RU2369915C1 - Electromagnet sound receiver with controlled magnet flow - Google Patents

Abstract

FIELD: electric engineering.

SUBSTANCE: invention is related to the field of electronics and may be used in design of electric musical instruments, which convert mechanical energy of strings oscillations into electric signals, for instance electric guitars, electric violins, electric pianos, etc. Electromagnet sound receiver with controlled magnet flow, comprising two flat pole cores, which are attached perpendicularly to opposite poles of permanent magnet, on which signal coils are installed, which generate AC voltage of sound frequency. At the same time magnetising coils are introduced in it, which are connected serially to electric source of magnetisation, moreover, coils are located in compliance with the following pattern: magnetising coil inside, signal coil outside, or the following pattern: one above another along vertical axis of pole core.

EFFECT: possibility to control magnet flow, higher validity of useful sound signal transfer in wide range of frequencies, higher noise immunity and stability of working characteristics.

1 dwg

Description

The invention relates to the field of electronics and can be used in the construction of electric musical instruments that convert the mechanical energy of string vibrations into electrical signals, for example electric guitars, electric violins, electric grandoes, etc.

Known electromagnetic pickups (adapters) mounted on electric guitars that use one coil (single coil), one or more magnets that create a magnetic field near the strings, which in the process of mechanical vibrations form an alternating component of the magnetic flux, which induces a sound frequency EMF in the stationary coil (L. Muravyova. Pickups. "Sound producer", 2003, No. 2).

The disadvantages of these devices are a weak signal at the terminals of the coil and high sensitivity to various kinds of external interference, for example, from the mains, fluorescent lamps, etc.

The closest analogue of the invention is an electromagnetic pickup for electric guitars and other stringed musical instruments, including two flat pole tips (cores) attached to opposite poles of a permanent magnet and spaced 3 ... 4 mm apart, on which an inductance coil is wound ( signal coils) connected in series and connected to the input of the amplifier with parallel negative feedback (RU 2289857 C1, 2006.12.20).

The main disadvantage of this design is the impossibility of changing the parameters of the magnetic system on which the inductive sensors are mounted, since the magnitude and configuration of the magnetic flux is determined by the design of the device, the type of permanent magnet, as well as constant geometric dimensions.

Another disadvantage is the small height of the magnetic flux, which closes in the air gap between the flat pole pieces, spaced from each other at a distance of 3 ... 4 mm in the area of strings. This circumstance causes periodic loss of flux linkage between the electromagnetic sensor and the string during its intense oscillations, which leads to large nonlinear distortions.

The known device has a low rate of rise of the voltage of the useful signal, since the magnetization and magnetization reversal of the massive pole pieces, on which the signal coils are wound, significantly affects the dynamics of the alternating voltage occurring in the coil. That is, the influence of the massive core begins to appear already at frequencies of 1500 ... 2000 Hz, and dynamic and frequency distortions of the useful signal arise.

An object of the invention is the creation of an electromagnetic pickup with a controlled magnetic flux, with high reliability of the transmission of a useful sound signal in a wide frequency range, high noise immunity and stability of performance.

This technical task is achieved by the fact that in a magnetic pickup with a controlled magnetic flux, containing two flat pole cores attached perpendicular to the opposite poles of the permanent magnet, on which the signal coils are mounted, magnetizing coils are introduced, connected in series to an electric magnetization source, forming a new one design, forming a controlled magnetic field of the adapter, providing high reliability of the transmission of the useful signal in w rock band.

The design of an electromagnetic pickup with controlled magnetic flux and the circuit for connecting it to an electric bias source are shown in the drawing.

Electromagnetic pickup with controlled magnetic flux contains two flat pole cores 5, 7 attached perpendicular to the opposite poles of the permanent magnet 6, on which signal coils 1, 4 and magnetizing coils 2, 3 are connected, connected to an electric magnetization source 8, and the coils are located along scheme: magnetizing coil 2 (3) inside, signal coil 1 (4) outside or according to the scheme: one above the other along the vertical axis of the pole core 5 (7).

Description of the operation of the device. Option 1

The magnetic flux-controlled pickup consists of a permanent magnet 6, two flat pole cores 5, 7, signal coils 1, 4, magnetizing coils 2, 3, and an electric magnetization source 8. The pole cores 5, 7 are attached perpendicular to the opposite poles of the permanent magnet 6 On each of the pole cores 5, 7 there are magnetizing coils 2, 3, on which signal coils 1, 4 are put on. Magnetizing coils 2, 3 are connected in series to the electric source stitching 8, and from the signal coils 1, 4 is removed an alternating voltage of the sound frequency (useful signal). The thickness of the pole cores 5, 7 is 1.2-2.5 mm. All coils 1-4 are wound with a copper insulated wire with a diameter of 0.047-0.15 mm.

The adapter is located in close proximity to the strings (not shown) of a musical instrument made of ferromagnetic material. The magnetic flux (shown by arrows) formed in the air gap between the cores 5, 7 is the result of the addition of two components: the flux of the permanent magnet 6 and the flux created by the magnetizing coils 2, 3. By changing the magnitude of the magnetization current in the coils 2, 3 using an electric source 8, you can change the total magnetic flux in the area of the strings, as well as its configuration. When the string located in a magnetic field oscillates in the signal coils 1, 4, an alternating voltage of sound frequency arises, the amplitude of which and the harmonic composition depend on the magnitude of the bias current in coils 2, 3. This mode allows you to quickly change the “purity” and color of the sound, minimizing nonlinear distortion at the output of the device.

The design of the pickup option 2 differs from option 1 by the location of the signal 1, 4 and magnetizing coils 2, 3 on the pole cores 5, 7. In this case, the signal coil 1 (2) is located above the magnetizing coil 4 (3) along the vertical axis of the pole core 5 ( 7).

In both versions, the signal coils 1, 4 can be connected in series, in parallel in phase or out of phase. The above circuits have a low level of noise and external interference.

The proposed design allows to increase the uniformity of the magnetic flux in the air gap between the cores 5, 7 due to the optimal choice of the bias current in the coils 2, 3.

Electromagnetic pickup with controlled magnetic flux has a high reliability of the transmission of the useful signal in a wide frequency range, high stability of performance, has a wide range of use and high reliability.

Claims (1)

Electromagnetic pickup with controlled magnetic flux, containing two flat pole cores attached perpendicular to the opposite poles of the permanent magnet, on which signal coils are installed, generating alternating voltage of sound frequency, characterized in that magnetizing coils are introduced into it, connected in series to an electric magnetization source, moreover, the coils are arranged according to the scheme: a magnetizing coil inside, a signal coil outside, or according to the scheme: one al another along the vertical axis of the pole core.