JPS6325794Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a public telephone for consignment use, whose management is entrusted to a specific consignee.

Figure 1 is a circuit diagram of the main parts of a conventional example. Normally, a DC voltage with line terminal L ₁ as the positive pole is applied from an exchanger to line terminals L ₁ and L ₂ via the line. , when making a call, if you insert a coin after off-hooking, the hook switch HS ¹ and coin detection contact CCL ¹ turn on, and the line terminal
L ₁ - Hook switch HS ¹ - Diode D ₁ - Coin detection contact CCL ¹ - Dial pulse contact Di - Diode D ₃ - Relay contact rr ² - Transmitter T - Blocking wire
A DC loop of CH ₂ - diode D ₄ - blockage wire CH ₁ - relay contact rr ¹ - line terminal L ₂ is constructed, and the exchange detects this and becomes ready for transmission, and sends out a transmission tone.

When the user confirms the dial tone and makes a dial call, a dial pulse is sent by turning the pulse contact Di on and off.The exchange responds to this and establishes an exchange connection.If the called party answers, the exchange Since a polarity reversal pulse signal with line terminal L ₂ as the positive pole is sent, line terminal L ₂ - contact rr ¹ - blocked wire
CH ₁ - Diode D ₅ - Contact rr ² - Transmitter T - Diode D ₆ - Pulse contact Di - Coin detection contact CCL ¹ -
Diode D ₂ - Relay M as a response detection relay - Hook switch HS ¹ - Relay M is operated by the route of line terminal L ₁ , self-holds by the holding mechanism, and operates until the holding mechanism is reset by the on-hook. maintain the condition.

Then, the circuit of the coin storage magnet (not shown in the figure) is completed, and the coin storage magnet operates in response to the polarity reversal pulse signal, so that when the called party answers, and after that, the unit call time is determined according to the communication distance. Coins are stored in accordance with the polarity reversal pulse signal that is sent out every time the period of time elapses.

In addition, when a ringing signal arrives in the on-hook standby state, the ringing signal is given to the bell BL via the capacitor _C1 and the switch ^HS2 , and when the bell BL rings and an off-hook is performed, the switch ^HS2 is switched. , the half wave of the ringing signal with line terminal L ₂ as the positive terminal is the line terminal
L ₂ - Contact rr ¹ - Blockage wire CH ₁ - Capacitor C _2. Relay RR as incoming call detection relay - Relay contact rr ⁰ -
Coin detection contact CCL ² - Key contact KS ¹ - Resistor R ₁ -
Hook switch HS ² - Capacitor C ₁ - Line terminal L ₁
Through this route, a polarized relay RR using a permanent magnet operates, and the permanent magnet performs self-retention.

Then, the contacts rr ⁰ to rr ² switch, and the contacts rr ² exclude the circuits required for transmitting the relay M to the diodes D ₃ to D ₄ , and directly switch the switch.
Configures a direct circuit to HS ¹ , and connects contact rr ¹
In some cases, a side current circuit is completed with a resistor _R2 installed in parallel to a capacitor _C3 for audio current distribution inserted in series with the induction wire IND, and turned on by off-hook. switch
For the DC component superimposed on the calling signal via HS ¹ with line terminal L ₂ as the positive terminal, line terminal L ₂ - contact rr ¹ - resistor R ₂ - guide wire IND - transmitter T - contact rr ² - Hook switch HS ¹ - Since the line terminal L ₁ forms a DC loop, the exchange detects this, stops sending out the ringing signal, and switches to applying DC voltage with the line terminal L ₁ as the positive pole, and the call status is established. shall be.

Therefore, when on-hook is performed after the end of the call, the DC loop is opened by turning off the switch HS ¹ , and at the same time, the short circuit to the relay RR is removed, so that the DC with the positive terminal at the line terminal L ₁ is connected to the line terminal L ₁ . − Contact rr ⁰ − Relay RR − Diode D ₃ − Zener diode ZD ₁ , ZD ₂ − Blockage wire CH ₂ − Guide wire IND − Resistor R ₂ − Contact rr ¹ −
It is connected through the route of line terminal _L2 , and relay RR is restored, and the DC loop is opened by turning off switch ^HS1 , so the exchange is restored accordingly.

In addition, when a call key for free calls owned by the trustee is inserted and operated, the key contacts KS ¹ ,
KS ² operates to short-circuit relay M, coin detection contact CCL ¹ , and relay RR, so that the operation of relay M and relay RR is blocked, and free calls are made possible.

However, in the conventional configuration shown in Figure 1,
If you go off-hook when a call signal arrives, a DC loop is immediately established and the call state is established.
In the case of a system where callers pay for calls called collect calls, there is a drawback that the call can be made even if someone other than the trustee takes off-hook, and if the receiver answers without intervention, the call is transferred to the operator. There is an increasing demand for a function that can notify people.

The purpose of this invention is to fully satisfy such requirements, and when the trustee performs a response operation without intervention, a specific audio frequency signal is automatically transmitted, thereby The present invention provides an extremely effective public telephone set for use on consignment that notifies the switchboard that a person other than the subscriber has answered.

Hereinafter, details of the present invention will be explained with reference to circuit diagrams from FIG. 2 showing an embodiment.

2 and 3 are main part circuit diagrams omitting the broken lines in FIG. The terminal voltage of the varistor VR inserted into the DC loop configured during a call is applied to the power terminals a and b of this as a power source, and a relay is connected between the varistor VR and the power terminal a. Insert a parallel circuit between contact ^m1 of M and contact ^rr3 of relay RR, and connect relay M and relay RR.
When any of the above operates, power is applied to the signal generator SG, thereby starting the signal generator SG.

The signal generator SG is designed to generate an audio frequency signal only during a certain period of time after startup.
This signal is sent out from the output terminals c, d via the transformer L, and in FIG _.
and line terminals L ₁ , L ₂ via the switch HS ¹
In FIG. 3, it is applied to the resistor R ₃ inserted into the DC loop, and
An audio frequency signal generated as a terminal voltage of this is sent to line terminals L ₁ and L ₂ via a DC loop.

However, if the trustee operates the call key, the operation of relays M and RR is blocked, so the contacts
Neither m ¹ nor rr ³ is turned on, and no audio frequency signal is transmitted.

Therefore, when a call is made or answered without the intervention of a trustee, an audio frequency signal is always sent out for a certain period of time, and it is possible to notify the other party that the call is made or answered by a public telephone.

Note that if a coin is inserted before or after the ringing signal arrives, the coin detection contact CCL ² will switch, and even if the incoming call detection relay RR does not operate, the line terminal L ₂ superimposed on the ringing signal will be set as the positive terminal. The direct current component is line terminal L ₂ - contact rr ¹ - blockage wire CH ₁ - diode D ₅
- Contact rr ² - Transmitter T - Blocking wire CH ₂ - Diode D ₆ - Pulse contact Di - Coin detection contact CCL ¹ - Diode D ₂ - Relay M - Hook switch HS ¹ - Line terminal L Connected by route of ₁ , relay M operates, so that an audio frequency signal is transmitted.

However, it is also optional that, with some modification, an audio frequency signal is transmitted only in response.

4 and 5 are circuit diagrams showing specific examples of the signal generator SG. In FIG. 4, the diode _D11 bypasses the application of a reverse polarity voltage such as a polarity reversal pulse signal, and the capacitor The terminal voltage of C ₁₁ is used as the power supply, and the programmable union transistor (PUT) Q ₁
and a timer section mainly consisting of a thyristor SCR
TM is provided, and an oscillating part OSC mainly composed of transistors Q ₂ and Q ₃ is provided, and the operation of the oscillating part OSC is started after a certain period of time after power is applied to the power terminals a and b by the operation of the timer circuit TM. It is intended to be stopped.

In other words, capacitor C ₁₂ is charged via resistor R ₁₁ , and the terminal voltage of capacitor C ₁₂ gradually rises until it reaches the reference voltage determined by resistors R ₁₂ and R _13. PUT・Q ₁ is turned on and the resistor In order to turn on the thyristor SCR by passing current through the resistors R ₁₄ and R ₁₅ , the power supply of the phase-shifted oscillation circuit made up of the resistors R ₁₆ to R ₂₀ , the capacitors C ₁₃ to _{C 15} and the transistor Q ₂ is connected to the resistors R ₁₉ , It is grounded at the connection point of R ₂₀ and stops the oscillating operation.

Note that the output of the phase-shifted oscillation circuit is connected to the resistor R ₂₁ ~
After being amplified by an amplifier circuit including R ₂₉ and transistor Q ₃ , the signal is sent between output terminals c and d.

In addition, in FIG. 5, the NOR gates G ₁ ,
A free-running multivibrator consisting of G ₂ , resistors R ₃₁ , R ₃₂ and capacitor C ₂₁ is used as the oscillation unit OSC, and its output is used as the oscillation unit OSC, consisting of NOR gate G ₃ , resistors R ₃₃ , R ₃₄ , and transistor Q ₂₁ While the signal is sent through _{the amplifier} circuit, the counter of _the timer section _TM is
After resetting CT ₁ and CT ₂ , the output of the oscillator OSC is counted by the counters CT ₁ and CT ₂ , and when the count output Q of the counter CT ₂ becomes high level after a certain period of time, the NOR gate G At _the same time, the output of counter CT ₂ is fixed to a low level, and the clock enable input CE of counter CT 2 is set to high level to stop the operation of counter CT ₂ and maintain this state.

In addition, the barista in Figures 2 and 3
VR can be replaced with a Zener diode, etc., and the insertion site can be placed elsewhere in the DC loop, and the site to which the output of the transformer L is connected can also be selected according to the conditions, and the signal generator Various modifications are possible, such as the possibility of using other configurations exhibiting similar functions as the SG.

As is clear from the above explanation, according to the present invention, calls made and responses without the intervention of a trustee are notified to the other party, such as a switchboard operator, by an audio frequency signal. Great benefits can be obtained from public telephones.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a main part showing a conventional example, Figs. 2 and 3 are circuit diagrams of a main part showing an embodiment of the present invention, and Figs. 4 and 5 are circuits showing a specific example of a signal generator. It is a diagram. RR...Relay (incoming call detection relay), M...Relay (response detection relay), KS ¹ , KS ² ...Key contact, ^m1 , rr ³ ...Contact, SG...Signal generator, L...
...transformer, C ₄ ... capacitor, R ₃ ... resistor.

Claims (1)

[Scope of utility model registration request] A response detection relay that is activated and self-maintained by a polarity change pulse signal that accompanies the called party's response when a call is made, an incoming call detection relay that is activated and self-maintained by off-hook after receiving a calling signal, and a free call. In a public telephone having a key contact that operates when a call key is operated and prevents the operation of the response detection relay and the incoming call detection relay, an audio frequency signal is generated only for a certain period of time after activation and then sent to the line terminal. a signal generator for transmitting a signal, a contact point of the incoming call detection relay that starts the signal generator by operation of the incoming call detection relay, and a contact point of the response detection relay that starts the signal generator by the operation of the response detection relay; A public telephone for consignment use, which is characterized by being equipped with.