Transformerless preamplifier with balanced input and output. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Transformerless preamplifier with balanced input and output. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Preamplifiers

Comments on the article

A transformerless preamplifier circuit with balanced input and output (Fig. 1) for a studio condenser microphone is proposed.

(click to enlarge)

The main amplification is performed by a specialized IC IC1 (a low-noise differential amplifier with a slew rate of 17 V / μs and a spectral density of noise voltage reduced to the input of 0,95 V / Hz), the gain of this stage is Ku = ( 10000 [Ω] / P1 + 100 [Ohm])+1 can be adjusted with trimmer P1.

The input is protected from both static electricity or voltage surges (D1-D4), and from radio frequency interference (C4). The second and third stages on op-amps IC2/1 and IC2/2, respectively, provide additional amplification (by a factor of R8/R7), decoupling for a standard 600-ohm load, and organization of an anti-phase (balanced) output without the use of a transformer.

The power supply, in addition to providing stabilized bipolar voltages for IC1, IC2, forms a highly stable phantom power supply (+48 V) for the microphone.

Author: Mick Tibor

See other articles Section Preamplifiers.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive

TRACO TMPS ultra-compact power supplies 24.08.2021

TRACO has launched ultra-compact PCB-mounted power supplies to the market. The family includes three series with output power of 3, 5 and 10 W (series TMPS 03, TMPS 05, TMPS 10, respectively).

The main feature of these series is small size; 3 and 5 W series have a seat size of 1"x1" (25,4x25,4 mm), and 10 W models have a size of 1,5"x1" (38,5x25,4 mm). In addition, the power supplies have reinforced 4000 V input-output isolation and do not require grounding (II electrical safety class), are characterized by low power consumption without load (<150 mW) and can be permanently connected to the mains. The 10 W models have an overload capacity of up to 130% for up to 30 seconds, which makes it easier to start the main stages of the device. The TMPS family IPs comply with IEC/EN 60335-1 and UL 62368-1 safety standards (for consumer and information technology devices). The power supply has a built-in class B EMC filter.

Products are intended for wide use in various applications where a minimum size of IP and high security requirements are required: IoT applications, devices for security systems, industrial automation control and monitoring devices, sensors.

Features:

Ultra compact size
Safety Compliance IEC/EN 60335-1 and UL 62368-1
Reinforced insulation 4000 V
EMC class B
Overload capacity up to 130% (for TMPS 10)
3 year warranty

Application:

IoT applications
SENSORS
Industrial automation
Household appliances and devices.

Other interesting news:

▪ New image sensor for automotive cameras

▪ Likes increase hate

▪ Night lighting from living plants

▪ AMD Radeon R9 290

▪ MiniCa miniature camera

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Radioelectronics and electrical engineering. Article selection

▪ Article Young Guard. Popular expression

▪ article Why was the pager invented? Detailed answer

▪ Ivan-chai article. Legends, cultivation, methods of application

▪ article Theory and practice of using the 555 timer. Part two. Encyclopedia of radio electronics and electrical engineering

▪ article Miracle album. Focus Secret

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews