JPS6311793Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a public telephone that can be used for both local calls and long distance calls, and can be applied to either a single billing method or a multi-charging method. .

[Prior art]

The permissible operation modes for public telephones vary depending on the type of exchange to which they are connected and the service type in the area where they are installed. When a single-digit dial call is to an area code such as "0", the call is forcibly blocked, and the call is forcibly disconnected as the predetermined unit call time elapses. Coins are stored for one unit of call time as a call charge, but in the case of a multi-charging system even if it is only for local calls, long-distance calls such as number 0 are blocked. Similarly, the call is not forcibly disconnected as the unit call time elapses, but coins are stored each time the unit call time elapses.

In addition, when the phone is used for long distance calls, long distance calls such as "0" are permitted, and coins are collected sequentially in response to a billing signal sent from the exchange each time a unit of call time has elapsed, making it possible to make calls for any length of time.

Therefore, the functions of conventional public telephones are determined depending on the area where they are installed and the type of exchange to which they are connected, and it is not possible to satisfy all the different functions with the same public telephone. As the number of types of telephones increases, mass production becomes difficult and it becomes difficult to lower prices. It had some drawbacks.

[Summary of the idea]

The present invention has the purpose of eliminating such drawbacks of the conventional ones at once, and includes a dial control circuit that determines whether a dialed number is a toll number or a local number, and a dial control circuit that determines whether a dialed number is a toll number or a local number. a timer circuit that generates a signal output each time a unit call time elapses after the called party answers in accordance with a control output when determining that the number is a call number; a first switching device that switches between a local call only and a long distance call; a second switching device that switches between the single billing method and the multi-charging method; and a first switching device that sends out a billing signal from the exchange and a signal output from the timer circuit as a coin storage signal in accordance with the switching status of the second switching device. By providing a gate circuit and a second gate circuit that sends the control output of the dial control circuit and the signal output of the timer circuit as a forced call disconnection signal according to the switching status of the first and second switching devices, all requests can be met. The purpose is to provide an extremely convenient and all-purpose public telephone that can satisfy the following needs.

〔Example〕

Hereinafter, details of the present invention will be explained with reference to figures showing embodiments.

Figure 1 is a connection diagram showing the main circuit of a public telephone. Between the line terminals L1 and L2 and the telephone call circuit TEL, there is a filter unit FLU for detecting billing signals,
A bridge circuit consisting of diodes D101 to D104, a power supply circuit PS, and a disconnection circuit CB are inserted, and terminals F1 and F of the filter unit FLU are inserted.
4 and between F3 and F5, respectively, so that when the hook switch HS3 is turned on by turning off the hook, the hook switch is turned on regardless of the polarity of the line terminals L1 and L2.
With the HS3 side as the positive electrode, if the disconnection circuit CB is on, the loop current passes to the communication circuit TEL, and this loop current circulates through the diode D11 and the Zener diode ZD1, thereby generating a Zener voltage in the Zener diode ZD1. This charges the capacitors C10 to C12 via the diodes D2 to D4, and this terminal voltage is used as a power source for various parts including the power source VDD of the semiconductor circuit.

In addition, in the disconnection circuit CB, when the switch HS3 is turned on, a positive voltage via the communication circuit TEL is applied as a forward bias to the transistor Q11 via the resistors R38 and R41, and the transistor Q
11 is turned on, transistors Q10 and Q
9 is also turned on by the forward bias applied by the resistor R42, and remains on unless the connection point between the resistors R38 and R41 becomes "L" (low level).

In addition, the capacitor C5 of the initial reset circuit IR follows the generation of the Zener voltage of the Zener diode ZD1 due to the circulation of the loop current.
It is charged via diode D10 and resistor R26, and capacitor C5 is charged depending on the time constant determined by the values of resistor R26 and capacitor C5.
Since the terminal voltage of the inverter 21N2 gradually increases, the output of the inverter _21N2 is also "L" while the terminal voltage is below the input threshold level of the inverter 21N1, and when the terminal voltage exceeds the input threshold level, the output of the inverter _21N2 is "L". , turns to "H" (high level).

Therefore, from the start of loop current flow due to hook-off, the output of inverter _21N2 becomes "H".
The "L" level up to this point is used as an initial reset signal.

Note that when the hook switch HS2 is turned off by turning on the hook, "H" is applied to the input of the inverter 12N through the resistor R24, and the output of the capacitor C5 changes to "L". is discharged through the output impedance of R25 and resistor R25.

In addition, there is a return magnet for the coin storage CM.
The RM is a self-retaining type having an operation winding P and a recovery winding S, and the operation of the RM drives a coin return lever (not shown in the figure). Further, depending on the operation of the coin storage magnet KM, a coin storage lever (not shown in the figure) is driven, and coins are stored.

Figure 2 shows a block diagram of the control system.
The billing signal receiving circuit inside detects this and sets the terminal F8 to "L" only during the period of the billing signal, so that this billing pulse is applied to the NAND gate 16N and the timer circuit TM.

Further, the dial control circuit DC is given a dial pulse that detects the intermittent loop current by the terminal voltage of the resistor R43 shown in Fig. 1, and this is counted by a decimal counter to detect the dialed number. At the same time, the number of digits of the dialed number is counted by a binary counter, and based on these counting results, the dialed number is determined to be an area code or a toll number depending on whether the first digit of the dialed number is "0" or not. After determining which local number it is, if this is “0”, output “0” Block
"L" for "1" to "9", "H" for "1" to "9",
A control output is generated depending on the dialed number.

On the other hand, as will be described later, the timer circuit TM is mainly composed of a clock counter and a counter that are activated in response to dialing, and counts the elapsed time after hook-off, and outputs a signal S every time a unit call time elapses. It is set as "L".

In addition, connector CN ₅ as a first switching device and connector CN ₃ as a second switching device are provided, and switching is performed by replacing connectors CN ₅ and CN ₃ , and the switching status of connector CN ₃ is changed. Accordingly, signal output S and filter unit FLU
The charging signal detected by is used as a coin storage signal,
While _the signal is sent from _the NAND gate 16N as the first gate circuit, the signal output S and the dial control circuit
The DC control output is sent out from the NAND gate 19N as a second gate circuit as a forced call disconnection signal.

Note that from FIG. 2 onward, numbers are assigned to the inputs and outputs of each gate, and when explaining the signal path, these numbers will be displayed together with changes in signal levels.

First, in the case of local call only and single billing method, short-circuit connectors CN ₃ and CN ₅ between 1 and 2,
Supply power VDD to OR gate 7N11 and inverter _3N39 to keep it at "H", and output "0" from dial control circuit DC to NAND gate 19N5.
Connect blocks.

Then, if the first digit of the dial call is "0" of the area code, the dial control circuit DC detects this and sets the output "0" Block to "L".
Connector CN ₅ 1-2 “L” → NAND gate 19
N5 “L”-19N13 “H” → Inverter 3N ₂
3"H" - 3N ₂ 4 "L" turns off the disconnection circuit CB in FIG. 1, thereby blocking transmission.

However, if the first digit is “1” to “9”, the output “0” block of the dial control circuit DC is “H”
Therefore, transmission is not blocked, and when a charging signal arrives from the exchange in response to a response from the other party, an "L" charging pulse is sent from terminal F8 of filter unit FLU, and NAND gate 16N5
“L”-16N4 “H” → Inverter 3N ₁ 1 “H”
-3N ₁ 2 "L" provides a coin storage signal of "L" to a drive circuit (not shown), and the coin storage magnet KM shown in FIG. 1 operates to store coins.

The billing pulse is also given to the timer circuit TM, which resets the clock counter and the counter as described later and restarts the operation, and the signal output S is output after a unit call time has elapsed since the billing pulse was generated. OR gate 15N to set it to “L”
9“L”-15N10“L”→NAND gate 19
N11 “L”-19N13 “H” → Inverter 3
N ² 3 “H” - 3N ₂ 4 “L”, the signal output S
The "L" signal from the terminal is sent as a forced disconnection signal.

Next, if you are using only local calls and multi-charging method, leave connector CN ₅ as described above and connect connector
Switch CN ₃ to short between 2 and 3.

Then, ground is applied via connector CN ₃ , and inverter 3N ₃ 9 “L” - 3N ₃ 8 “H” →
OR gate 15N8 “H” - 15N10 “H” →
NAND gate 19N11 “H”-19N13
"L" → Inverter 3N ₂ 3 "L" - 3N ₂ 4 "H"
As a result, "H" is applied to the disconnection circuit CB, so that forced disconnection is not performed, and the "L" signal from the signal output S of the timer circuit TM is passed through the OR gate 7N11 "L".
When the signal output S becomes “L”, OR gate 7N1
2“L”-7N10“L”→NAND gate 16N
6“L”-16N4“H”→Inverter 3N ₁ 1
By "H"-3N ₁ 2 "L", "L" of the signal output S is sent out as a coin storage signal.

In addition, in the case of long-distance calls and multi-charging method, connector CN ₃ is left short-circuited between 2 and 3 as described above, and connector CN ₅ is switched to short-circuited between 2 and 3, and connector CN ₅ is connected to NAND gate 19N5. Apply the power supply VDD through the terminal and fix it to “H”.
19N5 “H” - 19N13 “L” → Inverter 3N ₂ 3 “L” - 3N ₂ 4 “H” disconnects the circuit
Keep CB on.

On the other hand, when "0" is transmitted as the first digit,
Output “0” Block of dial control circuit DC is “L”
This is given to the timer circuit TM, and in order to maintain this state during the hook-off period, the timer circuit
TM stops operating and the signal output S remains at "H".

Therefore, OR gate 7N12“H”-7N
10 “H” → NAND gate 16N 6 “H” turns the NAND gate 16N on, and the charging pulse from the filter unit FLU goes “L”.
Each time this occurs, the NAND gate 16N4 changes from "L" to "H", which causes the inverter 3N ₁
After the signal is inverted and the coin storage signal becomes "L", the coin storage magnet KM is operated.

Figure 3 is a block diagram of the timer circuit TM.
The initial reset signal associated with hook-off is
When given to AND gate 6N ₁ 9, the same gate 6
The flip-flop circuit (hereinafter referred to as FF) _3N1 is reset by the “L” level of _N110 , and its output Q
becomes “L”, so FF・3N ₂ , 3N ₃ , 3N ₄
and clock counter 11N, counter 12N
is reset.

Next, when the first digit is dialed, the dial control circuit DC detects this and sets the start input ST to "L", so FF・_3N1 is set and its output Q becomes "H". .

Then FF・3N ₁ Q “H” → AND gate 6N ₂ 1
3 “H” - 6N ₂ 11 “H” → NAND gate 5N ₂
9"H" - 5N ₂ 10 "L" to release the reset state of the clock counter 11N and counter 12N, so that each of the counters 11N and 12N enters the operating state.

Note that the clock counter 11N is connected to the resistor R1.
1, R12, variable resistor VR11, and capacitor C11, it has a built-in oscillator whose frequency is determined, and in this example, the oscillation output with a frequency of 546.14 Hz is used as a clock pulse to perform counting operation.
After the start of operation, output Q5 every 29 msec, output Q6 every 58 msec, output Q9 every 468 msec,
The output Q10 is set to "H" every 937 msec, and the output Q14 is set to "H" after the same 15 seconds.
This is held for 30 seconds, then turned to "L", and the above operation is repeated.

Further, the counter 12N is the clock counter 1
The signal obtained by inverting the output Q14 of the clock counter 11N by the inverter _17N4 is used as a clock pulse to perform counting, and after the clock counter 11N starts operating.
The output Q1 is set to "H" at 30 seconds, the output Q5 is set to "H" at 1.5 minutes, and the output Q6 is set to "H" at 3.0 minutes.

Therefore, in this example, the unit talk time is 3.5
Therefore, if the strap terminal t is connected to _t2 , "H" is applied to the strap terminal t 3.0 minutes after the start of operation of each counter 11N, 12N, and t"H" → inverter 17 ₁ N1 “H”-17
FF・3N ₂ and 3N ₃ are set by ₁ N2 “L”, each output Q changes to “H”, and FF・3N ₃ Q “H”
NAND gate 5 of the audible signal generation circuit ASG
_N4 is turned on, a positive feedback circuit is formed via inverter _17N2 , and resistors R16 and R1
7. Variable resistor VR12 and capacitor C13
starts generating an 800Hz audible signal determined by
This is sent to the communication circuit TEL as a disconnection forecast tone via a separate circuit.

In addition, the audible signal 800Hz is also used as a coin insertion reminder sound in the multi-charging system. When used for this, the control output TCM is also used at the same time as described above, and the NAND gate 5N ₃ 4 is initially set to "H".
However, it becomes "L" approximately 468 msec after the audible signal generating circuit ASG is activated, and the coin insertion reminder sound is thereby cut off.

That is, the output Q6 of the counter 12N is "H"
So, when FF・3N ₂ and 3N ₃ are set,
NAND gate 4N _{1 1} , 8, 2 “H”-4N ₁ 9
“L”→NAND gate 5N ₂ 8 “L”-5N ₂ 10
Since the counters 11N and 12N are reset by "H", the output Q6 of the counter 12N immediately becomes "L", but the NAND gate 4N ₁ 1 "L" -
4N ₁ 9 “H”-NAND gate 5N ₂ 8 “H”-5
N ₂ 10 “L” causes each counter 11N, 12
After being reset momentarily, A starts operating again, and about 468 msec later, when the output Q9 of the clock counter 11N becomes "H", the NAND gates 5N ₃ 6
“H”-5N ₃ 4 “L” causes the control output TMC to change to “L”.

Note that the output Q9 of the clock counter 11N is approximately
It holds "H" for 468 msec and turns "L" at the same time, the output Q10 of the counter 11N goes "H".
Therefore, NAND gate 5N ₁ 2“H”−5N ₁
3 “L” → AND gate 5N ₃ 6 “L”-5N ₃ 4
FF・_3N3 is reset by “L”, and its output Q changes to “L” and the audible signal generation circuit ASG
NAND gate _5N4 is turned off, and the audible signal is
Stops the generation of 800Hz.

In addition, the signal output S is set to "L" for the signal used as the coin storage signal in the multi-charging method for local calls or the forced disconnection signal when the unit call time elapses in the single-charging method for local calls. It is sent by

That is, 30 seconds after restarting the above-mentioned operation, that is, 3.5 minutes after the start of the first operation, the counter 12N
The output Q1 of the clock counter 11N becomes "H" and is given to the NAND gate 4N ₃ 4, and at this time, the output Q5 of the clock counter 11N is "L", so this becomes the inverter 17N ₃ 11 "L" - 17N ₃ 10
“H” - NAND gate 4N ₃ 5 “H” is given, and FF・3N ₂ Q “H” is also given as NAND gate 4
By being given as N ₃ 3 “H”,
The NAND gate _4N36 becomes "L" and "L" is sent to the signal output S.

However, when the output Q5 of the clock counter 11N becomes "H" after about 30 msec,
NAND gate 4N ₃ 6 becomes “H”, so “L”
Sent as a pulse.

In addition, the “L” pulse of the signal output S causes the FF/
3N ₄ is set and its output Q is "H", and when the output Q5 of the clock counter 11N becomes "H", the NAND gates 4N ₂ 13, 12,
11 “H”-4N ₂ 10 “L” → AND gate 6N ₄
2 “L”-6N ₄ 3 “L”-AND gate 6N ₂ 12
"L" - 6N ₂ 11 "L" FF・3N ₂ , 3
N ₄ , each counter 11N, 12N is reset,
At the same time, FF・3N ₃ is also reset by “L” of FF・3N ₂ Q.

Then, the output Q5 of the clock counter 11N becomes "L", so the NAND gate 4N ₂ 11 becomes "L".
−4N ₂ 10 “H” → AND gate 6N ₂ 2 “H” −
6N ₄ 3 “H” → AND gate 6N ₂ 12 “H”-6
N ₂ 11 “H” → NAND gate 5N ₂ 9 “H”-5
N ₂ 10 “L” causes each counter 11N, 12
N starts operating again and repeats the above operations until the end of the call.

The timer circuit TM operates by controlling each counter 11N, 12 in response to a billing signal from the exchange.
It is necessary to regulate the start of operation of N, and when an "L" charging pulse is sent from the filter unit FLU in FIG. 1, the AND gate 6N ₄ 1 "L" - 6
N ₄ 3 “L” → AND gate 6N ₂ 12 “L” - 6N ₂
After resetting each counter 11N, 12N and each FF・3N ₂ , 3N ₃ , 3N ₄ by 11 “L”, if the billing pulse changes from “L” to “H”,
Since the AND gate 6N ₂ 11 becomes "H", each of the counters 11N and 12N is brought into operation.

Furthermore, when the first digit is "0", it is a state in which long-distance calls are allowed, or a state in which calls should be prevented when only local calls are made, and the operation of the timer circuit TM is not necessary, so as described above. dial control circuit
Output from DC “0” Block is “L” while hook-off
given as AND gate 6N ₁ 8“L”-6
With N ₁ 10 “L”, FF・3N ₁ maintains the reset state and the timer circuit TM does not operate.

In addition, the same applies if a switch or switching terminal is used instead of a connector as a switching device.
OR gate to NOR gate, NAND gate
Various modifications can be made depending on the conditions, such as replacing it with an AND gate.

[Effect of idea]

As is clear from the above explanation, according to the present invention, the functions of public telephones can be freely selected according to the exchange type and service type, so compatibility as public telephones is improved, and mass production of only the same model is possible. This makes it possible to easily reduce the price, and the installer can satisfy all the requirements by preparing a single model, providing great benefits in public telephones for various uses.

[Brief explanation of drawings]

The figures show an embodiment of the present invention; FIG. 1 is a connection diagram showing the main circuit of a public telephone, FIG. 2 is a block diagram of the control system, and FIG. 3 is a block diagram of the timer circuit. DC...Dial control circuit, TM...Timer circuit, CN ₃ ...Connector (second switch), CN ₅ ...
Connector (first switch), 7N, 15N...OR
Gate, 16N...NAND gate (first gate circuit), 19N...NAND gate (second gate circuit), S...signal output.

Claims (1)

[Scope of utility model registration request] a dial control circuit that determines whether a dialed number is an area number or a local number and generates a control output according to the dialed number; A timer circuit that generates a signal output every time a unit call time elapses after the called party answers according to the control output, and a first circuit that performs switching between exclusive use for local calls and dual use for long distance calls.
a switching device, a second switching device for switching between the single charging method and the multi-charging method, and a charging signal from the switching device and a signal output from the timer circuit as a coin storage signal according to the switching status of the second switching device. a first gate circuit that transmits the signal, and a second gate circuit that transmits the control output of the dial control circuit and the signal output of the timer circuit as a forced call disconnection signal depending on the switching status of the first and second switching devices. A public telephone set characterized by: