JPH06152805A - Public telephone system - Google Patents

Abstract

PURPOSE:To eliminate the need for a commercial power supply even when a public telephone set requiring much power consumption is installed to the system. CONSTITUTION:A station side equipment 2 is provided between an exchange 1 and a telephone set 3, a power supply device 22 is provided to the station side equipment and a battery BAT charged by the power supply 22 is provided to the telephone set, and the charging is stopped in the case of dialing/call reception of the telephone set, and power is supplied to each section of the telephone set from the battery. As a result, no commercial power supply is required even when a public telephone set requiring much power consumption such as a card type public telephone set is installed to the system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a public telephone system comprising a public telephone and a station-side device connected between the public telephone and an exchange.

[0002]

2. Description of the Related Art Conventionally, an exchange and a telephone line (hereinafter, line)
In the case of a coin type that stores only coins during a call, a public telephone connected via a telephone uses only a local power source supplied from the exchange because it consumes a small amount of power. In the case of the card type used, since the power consumption is large, a commercial power source is separately used to carry the card and record the frequency used.

[0003]

The conventional public telephone is
The card type, which consumes a large amount of power, requires a commercial power source, so that there is a problem that the telephone cannot be installed in a place where the commercial power source is not installed. Further, even if a commercial power source is installed, wiring to the telephone has to be performed, so that there is also a problem that power source installation work is required when installing the telephone.

Therefore, an object of the present invention is to provide a public telephone which does not require a commercial power source.

[0005]

In order to solve such a problem, the present invention comprises a station side device between an exchange and a public telephone, and the station side device is provided with an incoming signal coming from the exchange. An incoming signal detection unit for detecting, a reversal signal generation unit for generating a reversal signal to be sent to a public telephone, a loop disconnection signal detection unit for detecting a loop disconnection signal for disconnecting the loop of the public telephone, and a first A power supply, a second power supply that is charged by the first power supply and that includes a first power supply, a connection unit that connects one of the exchange and the first power supply to the public telephone, and a first power supply. A power supply output control unit that controls the output of the second power supply, a switching element that forms a loop by one of an off-hook signal and a polarization signal, a charge switching unit that switches charging to the second power supply, and a polarization signal. Reversal signal receiving unit for receiving , Those having a loop disconnection signal generator for generating a loop disconnection signal sent to the station apparatus, and a second control unit which is activated by the formation of loops in the public telephone. When making a call from the public telephone, the second control unit controls the charging switching unit and the power supply output control unit to prevent charging of the second power supply and to output the second power supply, and to disconnect the loop. Controls the signal generator to send a loop break signal,
When the first control unit receives the loop break signal, it controls the reversal signal generation unit to send a reversal signal indicating permission of dial transmission, and also controls the connection unit to connect the exchange and the public telephone. is there. Further, when the first control unit receives the incoming signal from the exchange, it controls the reversal signal generation unit to send out the reversal signal indicating the incoming signal, and the second control unit is activated by this reversal signal. Then, the charge switching unit and the power supply output control unit are controlled to prevent charging to the second power supply and output the second power supply, and when an off-hook is detected, the loop disconnection signal generation unit is controlled to control the loop. When the disconnection signal is transmitted and the loop disconnection signal is received, the first control unit controls the connection unit to connect the exchange and the public telephone.

[0006]

When a call is made from the telephone, the charging of the second power source from the first power source is blocked and the output of the second power source is performed to supply power to each part of the telephone, and the loop disconnection signal is sent. It is sent to the station side device. As a result, the station-side device sends a reversal signal indicating that dialing is allowed,
The exchange and the public telephone are connected. Also, when an incoming signal arrives from the exchange, a switching signal is sent from the station side device to activate the telephone, blocking charging of the second power source in the telephone and outputting from the second power source to each part of the telephone. And the loop break signal is sent to the station side device. As a result, the exchange and the public telephone are connected in the station side device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a public telephone system according to the present invention. This system is provided with a station side device 2 arranged near the exchange 1 and connected to the exchange 1, and this station side device 2. Public telephone connected to (hereinafter, telephone)
It consists of three. Here, the station side device 2 includes an incoming call detection circuit 21, a power supply device 22 (first power supply), a current limiting circuit 23, a loop break detection circuit 24, a control circuit 25, a CL relay 26 (connection portion), and an RV relay 27 ( It is composed of a reversal signal generating section), supplies power to the telephone 3, and controls connection with the exchange 1 when the telephone 3 makes and receives a call.

As shown in FIG. 2, the telephone 3 includes an incoming call detection circuit 31, a reversal detection circuit 32, a current limiting circuit 33,
Output control circuit 34 (power output control unit), communication circuit 35,
Control circuit 3 including dial circuit 36 and CPU
7, a GS relay 38 (charge switching unit) and the like. In the figure, BAT is a battery (second power source),
Q1 to Q3 are transistors, D1 to D9 are diodes,
ZD1 is a Zener diode, SCR is a thyristor, HS
1 and HS2 are hook switches, and GS1 and GS2 are contacts of the GS relay.

An outline of the operation of the public telephone system configured as described above will be described. Here, the battery BAT of the telephone 3 is normally provided with lines LN1 and LN2, a diode bridge including diodes D2 to D5, and a contact GS.
2, the diode D6, the current limiting circuit 33, and the transistor Q3 to charge from the power supply device 22 in the station side device 2. Now, when the telephone 3 is off-hook to make a call, the hook switch HS1 is closed, the thyristor SCR (switching element) supplied with power from the power supply device 22 is turned on, and the DC loop of the telephone 3 is closed.
As a result, the power supply voltage of the power supply device 22 is the line LN1,
LN2, the diode bridge, thyristor SCR,
Photodiode D7, transistor Q7 and communication circuit 3
Is applied to the power supply circuit of the telephone composed of the diode D8, the capacitor C1, and the Zener diode ZD1 via 5,
The power supply voltage V _DD is taken out from the diode D8 of the power supply circuit and supplied to the control circuit 37. In this case, the photodiode D7 connected to the thyristor SCR
From which an optical signal PH1 is generated. The optical signal PH1 is converted into an electric signal PH2 by the phototransistor Q4 and sent to the transistor Q3 and the output control circuit 1 via the OR circuit 39. As a result, the charging of the battery BAT is stopped, the output control circuit 34 for controlling the output of the battery BAT is operated, and the power source of the battery BAT is taken out as the power source of the voltage 5V, for example, and the diode D
The power supply voltage V _DD is supplied to each unit of the telephone 3 including the control circuit 37 via the control circuit 37.

When power is supplied to the control circuit 37, the output control circuit 34 and the transistor Q3 are connected via the OR circuit 39 in consideration of the case where the optical signal PH1 is not output from the photodiode D7 when switching the GS relay described later. In response to this, a signal PH3 is output to completely remove the power from the battery BAT and stop charging the battery BAT. Then, the GS relay 38 is turned on to switch the contacts, stop charging the battery BAT, and form a call loop. After that, transistor Q2
A signal FC is sent to the (loop break signal generation unit) to send an off-hook signal (strong cutoff signal) to the station side device 2 in which the call loop is cut off for a certain period of time. When the off-hook signal is detected by the loop break detection circuit 24, the control circuit 25 of the station side device 2 drives the RV relay 27 to connect its contacts RV1,2.
Is sent to the telephone 3 to switch the contact from the b side to the a side, then the CL relay 26 is driven to open the contact CL3, and the contacts CL1 and CL2 are switched from the b side to the a side, and the exchange 1 and the telephone. Connect with 3. Meanwhile, telephone 3
The control circuit 37 of the switch detects the reversal signal through the reversal detection circuit 32, and when it is confirmed that the switch 1 is connected, the operated dial is transmitted through the dial circuit 36 as a dial signal to the exchange 1. Send to. As a result,
Mutual communication is performed according to the response of the other party, and the control circuit 37 receives the incoming billing signal and performs the billing process.

When the call ends and goes off-hook, the control circuit 37 of the telephone set 3 detects the condition of the hook switch HS2 and turns off the transistor Q2 to send an on-hook signal to disconnect the call loop for a certain period of time to the station side device 2. To do.
After that, the control circuit 37 turns off the GS relay 38 to switch the contact GS2 to the charging side of the battery BAT, and the charging of the battery BAT is performed.
In addition, an inverted signal of the signal PH3 is sent to the transistor Q3 and the output control circuit 34 via the OR circuit 39 so that the power from the battery BAT is not supplied to each part of the telephone 3. As a result, the power supply to the control circuit 2 is stopped. On the other hand, when the control circuit 25 of the station side device 2 receives the on-hook signal via the loop break detection circuit 24, it drives the CL relay 26 and the RV relay 27 to change the contacts of these relays from the a side to the b side. Control is performed so that switching, separation from the exchange 1, and charging of the battery of the telephone 3 are performed.

Next, the operation of the public telephone system when making a call will be described with reference to the flowchart of FIG. First, the call origination operation of the telephone 3 shown in FIG. Phone 3
Is off-hook for outgoing calls (step 100)
And a loop is formed as described above (step 10
1), the control circuit (CPU) 37 is powered on, and then the reset of the control circuit 37 is released (step 10).
2). When the reset is released, the control circuit 37 outputs the signal PH3 to the output control circuit 34 and the transistor Q3 and drives the GS relay 38 to contact the contact GS.
1, GS2 is switched (step 103), charging of the battery BAT is stopped and a call loop is formed. After that, the signal FC is sent to the transistor Q2, and a strong cutoff signal for turning it off for a certain period of time is sent to the station side device 2 (step 104).

After that, it is judged whether or not the reversal signal indicating the permission of the dial transmission from the station side device 2 is received (step 1
05) When the reversal signal is received, the operated dial is detected and the dial signal is sent from the dial circuit 36 (step 106). Then, a mutual call is started in response to the other party's response (step 107). During this mutual call, in addition to the charging process, the hook switch HS2 is monitored to determine whether the on-hook is detected at all times (step 108). When the on-hook is detected, the transistor Q2 is turned off for a certain period of time. A disconnection signal is sent to the station side device 2 (step 109). After that, when the inverted signal of the signal PH3 is sent to the transistor Q3 and the output control circuit 34 and the GS relay 30 is switched (step 110), the loop is disconnected and the power supply from the battery BAT is stopped. The power supply to the circuit 37 is stopped, the power is turned off (step 111), and the circuit 37 is reset (step 112).

Next, the operation of the station side device 2 in response to the calling operation of the telephone 3 will be described with reference to the flowchart of FIG. The control circuit 25 of the station-side device 2 always determines to receive the off-hook deadline signal from the telephone 3 (step 150), and when the off-hook signal is received,
The RV relay 27 is driven and a reversal signal indicating dial dialing permission is sent to the telephone 3 (step 151). Then, after that, the CL relay is driven to connect the exchange 1 and the telephone 3 and the charging of the battery BAT of the telephone 3 is stopped (step 152). Then, the on-hook of the telephone 3 determines whether or not the aggressive signal indicating the on-hook signal transmitted from the telephone 3 is received (step 153), and when the aggressive signal is received, the CL relay 26 and the RV relay 27 are restored respectively. The connection between the exchange 1 and the telephone 3 is disconnected, and the battery BAT of the telephone 3 is charged from the power supply device 22 (step 154).

Next, FIG. 5 is a flow chart showing an incoming call operation of this public telephone system. Station device 2 when receiving a call
The operation will be described based on the flowchart of FIG. The control circuit 25 constantly determines whether or not there is an incoming call from the exchange 1 (step 200), and when the incoming call is detected via the incoming call detection circuit 21, the RV relay 2
A reversing signal for driving contact 7 to switch contact b to contact a is sent to telephone 3 as an incoming signal (step 201).
After that, the off-hook signal is detected and determined by the dead-end signal coming from the telephone 3 (step 202). When the off-hook signal is received, the CL relay 26 is driven to switch the contact b to the contact a side, and the exchange 1 Is connected to the telephone 3 and charging of the battery of the telephone 3 is stopped (step 203).

Thereafter, the on-hook of the telephone set 3 judges whether or not the strong-off signal indicating the on-hook signal transmitted from the telephone set 3 is received (step 204). When the strong-off signal is received, the CL relay 26 and the RV relay 27 are received. Are restored to disconnect the exchange 1 from the telephone 3 and the power supply device 23 charges the battery BAT of the telephone 3 (step 205).

Next, the operation of the telephone 3 in response to the operation of the station side device 2 at the time of an incoming call will be described with reference to the flowchart of FIG. The telephone 3 always judges whether the incoming signal is received by the polarization signal (step 250), the polarization signal arrives from the station side device 2, and the contact point GS1 and the diode D1 are received.
When this incoming signal is detected by the incoming call detection circuit 31 via, the call loop is formed by turning on the transistor Q1 and turning on the thyristor SCR connected thereto. As a result, the control circuit 37 is powered on (step 251), and then the reset of the control circuit 37 is released and activated (step 252). When the reset is released, the control circuit 37 outputs the signal PH3 to the output control circuit 34 and the transistor Q3, and the GS relay 3
8 is driven to switch the contacts GS1 and GS2 (step 353), charging of the battery BAT is stopped and a loop is formed. Then, the status of the incoming call detection circuit 31 is detected to recognize that the incoming call has been activated, and a buzzer (not shown) sounds the incoming call (step 254). Further, the state of the hook switch HS2 is detected and judged (step 25).
5) When the off-hook indicating the response to the incoming call is detected, the buzzer stops ringing (step 256), and the transistor Q2 is turned off for a certain period of time to send a deadline signal indicating the off-hook to the station side device 2. (Step 257).

By the transmission of this off-hook signal, the exchange side device 2 is connected to the exchange, so that the mutual call with the other side is started (step 258). After that, the hook switch HS2 is monitored to determine whether the on-hook is detected (step 259). When the on-hook is detected, the transistor Q2 is turned off for a certain period of time and a dead-cut signal is sent to the station side device 2 (step 260). ). Then transistor Q
3 and the output control circuit 34, the inverted signal of the signal PH3 is transmitted, and the GS relay 30 is switched (step 26).
If you perform 1), the loop will be disconnected and the battery BAT
Since the power supply to the control circuit 37 is stopped, the power supply to the control circuit 37 is stopped and the power is turned off (step 26).
2). As a result, the control circuit 37 is in the reset state (step 263) and the charging of the battery BAT is started.

FIG. 3 is a diagram showing an example of a specific circuit of the incoming call detection circuit 31 and the reversal detection circuit 32 in the telephone 3, which can be simply composed of transistors, diodes, resistors and the like. These incoming call detection circuits 31
The reversal detection circuit 32, when a reversal signal indicating an incoming call, a dial permission signal, or the like arrives from the station-side device 2, the control circuit 3 outputs an incoming signal RNG and a reversal signal RVS, respectively.
Notify 7.

In this embodiment, the off-hook signal and the on-hook signal by the deadline signal are transmitted from the telephone side at the time of making and receiving the call from the public telephone system, and the dial permission signal by the reversing signal is transmitted from the station side device. However, transmission / reception circuits for the DTMF signal and the modem signal may be provided in the station side device and the telephone, respectively, and the on-hook signal and the like may be transmitted as the DTMF signal and the modem signal.

[0021]

As described above, according to the present invention, the station side device is provided between the exchange and the telephone, the station side device is provided with the first power source, and the second power source is charged by the first power source. Since the above-mentioned charging is stopped and the respective parts of the telephone are supplied with power from the second power source when the telephone is called or called, a telephone with high power consumption such as a card-type public telephone is installed. In such a case, commercial power supply becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a public telephone system according to the present invention.

FIG. 2 is a block diagram of a public telephone that constitutes the system.

FIG. 3 is a circuit diagram showing a specific example of the public telephone.

FIG. 4 is a flowchart showing an operation of the public telephone system when making a call.

FIG. 5 is a flowchart showing an operation of the public telephone system when an incoming call is received.

[Explanation of symbols]

 1 Switchboard 2 Station side device 3 Public telephone 21, 31 Incoming call detection circuit 22 Power supply device (first power supply) 24 Loop break detection circuit 25, 37 Control circuit 26 CL relay (connection part) 27 RV relay (polarization signal generation part) ) 32 polarity reversal detection circuit 34 output control circuit 35 communication circuit 36 dial circuit 38 GS relay (charge switching unit) BAT battery (second power supply) Q1, Q3 transistor Q2 transistor (loop break signal generation unit) SCR thyristor (switching element) )

Claims (3)

[Claims] 1. A public telephone system comprising a public telephone and a station-side device connected between the public telephone and the exchange, wherein an incoming signal detection unit for detecting an incoming signal from the exchange and sending to the public telephone. A reversal signal generator that generates a reversal signal, a loop breaker signal detector that detects a loop breaker signal that breaks the loop of a public telephone, a first power supply, a switch, and a first power supply. A station side device is provided with a connection unit for connecting one to a public telephone and a first control unit, and a second power source charged by the first power source and an output of the second power source are controlled. A power supply output control unit, a switching element that forms the loop by one of an off-hook signal and a reversal signal, a charge switching unit that switches charging of the second power supply, and a reversal signal reception unit that receives the reversal signal. And station equipment Public telephone system to the loop disconnection signal generating unit, characterized by comprising a second control unit which is activated by the formation of loops to a public telephone which generates a loop disconnection signal sent. 2. The public telephone system according to claim 1, wherein the second control unit controls the charge switching unit and the power supply output control unit when transmitting from the public telephone to prevent charging to the second power source. The second power source is output and the loop break signal generation unit is controlled to send the loop break signal. When the first control unit receives the loop break signal, the reversal signal generation unit is controlled to permit dialing. The public telephone system is characterized in that the switching unit and the public telephone are connected by sending a reversing signal indicating the above. 3. The public telephone system according to claim 1, wherein the first control unit controls the reversal signal generation unit when receiving the incoming signal from the exchange, and sends the reversal signal indicating the incoming signal, When the control unit of No. 2 is activated by this reversal signal, it controls the charging switching unit and the power output control unit to prevent charging to the second power source and output the second power source, and the off-hook is detected. Then, the loop break signal generation unit is controlled to send out the loop break signal, and when the first control unit receives the loop break signal, the first control unit controls the connection unit to connect the exchange and the public telephone. Public telephone system.