JPS63299643A - On-hook dial signal sending circuit for telephone set - Google Patents

Abstract

PURPOSE:To automatically release a line close state even if the on-hook dial switch of a telephone set is unconsciously or erroneously turned on, by connecting a timer circuit and a switch circuit, which is controlled by the output of this timer circuit, in parallel with the on-hook dial switch. CONSTITUTION:When an on-hook dial switch 8 is depressed, a dial pulse sending circuit 2 is operated to close a line and reset of a counter circuit 104 is released to start the counting operation. If dial transmission is performed within T seconds, the counter circuit 104 is reset. When T seconds elapse after depression of the on-hook dial switch 8, an output terminal O of the counter circuit 104 is switched to the high level from the low level and a switch circuit 81 is turned on, and the state is equivalent to depression of the on-hook dial switch 8, and the telephone set is released to the initial state of on-hooking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an on-hook dialing signal sending circuit for a telephone.

[Conventional technology]

Recently, an increasing number of telephones are equipped with an on-hook dialing function that allows dialing without leaving the handset.

FIG. 2 is a block diagram showing an example of an on-hook dial signal sending circuit of a conventional telephone.

In FIG. 2, the on-hook dial signal sending circuit of this conventional telephone has a power supply circuit 5 connected in parallel between a pair of line terminals L1 and L2, and a first dial pulse sending circuit 1 and a telephone line connected in series. The circuit 3 is connected in parallel, and further connected in parallel with the second dial pulse sending circuit 2 connected in series and the receiving loudspeaker circuit 4 connected to the speaker 41. Also, a dialer circuit 6 for transmitting dial pulses, and this dialer circuit are connected in parallel. The oscillating dial pulse of 6 causes the first dial pulse sending circuit 1 and the second dial pulse.
A state control circuit 7 that controls the dial pulse sending circuit 2 of
In addition, a non-locking on-hook dial switch (LK) 8 connected to the LK terminal of the state control circuit 7 and turned on and off by manual operation, and a handset (not shown) connected to the HK terminal of the state control circuit 7 are installed. It is configured to include a hook switch (HK) 71 that turns on and off by lifting it up.

The power supply circuit 5 is a circuit that obtains a constant drive voltage for driving the dialer circuit 6 and the state control circuit using power supplied from an external circuit through a pair of line terminals LL and L2, and has a current limit. resistors R1, R2, R3 for
Diodes Di, D2. for backflow elements. D3, a Zener diode ZD for output voltage stabilization, and a smoothing capacitor C.

Further, a dial panel 9 externally attached to the dialer circuit 6
1 for dial operation. -9,0 dial switch 91 is provided. When dial operation is performed using this dial switch 91, the dialer circuit 6 changes to DP.
A dial pulse is output from the terminal to the DP terminal of the state control circuit 7.

Next, the operation of the conventional telephone on-hook dialing signal sending circuit will be explained.

In the case of a normal dial operation with the handset lifted, the dial pulse sending circuit 1 connected in series with the telephone call circuit 3 is controlled by the state control circuit 7 and outputs a dial pulse.

In addition, in the case of on-hook dialing operation with the handset left, the operation is started by pressing the on-hook dialing switch 8. Pressing this on-hook dial switch 8 sends the same instruction to the state control circuit 7 as when lifting the handset. In this case, when a dial operation is performed using the dial switch 91, the state control path 7 sends a dial pulse to the dial pulse sending circuit 2 connected in series to the receiving loudspeaker circuit 4. A dial pulse is sent. In this case, the dial tone and the response of the other party can be monitored from the speaker (SP) 41 connected to the receiving loudspeaker circuit 4. Finally, when the on-hook dialing button 8 is pressed again, the line is released and at the same time the telephone is restored to its initial on-hook state.

[Problem that the invention seeks to solve]

The above-mentioned on-hook dialing signal sending circuit of the conventional telephone does not remove the handset from the telephone body when performing on-hook dialing, unlike when dialing normally, so the on-hook dialing signal transmission circuit does not respond when the on-hook dialing switch is pressed or after the on-hook dialing switch is pressed by some external force. If the telephone line is left closed and the telephone set is left connected, a switchboard with a howler sound sending function will send a howler sound for about 10 milliseconds every 5 minutes, but for example, if the telephone line is left connected, a howler sound will be sent out for about 10 milliseconds every 5 minutes. If the volume is turned down, there is a drawback that the user will not notice the howler sound and the phone will be left unattended with the telephone line still connected.

[Means for solving problems]

The on-footer dialing signal sending circuit of the telephone according to the present invention includes:
A first dial pulse sending circuit and a talking circuit are inserted between a pair of line terminals and connected in series, and a second dial pulse sending circuit and a receiving loudspeaker circuit are connected in parallel to these circuits and connected in series, and send dial pulses. a state control circuit that controls the operation of the first and second dial pulse sending circuits by the dial pulse, a hook switch, and an on-hook dial switch, the output terminal of the hook switch and the on-hook The output ends of the dial switches are respectively connected to the state control circuit, and when the dial is operated in the off-hook state, the dial pulse is sent out from the dial pulse sending circuit 1, and when the dial is operated in the on-hook state, the dial pulse is sent out from the dial pulse sending circuit 1. The on-hook dial signal sending circuit of the telephone that sends out the dial pulse from the second dial pulse sending circuit includes a switch circuit and a timer circuit, and the switch circuit has its output end connected to the output end of the on-hook dial switch. , the timer circuit has its output terminal connected to a control input terminal of the switch circuit, and the input terminal of the timer circuit is connected to a control output terminal of the state control circuit and an output terminal of the hook switch, respectively. made up of.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, the on-hook dial signal sending circuit of the telephone of this embodiment has a pair of line terminals LL, similar to the on-hook dial signal sending circuit of the conventional telephone shown in FIG.
A power supply circuit 5 is connected in parallel between L2, and similarly, the first dial pulse sending circuit 1 and the talking circuit 3 are connected in series, and the second dial pulse sending circuit 2 and the receiving loudspeaker circuit 4 are connected in series. In addition to a dialer circuit 6 and a state control circuit 7 connected in parallel to control the dial pulse sending circuit 1 and the dial pulse sending circuit 2, a switch circuit 81 and a timer circuit 10 are added. The switch circuit 81 is connected in parallel to the on-hook dial switch 8, and the control input terminal C of the switch circuit 81 is connected to the output of the timer circuit 10 and is controlled by the output of the timer circuit 10.

The timer circuit 10 includes a counter 104, a flip-flop (hereinafter referred to as FF) 101, a three-man power AND circuit (hereinafter referred to as AND circuit) 102, and an inverter circuit (hereinafter referred to as INV) 103. The output terminal 0 of the counter circuit 104 becomes the output terminal of the timer circuit 10 and is connected to the control input terminal C of the switch circuit 81, and the reset input terminal R of the counter circuit 104 becomes the output terminal of the timer circuit 10.
connected to the output end of the The three input terminals of the AND circuit 102 are connected to the output terminal Q of FFl0I, the output terminal of the hook switch 71, and the output terminal of the INV 102, respectively. I
The input terminal of NV102 is connected to the output terminal H3 of the state control circuit 7. Further, the output terminal DP of the dialer circuit 6 is connected to the clock input terminal C of the FF 101, the output terminal of the hook switch 71 is connected to the reset input terminal R1, and the output terminal of the hook switch 71 is connected to the reset input terminal R2.
The output of INV103 is connected to the input terminal, and the power supply VDD is connected to the input terminal.

Next, the operation of on-hook dialing in this embodiment will be explained.

When the on-hook dial switch 8 is pressed, the output terminal D2 of the state control circuit 7 goes to a high level (hereinafter referred to as H) and the output terminal H3 goes to a low level (hereinafter referred to as below), and the dial pulse sending circuit 2 operates to disconnect the line. At the same time as closing
The output terminal of the AND circuit 102 becomes H, and the counter circuit 1
The reset of 04 is released and the counter operation is started.

If the counter timing is T seconds, the output terminal O of the counter circuit 104 becomes H after T seconds.

Here, when dialing is to be made within T seconds, when the dial switch 91 is pressed, the output terminal DP of the dialer circuit 6 operates from H-+L to H, and the FF 101 operates and its output terminal Q changes from H-+L to H. The output terminal of the AND circuit 101 becomes L, and the counter circuit 104 is reset. After sending the dial pulse, the other party answers and sets the handset (
(not shown), the output terminal of the hook switch (HK) 71 becomes L, and the output terminal D1 of the state control circuit 7 becomes H1.
The output terminal D2 becomes L, the dial pulse sending circuit 1 operates, and the telephone call circuit 3 is connected between the lines connected to the terminals LL and L2, and a telephone call is possible. At the same time, FF 101 is reset.

Next, T seconds after pressing the on-hook dial switch 8, the output terminal O of the counter circuit 104 becomes L-+H, and the switch circuit 81 is turned on, which is equivalent to pressing the on-hook dial switch 8, and the telephone returns to the initial state of on-hook. Recover.

If the counter timing T seconds is about 30 seconds, even if the on-hook dial switch 8 is pressed unconsciously,
Normally, you will not receive the first howler sound, but if you think it would be better to be able to confirm the first howler sound, T may be set to about 60 seconds.

〔Effect of the invention〕

As explained above, the present invention provides a conventional on-hook dial signal sending circuit with a timer circuit that starts counting time at the same time as the on-hook dial switch is turned on, and a switch circuit that is controlled by the output of the timer circuit, which is connected in parallel to the on-hook dial switch. By connecting, the line is automatically disconnected even if no dialing is performed within the preset on-hook time, so for example,
Even if the on-hook dial switch of the telephone is turned on unconsciously or by mistake, the telephone automatically restores the initial state without receiving a howler sound, and automatically releases the line closed state, This has the effect of eliminating unnecessary line connections to the exchange.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of an on-hook dial signal sending circuit of a conventional telephone. DESCRIPTION OF SYMBOLS 1... Dial pulse sending circuit, 2... Dial pulse sending circuit, 3... Call circuit, 4... Receiving loudspeaker circuit, 5... Power supply circuit, 6... Dialer circuit, 7...
... State control circuit, 8 ... On-hook dial switch (LK), 71 ... Hook switch (HK), 81
...Switch circuit, 9...Dial panel, 91.
...Dial switch, 10...Timer circuit, 10
1...Flip-flop (FF), 102...3 manual AND circuit (AND), 103...Inverter circuit (INV).

Claims (1)

[Claims] A first dial pulse sending circuit and a talking circuit are inserted between a pair of line terminals and connected in series, and a second dial pulse sending circuit and a receiving loudspeaker circuit are connected in parallel to these circuits and connected in series, and send dial pulses. a state control circuit that controls the operation of the first and second dial pulse sending circuits by the dial pulse, a hook switch, and an on-hook dial switch, the output terminal of the hook switch and the on-hook The output ends of the dial switches are respectively connected to the state control circuit, and when the dial is operated in the off-hook state, the dial pulse is sent out from the dial pulse sending circuit 1, and when the dial is operated in the on-hook state, the dial pulse is sent out from the dial pulse sending circuit 1. The on-hook dial signal sending circuit of the telephone that sends out the dial pulse from the second dial pulse sending circuit includes a switch circuit and a timer circuit, and the switch circuit has its output end connected to the output end of the on-hook dial switch. , the timer circuit has its output terminal connected to a control input terminal of the switch circuit, and the input terminal of the timer circuit is connected to a control output terminal of the state control circuit and an output terminal of the hook switch, respectively. An on-hook dialing signal transmission circuit for a telephone, characterized in that the circuit comprises: