Abstract: An electronic circuit for demagnetizing ferromagnetic material includes a voltage source and a conductor loop connected thereto, a demagnetizing resonant circuit is arranged in the conductor loop for forming a decaying alternating magnetic field. In the conductor loop, a resonant circuit battery switch is arranged in series with the demagnetizing resonant circuit, and a recharge resonant circuit for pulsed recharging of a charging current into the demagnetizing resonant circuit is arranged in parallel with the demagnetizing resonant circuit and with the resonant circuit battery switch. A recharge store which is arranged in parallel with the voltage source, with the recharge resonant circuit and with the demagnetizing resonant circuit, as well as a recharge switch for interrupting a charging current from the recharge store are located in the conductor loop. The circuit can be operated by a controller for controlling the voltage source and all switches.

Abstract: A device for demagnetizing a ferromagnetic, elongated component of any length having a uniform profile which has an accessible surface on one side along its length. The device comprises a rod-shaped, ferromagnetic core having a circumferential shell surface, which is closed off by a front end face and a rear end face. At least one coil is wrapped around the shell surface, with the coil connected to a current source which can generate an alternating current, whereby a magnetic alternating flux is induced in the ferromagnetic core, the flux entering and exiting at the two end faces. A coil is wrapped around the shell surface, with the coil connected to a current source which can generate a direct current to superimpose the magnetic alternating flux with a thereby induced magnetic unidirectional flux through the ferromagnetic core, the flux entering and exiting at the two end faces.

Abstract: A particularly useful, technically robust, simply constructed and energy-saving device generating a magnetic field of alternating polarity by means of a current-carrying coil for the demagnetization of ferromagnetic materials.

Abstract: A device for demagnetizing a ferromagnetic, elongated component of any length having a uniform profile which has an accessible surface on one side along its length. The device comprises a rod-shaped, ferromagnetic core having a circumferential shell surface, which is closed off by a front end face and a rear end face. At least one coil is wrapped around the shell surface, with the coil connected to a current source which can generate an alternating current, whereby a magnetic alternating flux is induced in the ferromagnetic core, the flux entering and exiting at the two end faces. A coil is wrapped around the shell surface, with the coil connected to a current source which can generate a direct current to superimpose the magnetic alternating flux with a thereby induced magnetic unidirectional flux through the ferromagnetic core, the flux entering and exiting at the two end faces.

Abstract: For an uncontrolled alternating-current demagnetiser (1), comprising an alternating-current circuit (10) and an AC voltage source (100), wherein the alternating-current circuit (10) allows the AC voltage loading, by means of the actuation of a switch (S), of a parallel resonant circuit (P) comprising a demagnetising coil (L) and a parallel capacitor (C1) connected in parallel to the demagnetising coil (L), the option should be created to minimise the error proneness during demagnetisation, even of users, who do not have any knowledge of the processes during the demagnetisation. This is achieved in that the alternating current in the inductance L freely decays when the semiconductor element D is switched off. To limit the inrush current owing to the parallel capacitor C1, at least one electronic component (D) is arranged in series to the AC voltage source (100) and can be operated by means of switch (S).

Abstract: The aim is to improve the demagnetisation of ferromagnetic components by means of simple enhancements of a demagnetising device in such a manner that, in spite of the demagnetisation at approximately room temperature, ferromagnetic components with vanishingly low residual magnetism, as was previously only achievable by means of thermal demagnetisation, are achieved. This is achieved in that a chamber with walls made from magnetically highly-permeable ferromagnetic material for shielding from external interference fields, for example the magnetic field of the Earth, is used in the demagnetising coil of a demagnetising device, whereby an interference-field-free chamber interior is pushed with a reduction of the interference field strength in the chamber interior to such a small magnetic interference field, that the residual magnetism at the treated objects has a lower value after demagnetisation than the interference field outside of the chamber space.

Abstract: The present invention describes a release mechanism (1) for releasing magnetically releasable anti-theft devices consisting of a multiplicity of permanent magnets in the form of a Halbach array, which are disposed on a plane. While the highly magnetised top side (10) of the release mechanism (1) is covered by the cover plate (6) on the release side, a base plate (5) used for mounting or support is located on the underside (11) of the release mechanism (1). The permanent magnets encompass a continuous, self-contained frame magnet (2), which is magnetised in an axial direction and has a first recess. Inserted in this first recess is a segmented magnet (3), wherein the individual segments are magnetised perpendicularly to the magnetization direction of the frame magnet (2) and a second recess is left open, in which an axially magnetised magnetic core (4) is inserted.

Abstract: The present invention describes a release mechanism (1) for releasing magnetically releasable anti-theft devices consisting of a multiplicity of permanent magnets in the form of a Halbach array, which are disposed on a plane. While the highly magnetised top side (10) of the release mechanism (1) is covered by the cover plate (6) on the release side, a base plate (5) used for mounting or support is located on the underside (11) of the release mechanism (1). The permanent magnets encompass a continuous, self-contained frame magnet (2), which is magnetised in an axial direction and has a first recess. Inserted in this first recess is a segmented magnet (3), wherein the individual segments are magnetised perpendicularly to the magnetisation direction of the frame magnet (2) and a second recess is left open, in which an axially magnetised magnetic core (4) is inserted.

Abstract: A method is presented for demagnetizing ferromagnetic components in an alternating field of an externally excited electrical series resonant circuit. A supply voltage having an excitation frequency (f) is applied in parallel to a demagnetization coil having a no-load inductance of the series resonant circuit, because of which an alternating current (I) flows through the series resonant circuit (1), which generates a magnetic alternating field. In the event of suitable selection of the excitation frequency (f) in such a way that the product of the excitation frequency (f) in Hz multiplied by the no-load inductance (L0) in Henry is f*L0?0,22 Hz*H, the excitation frequency is in an operating range (5) and the series resonant circuit (1) may be used without further regulation technology to demagnetize components which are led through the inner chamber of the demagnetization coil (2) and form a fill level.

Abstract: A method is presented for demagnetizing ferromagnetic components in an alternating field of an externally excited electrical series resonant circuit. A supply voltage having an excitation frequency (f) is applied in parallel to a demagnetization coil having a no-load inductance of the series resonant circuit, because of which an alternating current (I) flows through the series resonant circuit (1), which generates a magnetic alternating field. In the event of suitable selection of the excitation frequency (f) in such a way that the product of the excitation frequency (f) in Hz multiplied by the no-load inductance (L0) in Henry is f*L0?0.22 Hz*H, the excitation frequency is in an operating range (5) and the series resonant circuit (1) may be used without further regulation technology to demagnetize components which are led through the inner chamber of the demagnetization coil (2) and form a fill level.

Abstract: A device for magnetizing a magnet system preferably having several pulse-generator circuits which are mutually arranged so that their magnetic fields superimpose in a cumulative manner. Each pulse-generator circuit includes a capacitor element, a magnetization coil electrically connected to the capacitor element and a switch element by way of which actuation the magnetization coil can be impinged with a current pulse of a limited pulse duration arising by the discharge of the capacitor element, and thus the build-up of a magnetic field may be triggered. The pulse-generator circuit is built up so that the pulse duration of the current pulse is limited to a value between 10 ?s and 500 ?s. With such short pulse durations, undesirable heating of the magnetization coil is short so that the device may be applied in automatic production installations with cycle times of below 1 s.

Abstract: A method for the reproducible, capacitor-free demagnetization of objects with residual magnetism by way of at least one low-frequency and frequency-modulated alternating current impulse (1) of variable amplitude and alternating current impulse width (2) in a flexible, completely insulated, unshielded conductor is suggested, by which means a magnetic field impulse is created in the proximity of the conductor. A current control (24) with an inverter (20), a current sensor (22) and a closed control circuit produces the alternating current impulse (1) as a chain of individual demagnetization impulses (5) with a settable alternating current impulse frequency (4) and demagnetization impulse amplitude (6). The demagnetization impulse amplitude (6) is controlled with a closed loop to zero along a demagnetization curve (7), by which means the objects (30) in the vicinity of the conductor which may be applied into any shaped conductor loop (29), are demagnetized.

Abstract: The method according to the invention for demagnetization is effected in two separate steps. Firstly magnetically hard locations, such as weld seams, pressure locations etc., of an object to be demagnetized is pre-treated locally with high fields by way of choke coils in an alternating field. These magnetically hard locations are at least partly demagnetized by way of this. Subsequently the complete demagnetization is effected in a decisive second step. The object remains for a certain time in an alternating field. Now the alternating field is stepped down in that the current in a series oscillation circuit is stepped down in a current-controlled manner with two coils.

Abstract: A device for magnetizing a magnet system preferably having several pulse-generator circuits which are mutually arranged so that their magnetic fields superimpose in a cumulative manner. Each pulse-generator circuit includes a capacitor element, a magnetization coil electrically connected to the capacitor element and a switch element by way of which actuation the magnetization coil can be impinged with a current pulse of a limited pulse duration arising by the discharge of the capacitor element, and thus the build-up of a magnetic field may be triggered. The pulse-generator circuit is built up so that the pulse duration of the current pulse is limited to a value between 10 ?s and 500 ?s. With such short pulse durations, undesirable heating of the magnetization coil is short so that the device may be applied in automatic production installations with cycle times of below 1 s.

Abstract: The method according to the invention for demagnetization is effected in two separate steps. Firstly magnetically hard locations, such as weld seams, pressure locations etc., of an object to be demagnetized is pre-treated locally with high fields by way of choke coils in an alternating field. These magnetically hard locations are at least partly demagnetized by way of this. Subsequently the complete demagnetization is effected in a decisive second step. The object remains for a certain time in an alternating field. Now the alternating field is stepped down in that the current in a series oscillation circuit is stepped down in a current-controlled manner with two coils.

Abstract: A releasing magnet for anti-theft devices for sales goods with a permanent magnet and a housing having a disc-shaped collar and a fastener for securing the housing to a table. The housing is made of plastic and at least almost surrounds the permanent magnet which prevents corrosion and allows the releasing magnet to be washed so that its use is hygienic.

Abstract: An apparatus and method for using a permanent magnet with a high coercive force and a permanent pole-reversible magnet with a low coercive force used in securing members in cooperation with wedging members. The apparatus also includes a release device, with a securing member inserted, and a combined control and feed device and a verification device, in the form of a till. The entire release device can therefore be, for example, directly linked to invoicing for a paid sum. The control and feed device controls and feeds the electromagnet coil of the magnetizing device. To release a securing member, the magnetizing device is activated, thereby reversing the poles of the permanent pole-reversible magnet. Both permanent magnets in the securing member subsequently repel, the wedge is released and the pin can be withdrawn from the locking section.