The working principle of the ground induction coil, what wire is used in the ground induction coil

The ground induction coil is an oscillating circuit that detects whether a car is passing by and at what speed.

The principle of action is to create a circular trench in the ground, about 1 meter in diameter, or a rectangular trench with an equivalent area, and bury two to three turns of wire in the trench, which constitutes an inductance coil buried in the ground.

This coil is the part of the oscillating circuit, which is formed by it and the capacitor. The oscillation signal is sent to the microcontroller by transformation.

The frequency of this oscillator can be measured by a frequency measurement circuit.

When a large metal object such as a car passes by, the oscillation frequency changes due to the change of the space medium (the oscillation frequency increases when there is a metal object), the single-chip microcomputer can measure the frequency value of the change, that is, it can sense that a car is passing by. At the same time, the time interval between the start and end of this signal can be used to measure the speed of the car.

"Ground Sense Coil" is one. When a large metal object such as a car passes by, the oscillation frequency changes due to the change of the space medium (the oscillation frequency increases when there is a metal object), and this change is an oscillation circuit. It is composed like this, first make a circular trench on the ground, with a diameter of about 1 meter, or a rectangular trench with an equivalent area, and then bury two to three turns of wire in this trench, which constitutes an inductance coil buried on the surface, this coil is a part of an oscillation circuit, composed of it and the capacitor to form an oscillation circuit, the principle is that the oscillation is stable and reliable, the oscillation signal is sent to the frequency measurement circuit composed of a single-chip microcomputer through transformation, and the single-chip microcomputer can measure the frequency of this oscillator as a carThe confirmation signal of the "ground induction coil", and the time interval between the start and end of this signal can be used to measure the speed of the car.

This is the "ground induction coil". The key to the technology is to design an oscillator that is stable and reliable, and the frequency changes significantly when a car passes.

The "ground induction coil" is an oscillating circuit. It is constructed in such a way that a circular trench is made in the ground, about 1 meter in diameter, or a rectangular trench of comparable area, and then two or three turns of wire are buried in this trench, which constitutes an inductive coil buried in the ground, which is part of an oscillating circuit. It and capacitors form an oscillation circuit, the principle of which is that the oscillation is stable and reliable, and the oscillation signal is sent to the single-chip microcomputer through conversion.

Wires:

A wire is a wire that transmits electrical energy. It is divided into bare wire, magnet wire and insulated wire. Bare wires are not insulated, including copper and aluminum flat wires, overhead stranded wires, and various profiles.

It is mainly used for outdoor overhead and indoor busbars and switch boxes. Magnet wire is an insulated wire that generates a magnetic field when energized or induces an electric current in a magnetic field. It is mainly used for motor and transformer coils and other related electromagnetic equipment.

Its conductor is mainly copper wire, which should have a thin insulation layer and good electrical and mechanical properties, as well as heat, moisture, solvent resistance and other properties.

Under ideal conditions (regardless of the influence of all environmental factors), the burial of the inductor coil only considers the size (or circumference) and the number of turns, and the material of the wire can be disregarded. However, in the actual project, the mechanical strength of the wire and the high and low temperature anti-aging problems must be considered, and the acid and alkali corrosion resistance must also be considered in some harsh environments.

The vehicle detector will not function properly if the conductor is damaged due to aging or insufficient tensile strength. In the actual project, it is recommended to use the above Teflon high-temperature flexible wire.

Teflon high temperature wire. Multi-strand copper tinned.

Summary. When the ground induction coil is energized, an electromagnetic field is generated. The ground inductance coil is a device that uses the principle of electromagnetic induction to measure the alternating current, and uses the principle of partial inductance to determine whether there is an electric current passing through by detecting the electromotive force between the changing current coil (just like the inductor) and the ground.

Therefore, when an electric current passes through the inductive coil, it generates an electromagnetic field. Specifically, there is a closed conductor inside the ground induction coil as a coil, and there is a magnetic field inside the conductor, and when the coil moves in the magnetic field, the magnetic flux in the conductor changes, resulting in an induced electromotive force. The magnitude of this induced electromotive force is related to the speed at which the coil is moving and the strength of the magnetic field.

In short, an electromagnetic field is generated when an electric current passes through the induction coil, and this electromagnetic field can be used to detect whether there is an electric current passing through.

When the ground induction coil is energized, an electromagnetic field is generated. The ground inductance coil is a device that uses the principle of electromagnetic induction to measure the alternating current, and uses the principle of partial inductance to determine whether there is a current balancing by detecting the electromotive force between the changing current coil (just like the inductor) and the ground. Therefore, when an electric current passes through the inductive coil, it generates an electromagnetic field.

Specifically, there is a closed conductor inside the induction coil as a coil, and there is a magnetic field inside the conductor court, and when the coil moves in the magnetic field, the magnetic flux in the conductor changes, resulting in an induced electromotive force. The magnitude of this induced electromotive force is related to the speed at which the coil moves and the strength of the magnetic field. In short, an electromagnetic field is generated when an electric current passes through the induction coil, and this electromagnetic field can be used to detect whether there is an electric current passing through.

I'm still a little confused, can you be more detailed?

When the ground induction coil is energized, an electromagnetic field is generated. The ground inductance coil is a device that uses the principle of electromagnetic induction to measure the alternating current, and uses the principle of partial inductance to determine whether there is a current balancing by detecting the electromotive force between the changing current coil (just like the inductor) and the ground. Therefore, when an electric current passes through the inductive coil, it generates an electromagnetic field.

Specifically, there is a closed conductor inside the induction coil as a coil, and there is a magnetic field inside the conductor court, and when the coil moves in the magnetic field, the magnetic flux in the conductor changes, resulting in an induced electromotive force. The magnitude of this induced electromotive force is related to the speed at which the coil moves and the strength of the magnetic field. In short, an electromagnetic field is generated when an electric current passes through the induction coil, and this electromagnetic field can be used to detect whether there is an electric current passing through.

The first step in coil burial is to cut a groove out of the road surface with a road cutter. A 45-degree chamfer is performed on the four corners to prevent sharp corners from breaking the coil cable. The grooving width is generally 4 to 8 mm and the depth is 30 to 50 mm.

Also cut a slot for the coil leads to the curb side. However, it should be noted that the groove must be clean and free of water or other liquids.

The coil must be straightened when winding the coil, but not too tightly and snugly against the bottom of the groove. After the coil is wound, the twisted output leads are led out through the lead-out trunking.

**During the winding process of the coil, the inductance value of the inductance coil should be tested by using an inductance tester, and the inductance value of the coil should be between 100UH and 300UH. Otherwise, the number of turns of the coil should be adjusted.

When winding the coil, it is necessary to leave a sufficient length of wire to connect to the loop sensor and ensure that there is a joint in the middle. After winding the coil cable, the lead cable must be made into a tight twisted pair form, requiring at least 1 meter to be twisted 20 times. Otherwise, the output leads of the uncoded collapsing twisted pair will introduce dry wrapping, making the coil inductance value unstable.

The length of the output leads should generally not exceed 5 meters. Since the sensitivity of the probe coil decreases as the length of the lead wire increases, the length of the lead cable should be as short as possible.