JPS6246360Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a push-button dial telephone for high-loss subscriber lines.

FIG. 1 shows a circuit diagram of this type of conventional push-button dial telephone for high-loss subscriber lines.
The dial circuit takes the form of a two-trans bridge type side sound prevention circuit consisting of two guiding rings LD ₁ and LD ₂ , a transmitter T, a receiver R, a balanced circuit network _Zo , and a capacitor C ₁ . D is input/output terminal P ₁ , P ₂ , P ₃
The dial common switch SW, which is a continuous contact type and has three terminals, make terminal M, break terminal B, and common terminal C, opens the make terminal M connected to terminal P ₂ of the dial circuit during a call. Then, the transmitter T, the receiver R and the side sound protection circuit Z _o
The break terminal B connected to the connection point with the line connection terminal L2 and the common terminal C connected to the line connection terminal _L2 form a communication circuit, and when the dial button is pressed, the break terminal B is released and the make terminal is connected to the make terminal. The configuration was such that M and the common terminal C were in contact with each other to form a dial circuit.

Fig. 2 is an equivalent circuit diagram of Fig. 1 when _{a dial} signal is sent out _. One end of the speaker T is connected, the other end is connected to one end of a capacitor C ₁ , the other end of the capacitor C ₁ is connected to one end of a resistor R ₁ , and the other end of the resistor R ₁ is connected to a second line connection. Since the circuit connected to terminal L ₂ is connected in parallel to terminals P ₁ and P ₂ of dial circuit D via resistor R ₂ , a low impedance circuit is connected in parallel to dial circuit D via capacitor C ₁ . The transmitter T was connected, creating an AC load and causing a drop in signal level.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the conventional circuit and to provide a push-button dial telephone set for high-loss subscriber lines, which has a circuit that prevents a drop in signal level without changing the various characteristics of the telephone set. It is in.

According to the present invention, a first guide ring composed of three windings, a second guide ring composed of two windings, a transmitter, a receiver, a balanced circuit network, a capacitor, It includes a dial circuit having three input/output terminals and a dial common switch of continuous contact type, one end of the primary winding of the first guide wire ring is connected to the first line connection terminal, and the The second coil is connected to the connection point between the primary winding and the secondary winding of the first guide ring.
Connect the primary winding of the guide ring, connect one end of the balanced circuit network to the other end of the secondary winding of the first guide ring, and connect both ends of the tertiary winding of the first guide ring. connects the handset, connects the other end of the balanced network to one end of the transmitter and the break terminal of the common dial switch, and connects the primary and secondary windings of the second guide ring. The other end of the transmitter and the first terminal of the dial circuit are connected to the connection point of the dial circuit, and the other end of the second winding of the second guide wire is connected to one end of the capacitor and the first terminal of the dial circuit through a resistor. the other end of the capacitor is connected to a second line connection terminal and the common terminal of the dial common switch, and the second terminal of the dial circuit is connected to the make terminal of the dial common switch. A push-button dial telephone set for high-loss subscriber lines is obtained.

FIG. 3 is a circuit diagram of an embodiment of the present invention, and FIG. 4 shows an equivalent circuit diagram when the dial signal is sent out.
In Figure 3, LD ₁ is the first guide ring consisting of three windings n ₁₁ , n ₁₂ , n ₁₃ , and LD ₂ is the first induction ring consisting of two windings.
The second guiding wire ring is composed of n ₂₁ and n ₂₂ , T is the transmitter, R is the receiver, Z _o is the balanced network, C ₁ is the capacitor, L ₁ and L ₂ are the first and second lines. Connection terminal D is a dial circuit equipped with input/output terminals P ₁ , P ₂ , P ₃ , and SW is a dial common switch equipped with continuous contacts.

Then, the first line connection terminal L ₁ is connected to the primary winding n ₁₁ of the first guide wire LD ₁ , and the first guide wire
_The primary winding n 21 of the second guiding wire LD ₂ is connected to the connection point between the primary winding n ₁₁ and the secondary winding n ₁₂ of the LD ₁ , and the secondary winding of the first guiding wire LD ₁ is One end of a balanced circuit network Z _o is connected to the other end of the winding n ₁₂ , and a receiver R is connected to both ends of the tertiary winding n ₁₃ of the first guiding wire LD ₁ . The other end of Z _o is connected to one end of the transmitter T and the break terminal B of the dial common switch SW, and the primary winding n ₂₁ and the secondary winding n ₂₂ of the second guide wire ring LD ₂ are connected. The other end of the transmitter T and the first terminal _P1 of the dial circuit D are connected to the connection point of the dial circuit D.
Connect the other end of the secondary winding n ₂₂ of the induction wire LD ₂ to a capacitor.
The dial circuit D through one end of _C1 and resistor _R1
Connect the third terminal P ₃ of the and the other end of the capacitor C _1
L2 terminal is connected to the common terminal C of the switch SW, and the second terminal _P2 of the dial circuit is connected to the make terminal M of the switch SW.

In this way, one end of the capacitor _C1 , which was connected to the connection point between the transmitter T and the balanced network Z _o , is connected to the line connection terminal L ₂ and the common terminal C of the dial common switch SW. As shown in FIG. 4, the low impedance transmitter T, which was connected in parallel through the dial circuit through the capacitor _C1 , is disconnected, making it possible to suppress a drop in the signal level.

Furthermore, the DC loop during dialing is connected from the first line connection terminal L ₁ to the first guide line ring LD ₁ as shown in Figure 4.
The primary winding n ₁₁ of the second guiding ring LD ₂ , the primary winding n ₂₁ of the second guiding ring LD 2
, and from the dial circuit D to the second line connection terminal L ₂ , and the DC loop at the time of communication is connected from the first line connection terminal L ₁ to the first lead in FIG. 3. Primary winding n ₁₁ of wire ring LD ₁ ,
Since the route is taken to pass through the primary winding _n21 of the second guide ring _LD2 and exit from the transmitter T to the second line connection terminal _L2 , the direct current characteristics are not affected.

According to the present invention, as explained above, a push-button dial telephone set for a high-loss subscriber line can be obtained which has a circuit for transmitting signals and preventing a drop in the bell level without changing the various characteristics of the telephone set.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of what was previously considered, Figure 2
The figure shows an equivalent circuit diagram when the dial signal is sent out, FIG. 3 shows a circuit diagram of an embodiment of the present invention, and FIG. 4 shows an equivalent circuit diagram when the dial signal shown in FIG. 3 is sent out. L ₁ , L ₂ ... Line connection terminal, T ... Transmitter,
R...Telephone receiver, LD ₁ ...First guide ring, LD ₂ ...
2nd guide wire ring, C... capacitor, Z _o ... side sound protection circuit network, R ₁ , R ₂ ... resistor, D... dial,
P ₁ , P ₂ , P ₃ ... Dial input/output terminal, SW ...
Dial common switch with continuous contacts, n ₁₁ , n ₁₂ , n ₁₃ ... 1st to 3rd windings of the first guide ring, n ₂₁ , n ₂₂ ... 1 to 2 of the second guide ring Next winding.

Claims (1)

[Scope of utility model registration request] A first guide ring composed of three windings, a second guide ring composed of two windings, a transmitter,
It includes a telephone receiver, a balanced circuit network, a capacitor, a dial circuit having three input/output terminals, and a continuous contact type dial common switch, and one end of the primary winding of the first guide ring. connected to the first line connection terminal, and connected to one of the first guide wire wheels.
The primary winding of the second guiding coil is connected to the connection point between the primary winding and the secondary winding, and one end of the balanced circuit network is connected to the other end of the secondary winding of the first guiding coil. and both ends of the tertiary winding of the first guiding wire are connected to the receiver, the other end of the balanced circuit network is connected to one end of the transmitter and a break terminal of the common dial switch, and The other end of the transmitter and the first terminal of the dial circuit are connected to the connection point between the primary winding and the secondary winding of the second guiding wire, and the other end of the dial circuit is connected to the second winding of the second guiding wire. One end of the capacitor is connected to the third terminal of the dial circuit via a resistor, the other end of the capacitor is connected to the second line connection terminal and the common terminal of the dial common switch, and the other end of the capacitor is connected to the second line connection terminal and the common terminal of the dial common switch. A push-button dial telephone for a high-loss subscriber line, characterized in that a second terminal is connected to a make terminal of the common dial switch.