HU176960B - Telephon arrangement to simple or doule used usbscriber's lines - Google Patents

Abstract

The transformerless, transistor circuit for telephone subscriber appts. in two-party line systems consists of a terminating network formed from resistors (R2, R3) together with a line balancing resistor and capacitor network (R4, R5, C7). In the diode bridge at the a and b line inputs to the appts. two links are provided (B1, B2) which may be removed for conversion to party-line use. The receivers transistor amplifier has its base connected to a change-over contact (GU2) operated by the cradle switch. In place of a bell, the transistor may be converted to a tone oscillator by means of a network (C8-10, R11, 12) connected to the base via the cradle contact.

Description

BACKGROUND OF THE INVENTION The present invention relates to a circuit arrangement for telephone sets, in particular with a transformer-free fork circuit and transistor receiver amplifiers, wherein the telephone set can optionally be connected to single or double utilized subscriber lines.

From the prior art, there is a tendency to recognize the increasing use of switching arrangements for telephone sets which do not include coils. They also improve the quality of transmission by using high quality converters and controlling the transmission, reception or loopback. In most cases, Graetz coupling is used to achieve polarity independence. With the increase in π shortage of telephone subscribers, the economical use of copper and the 176960 making investments more economical, the use of subscriber lines is of increasing importance.

Dual Utilization of Subscriber Lines Either one of the calls is transmitted at carrier frequency or a common switch is used in which the selection criterion is provided by the polarity of the central power supply, for example partly electronic or electronic dual connectors.

For this purpose, the use of diodes alternately upstream of the device circuit will electrocute the device following its technical difficulties, since the four consecutive diodes will reduce the available voltage and thereby maximize the available line length.

This solution requires electronic components, both for the dual connection and the electronic circuitry of the device.

It is an object of the present invention to overcome the aforementioned drawbacks of known switching arrangements and to provide a relatively inexpensive solution by multiple utilization of components. At the same time, a universally applicable telephone is used to simplify storage, quickly eliminate malfunctions and quickly connect new devices.

parents should be established that the additional costs and the decline in value in use compared with no special telephone end user device, the location of use easily átsze- ⁷ relhető the single-occupancy subscriber lines doubly kihasználtakra and vice versa.

- 3 176960

It is an object of the present invention to provide a telephone terminal which can be connected to both single and double utilized subscriber lines. In addition, by reducing the number of active elements to be connected sequentially, the voltage and thus the available wire length are utilized optimally and without distortion. By using a transformer-free circuit and a stable voice converter, we improve transmission quality.

According to the invention, the object is solved by the subscriber connection wires being connected to a first transistor via a Graetz circuit comprising a dimmable diode, the base of which is connected to a call discharge switch or a fork circuit via a contact of a fork switch or a subscriber connection line. connected to form a receiver amplifier, and its collector is connected as an inductor to a transistor connected thereafter, and a bell combination is disposed between a diode-resistor connection point connected in series to the emitter of the first transistor and the other subscriber connection line.

In addition, the present invention advantageously allows the ring combination to be replaced by a capacitor and a resistor in series, and to provide the first transistor with a voice network coupling network.

The invention will now be described in more detail with reference to embodiments and drawings.

In the drawings it is

1769 ")

1 and 2 illustrate embodiments of the present invention.

The circuit comprises diodes D1, D2, D3, D4 of a Graetz circuit to which the number switch contacts nsa, nsi, diodes D5, forks Gul, Gu2, Gu3 and a bell combination consisting of capacitor 02 and bell Wk are connected.

After the Gul contact of the fork switch of the telephone device, a fork circuit consisting of a resistor R2, R3, and a synthetic line containing the resistors R4, R5 and a capacitor 07 is connected. In the bridge of the fork circuit, a preferably stable, piezoceramic or dynamic microphone Mi is connected in parallel to the series circuit formed by the resistor R3 or a line comprising the resistors R4, R5 and the capacitor 07. In parallel to the serial switching of the fork switchgear Gul contact and the fork circuit, the transistor TI is connected to which a transistor T2 connected in series as an inductance is connected.

The collector of the TI transistor is connected via the capacitor 05 and the listener Pe to the open Gu3 contact of the fork switch. A resistor R8 is connected between the Gu3 pin of the fork switch and the emitter TI of the transistor. The base of the transistor TI is connected to the fork circuit either through the contact terminal Gu2 of the fork switch, or alternatively between the resistor R3 and a line of resistors R4, R5 and capacitor 07.

- 5 176060

The diode D5 is connected via resistor R8 to the emitter of transistor T1, and to a ring combination consisting of capacitor C2 and bell Wk, while its anode is connected to terminal T1 of the subscriber connection wire and of the fork switch.

The D1, D2, D3, D4 diodes of the Graetz circuit make the circuit polarity-independent and enable connection to single-use "a, b" subscriber lines.

When used twice for connection to a, b subscriber connection wires, the diodes D2, D3 of the Graetz circuit can be bypassed by removing the advantageously soluble bridges B1, B2, thus rendering the circuit polarity dependent. In the case of double utilization, the diodes D1, D4 determine the operation of the telephone circuit according to the power polarity of the telephone exchange. In single and double utilization, on an incoming call, the capacitor C2 of the bell combination consisting of capacitor J2 and bell Wk is charged through diode D5 with the transistor T1 still closed. Since capacitor C2 is off when D1, D2, D3, D4, not possible through diodes, the capacitor C2 is discharged through a call-off switch consisting of a transistor TI with resistors R6, R8 and a transistor T2 with capacitors R9, R10 and a capacitor C4.

This is done by charging the capacitor C2 and closing the diode D5 and reversing the polarity of the base and emitter of the transistor TI, causing the transistor TI to conduct and thus the discharge current through the resistor R8, the transistor T2 and the inductor can flow.

The resistors R9, R10 and the capacitor C4 of the transistor T2 as an inductor are dimensioned such that the capacitor C2 discharges at a favorable rate for the bell Wk. For the transistor Ti, the fork switch Gul and

Target with Gu2 contact

After the handset is lifted, the circuit is transformed into a circuit known as the telephone. Thus, the TI transistor acts as a call discharge switch or receiver amplifier. By simultaneously operating the Gu3 contact, the Fe earpiece is activated when the handset is lifted.

Fig. 2 shows a circuit of a telephone with a voice call. This circuit has the essential characteristics of the circuit shown in FIG. 1, such as the placement of the Graetz circuit containing the diodes D1, D2, D3, D4, the position of the fork circuit and the Gul, Gu2 contact of the fork circuit and the fork switch. terms.

For the voice telephony circuit, the bell Wk is replaced by a resistor R13, the transistor TI is provided with a three-member capacitor resistor circuit formed by a capacitor 08, a resistor R11, a capacitor C9, a resistor R12 and a capacitor C10, and The Fe student is connected via capacitor C5 to the resistor R14 connected to the collector circuit of the TI transistor.

- 7 170060

The TI transistor also functions as a call discharge switch and a voice call oscillator on incoming calls. The voice call and the alternating voltage of the listener are disconnected via resistor R14 and capacitor G5. After lifting the handset, the fork switch Gul,

The circuitry containing the contacts of Gu2 is again transformed into a telephone terminal of the known type, where the TI transistor acts as a receiver amplifier.

Claims (2)

PATENT CLAIMS A telephone apparatus for switching single or double utilized subscriber lines, preferably comprising a Graetz circuitry with bypassable diodes and a fork-free transformer circuit to which a receiver amplifier and an inductively connected transistor are connected, characterized by a transistor of the receiver amplifier T (Gu2) is connected either to a subscriber connection wire (a) or to the fork circuit, and the base of the transistor (TI) is via the fork switch contact (Gu2), a diode (D5) and a resistor (R8) with the emitter of the transistor (TI). and is connected between a common point of the diode (D5) and the resistor (R8) and the other subscriber connection cable (b) from a capacitor (C2) and a bell (Wk / stationary bell combination). An embodiment of a switching arrangement according to claim 1, characterized in that the ring combination consisting of a capacitor (C2) and a bell (Wk) is replaced by a series switching of a capacitor (C2) and a resistor (R13), and capacitors (C8, C9). , C10) and a resistor (R11, R12) three-member capacitor resistor circuit input to the receiver amplifier transistor (TI) collector, output to the transistor (TI) base, and a common connection point for the input and output diode (D5) and resistor (R8).