switch element to connect and disconnect the line and send dial pulses to the line, and it has the advantage that the semiconductor switch element used for line connection can also be used as a switch element that sends out dial pulses. .

Furthermore, the invention according to claim 5 provides a group of control switches for instructing the control circuit to send out a control signal, and when a switch of the il+ control switch group is operated, the first semiconductor switch is turned on and off in response to the switch. 46 from the control circuit and sends a control signal consisting of a pulse train to the line, so if the control switch group is operated while the line is closed, the control circuit will switch to the first semiconductor. It is possible to turn on and off a switch element to send out an il + okutsugo consisting of a pulse train to a line, and it is useful when sending control signals to home telephone exchanges, etc. Moreover, it uses a semiconductor switch element for line closure. This has the advantage that it can be used as a switching element for signal generation.

[Brief explanation of the drawing]

1 is a circuit diagram of the first embodiment of the present invention, FIG. 2 is a time chart for explaining the operation of the same as above, FIG. 3 is a circuit diagram of the second embodiment of the present invention, and FIG. 4 is a timing chart for explaining the operation of the same as above. 11 charts,
5 is a circuit diagram of the third embodiment of the present invention, FIG. 6 is a time chart for explaining the operation of the same as above, FIG. 7 is a circuit diagram of the fourth embodiment of the present invention, and FIG. 8 is a time chart for explaining the operation of the same as above. 9 is a circuit diagram of the fifth embodiment of the present invention, FIG. 10 is a time chart for explaining the operation of the same, FIG. 11 is a system configuration diagram of a telephone exchange system using the same, and FIG. 12 is a conventional example. The circuit diagram shown in FIG. @13 is a circuit diagram of another conventional example. 3 is a diode bridge, 7 is a control circuit, 8 is a control circuit, 10 is a switch, L, , , L 2 is a line, Q
+tQ2 is a transistor. Agent Patent Attorney Ishi 1) Ai Nanaatsu 2 Ken @ 4 Figure 6 Senchi I 8 Shitajo 10 Figure

Claims (5)

[Claims] (1) A first semiconductor switch element that is connected in parallel to the line via a diode bridge and closes the line via the diode bridge when turned on, and a second semiconductor switch element that turns on when this semiconductor switch element is turned on. a power supply circuit that receives power from the diode bridge through the second semiconductor switch element; a control circuit that receives power from the power supply circuit and outputs an on signal to the first semiconductor switch element; A line closing switch circuit comprising a one-push type switch that provides an on signal to the first semiconductor switch element. (2) When a one-push type switch is turned on, it is charged in a short time, and when the switch is turned off, the charged charge is released over a long period of time, and the discharge current caused by this release is used as the on signal for the first semiconductor switch element. 2. The line closing switch circuit according to claim 1. (3) A means is provided to detect the operation of the one-push type switch and input the detection signal to the control circuit, and the control circuit outputs the ON signal of the first semiconductor switch element when the switch is operated after the line is closed. Claim 2 characterized in that it stops.
Switch circuit for closing the line as described. (4) The control circuit is provided with a dial switch group that instructs dial pulse transmission, and when the dial switch group is operated, the control circuit outputs a signal that turns the first semiconductor switch on and off in response to the switch, and the circuit The line closing switch circuit according to claim 3, characterized in that it sends out a dial pulse. (5) providing a control switch group for instructing the control circuit to send a control signal, and outputting a signal from the control circuit to turn on and off the first semiconductor switch in response to the switch when the control switch group is operated; 5. The line closing switch circuit according to claim 3, wherein a control signal consisting of a pulse train is sent to the line.