JPS62237845A - Control system for dial circuit of telephone set - Google Patents

Abstract

PURPOSE:To prevent a dial signal from being outputted from a power failure dial circuit at power application by supplying a signal controlling always turning on a switching circuit to the 2nd dial circuit at power application. CONSTITUTION:A dial signal generating circuit 9 receives a current from a constant current circuit 10 and is brought into the operating state at the talking enable state, a signal is outputted to a terminal 9a to turn on the switching circuit 12. On the other hand, since the same potential as that of the other power input terminal 9c is applied to a control input terminal 9b by a photocoupler 13 always turned on, the circuit 9 is inactivated and no dial signal generating output is sent even with the operation of a keyboard 8. When the talking is finished and a hook switch 15 is opened it is detected by,e. g., the master equipment, its information is supplied to a control circuit 5 and the relay A is driven, then the state is brought into the preceding state.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention is provided with a dial circuit that operates when a commercial power source is energized, and a dial circuit that operates during a power outage.
The present invention relates to a dial circuit control system for a telephone in which at least the operating pushbuttons of each dial circuit are shared.

"Prior Art" For example, key telephone devices, multi-function telephones, etc. are equipped with a dial circuit that operates when commercial power is turned on, and a dial circuit that can operate regardless of the commercial power in case of a power outage. It is commonly practiced.

Since the push button operation parts of these dial circuits are usually shared, the dial signal from the dial circuit for power outage is not output when the power is on. Conventionally, this method has been to provide a switching circuit that disconnects the power outage dial circuit from the communication path when the power is on, and to drive the switching circuit to connect the power outage dial circuit to the communication path during a power outage. Since the switching circuit is generally constructed using a relay, it has been an obstacle in reducing the size and cost of the device.

"Problems to be Solved by the Invention" In view of the above-mentioned problems, the present invention provides a telephone that eliminates the need for the switching circuit using a relay or the like, and that does not require a dial signal to be output from the power outage dial circuit when energized. The present invention is intended to provide a dial circuit control system.

"Means for Solving the Problem" Therefore, the present invention is provided with a first dial circuit that operates when the commercial power supply is turned on, and a second dial circuit that operates when the commercial power supply is turned on, and at least an operation of each dial circuit. In a telephone set in which a push button is shared, the telephone line terminal is connected to the telephone circuit network during power on and during power outage through a switching circuit controlled by the second dial circuit. However, when the power is turned on, a signal for controlling the switching circuit to be always on is applied to the second dial circuit.

"Embodiments and Effects" The figure is a block diagram for explaining a telephone dial circuit control system according to the present invention. Reference numeral 1 denotes a telephone, for example, a built-in calling/receiving telephone for power outages, which is the main device in a key telephone device. Reference numerals 2 and 2' denote communication line terminals, which are connected to a central office line or the like. 3 is a dial circuit that is activated during a power outage, 4 is a dial circuit that is activated when power is supplied, 5 is a control circuit, A is a relay driven by the control circuit 5, and aL+82 is its contact point. A power supply circuit 6 supplies operating current to the dial circuit 4 and the control circuit 5. For example, a bell may be used in the 7 beam/ga circuit. 15 is a hook switch.

Reference numeral 8 denotes a keyboard, which is constructed so as to be used in common with the dial circuit 4 as in the past, and at least the push buttons are common. 9 is a dial signal generation circuit, 10 is a constant current circuit, 1.1 is a dial signal sending circuit, 12 is a switching circuit, and 13 is a photocoupler.
It is controlled to be always ON by the power supply circuit 6. 14 is a telephone communication network.

Next, the operation will be explained.

When the commercial power supply is energized, the control circuit 5 controls the relay A so that its contact al p a2 is on the dotted line side, and when a dial number is operated on the keyboard 8, the dial circuit 4 disconnects the call line in response. A dial signal is sent to the terminals 2 and 2'. At this time, the dial circuit 4 is controlled by the control circuit 5 based on the central office line type information given by a setting switch (not shown), etc.
For the P-fold signal, the DTMF signal is selected and sent/output, etc.
The function of the button telephone device as a telephone when energized is the same as before. When the transmission of the dial number is completed, the control circuit 5 drives the relay A, and its contact al.

Since a2 is switched to the solid line side, the communication circuit network 14 is connected to the communication line terminals 2 and 2' via the switching circuit 12 and the hook switch 15, and communication is possible. By the way, in the conventional system, this causes the dial circuit 3 for power outage to
receives current from the constant current circuit 10 and enters the operating state, and when the keyboard 8 is operated, the dial signal generation circuit 9 responds and activates the dial signal sending circuit 11 to send out a dial signal. To avoid such inconveniences, the telephone network 14 is disconnected from the dial circuit 3 while the power is on, and connected to the telephone line via a separately provided switching circuit. Therefore, there were problems as mentioned above.

According to the present invention, the dial signal generating circuit 9 is supplied with current from the constant current circuit 10 in the above-mentioned call enabled state and enters the operating state, outputting a signal to the terminal 9a and turning on the switching circuit 12.

On the other hand, the control input terminal 9b is given the same potential as the other power input terminal 9C by the above-mentioned photocoupler 13 being always ON, so the dial signal generating circuit 9 is in an inactive state (switching circuit 12 is ON). The dial signal generation output is not sent even if the keyboard 8 is operated. When the call ends and the hook switch 15 is opened, this is detected, for example, by the main device, and this information is given to the control circuit 5, and the relay A is driven again to return to the previous state. Next, when the commercial power supply fails, the power supply from the power supply circuit 6 to the control circuit 5 and the like is cut off, and the relay A is restored and its contacts a and I 82 are switched to the solid line side. Further, since the power supply circuit 6 no longer controls the photocoupler 13 to be always ON, the potential of the control input terminal 9b approaches one of the power supply input terminals 9e, and the above-mentioned non-operating state is released.

The present invention can also be implemented in a dial circuit configured to send out a dial pulse signal.

[Effects of the Invention] As explained above, according to the present invention, there is no need to separate the telephone call network from the power outage dial circuit to construct the telephone call circuit even when the power is on. Therefore, the switching circuit, which is generally composed of relays, etc., can be omitted, so that the device can be constructed in a smaller size and at a lower cost.

[Brief explanation of drawings]

The figure is a block diagram illustrating a telephone dial circuit control system according to the present invention. l... Telephone, 2, 2'... Call line terminal, 3, 4... Dial circuit, 6...
Power supply circuit, 8...Keyboard, 9...
Dial pulse generation circuit, 12... song switching circuit

Claims (1)

[Claims] a first dial circuit that operates when commercial power is energized;
In a telephone set that is provided with a second dial circuit that is activated during a power outage, and in which at least the operating pushbuttons of each dial circuit are shared, the connection between the telephone line terminal and the telephone network during power supply and power outage is provided. The connection is the second one above.
The second dial circuit is configured such that the switching circuit is controlled by the second dial circuit, and when the power is applied, a signal is given to the second dial circuit to control the switching circuit to be always on. Characteristic phone dial circuit control system