The transmitting circuit consists of a simple electronic switch that connects the coil for a short time on the battery. Coil resistance is very small, so the coil current can flow force of several amperes . While the current is large, but the time of its occurrence is very short. Electronic key supplies a pulse of current in the coil , then cuts him off , then on again to feed the next pulse . Duty cycle , the ratio of those time during which the current is on to the time when current is switched off is normally about 4%. This will protect the transmitter and the coil from overheating and reduces battery drain. Pulse repetition rate (frequency of the transmitter ) with a typical pulse induction metal detector is approximately 100 Hz. Different models of the MD using frequencies from 22 Hz to several kHz . The lower frequency range , the greater radiated power .
At lower frequencies, it provides more depth and sensitivity of detection of objects made of silver, but it decreases the sensitivity to nickel and alloys of gold. Such devices have a delayed reaction , therefore, require a very slow movement of the frame.
detector pulse PI- Pulse Induction
The transmitting circuit consists of a simple electronic switch that connects the coil for a short time on the battery. Coil resistance is ...
Pulse Induction Metal Detector Circuit
Pulse Induction Metal Detector Circuit In the category Metal Detectors Videos more articles and learn more information about Pulse Inductio...
thrace terra 2 pulse induction metal detector discriminator
thrace terra 2 pulse induction metal detector discriminator In the category Metal Detectors more articles and learn more information about ...
Higher frequencies increase sensitivity to nickel and its alloys, but are less allergic to silver. Radiation frequency can not penetrate deeply underground as a low frequency, but the coil can move more quickly. This allows you to test a large area over a specific period of time, and these devices are more sensitive to concludes the main beach-products made of gold.
Exploratory ring with pulse induction detector consists of a single coil, which serves to transmit and receive signals. The transmitter acts like a car’s ignition coil . Each current pulse in a transmitter coil produces a magnetic field . When the current is cut off , the magnetic field around the coil suddenly disappears , but at this point, a voltage pulse of opposite polarity , and a large amplitude appears at the terminals of the coil. This is called a voltage surge counter electro – the driving force , or anti – EMF . The car is exactly the high voltage that ignites a spark in the spark plug. In this case the detector with a pulse amplitude of the induction discharge below – typically 100 to 130 volts peak. For the duration of the momentum is very small – the 30 millionth of a second (30 microseconds). It is called ” reflected pulse .”
Pulse induction at the Walk through metal detectors
When a metal object passes through a metal detector , the initial impetus in this subject creates an electromagnetic field of opposite pola...
Vlf Versus Pulse Induction Metal Detectors Review
Vlf Versus Pulse Induction Metal Detectors Review In the category treasure hunting more articles and learn more information about Vlf Vers...
pulse induction metal detectors STINGER 2
pulse induction metal detectors STINGER 2 “PI (pulse induction) metal detectors” STINGER 2 pulse metal detector with LCD display, digital ...
receiver
The signal obtained has a PI detector change in the decay rate , when compared with the original signal , the horizontal axis when the coil passes over the object.On the electric resistance of the coil with a wire depends on the decay time of the electric pulse . The complete absence of resistance, or in front of a very high value will make its momentum falter .
With sufficient electrical resistance pulse decay time is shortened and the reflected pulse ” smoothed “. Excessive or insufficient suppression will contribute to job instability and mask signals from highly conductive metals such as gold and reduce the depth of detection .
When a metal object is close to the search coil , it stores a certain part of the pulse energy , which leads to the protraction of the damping pulse to zero. The change in the width of the reflected pulse is measured and indicates the presence of a metal object. In order to isolate the signal of the object we need to measure the portion of the pulse , where it drops to zero ( tail) .
pulse induction metal detector
pulse induction metal detector In the category Metal Detectors more articles and learn more information about pulse induction metal detecto...
Pulse metal detectors PI technology
The Pulse metal detector or pulse induction metal detector Is the most sensitive of all detectors , responds to any metals, does not disti...
Pulse metal detectors casper
Casper – a modern pulse detector on the microcontroller . Designed to search for metal objects in the ground , the sand, the walls, the thi...
At the receiver coil is limiting resistor and diode circuit , which is cut off voltage of the input pulse to a value of 1 volt , so as not to overload the input of the circuit .
The signal receiver consists of a pulse from the transmitter and reflected pulses . Usually, the receiver gain is 60 dB. This means that the area where the reflected signal decreases to zero can be increased 1000 times .
Gate circuit .
The amplified signal from the receiver enters the circuit that measures the time the voltage drops to zero. The reflected pulse is converted into a sequence of pulses.
When a metal object is close to the coil , the shape of the transmitted pulse will not change, but the reflected pulse will be a little longer. Increasing the duration of the “tail ” of the pulse of a few millionths of a second (microseconds ) sufficient to determine the presence of a metal coil. This reflected pulse is superimposed pulses ( gates ) , synchronized with the start of the transmitted pulse and the output of the electronic circuit turns a series of gates , the number of which is proportional to the length of the “tail ” of the pulse .
The most sensitive pulse is as close to the end of the tail where the voltage is very close to zero. This is usually a temporary area of about 20 microseconds after the turn of the transmitter and the beginning of the reflected pulse. Unfortunately, it is also the area where the work is a pulse induction metal detector becomes unstable. For this reason, most of the models with pulse induction metal detectors continue to produce more range gates 30-40 microseconds after the complete decay of the reflected pulse.
Integrator .
Next gated signal must be converted into a DC voltage . It does this scheme – integrator that averages a sequence of pulses and converts them into the corresponding voltage , which increases when an object close to the frame and is reduced when the object is removed . The voltage is amplified and additionally controls a sound control .
- thrace terra 2 pulse induction metal detector discriminator
- Metal Detector Circuit Design electronic pulse metal detector circuit
The time period during which the integrator collects incoming strobes said integrator time constant – ( PVI ) . It determines how quickly the detector responds to a metal object . Long PVI ( order of seconds ) has the advantage of reducing the noise and simplify monitor setup , but it requires a very slow movement of the search coil , as the object can be passed in fast motion . Short PVI ( the order of tenths of a second) faster response to the target , allowing you to quickly move the coil , but the noise immunity and stability deteriorate.
DISCRIMINATION
With pulse induction metal detector is not capable of the same degree of discrimination as VLF devices . By measuring the time period between the widening end of the transmitter pulse and the point at which the reflected pulse is absorbed to zero ( time delay ) can filter objects consisting of a number of metals .
The first place in this characteristic is aluminum foil, then fine nickel coins , buttons and gold. Some coins can be calculated for a very long tail of momentum, but the iron is thus not determined .
There have been many attempts to create a pulse induction metal detector capable of detecting iron, but all these attempts had very limited success. Although iron and gives a long “tail” of silver and copper have the same characteristics . Such a long delay is bad for the determination of depth. Mineral content in the soil will also lengthen the reflected pulse , changing the point at which the object is identified or is rejected. If the time constant of the integrator is set up so that the gold ring is determined in the air, the same ring can “light up” the soil saturated with salts. Thus , the soil is saturated with salts , changes all that relates to the timing and selectivity of a pulse induction metal detector .
Deviation from the ground.
Deviation from the land is very critical for VLF – (Very low frequency) devices , but not with pulse induction metal detectors . On average, the soil does not stores a significant amount of energy from the search coil and itself typically provides no signal. The soil will not mask the signal from the object , and even opposite , the mineralization of the soil slightly lengthens the signal in proportion to the depth of the subject. With respect to the MD with pulse induction often uses the term ” automatic tuning out from the earth » (automatic ground balance), they usually do not react to excessive salinity of the soil, does not require external adjustment for different types of soil. An exception is one of the most unpleasant soil components – magnetite, or a magnetic iron oxide. It causes an overload of input coils VLF (Very low frequency ) type detectors , strongly reducing their sensitivity , with pulse induction metal detectors will work, but may show a false target , if you bring the coil is too close to the ground . You can minimize this adverse effect , lengthening the delay time between the end of the transmitted pulse and the start of sampling . When setting up this time constant can check out from interference caused by ground mineralization .
Automatic and manual tuning .
Most metal detectors with pulse induction have a manual setting. This means that the operator must turn the setting as long until you hear a clicking sound , or itching in the headphones.
If the soil is changed in the search area and from the neutral sand or dry soil to sea water , in which case adjustment is necessary. If you do not, you may lose in the depth of detection and miss some objects . Manual tuning is very difficult when using a short time constant of the integrator (HPV). Therefore, many devices at the manual have a long (IPO) and require a slow moving the search coil .
There is no problem with the use of a pulse induction detector for underwater search , because this is not the search coil is moved quickly. When used in the surf , the coil will be is something in the water, under the water, and under such circumstances, the use of devices with manual adjustment can greatly disappoint you , because we need to continuously adjust the threshold. Certain statements in this case, immediately set up the unit just below the threshold. However, this may lead to reduction in the depth of detection, when the characteristics of the soil .
Auto (SAT-self adjusting Threshold) gives a significant advantage when looking over the salt water or in soils with high salt content. It allows you to use the detector to maximum sensitivity without constant adjustment. This improves stability, noise immunity and allows you to use a larger gain.
Pulse induction DETECTOR does not emit strong negative signals as VLF devices. Therefore, they are not going wild at the pits with minerals. You need to continuously move the coil metal detector equipped with a lock, if you stop the coil configuration breaks down or stops responding.
Audio control.
Schemes sound alarm pulse induction DETECTOR fall into two categories: variable frequency (Hammerhead) and changing volume.
Variable frequency scheme based on voltage controlled generator, good for recording small items, because the change in frequency is easier to catch the ear than a change in volume, particularly when small volume, especially for devices with manual tuning.(principle as the Hammerhead)
However, many people prefer a more traditional tone with increased volume and not the frequency. Sound control systems work well in devices with fast moving frame, in the devices with automatic tuning and they sound similar to devices with VLF.
Conclusions on MD pulse induction.
These specialized tools. It is not suitable for his work in urban areas, is unable to filter and scrap iron. They can be used for archaeological research in rural areas, where there was no wreckage of iron in large numbers, and search for gold nuggets in extreme depth in extreme conditions, such as seashores or the place where the earth strongly Minareliserovana. Detect such show excellent results under such circumstances, generally, are comparable to the very low-frequency devices, especially about the ability of the soil does not care about “punching” them to the maximum depth.
Include the dignity of the same stability, compared with the Managing Director with very low frequencies, who mostly work on the principle of IB (balance), which has often Press.
Gold ions and the discovery of gold
Find the treasure by billions of dollars in India
Sale of old money
The metal discrimination
Questions and answers about metal detectors
treasure seekers visions of gold
the secret a treasure hunt treasures
Is it worth looking for gold with a metal detector?
What is a metal detector and how does it work?
If the police came to your cop. What to do?
what is a pi detector metal detectors for pulse induction pulse induction detector gold best pulse metal detector pi metal detector reviews best pulsedive metal detectors nokta pulse metal detector reviews, pulse induction vs vlf best pulse induction detectors best pulse induction metal detectors cheapest pulse induction metal detector deepest pulse induction metal detector pulse induction metal detectors.
detector pulse PI- Pulse Induction In the category treasure hunting more articles and learn more information about detector pulse PI- Pulse Induction Reviews Price Specifications Features Image manuals videos Accessories All this in metal detectors for gold.
