One type of metal detector is a type of beat frequency oscillator (BFO). The methods used in metal detectors in general are changing the characteristics of the oscillator when there are close to the metal sensor. The detector works based on the resonant frequency that has been set change when there is a metal object is located quite close to the s
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earch coil sensors. Tuning circuit (tuned circuit) should be a part of our oscillator circuit so that if approached by a metal coil sensor specific hence the output frequency of the oscillation circuit is about to change. Variation changes the output frequency depends on the frequency chosen. The selection of the higher frequency will cause the circuit sensitivity increases because the greater the frequency change. Stay if the selection frequency is too high then the practice will produce a system that is not sensitive. This is because the high frequency of most will not be reflected back but will be absorbed by the soil, building materials. Frequency used (f1-produced by the tank circuit with L1) is usually above the human hearing ability. Because it can not be heard by human pendegaran the frequency changes that occur will also not be heard as well. To overcome this it should be made a separate tone (audible frekuency-f2) which shows the change in frequency. This is said with the beat. By mixing the two signals (f1 and f2) will produce signals f1, f2, (f1 + f2), and (f1-f2). The signal can be heard by human hearing is a signal (f1-f2). So when there are changes in frequency caused by changes in the characteristics of the search coil can be heard by humans as a rhythm-beat changing. Rhythm-beat is what is the signal (f1-f2) earlier. VC1 setting is not easy because it requires experiments on certain metals. Similarly, for...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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