JPH02268588A - Key telephone system - Google Patents

Abstract

PURPOSE:To only connect one an extension telephone set for a power failure to plural telephone circuits and to reduce the cost of facilities by providing an in-power-failure connecting circuit which connect telephone circuits and the power failure extension telephone set in parallel in the case of a power failure, a power failure detecting circuit, etc. CONSTITUTION:The key telephone system which has plural telephone circuits 1a-1n is provided with the power failure detecting circuit 3 and the in-power- failure connecting circuit 2 which connects the telephone circuits 1a-1n to the power failure extension telephone sets 4 in parallel with the signal from the power failure detecting circuit 3. Further, this system is provided with an incoming signal detecting circuit 5 for detecting the incoming signals of the telephone circuits 1a-1n, a switch A which connects the telephone circuits at the time of termination, a switch B which is connected to the switch A in parallel, and a current detecting circuit 6 which detects DC currents generated on the telephone circuits by the off-hook operation of the power failure extension telephone set 4. Consequently, this one power failure extension telephone set 4 can detect the incoming signals of all the telephone circuits and the cost of the facilitates is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a button telephone device, and in particular, it has a plurality of telephone lines and one extension telephone for power outage, and is powered by a power source other than a central office line. The present invention relates to a button telephone device that can answer incoming calls during a power outage.

[Prior Art] A button telephone device includes a main device, a plurality of button telephones,
It consists of cables that connect these lines, allowing a small number of telephone lines to be shared efficiently by a large number of telephones, and a feature that allows you to make and answer calls to any central office line from any telephone with the touch of a button. have.

Conventionally, in such key telephone devices, one extension telephone for power outage was connected to one telephone line.

[Problem to be solved by the invention] The conventional button telephone device described above has one telephone line per telephone line.
Since one extension telephone for power outages is connected, the number of extension telephones for power outages equal to the number of telephone lines is required, which has the disadvantage of increasing equipment costs.

Means for Solving the Problems] An object of the present invention is to solve the problems of the prior art described above, and to provide a button telephone device in which it is sufficient to connect one extension telephone for power outage to a plurality of telephone lines. That's true.

The present invention provides a telephone device that has a plurality of telephone lines and one extension telephone for power outage and is capable of answering incoming calls during a power outage by supplying power from a power source other than a central office line. a power outage detection circuit that detects a power outage condition and operates the power outage connection circuit in the event of a power outage; an incoming signal detection circuit that is connected to a telephone line and detects an incoming signal; Switch A is located between the signal detection circuit and the power outage connection circuit, and connects the telephone line and the power outage extension telephone when a call is received under the control of the incoming signal detection circuit, and opens the telephone line when there is no incoming call.
and a switch B connected in parallel to switch A, which is located on the telephone line between the incoming signal detection circuit and the power outage connection circuit, detects the direct current of the telephone line, and determines the current value of the telephone line in advance. If the current value of the telephone line is less than a predetermined value, the incoming signal detection circuit of all telephone lines connected to the PP power standby connection circuit is stopped at the same time as switch B is connected. , and a current detection circuit that opens switch B.

Embodiments] Next, a key telephone device according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a key telephone device according to the present invention.

The button telephone device according to the present invention includes a plurality of telephone lines 1a to 1a.
In the button telephone device having 1n, the power failure detection circuit 3
, multiple telephone ports R1 are activated by the signal from the power outage detection circuit 3.
A power outage connection circuit 2 connects a to 1n and power outage extension telephones 4 in parallel, an incoming signal detection circuit 5 to detect incoming signals on each of the telephone lines 1a to 1n, and connects the telephone lines when a call is received. It has a switch A, a switch B connected in parallel to the switch A, and a current detection circuit 6 that detects the direct current of the telephone line caused by the off-hook of the extension telephone 4 for power outage. When the current detection circuit 6 detects the direct current of the telephone line, it stops the operation of the incoming signal detection circuits 5 of all the telephone lines 1a to 1n, and further turns on the switch B.

Next, the operation of the button telephone device of the present invention will be explained with reference to FIG.

When there is no power outage, the power outage connection circuit 2 is open and the telephone operates as a normal key telephone device. In the event of a power outage, the power outage detection circuit 3 operates the power outage connection circuit 2, which connects the power outage extension telephone 4 and the telephone lines 1a to 1n in parallel.1 When a call is received, the incoming signal detection diagram n5 is activated and the switch A is closed. , sends an incoming call signal to the power outage extension telephone 4. When the power outage extension telephone 4 goes off-hook, a direct current flows, the current detection circuit 6 is activated, and the switch B is closed.
The operation of the incoming signal detection circuits 5 of all telephone lines 1a to 1n is stopped.

[Effects of the Invention] As explained above, the present invention provides a power outage connection circuit that connects a telephone line and a power outage extension telephone in parallel during a power outage, and a power outage connection circuit that detects a power outage state and operates the power outage connection circuit during a power outage. A power outage detection circuit, an incoming signal detection circuit that is connected to the telephone line and detects incoming signals, and an incoming signal detection circuit that is located between the incoming signal detection circuit and the power outage connection circuit, and is connected to the telephone line when a call is received under control from the incoming signal detection circuit. a switch A that connects an extension telephone for power outage and opens the telephone line when there is no incoming call, and a switch B connected in parallel to switch A;
It is on the telephone line between the incoming signal detection circuit and the power outage connection circuit, detects the direct current of the telephone line, and if the current value of the telephone line exceeds a predetermined value, switch B is connected and the power outage occurs. 1. A current detection circuit that stops the incoming signal detection circuits of all telephone lines connected to the connection circuit and, on the other hand, opens switch B when the current value of the telephone line is below a predetermined value. It has the effect of detecting incoming signals from all telephone lines with one extension phone for power outages.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a key telephone device according to the present invention. 1a to 1n...Telephone line 2...Power outage connection circuit 3...Power outage detection circuit 4...Extension telephone for power outage 5...Incoming signal detection circuit 6...Current detection circuit

Claims (1)

[Scope of Claims] A telephone device having a plurality of telephone lines and one extension telephone for power outage, and capable of answering incoming calls during a power outage by supplying power from a power source other than a central office line, comprising the following: A power outage connection circuit that connects extension telephones in parallel; a power outage detection circuit that detects a power outage condition and operates the power outage connection circuit in the event of a power outage; and an incoming call signal that is connected to a telephone line and that detects an incoming signal. a detection circuit, located between the incoming signal detection circuit and the power outage connection circuit, which connects the telephone line and the power outage extension telephone when an incoming call is received under control from the incoming signal detection circuit, and connects the telephone line when no incoming call is received; a switch A that opens the line, a switch B connected in parallel to the switch A, and a DC current of the telephone line on the telephone line between the incoming signal detection circuit and the power outage connection circuit. detect,
When the current value of the telephone line is equal to or higher than a predetermined value, at the same time as the switch B is connected, the incoming signal detection circuits of all the telephone lines connected to the power failure connection circuit are stopped; A button telephone device comprising: a current detection circuit that opens the switch B when the current value of the telephone line is less than or equal to a predetermined value.