Elimination of spontaneous switching in SVP-4-5. Scheme, description

Free technical library

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

Elimination of spontaneous switching in SVP-4-5. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Телевидение

Comments on the article

During the operation of the Vesna-276 TV, a malfunction occurred in the SVP-4-5 program selection device - after a while, the TV began to spontaneously switch to other channels.

Switching, the TV after an arbitrary period of time again switched to any other channel. Pressing the sensors for selecting programs SB1 ... SB6 (the designations are given according to the schematic diagram [1]) in most cases did not give the desired result. Measuring the voltages in the power circuits, at the pins of the D2 (K155IE9) and D4 (K155ID1) microcircuits, as well as at the pins of all transistors, showed that they are within the passport values. When checking by soldering and "ringing" transistors VT12, VT11, VT6, VT3, VT4, VT5, it turned out that they were working. A similar check of all other electro-radio elements also showed their serviceability. Replacing the D2 and D4 chips with serviceable ones did not work.

The normal functioning of the TV was restored only after replacing the transistor VT12 - stabilizer + 5V (KT645A). The internal defect of this transistor could not be detected by the above measurements and checks.

Literature

1. Elyashkevich S.A. Color TVs ZUSTST: A reference guide. - M.: Radio and communication, 1990.

Author: R.Obakov, Ulyanovsk

See other articles Section Телевидение.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Traffic noise delays the growth of chicks 06.05.2024

The sounds that surround us in modern cities are becoming increasingly piercing. However, few people think about how this noise affects the animal world, especially such delicate creatures as chicks that have not yet hatched from their eggs. Recent research is shedding light on this issue, indicating serious consequences for their development and survival. Scientists have found that exposure of zebra diamondback chicks to traffic noise can cause serious disruption to their development. Experiments have shown that noise pollution can significantly delay their hatching, and those chicks that do emerge face a number of health-promoting problems. The researchers also found that the negative effects of noise pollution extend into the adult birds. Reduced chances of reproduction and decreased fertility indicate the long-term effects that traffic noise has on wildlife. The study results highlight the need ... >>

Wireless speaker Samsung Music Frame HW-LS60D 06.05.2024

In the world of modern audio technology, manufacturers strive not only for impeccable sound quality, but also for combining functionality with aesthetics. One of the latest innovative steps in this direction is the new Samsung Music Frame HW-LS60D wireless speaker system, presented at the 2024 World of Samsung event. The Samsung HW-LS60D is more than just a speaker system, it's the art of frame-style sound. The combination of a 6-speaker system with Dolby Atmos support and a stylish photo frame design makes this product the perfect addition to any interior. The new Samsung Music Frame features advanced technologies including Adaptive Audio that delivers clear dialogue at any volume level, and automatic room optimization for rich audio reproduction. With support for Spotify, Tidal Hi-Fi and Bluetooth 5.2 connections, as well as smart assistant integration, this speaker is ready to satisfy your ... >>

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Random news from the Archive

Smartphone Smartisan T2 10.01.2016

The Chinese company Hammer Technologies has introduced the Smartisan T2 smartphone, which is already available for order at a price of about $385.

The novelty received a Snapdragon 808 processor developed by Qualcomm. This 64-bit chip contains two ARM Cortex-A57 cores (up to 1,8 GHz) and four power-efficient Cortex-A53 cores (up to 1,4 GHz), an Adreno 418 graphics controller, and a Cat 6 LTE Advanced modem.

The device carries on board 3 GB of RAM. The capacity of the flash module is 16 GB for the younger version and 32 GB for the older one. The equipment includes Wi-Fi 802.11ac and Bluetooth 4.1 wireless adapters, an NFC module, a GPS navigation system receiver and a basic set of sensors.

The smartphone is endowed with a 4,95-inch 1080p display (1920 x 1080 pixels). Brightness is 400 cd/m2, contrast ratio is 1000:1. Under the screen are hardware control buttons.

Power is provided by a non-removable 2670 mAh battery. Dimensions are 144,6 x 70,8 x 7,5 mm, weight - 146 grams. The smartphone has a proprietary operating system Smartisan OS based on Android with a significantly redesigned user interface.

Other interesting news:

▪ Electric shock against weeds

▪ Meat grown in space

▪ hydrogen bubble

▪ Output from mobile phone to printer

▪ World's largest electric skyscraper to be built

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Indicators, sensors, detectors. Article selection

▪ article by Bernard Le Bovier de Fontenelle. Famous aphorisms

▪ article Who is Lord Nelson? Detailed answer

▪ article Working on a cardboard grinder. Standard instruction on labor protection

▪ article Dependent switching on of electrical and radio devices. Encyclopedia of radio electronics and electrical engineering

▪ article Three cards move from one part of the deck to another. Focus secret

Leave your comment on this article:

All languages of this page

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