Menu English Ukrainian russian Home

Free technical library for hobbyists and professionals Free technical library


Surge Protectors. Schemes, articles, descriptions

Free library / Schemes of radio-electronic and electrical devices

Surge Protectors

We recommend reading in our Free Technical Library:

Two antennas for CB radio station



HF Antenna Section. Sometimes radio amateurs try to squeeze as much output power out of their radio as possible without paying enough attention to the antenna (especially in portable radios). But the communication range largely depends on the operation of the antenna-feeder path, on how well it is matched with the transmitter output. The field strength indicator only provides an approximation of the antenna alignment. But with the help of an SWR meter, you can quite accurately tune the antennas, which will be described below. ... >>

Detectors for PLL receivers



Section Radio reception. The detectors (Fig. 1 and 2) for direct conversion FM receivers with phase locked loop frequency [1] offered to the attention of readers are made on the basis of a similar device described in [2]. Unlike the prototype, both of them have a high sensitivity, and the detector according to the scheme of Fig. 2, in addition, and higher selectivity. The detecting device, the scheme of which is shown in Fig. 1 is a frequency converter with a combined local oscillator, which simultaneously performs the functions of a synchronous detector. The input circuit L1C2 is tuned to the frequency of the received signal, and the local oscillator circuit L2C5 is tuned to a frequency half that. The conversion takes place at the second harmonic of the local oscillator, so the intermediate frequency lies in the audio frequency range. The local oscillator frequency is controlled by the VTI transistor itself by changing the capacitance of the collector junction, which depends on the output signal of the detector. The use of inductive coupling (L3) in the local oscillator made it possible to get rid of the resistor in the emitter circuit of the VTI transistor [2] and, thus, to provide greater amplification of the detector at audio frequencies, i.e., to increase its sensitivity (up to 50..,100 μV) ... >>

Frequency synthesizer for a radio station in the range 144-146 MHz



Section Frequency synthesizers. At present, the industry has mastered the production of a microchip of a single-chip frequency synthesizer built according to the prescaler scheme. This K1508PL1 chip is made using CMOS technology in a planar 14-pin package. The division coefficients are loaded into the control register of the microcircuit in a serial code. The microcircuit contains in its composition a frequency divider with a fixed division ratio (DFKD) and a frequency divider with a variable division ratio (CVD). The input is made through pin 4 of the microcircuit. The code has a length of 19 digits (Table 1), and the digits F0...F15 determine the division factor of the DPCD, and the digits R0...R2 - the division factor of the DPCD ... >>

To any article in this section and all Encyclopedias you can leave your comment.

Articles on Voltage Stabilizers

Articles on voltage stabilizers; voltage stabilizer circuits; descriptions of voltage stabilizers: 173 articles

 


 

All articles on power supply

 


 

Latest news of science and technology, new electronics:

Using Apple Vision Pro during surgery 16.03.2024

The medical team at Cromwell Hospital in London used Apple Vision Pro for the first time during two spinal surgeries. This event confirms the headset's potential as a medical tool that will change the way surgical practice is performed. Although the doctors themselves did not use Vision Pro, the operating room nurse worked with virtual reality using glasses while preparing and performing procedures. The headset made it possible to view virtual screens in the operating room, select instruments and monitor the progress of the operation. Software developed by eXeX, a company that specializes in creating artificial intelligence-based applications for surgery, has significantly improved the patient care process. Using Apple Vision Pro opens up new opportunities for developing healthcare applications such as clinical education, surgical planning, training and medical imaging. Implementation of Apple Vision Pro in the medical industry ... >>

Carbon storage in the North Sea 16.03.2024

Norwegian Energy Minister Terje Åsland has announced the launch of the Longship project, which aims to create a central carbon dioxide storage facility in the North Sea. This ambitious project is valued at $2,6 billion and aims to apply CCS (carbon capture and storage) technology to mitigate the impact of climate change. Norway already has experience in CCS, thanks to the successful Sleipner and Snohvit projects, and is now looking to increase the amount of carbon sealed beneath the seabed. Longship's plan calls for capacity to capture and store 1,5 million tons of carbon annually over 25 years. Despite the positive outlook, there are concerns about the long-term consequences of such storage. However, proponents of the project argue that offshore carbon storage has a number of advantages, including minimal environmental impact. The Longship project is carried out with the participation of Equinor, Shell and TotalEnergies through the joint venture Northern Li ... >>

Mini-organs grown from human amniotic fluid 15.03.2024

An international team of scientists led by Professor Fan Xiulin from Zhejiang University has developed a unique method of growing mini-organs from cells found in human amniotic fluid. This significant medical breakthrough could lead to improved diagnosis and treatment of congenital diseases. The organoids, which are three-dimensional cellular structures that mimic organs on a smaller scale, were grown from lung, kidney and small intestine cells found in amniotic fluid. This method opens up new possibilities for studying various fetal conditions and may be the key to early diagnosis and treatment of birth defects. Although no treatment has yet been attempted, the scientists hope their research will help combat the serious congenital diseases that affect millions of newborns each year. This breakthrough could change medical interventions by making it possible to diagnose and treat congenital diseases. ... >>

Random news from the Archive

Sony IMX324 Ultra-Sensitive Automotive Image Sensor 28.10.2017

Sony has introduced a new 7,72-megapixel IMX324 sensor. The sensor has 7,42 million effective pixels, the highest in the industry. Sensor aspect ratio 1/1,7. Sensitivity is determined at the level of 2666 mV. The resolution of the sensor is such that the camera using it is able to obtain a clear image of a road sign from a distance of about 160 meters. A man can't do that.

Such sensors are designed to work in ADAS (advanced driver-assistance systems) electronic driver assistance systems. This development, according to Sony, is compatible with the EyeQ4 and EyeQ5 image processors from Mobileye, previously acquired by Intel.

At night, the IMX324 sensors work both in "burst" mode with RCCC filters (red, three clean), when four adjacent pixels work as one (pixel binning mode) to increase sensitivity, and in alternating light / shadow mode. The pixel array for each frame alternately switches from high sensitivity mode for capturing images in dark areas of the scene, to capturing highlights in bright street lighting and in the light of car headlights. The final image, which is "glued together" by a specialized processor, is detailed and relatively contrasting in the shadows and in the light.

Sony IMX324 sensors are capable of capturing images with ambient light as low as 0,1 lux. It's like shooting under the light of a full moon on a cloudless day. Sensors will help to distinguish a pedestrian on the track and possible obstacles at a great distance. Sensors, which is typical for Sony, are multi-layered and designed for stacking, which allows you to make cameras with them compact.

Other interesting news:

▪ Quantum innovations from IBM

▪ Vector network analyzer up to 26,5 GHz from Rohde & Schwarz

▪ Wormhole transport network

▪ Electrical stimulation of the brain helps to cope with a stroke

▪ Embedded UFS 2.1 96-layer 3D NAND Flash

News feed of science and technology, new electronics

 

Interesting materials of the Free Technical Library:

▪ website section Television. Article selection

▪ Jung Carl article. Biography of a scientist

▪ article Why do deer shed their antlers? Detailed answer

▪ article I say. Legends, cultivation, methods of application

▪ article Transistor converter at 144 MHz. Encyclopedia of radio electronics and electrical engineering

▪ article Flying traffic jams. Focus Secret


All languages ​​of this page

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

www.diagram.com.ua

www.diagram.com.ua
2000-2024