JPH0114743B2 - - Google Patents

Description

Detailed Description of the Invention This invention combines unlimited short-distance calls in which a charging signal arrives from the exchange only once when the called party answers, and normal calls in which charging signals arrive sequentially from the exchange at intervals of one call time. Regarding public telephones.

For types of calls made on public telephones, a charging signal arrives only once when the called party answers, and the charge for one call (in coins or credits) is collected, and after that, no charging signal arrives and the time is unlimited. There are unlimited short-distance calls that can be made to. This unlimited short-distance call requires only the fee for one call, so there is no need to send a reminder signal.

However, as shown in FIG. 1, the conventional reminder signal sending control device 1 includes a billing signal receiving circuit 3 that outputs a billing signal detection signal upon receiving a billing signal coming from an exchange 2, and a billing signal receiving circuit 3 that outputs a billing signal detection signal when receiving a billing signal coming from an exchange 2. and a reminder signal sending circuit 4 which compares the remaining amount inserted (coins or credits) with the call charge for one call and sends out a reminder signal if there is no amount remaining for one call or more. . For this reason,
In the case of unlimited short-distance calls mentioned above, even though a reminder signal is not required, one billing signal arrives after the called party answers, and the remaining amount after collecting the charges for one call is There was a drawback that a reminder signal would be sent if the price fell below the toll.

In Figure 1, 5 is a public telephone, 6 is a telephone circuit, 7a is a telephone line, 7b is ground, L1, L
2 is a line terminal.

This invention corrects these drawbacks by identifying whether or not the type of call is an unlimited short-distance call based on the number of times charging signals arrive, and does not send a reminder signal in the case of an unlimited short-distance call. The purpose is to provide public telephones.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 2 shows an embodiment of a public telephone according to the present invention, in which the same components as those in FIG. 1 are given the same reference numerals, and the details thereof are omitted.

In FIG. 2, reference numeral 11 denotes an identification circuit that receives the billing signal detection signal sent from the billing signal receiving circuit 3 and identifies whether the billing signal has arrived twice or more. This identification circuit 11 includes a counter 12 for counting the charging signal detection signal, which is a short pulse, and a counter 12 for counting the charging signal detection signal, which is a short pulse. It is composed of an inverter 13 and an AND circuit 14 to prevent the signal from being input to the circuit. The counter 12 is reset in the initial state so that the A to D outputs become O.

The B output of the counter 12 is input to the reminder signal sending circuit 15 in addition to the billing signal detection signal. When the B output of the counter 12 is "0", the reminder signal sending circuit 15 does not send out a reminder signal even if the remaining input amount is less than the call charge for one call; When the charging signal detection signal is received from the charging signal receiving circuit 3 and the remaining amount falls below the call charge for one call, a reminder signal is sent out.

The operation in the above configuration will be explained.

A billing signal is sent from the exchange 2 between the call line 7a or between the call line 7a and the ground 7b. When the billing signal receiving circuit 3 receives this, it passes the billing signal detection signal to the identification circuit 11 and the reminder signal sending circuit 1.
Output to 5.

Initially, the counter 12 is reset and its outputs A to D are in the "0" state. Since output B is “0”, the output of inverter 13 is “1”
It's getting old. Therefore, when the first billing signal arrives, a billing signal detection signal is output from the billing signal receiving circuit 3, and is input to the counter 12 through the AND circuit 14, and the outputs A=1, B, C, D=0. becomes. When the second billing signal arrives, A, C, D
=0, B=1. As a result, inverter 13
Since the output of the counter 12 becomes "0", the output state of the counter 12 does not change even if a billing signal arrives thereafter. Therefore, in the case of an unlimited short-distance call in which the charge signal arrives only once, the B output of the counter 12 always remains "0", and in the case of a long-distance call in which the charge signal arrives twice or more, the B output becomes "1". ” is maintained. Therefore, in the case of an unlimited short-distance call, even if the charge for one call is collected due to the arrival of the charge signal and the remaining amount is less than the charge for one call, the B output is "0" and no reminder signal is sent. In the case of a long-distance call, the B output is "1", so if the remaining amount falls below the amount for one call when the billing signal arrives, a reminder signal is sent out from the reminder signal sending circuit 15.

The public telephone of this invention counts the number of incoming billing signals to determine whether or not it is an unlimited short-distance call and controls the sending of the reminder signal, so you can make unlimited calls for a single call charge. When making unlimited short-distance calls, you no longer have to worry about reminder signals as in the past. Incidentally, when the charge system is different between short-distance calls and long-distance calls, the output signal of the identification circuit can also be used to switch the charge system.

[Brief explanation of drawings]

FIG. 1 shows a conventional public telephone, and FIG. 2 shows an embodiment of the present invention. 1... reminder signal sending control device, 2... switchboard,
3... Charging signal receiving circuit, 5... Public telephone, 6
... Call circuit, 11 ... Identification circuit, 12 ... Counter, 15 ... Reminder signal sending circuit.

Claims (1)

[Claims] 1. A public telephone service in which unlimited short-distance calls, in which a charging signal arrives from the exchange only once when the called party answers, and normal calls, in which charging signals arrive sequentially from the exchange at intervals of one call time, are used together. The telephone includes: a billing signal receiving circuit that receives the billing signal coming from the exchange and outputs a billing signal detection signal; and counting the billing signal detection signal from the billing signal receiving circuit until the counted value is 2 or more. an identification circuit that outputs an identification signal indicating whether or not the charging signal is present; and a prompting signal only when receiving both the charging signal detection signal from the charging signal receiving circuit and the identification signal representing 2 or more from the identification circuit. A public telephone equipped with a reminder signal sending circuit that sends out a reminder signal.