A demagnetizing circuit has a positive characteristic thermistor and a demagnetizing coil connected in series with an alternating current power supply and is so constructed that it is possible to suppress the production of a low-frequency electromagnetic field. After the completion of a demagnetizing operation, the demagnetizing coil and the alternating current power supply can be completely isolated from each other, i.e. both ends of the demagnetizing coil can be electrically cut off from the a...

For achieving a desired course in the demagnetizing circuit (I1) and power dissipation that is as low as possible during continuous operation of a color television set, a demagnetizing circuit for controlling the demagnetizing current (I1) includes two transistors (T1, T2) that are controlled via a common or via two separate capacitive voltage dividers (C1-C4). A rectified alternating voltage is applied to the capacitive voltage dividers (C1-C4). The demagnetizing current (I1) controlled by the ...

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...

A demagnetizing device for a cassette tape player includes a cassette shell which defines a generally oval-shaped guide track extending around the interior of the shell. A magnet assembly is provided with shafts which fit within the guide track such that the magnet assembly is free to rotate within the guide track and to translate along the length of the guide track. The magnet assembly is rotated by a drive belt which in turn is driven by two hubs rotatably mounted in the cassette shell. An aut...

Apparatus for controlling the magnetizing and demagnetizing of the chuck in a machine tool, and the workpieces held thereon. A plurality of individual chucks are incorporated in the machine tool, and they are selectively brought into circuit according to the characteristics of workpieces. The demagnetizing phase is controlled as to length of overall period and the number of reversing steps in that period.

To demagnetize a transformer (TR) in a single-ended forward DC/DC converter with self-driven synchronized rectifiers (V1, V2) connected across the secondary winding (N2) of the transformer (TR), a diode (D1) is connected in series with a capacitor (C1) across the primary winding (N1) of the transformer. The diode (D1) transfers magnetization energy stored in the transformer to the capacitor (C1) every time a primary switch (V3) of the converter is turned off. To ensure optimum efficiency of the ...

An appliance for magnetizing and demagnetizing permanent magnets, incorporating an electrical circuit arrangement consisting essentially of at least one chargeable condenser, a magnetizing and demagnetizing coil, an electronic switch, and wherein a diode is arranged in parallel to the said condenser, and two switch means are provided for optionally connecting the said diode to the one or the other end of the said coil.

An apparatus for demagnetizing parts after they have been subjected to the action of a magnetic field having coils (1,2) connected to an a-c power supply source and disposed one inside the other at one and the same angle with respect to a trough (3) extending through the inner coil. The coils (1,2) are mounted in such a manner that the angle (.alpha.) therebetween can be adjusted.

Apparatus for selectively magnetizing and demagnetizing a small tool, such as a screwdriver, by providing an enclosure having a first opening to receive a tool for magnetizing a desired portion of the tool, and a second opening to receive a tool for demagnetizing a selected portion of the tool. The demagnetizing opening is surrounded by a demagnetizing coil that is directly connected through a first switch with a source of alternating current to provide an alternating magnetic field for demagnet...

A machine having a conveyor for carrying a workpiece to be magnetized therethrough. It includes two demagnetizing magnets arranged at a mutual angle of 90.degree. and both at 45.degree. to the direction of travel on the conveyor. The magnets are arranged respectively above and below the conveyor, and hence above and below the workpiece on the conveyor, and are spaced apart in the direction of travel of the conveyor. The conveyor, structurally, includes a stationary base, and endless belts carryi...