JPH0325068B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a circuit that regulates telephone calls from public telephones according to coin insertion conditions, dialed numbers, and the like. [Prior Art] Public telephones employ various call control means depending on the type of telephone, and generally the loop circuit is disconnected to silence the telephone regardless of whether there is an erroneous operation when making a paid call or an unauthorized operation when making a free call. This creates a drawback in that it is unclear to the user which reason the call was restricted. [Summary of the Invention] The present invention has the purpose of fundamentally solving the conventional drawbacks, and includes a series circuit of a backflow blocking diode D1 inserted into a loop circuit and a coin detection contact CCL, and A series contact circuit in which the contact ans1 of the response detection relay ANS, which is connected in parallel with the circuit and turns on when the call permission condition is established, and the contact lp1 of the loop relay LP, which turns on when a coin is inserted, are connected in series. , contact lp of the response detection relay is activated by operating the emergency switch ES after off-hook.
1 turns on circuit HS1, D1, D2, HS2,
ANS, ES, ans2, D3 and the loop relay contact lp1 are connected to the side bypassing part when it is off, and when the contact is always on and a free call is made, the prohibited numbers (100, 104, etc.) are RL contact rl1 of the disconnection relay, which turns off when a dial call is made;
When the transmitter T is connected to the bypass part and a paid call is made based on coin insertion, the prohibited number (100
Contact ts1 of the blocking relay TS that turns on when a call is made by dialing a number (number, 115, etc.) to disable the transmission.
It is composed of. In such a configuration, if a user accidentally dials a prohibited number such as a call to a relay stand during a paid call, the contact ts1 is turned on and the call becomes impossible. On the other hand, if a prohibited number that results in an unauthorized call is dialed due to an erroneous operation or the like during a free call, contact rl1 is turned off to open the DC loop and restore the exchange. This allows you to determine whether the situation in which you are unable to make a call is due to an erroneous operation during a paid call or an erroneous operation during a free call, depending on whether the situation is ``Unable to make a call'' or ``Recovery of the exchange.'' [Example] Hereinafter, details of the present invention will be explained with reference to circuit diagrams showing examples. In the figure, the anode of a diode D ₁ provided for backflow prevention is directly connected to the make contact HS ¹ of the switch, which is connected to the line terminal L ₁ to which the positive line of the telephone line is connected, and its cathode and the communication circuit via diode D ₅
A coin detection contact (hereinafter referred to as detection contact) CCL is connected to one end of TKC, and a diode D ₂ is connected between diode D ₁ and detection contact CCL.
The anode of this is connected, and the cathode of this is connected to one end of a magnetic latching type response detection relay (hereinafter referred to as detection relay) ANS via the make pole of the transfer contact HS ² of the switch. In addition, the other end of the detection relay ANS is connected via the break pole side transfer contact of the emergency switch ES.
Connected to line terminal L ₁ , detection relay ANS
The transfer contact ans ² of the emergency switch ES has a break pole connected to the other end of the detection relay ANS through the make type of the transfer contact of the emergency switch ES, and the transfer contact of the emergency switch ES.
Detection relay through break pole in HS ²
A make pole is connected to one end of the ANS, and
The anode of a diode D ₃ is connected to the main pole of the contact ans ² , the cathode of which is connected to the line terminal L ₂ and connected to the other communication circuit TKC via the diode D ₆ and the constant voltage diode ZD ₁ . connected to the end. On the other hand, in the series circuit of the diode D ₁ inserted into the loop circuit between the line terminal L ₁ and the communication circuit TKC and the detection contact CCL, the make contact ans ¹ of the detection relay ANS and the loop are connected in parallel. A series contact circuit is connected to the make pole side of transfer contact lp ¹ of the relay LP, and the break pole and make pole of contact lp ¹ are used as parts to bypass this when the make pole of contact lp ¹ is off. Transfer contact rl ¹ of disconnect relay RL connects the main pole to contact
It is connected as the break pole side of lp ¹ , and the contact
A resistor Rt having a high resistance value for trickle charging the capacitor _C1 is connected between the make and break poles of rl ¹ . In addition, the communication circuit TKC and constant voltage diode
On the line terminals L ₁ and L ₂ of ZD ₁ , there are diodes D ₅ to
A bridge circuit with D ₈ is inserted, which keeps the polarity of the loop current flowing to the communication circuit TKC and the constant voltage diode ZD ₁ constant regardless of the polarity of the line voltage, and also disconnects it in series with the diode D ₈ . Insert make contact rl ² of relay RL and polarity reversal detection relay (hereinafter referred to as polarity reversal relay) KP,
It is designed to detect polarity reversal pulses sent from the exchange as billing signals. Therefore, when a coin is inserted after the off-hook, the switch HS ¹ is turned on and the detection contact CCL is turned on, thereby closing the DC loop via the communication circuit TKC and the constant voltage diode ZD ₁ . A constant voltage diode is inserted to enable dialing and to generate a Zener voltage for the loop current.
The Zener voltage of ZD ₁ charges the capacitor C ₁ via the discharge blocking diode D ₉ , and the terminal voltage of this is supplied as a local power supply to the control unit CNT, which consists of a processor such as a microprocessor, memory, etc. The control unit CNT performs recovery control of each relay by initializing in response to a rise in power supply voltage, and then starts control operation. That is, the control unit CNT includes a detection output of a coin detection circuit CCD using a photoelectric detector etc. arranged in each part of the coin storage mechanism (not shown in the figure), and a dial corresponding to the output of the dial circuit or the transmission status of dial pulses. The detection output of the detection circuit DID is given, as well as the information from the contact kp ¹ of the polarization relay KP and the contact ans ³ of the detection relay ANS. According to the judgment results in the table below, magnetic latching is applied to each of them. Loop relay LP using shapes,
Operating winding F of disconnection relay RL and blocking relay TS
Alternatively, the recovery winding R is driven to control these operations and recovery.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, depending on whether the situation in which calls are no longer available is "unable to send calls" or "recovery of the exchange," the cause is dialing a prohibited number due to an erroneous operation during a paid call. This makes it possible to determine whether the user made a call by dialing a prohibited number that is an unauthorized number due to an erroneous operation during a free call, and this is particularly effective in public telephones, which are treated the same as subscriber telephones.

[Brief explanation of the drawing]

The figure is a circuit diagram showing an embodiment of the present invention. L ₁ , L ₂ ...Line terminal, HS ¹ ...Hook switch (make contact), HS ² ...Hook switch (transfer contact), D ₁ to D ₉ ...Diode, CCL...Detection contact (coin detection contact), TKC...Talking circuit , ANS...detection relay (response detection relay), LP...loop relay,
RL...Disconnection relay, TS...Blocking relay, ans ¹ ,
ans ² , lp ¹ , rl ¹ , rl ² , ts ¹ ...contact, T...telephone,
CNT…Control unit.

Claims (1)

[Scope of Claims] 1. A series circuit of a backflow blocking diode and a coin detection contact inserted into a loop circuit, and a circuit connected in parallel with the series circuit, which is turned on in response to establishment of a call permitting condition. A series contact circuit that connects in series a contact of a response detection relay and a contact of a loop relay that turns on when a coin is inserted, and a circuit that turns on the contact of the response detection relay by operating an emergency switch after off-hook. and a disconnection relay contact, which is connected to a part that bypasses the contact when the loop relay contact is off, and is always on and turns off when a prohibited number for toll-free calls is dialed during toll-free calls; A contact point for a blocking relay is connected to a part that bypasses the transmitter, and is turned on when a prohibited number for a paid call is dialed during a paid call based on the insertion of a coin, thereby disabling the call. A call regulation circuit for public telephones featuring: