A simple metal detector with an indicator on a VHF (FM) receiver (64-108 MHz). Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / metal detectors
Comments on the article
Schematic features
The scheme of this metal detector is distinguished by ease of manufacture and an unusual principle of operation:
- VHF (FM) receiver (64-108 MHz) is used as an indicator;
- as a search coil - a piece of television cable.
Due to the fact that the generator on the VT3 transistor (low-power transmitter) operates at a high frequency, it was possible to achieve high sensitivity and simplify the design of the coil.
Schematic diagram and principle of operation
The coil is a coil of a television cable with a diameter of 15-25 cm (depending on the frequency and VHF range). It is only necessary to have a switchable AFC in the receiver, which significantly increases the sensitivity (Fig. 2.27).
Rice. 2.27. Schematic diagram of a metal detector with an indicator on a VHF (FM) receiver (64-108 MHz)
A multivibrator is used to modulate the high frequency oscillator. The receiver is tuned to the frequency of the metal detector so that it is at the very edge of its bandwidth. When metal objects approach the coil, the generator frequency changes, and the signal disappears in the receiver.
Author: Martynyuk N.
See other articles Section metal detectors.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Artificial leather for touch emulation
15.04.2024
In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>
Petgugu Global cat litter
15.04.2024
Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>
The attractiveness of caring men
14.04.2024
The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>
| Random news from the Archive Charger on wheels
12.08.2011
With the spread of electric vehicles, there will inevitably be a problem of running out of batteries away from places where there is a charging station.
In such a case, the Japanese company Nissan, together with the Japan Automobile Owners Association, is testing a mobile charging station that can arrive on a call to a stuck electric car and recharge it from a diesel engine.
|
Other interesting news:
▪ Ultra compact wood
▪ Transistors that work 10 times faster than brain synapses
▪ New source of cosmic rays
▪ Likes don't cheer you up
▪ Alcatel Vision virtual reality helmet
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ site section Parameters, analogues, marking of radio components. Article selection
▪ article Strikebreaker. Popular expression
▪ article What was Mozart's middle name? Detailed answer
▪ article Sandblasting. Standard instruction on labor protection
▪ article A simple microcontroller programmer. Encyclopedia of radio electronics and electrical engineering
▪ article Playing with the clock. Focus Secret
Leave your comment on this article:
All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese