JPS6016090A - Button telephone device - Google Patents

Abstract

PURPOSE:To attain stable operation by using a photocoupler between main wire to turn on/off a communication loop thereby eliminating the loss at talking. CONSTITUTION:When a caller is about to make a call, a voltage between terminals 21 and 22 is decreased from 48V to nearly 6V, a voltage rectified by a diode bridge 25 and corrected by a resistor 28, a capacitor 32 and a Zener diode 31 becomes a voltage being an OFF voltage or below of the Zener diode 31 and a call is detected at an IN terminal of an IC35. When the caller depresses a dial key 36, the IC35 detects a depressed dial to allow the IC35 to turn on/off resistors 29, 30 and a transistor 27 by the share of a depressed dial data, the signal turns on/off a transistor of a photocoupler 26 and a dial pulse is transmitted to a telephone station.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a button telephone device used for dialing over a telephone line.

Conventional configuration and its problems FIG. 1 shows a conventional key telephone device.

The configuration of this conventional example will be explained below with reference to FIG. 1.

In Figure 1, terminals 1 and 2 are connected to the central office line, and terminal 3
, 4 are connected to the telephone side. 12 is a rectifying diode bridge, and the DC voltage from this bridge is passed through a resistor 13. Capacitor 14. A constant voltage is established with a Zener diode 8, and a pulse dialer integrated circuit (hereinafter referred to as IC) is created.
Give power to 7. Resistance 18. Capacitor 17. Variable resistor 16 is an IC oscillation circuit, 9 is a dial key, transistor 5.6 and resistor 10, 11.15 are IC7 (7)
It outputs dial signals to the central office line.

Next, the operation of the above-mentioned conventional key telephone device will be explained. In FIG. 1, step C7 changes the data of the dial key 9 to a dial pulse, and the voltage between terminals 1 and 2 is rectified by a diode 12, and a resistor 13. capacitor 14
．． After voltage correction with Zener diode 8, supply it to IC7,
Turn on IC7. IC7 is resistor 18. It self-oscillates with the capacitor 17 and variable resistor 16, and begins scanning the dial key 9. When the caller presses the dial key 9 to make a call, the IC-r detects the pressed dial and presses a resistor 1 corresponding to the pressed dial data.
6. The transistor 16 is turned on and off. This results in resistance 1
o and 11. Turn on and off transistor 5, and connect terminal 1
By turning ON-OFF between and 3, it is sent to the central office line as a dial pulse.

However, in the above conventional example, terminal 1→terminal 3
→ Telephone circuit network → Terminal 4 → Since transistor 5 is inserted between the central office line loops consisting of terminal 2, current flows through transistor 6, resistor 1o, and transistor 6 during a call.
Loss of communication current to the telephone network. Further, since the driving current for the IC 7 is taken from the terminal 10 station line, there is an additional loss of communication current. These effects become more significant as the distance from the central office exchange to the caller increases, and the lower the current is, the lower the call current becomes, causing the problem that calls become sluggish.

OBJECTS OF THE INVENTION The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional system, and to provide a key telephone device that can operate stably even when far from a central office exchange and eliminates loss during calls. do.

Structure of the Invention In order to achieve the above object, the present invention does not include a transistor between the office lines and uses a photocoupler to turn off the call loop, thereby completely eliminating loss during a call.
This has the effect of increasing the stability of motion.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, terminals 21 and 22 are connection ends to the office line, and terminals 23 and 24 are connection ends to the telephone set. 26 is a rectifying diode bridge, and resistor 28.
Capacitor 32. A Zener diode 31 constitutes a call detection circuit. IC35 is a pulse dialer ~, 36
are dial keys, resistors 29, 30. ) The transistor 27 and the photocoupler 26 are elements for turning on and off the central line loop, and the variable resistor 34 and capacitor 33 are elements for oscillating the IC 35.

Next, the operation of the above embodiment will be explained. In FIG. 2, when the caller attempts to make a call, the voltage across terminals 21 and 22 drops from 48V to approximately 6V, which is rectified by diode bridge 26, resistor 28, and capacitor 32. The voltage corrected by the Zener diode 31 becomes lower than the OFF voltage of the Zener diode 31, and the IC3
50 "A call is detected at the K terminal. Furthermore, when the caller presses the dial key 36, 1035 detects the pressed dial, and the IC 35 turns on the resistor 29, 30° transistor 27 by the pressed dial data. -OFF, and the transistor of the photocoupler 26 turns ON with that signal, 0FFl
, and sends a dial pulse to the central office.

In this example, there is no call loss because a 7-auto coupler is used in the communication path, and there is no communication loss.
Since power for C is supplied separately, the distance from the telephone office to the device does not matter, and it has the advantage of stable operation.

Effects of the Invention The present invention has the above configuration, and has the following effects.
It is something that can be done. First, since the 6"-i is separated from the call loop by a photocoupler, there is no loss in calls at all, so it is possible to make good calls. Next, the power for ICl3 is supplied separately. Rather than being
It is possible to stabilize the operation regardless of the distance from the station to the device.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional button telephone device, and FIG. 2 is a circuit diagram of a button telephone device according to an embodiment of the present invention. 21.22... Connection end to central office line, 23.24.
... Connection end to telephone, 25 ... Diode bridge, 26 ... Photocoupler, 2 ends ... Transistor, 28-3o ...・Resistance, 31... Zener diode, 32.33
・・・・・・Capacitor, 34... River variable resistor, 35
...Pulse dialer IC, 36...
dial key. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (1)

[Claims] A circuit that includes a circuit that rectifies the voltage supplied from the office line, a circuit that detects calls and responses on the office line, and a photocoupler that turns on and on the office line loop composed of the office line and the telephone circuit network. and a circuit that detects a pressed dial and turns on and off the photocoupler.