SU1543565A1 - Device for transmission of speech signal - Google Patents

Abstract

The invention relates to a telephone communication technique and can be used in terminal telephone devices. The purpose of the invention is to stabilize the output signal by providing stable microphone power. The device comprises a microphone 1, five resistors 2-6, three capacitors 6, 7, 8, two transistors 10, 11, a zener diode 12, two terminals 13, 14 of a voice signal transmission device of a telephone set (TA). To achieve the goal, the second output of the resistor 5 and the emitter of the transistor 11 are connected respectively to the second and first leads of the microphone 1. When connected in parallel with the TA containing the device, another TA with low internal resistance, the DC voltage at the terminals 13, 14 decreases. In this case, Zener diode 12 exits the voltage stabilization mode and the linear current flows through the resistor 6, the voltage drop on which is determined by the ratio of the resistances of the resistors 3, 4, 5 and is 1.8-2 V. This voltage is applied through Resistor 2 guaranteed microphone power 1. 1 Il.

Description

The invention relates to a telephone communication technique and can be used in terminal telephone devices.

The aim of the invention is to stabilize the output signal by providing stable microphone power.

The drawing shows a circuit diagram of a voice signal transmission device of a telephone apparatus.

The voice signal transmission device of the telephone set contains a microphone 1, the first-fifth resistors 2-6, the first 7, the second 8 and the third 9

capacitors, the first 10 and second 11 transistors, the Zener diode 12, the first 13 and second 14 pins of the voice signal transmission device of the telephone set.

The device of the speech signal transmission of the telephone apparatus operates as follows.

The terminals 13 and 14 are connected to the telephone line, while the capacitor 8 is charged through the resistor 3. The voltage from the divider formed by the resistors 4 and 5 is fed to the base of the transistor 11, and the transistors 11 and 10 are opened. The current from the telephone line flows through the transistor 10

O Ј SA O O O O

and Zener diode 12, where a constant voltage of about 3.7 V is released at a linear current of about 0 mA. From this voltage across the resistor 2, the microphone 1 is energized. The pulsations of this voltage are smoothed by the capacitor 7.

The acoustic speech signal is converted by the microphone 1 into an electric one, which, having passed through the capacitor 9, is amplified by transistors 11 and 10 and through the terminals and 13 of the device enters the telephone line.

When connected in parallel to a telephone set containing a ttao device, another telephone set g Low internal resistance (in the M case 150 Ohms) the DC voltage at terminals 13 and I decreases to 3.6-4 V. In this case, the zener diode 12 exits voltage stabilization mode and the linear current flows through resistor 6, the voltage drop across which is determined by the ratio of resistors 3, f and 5 and is about 1.8-2 V. This voltage is applied through resistor 2 microphone 1.

Thus, the use of the device in telephone sets makes it possible to provide the microphone with necessary power, and therefore the device is not only operational in the full range of line resistances (from 0 to 1 kOhm), but also with parallel radar (5 here with any telephone sets). .

0

0

five

Claims (1)

Invention Formula A voice CHI transmission device containing a microphone, the first terminal of which is connected to the first terminals of the first resistor and the first capacitor, the second microphone terminal is connected to the second terminals of the first capacitor, a zener diode, an fifth resistor and the second capacitor phone, the second output of which VL - emigter of the first transistor connected to the first output of the second resistor, the second output of which is under the | The third resistor is connected to the first terminals of the fourth resistor, the third capacitor and the base of the second transistor, whose collector is connected to the base of the first transistor, and the collector of the microphone is connected The second terminal of the third capacitor, characterized in that, in order to stabilize the output signal by providing stable power to the microphone, the second terminal of the fourth resistor and em tter second transistor connected respectively to the second and first terminals of the microphone. L. Veselovska Tehred A. Krazchuk Order A09 Circulation 525 Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab., T./5 Proofreader A-Obruchar