JPH0614532Y2 - Telephone hold melody sound sending device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a telephone having a holding melody sound sending device.

BACKGROUND ART FIG. 2 shows a conventional held melody tone transmitting device for a telephone of this type. In the figure, telephone A is in a call because telephone line L is set when the handset is lifted.
₁ and L ₂ are closed via the closing resistance in the telephone A, and even if the handset is dropped in this state, the telephone line L
_In order to prevent ₁ and L _{2 from} being cut off, that is, to put them in a holding state, the holding relay contact x ₁ connects the closing resistance R ₁ to the telephone lines L ₁ and L ₂ in parallel. At this time, the hold set switch S ₁ energizes the hold relay coil X ₁ , and at the same time, a voltage is supplied to the melody sound generation circuit ME including the melody generation integrated circuit IC ₁ and the output transistor TR _1. Is
The output is sent to the telephone lines L ₁ and L ₂ via the transformer T.

However, in the conventional circuit configured as described above, a relay or a transformer is required to insulate the telephone lines L ₁ and L ₂ from the DC power source E, which increases the cost and consumes the holding relay. There is a drawback that the battery is consumed greatly due to the large current.

[Object of the Invention] The present invention has been made in view of the above point, and the object thereof is to reduce the cost because it does not require an insulating relay or transformer, and the battery consumption is small. It is an object of the present invention to provide a holding melody sound transmitting device for a telephone that can last a long time.

DISCLOSURE OF THE INVENTION However, in the device for sending out the held melody of the telephone according to the present invention, the primary side is connected to the secondary side of the rectifier connected to the telephone line in parallel with the secondary side of the photocoupler from the positive side. The connection resistor and the Zener diode are connected in series, the voltage across the Zener diode is supplied to the melody sound generation circuit, and the signal output end of the melody sound generation circuit is connected to the positive electrode side of the closed resistance via the coupling capacitor. The primary side of the photocoupler is connected to the DC power supply via a current limiting resistor and a switch for holding setting.The melody sound generation circuit itself is inserted in series with the closing resistor, and the photocoupler is used instead of the relay contact. Since the DC power supply is used, it is only necessary to supply the primary current of the photocoupler from the DC power supply, and the feature is that the transformer can be omitted. It

[Embodiment] FIG. 1 shows an embodiment of the present invention, in which a rectifier D whose primary side is connected in parallel with a telephone set A to telephone lines L ₁ and L _2.
Between the secondary side terminals of B, the photocoupler PC in order from the positive side
The secondary side phototransistor, the closing resistor R ₁ and the Zener diode ZD ₁ are connected in series, and the voltage across the Zener diode ZD ₁ is applied to the melody sound generation circuit ME.
Is being supplied to. The melody sound generating circuit ME is composed of a melody generating integrated circuit IC ₁ and an output transistor TR ₁ for amplifying its output signal. The signal output terminal of the melody sound generating circuit ME has a coupling capacitor C ₁
Is connected to the positive electrode side of the closing resistor R ₁ via a current limiting resistor R ₂ and the holding set switch S ₁ and is connected to the DC power source E via a current limiting resistor R _2. ing.

In FIG. 1, when the holding set switch S ₁ is open, the secondary side terminals of the rectifier DB are cut off by the photocoupler PC, and the holding set switch S ₁ is closed here. Then, current is supplied to the photocoupler PC so that its secondary side becomes conductive, and the telephone lines L ₁ , L
_{Since the two} are closed by the closing resistor R ₁ , even if the handset is taken down in the telephone A thereafter, the telephone line L ₁ ,
The L ₂ are connected through a holding resistance R ₁ for holding, and the call state is maintained to the outside. At this time, the melody sound generation circuit ME is supplied with a voltage which is made constant by the Zener diode ZD ₁ through the closing resistor R _1, and the melody sound signal generated by the melody generation integrated circuit IC ₁ is thereby supplied. It is amplified by the output transistor TR ₁ and sent to the telephone lines L ₁ and L ₂ through the coupling capacitor C ₁ and the closing resistor R ₁ . Also, switch S for holding set
_{When 1} is opened, the telephone lines L ₁ and L ₂ are cut off,
At the same time, the power supply to the melody sound generation circuit ME is cut off.

[Effects of the Invention] As described above, the present invention connects the secondary side of the photocoupler, the closing resistor, and the Zener diode in series to the secondary side of the rectifier whose primary side is connected to the telephone line. The voltage is supplied to the melody sound generation circuit, and the primary side of the photocoupler is connected to the DC power supply via the switch for holding set.The melody sound generation circuit itself is connected to the telephone line side as a part of the closing resistance. Receive power supply,
Moreover, since the photocoupler is used instead of the relay, the DC power supply supplies only the primary side current of the photocoupler and the current consumption is extremely small. Since the transformer can be omitted, the cost can be reduced. Also,
A photocoupler controlled by turning on / off the hold set switch turns on / off the output of the melody sound signal output from the melody sound generation circuit to the telephone line and simultaneously turns on / off the power supply to the melody sound generation circuit. Since the power is not supplied to the melody sound generation circuit except in the off state and the hold state, there is an effect that power saving can be achieved without consuming power in the melody sound generation circuit and the photocoupler in the state other than the hold state. is there. Moreover, since the melody sound signal output from the melody sound generation circuit is transmitted to the telephone line through the rectifier, it is possible to share the line for power supply to the melody sound generation circuit and the line for melody sound signal transmission. The effect is that the circuit configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional example. A ...... _{telephone, L 1,} L ₂ ...... telephone line, DB ...... rectifier, PC ...... photo-coupler, _{R 1} ......閉結resistance, _{R 2} ...
… Current limiting resistance, ZD ₁ …… Zener diode, ME
...... Melody sound generation circuit, S ₁ …… Holding set switch, C ₁ …… Coupling capacitor, E …… DC power supply.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroaki Takeyama, Inventor Hiroaki Takeyama 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Kiyotaka Takehara, 1048, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works, Ltd. (56) References JP-A-60-174567 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A secondary side of a rectifier whose primary side is connected to a telephone line in parallel with a telephone, and a secondary side of a photocoupler, a closing resistor and a zener diode are connected in series from the positive side in sequence.
The voltage across the Zener diode is supplied to the melody sound generation circuit, and the signal output end of the melody sound generation circuit is connected to the positive side of the closing resistor via a coupling capacitor, and the primary side of the photocoupler is used as a current limiting resistance and hold. An on-hold melody tone sending device for a telephone that is connected to a DC power source via a set switch.