pirate pi metal detector russian pcb eagle

That’s why I decided to go for a 1 meter coil.Īlthough the physical size and shape of the coil may vary (square or elliptical coils are used in specific situations and work just as well as round ones), the inductance of coils only varies slightly between different physical designs. In my situation I needed to locate iron 100 mm water pipes at a depth of two meters. For those situations a 250 or 400 mm coil will do. Many people will use metal detectors to search for coins and jewelry. It gives however an idea what type of coil you need for a specific problem. It is obvious that with a one meter coil you won’t detect a five centimeter object at five meters deep. These are maximum values and depend heavily on the situation. In general you can say that the maximum theoretical detection depth of a coil is five times the diameter and the minimum size of an object detected with a coil is five percent of the diameter. The size of the coil is mainly dependent on the required detection depth and the minimum size of objects that still should be detected. The main part to generate magnetic pulses is the coil. Although they differ in the way the signals are processed, the electronics which generate the magnetic field pulses is almost always identical. There are many projects floating around on the internet regarding pulse induction metal detectors. To achieve this, the processing of the signals is done entirely digitally with a digital signal processor, DSP. Because of the specific needs when I started this project, this page describes a pulse induction metal detector with as much as possible discrimination between different metals. Pulse induction can often reach deeper targets than frequency based detectors, but discrimination between different types of metals is more difficult. If the magnetic field is switched of fast enough, the eddy currents can be detected with the transmit coil, which then acts as a receiver. The magnetic field caused by these pulses start eddy currents in metals close to the coil. In the other approach, current pulses are sent to the transmit coil. The amount of amplitude change and phase change is an indication for the size and distance of the metal, and can also be used to discriminate between ferrous and non-ferrous metals.

If a piece of metal comes inside the range of the magnetic field lines, the receive coil can detect a change in both amplitude and phase of the received signal. A receive coil is used to pick up the magnetic field generated by the transmitter. In one approach, an alternating current is provided to a transmit coil. There are two general approaches to detect these changes.

Most metal detectors work on the fact that metals in a magnetic field change the behavior of the field.

Pirate pi metal detector russian pcb eagle