Abstract: Various embodiments relate to an electronic device including an antenna. The electronic device may include: a foldable housing; a flexible display disposed on the foldable housing wherein at least a part of the flexible display is configured to be folded; and a frame disposed on a boundary portion of the flexible display and coupled to a side member of the foldable housing. The side member may include a conductive portion electrically connected to a communication circuit, and the frame may include a low-permittivity material.

Abstract: The system described herein relates to a particle beam apparatus for analyzing and/or for processing an object and to a method for operating a particle beam apparatus. The particle beam apparatus is designed for example as an electron beam apparatus and/or an ion beam apparatus. The particle beam apparatus comprises a beam deflection device, for example an objective lens, which is provided with a first coil and a second coil. The first coil is operated with a first coil current. The second coil is operated with a second coil current. The first coil current and/or the second coil current may always be controlled in such a way that the sum of the first coil current and the second coil current (the summation current) or the difference between the first coil current and the second coil current (the difference current) is controlled to a setpoint value.

Abstract: A bulk erase tool to erase a perpendicular media recording (PMR) disk of a disk drive is disclosed. The bulk erase tool comprises a housing to receive a disk drive and at least one of a first pair of magnets mounted in the housing to be positioned above the received disk drive to provide a magnetic field to erase the top side of the disk and a second pair of magnets mounted in the housing to be positioned below the disk drive to provide a magnetic field to erase the bottom side of the disk.

Abstract: Generation of an intense magnetic field to erase high coercivity magnetic media uses delivery of energy to a degaussing cavity. To conserve energy storage and delivery requirements and to obtain a desired magnetic strength generally uniformly within the cavity, strategic placement of supplemental turns at ends of the magnetic field generating coil wound around the cavity can promote uniformity. Construction of at least cavity ends from an adequate quantity of magnetically soft ferrous material can also promote uniformity. A combination of both approaches is possible.

Abstract: One or more pairs of magnet assemblages (14 and 16) are provided with magnetized segments (21-30) arranged in a Halbach-like array. The magnet assemblages (14 and 16) define a gap (18) through which magnetic data storage media (12) pass in a direction (20) across the segments (21-30). The magnetized sides (36) of the magnet assemblages (14 and 16) face each other thereby creating strong magnetic fields which degauss the magnetic data storage media (12) passing through the gap (18).

Abstract: A bulk degaussing system for the erasure of magnetic storage media by means of permanent magnets. The bulk degaussing system includes a rotatably mounted carousel and an angular displacement means that angularly displaces the carousel through a predetermined angle after passage of the carousel through a degaussing gap.

Abstract: To provide a degaussing coil holder for fastening a degaussing coil around a cathode ray tube which is easy in use and capable of stretching and fastening the degaussing coil in position, the degaussing coil holder is made of a resin mold having a hook to hang the degaussing coil, a catch to fixedly fit in a small hole made in a selected CRT fastening metal and an expandable strip integrally connected at both ends to the hook and catch.

Abstract: The circuit arrangement has a mains connection, a mains switch with two switching contacts, a demagnetization coil and a switch-mode power supply, which contains a driver circuit for producing a control voltage for the switching transistor of the switch-mode power supply. A first switching contact of the mains switch is arranged between the mains connection and the demagnetization coil in order to switch the demagnetization coil on and off, and the second switching contact is connected to a supply or control voltage for the driver circuit, in order to switch off the switch-mode power supply. In consequence, a power factor coil can be used between the mains connection and the switch-mode power supply for power factor correction, without the mains switch being loaded by the inductance of the power factor coil.

Abstract: A degaussing circuit for compulsorily degaussing a picture tube of a CRT monitor by causing alternating current to flow through a degaussing coil. A switching part, connected to a first end of the degaussing coil, switches a current flowing into the degaussing coil on/off. A chargeable device connected to the first end or to a second end of the degaussing coil removes a potential difference across the degaussing coil when the switching part is turned off. Alternatively, chargeable devices may be connected to both the first and second ends of the degaussing coil. Thus, an electromagnetic field is prevented from being generated by the residual current in the degaussing coil, to thereby meet electromagnetic field safety standards for the monitor.

Abstract: A CRT (cathode-ray tube) degaussing circuit comprises: an AC (alternating current) power source; a PTC (positive temperature characteristic) resistor; a heat sense switch, provided as a single unit with the PTC resistor for controlling the current flow of the entire circuit so as to be turned on/off according to a surface temperature of the PTC resistor; and a degaussing coil for demagnetizing metallic components of the CRT when the current is applied. The AC power source, the PTC resistor, the degaussing coil, and the heat sense switch form a closed-loop circuit, and the heat sense switch is connected thereto so as to turn on/off the current flow in the closed-loop circuit.

Abstract: To provide a degaussing coil holder for fastening a degaussing coil around a cathode ray tube which is easy in use and capable of stretching and fastening the degaussing coil in position, it is made of a resin mold having a hook to hang the degaussing coil, a catch to fixedly fit in a small hole made in a selected CRT fastening metal and an expandable strip integrally connected at both ends to the hook and catch.

Abstract: A degaussing circuit for compulsorily degaussing a picture tube of a CRT monitor by causing alternating current to flow through a degaussing coil. A switching part, connected to a first end of the degaussing coil, switches a current flowing into the degaussing coil on/off. A chargeable device connected to the first end or to a second end of the degaussing coil removes a potential difference across the degaussing coil when the switching part is turned off. Alternatively, chargeable devices may be connected to both the first and second ends of the degaussing coil. Thus, an electromagnetic field is prevented from being generated by the residual current in the degaussing coil, to thereby meet electromagnetic field safety standards for the monitor.

Abstract: A degaussing coil is retained on the conical portion of a cathode ray tube by a resilient clip which snaps over a lug which is used to mount the cathode ray tube in its associated cabinet. The clip can be snapped over its respective mounting lug after the cathode ray tube has been mounted in its associated cabinet.

Abstract: By passing electric current through a degaussing coil within a vertical retrace period, a displayed image is prevented from disturbance and yet color blurs on the way of degaussing process are made indiscernible. In the process of discharging charges filled in capacitors C1 and C2 through the degaussing coil, a damped oscillation current by a closed loop of one of the capacitors and the degaussing coil is generated, and then a damped oscillation current of opposite polarity generated by a closed loop of the other capacitor and the degaussing coil is passed, within such a short time as color blurs in the degaussing process cannot be discerned and during the vertical retrace period. With these two damped oscillation currents paired, degaussing operation is fulfilled.

Abstract: A degaussing coil fixing holder. One degaussing coil fixing holder formed horizontally which comprises a horizontal bar including a guide groove and receiving a degaussing coil, at least one protruding part protruded backwards from the horizontal bar and including a through-hole, a snap member formed at an inner side of the guide groove and preventing the degaussing coil from separating from the guide groove, and a supporting member formed integrally at the protruding part and supporting elastically the horizontal bar and the protruding parts, fixes the degaussing coil by locking a screw penetrating the through-hole in holes formed at the upper and lower part of a shielding.

Abstract: An apparatus and method for degaussing a cathode ray tube including an alternating current (AC) source; a positive temperature coefficient (PTC) element; a resistance; a first switch coupled between said AC source and said PTC element in turn coupled to the resistance switching between a first position and a second position; a second switch coupled between the AC source and the PTC element switching between a first position and a second position; wherein in 110 volt operation, the first switch switched in a first position and the second switch switched in a second position; and conversely in 220 volt operation, the first switch switched in a second position and the second switch switched in a first position.

Abstract: A sequential driving type degaussing circuit includes a rotation direction and angle detector for generating each pulse by using a pair of photo sensors and slits to detect a rotation angle and a rotation direction of a television set when it is rotated manually by a viewer; a microcomputer for judging the direction and the angle of the television as rotated manually on the basis of an output pulse of the rotation direction and angle detector, judging the rotation direction and angle of the television when it is rotated automatically by a motor, and outputting a control signal to sequentially drive the degaussing circuit if it is judged that the television set was rotated more than a predetermined angle; and a degaussing circuit unit for sequentially driving one by one a plurality of degaussing circuits under the control of the microcomputer and performing a degaussing function of a CRT.

Abstract: A cathode-ray tube video device connected to a power source and having a first normal operating state and at least a second operating state at reduced power (stand-by mode) includes a switching power supply and a circuit portion for demagnetizing the cathode-ray tube coupled to the power source through an electrically actuated switch. The switch is closed to demagnetize the cathode-ray tube during the first operating state of the device, and opened during the second operating state at reduced power of the device.

Abstract: An apparatus for attaching a degauss coil to a cathode-ray tube can simplify a manufacturing process by reducing the number of assemblies for attaching a degauss coil stretched over a curved surface of a funnel of a cathode-ray tube. This apparatus includes a front cabinet for holding a cathode-ray tube with a screen on which an image is displayed by the scanning of electron beams and a degauss coil disposed at the rear of the cathode-ray tube for degaussing the cathode-ray tube wherein degauss coil holders for holding the degauss coil are unitarily formed as one body with the front cabinet.

Abstract: A degaussing coil is driven when a driving request for the degaussing coil is received after turning on of a main power supply of a cathode ray tube and a driving request for the degaussing coil is set when the driving time of the degaussing coil is less than a reference time in case that the main power supply is turned off within the predetermined reference time. Consequently, the degaussing coil is driven regardless the time from turning off to turning on of the main power supply. Accordingly, the method for controlling the degaussing coil of the cathode ray tube can prevent the remanence of the cathode ray tube and always provide a safe image to a user.

Abstract: An automatic degaussing circuit for a color picture tube (CPT) capable of automatically degaussing the CPT when a power conservation mode is released in a monitor having a power conservation function. The degaussing circuit includes a degaussing coil for eliminating electromagnetic waves produced from the CPT, a power conservation mode detecting section for detecting the release of the power conservation mode in accordance with a power conservation mode signal of the CPT inputted thereto and providing a degaussing control signal for controlling the operation of the degaussing coil if the release of the power conservation mode is detected, and a degaussing coil driving section for driving the degaussing coil for a predetermined time in accordance with the degaussing control signal when the power conservation mode is released.

Abstract: Circuitry to control a power supply of a degaussing coil of a cathode ray tube, said degaussing coil is coupled to a main voltage supply through a switching device the circuitry has inputs coupled to a direct source of current of a switched mode power supply, the switched mode power supply comprises a switched mode transformer with primary windings coupled to the main source of voltage, and secondary windings and the switched mode power supply is switched in a first range of frequencies when the power supply is in a "standby" mode and in a second range of frequencies when the power supply is in an "on" mode wherein said circuitry comprising a detecting circuit which detectes a change in the range of switching frequencies when the power supply is switched from standby to on, the detecting circuit having an input coupled to a direct current source being downstream of a primary winding of the switched mode transformer and an output coupled to an input of a control circuit of the switching device the control circ

Abstract: A picture tilt complementing circuit in a display device includes: a microcomputer for receiving horizontal and vertical sync signals from a computer and generating a tilt control signal; a horizontal sawtooth wave generation unit for converting the tilt control signal transmitted from the microcomputer into a sawtooth wave signal according to a horizontal fly back signal; a vertical sawtooth wave generation unit for converting the tilt control signal transmitted from the microcomputer into a sawtooth wave signal according to a vertical fly back signal; a vertical center control unit for synthesizing a horizontal sawtooth wave signal generated by the horizontal sawtooth wave generation unit with a vertical position control signal transmitted from the microcomputer and sending the synthesized result to a vertical output unit; and a horizontal position control unit for synthesizing a vertical sawtooth wave signal generated by the vertical sawtooth wave generation unit with a horizontal position control signal t

Abstract: A degaussing circuit includes an AC mains voltage, a series arrangement of a degaussing coil (Ld) and a switching element (S1) coupled between the input terminals (it1,it2). A measuring circuit (3) continuously measures a value (Ms) representing an actual value of either the degaussing current (Id) through the degaussing coil (Ld) or the AC mains voltage (Vac). A detecting circuit (2) detects a level crossing instant (ts) at which the actual value (Ms) crosses a predetermined value (Vref2). A control circuit (1) determines a switching instant (tei,tstv) of the switching element (S1) in response to the level crossing instant (ts) for generating a peak value of the degaussing current (Id) related to the actual value of the degaussing current (Id) or the AC mains voltage (Vac) at the level crossing instant (ts).

Abstract: A demagnetizing circuit and a current limiting device for being built into a power supply circuit of a color television receiver or color monitor display or the like with which it is possible to effect a reliable demagnetizing operation using existing components and without using either a positive characteristic thermistor which reaches a high temperature or a relay circuit. The demagnetizing circuit is connected in parallel with a power supply circuit having a smoothing capacitor and a negative temperature characteristic thermistor or fixed resistance for suppressing surge currents to the smoothing capacitor. It has a thermally actuated switch connected in series with one end of a demagnetizing coil by way of a positive temperature characteristic thermistor which is actuated by heat produced by the temperature negative characteristic thermistor or fixed resistance to cut off a demagnetizing current.

Abstract: In a method of testing a color cathode ray tube, an electron gun assembly is energized to emit electron beams and only a horizontal deflection magnetic field is applied to the electron beams so that a line image is displayed on a screen. A degaussing coil is located in front of the panel and a degaussing magnetic field having a frequency the same as that of a commercial power source. Thereafter, the degaussing coil is moved in a direction away from the panel and is deenergized when the coil is removed from the panel at a predetermined distance. A vertical deflecting coil is energized to display an image and a picture quality of the tube is tested.

Abstract: A component for a demagnetization circuit includes a thermistor with positive temperature characteristic having a first electrode and a second electrode, another thermistor with negative temperature characteristic having a third electrode and a fourth electrode and being disposed such that the first and third electrodes are opposite to each other, a heat-sensitive switch disposed between these two thermistors, a case which contains the thermistors and a heat-sensitive switch, and terminals which extend outward from inside the case.

Abstract: A holder for supporting a degaussing coil on a cathode ray tube. The degaussing coil holder is a flexible sheet having holes formed in each end to receive a lug of the cathode ray tube.

Abstract: A tilt compensation circuit for a picture tube is provided to correct an image rotation phenomenon of a currently displayed image on a screen caused by an outer interference such as terrestrial magnetism. In the picture tube, an alternating current for driving the tube is applied to a power supply circuit for voltage conversion through an AC line filter and to a degaussing coil as well. The circuit includes a tilt adjustment circuit for comparing a tilt compensation control signal of a predetermined voltage level with a voltage feedback signal from the degaussing coil thereby generating current corresponding the difference therebetween. The circuit further includes a switching circuit responsive to a state of the tilt compensation control signal for selectively switching between a first circuit loop incorporating the AC line filter and the degaussing coil and a second loop incorporating the tilt adjustment circuit and the degaussing coil.

Abstract: A magnetic field shielding device of a CRT (cathode ray tube) display includes a degaussing coil for preventing a magnetic field, generated by a voltage supplied to a deflection coil of the display, from being emitted from the display. A tilt coil maybe disposed at the middle portion of the degaussing coil so as to surround an electron gun of the cathode ray tube. The top and bottom portions of the degaussing coil are arranged so as to be horizontal. Both sides of the middle portion of the degaussing coil are bent inward so as to approach to each other, and so as to have a predetermined distance therebetween. The shielding device prevents dark color purity from being generated at the lower portion of the display.

Abstract: A magnetic compensating circuit includes a magnetic sensor (1), a control circuit (2) for generating a signal for magnetic compensation, and coils (3) for magnetic compensation. The magnetic sensor has a pair of amorphous magnetic substance wires (101) arranged in parallel, coils (102) for providing the pair of amorphous magnetic substance wires with bias magnetic fields in directions opposite to each other, a high-frequency power source (105) for supplying the pair of amorphous magnetic substance wires with high-frequency currents, and circuits (106, 107, 108, 109) for outputting a potential difference derived from the output of the pair of amorphous magnetic substance wires. Thus, this magnetic compensating circuit is capable of detecting a minute external magnetic field with high accuracy.

Abstract: An improved degaussing circuit for a television set capable of preventing color blurring phenomenon and picture quality deterioration by degaussing television set of which its picture quality is affected by an external magnetic field at the time of turning on and turning off the television set, which includes an LC oscillating circuit for receiving a first direct current voltage and for flowing a degaussing current; a switching unit sequentially turned on in accordance with a turning on/off operation of a television set for enabling an oscillating operation of the LC oscillating circuit; a first trigger circuit for receiving a second direct current voltage and for enabling the LC oscillating circuit by turning on the switching unit after a certain time is lapsed after the television set is turned on; a second trigger circuit for receiving a second direct current voltage for turning off the switching unit when the LC oscillating circuit completes the degaussing operation in accordance with a control of the fir

Abstract: Apparatus for mitigating the adverse effects of magnetic interference on the operation of a CRT is provided. More specifically, magnetic sensors are placed in a gap formed between a front bezel and a rear enclosure comprising a magnetic shield enclosing all but the viewing surface of a CRT. The gap serves to concentrate the on-axis magnetic field and the resultant signal from the sensors is amplified to drive current through a compensation coil located inside the front bezel and in front of the viewing surface of the CRT. The current generates a compensation field that mitigates the incoming on-axis magnetic field. The ambient magnetic field is also sensed by a three axis magnetic sensing assemblage located outside the magnetic shield. The output of the sensing arrangement is operated on to produce a trigger to start a degauss cycle.

Abstract: A system for degaussing a cathode ray tube (CRT) which avoids displaying a distorted picture to the user when a magnetic field is degaussed while the CRT is on. The system of the present invention recognizes when a user has pressed a button to initiate the manual degaussing operation, controls the brightness and contrast of the CRT so that the displayed picture becomes black, degausses the CRT while the picture appears black, and controls the brightness and contrast of the CRT to levels present before degaussing.

Abstract: A bus controlled pulse modulator receives a digitally coded signal and generates a pulse-width modulated signal. The pulse-width modulated signal is coupled to a base electrode of a non-committed or open collector transistor. The transistor switches with a controlled duty cycle. The collector of the transistor is coupled to an inverting input terminal of an amplifier via a resistor. The amplifier produces a compensation current in a tilt compensation coil. The voltage at the inverting input terminal is maintained constant in closed loop operation. The constant voltage produces a magnitude of a collector current in the transistor that is unaffected by the duty cycle of the pulse-width modulated signal. The compensation current thereby varies linearly with the duty cycle.

Abstract: A demagnetizing device for a cathode ray tube having a screen portion and a funnel portion, comprising:an outer magnetic shielding member which is arranged so as to surround a funnel portion of a cathode ray tube, and which is formed of a magnetic sheet; anda demagnetizing coil which is arranged so as to encircle a screen portion of the cathode ray tube;wherein the demagnetizing coil is arranged so as to be apart from the outer magnetic shielding member by not less than 9.5 mm.

Abstract: A cathode ray tube may utilize a focus mask color-selection structure. The focus mask structure is susceptible to localized, transient short circuit events, or breakdown events. These events may be caused by conductive particulates that become free within the cathode ray tube and provide a short circuit between first and second layers of the focus mask. The breakdown events are undesirable because they may result in cross-strand currents causing mask strand magnetization that can interfere with a video image on the screen of the cathode ray tube. A rapid degaussing operation is initiated during the next subsequent vertical blanking period following detection of the breakdown event.

Abstract: A demagnetization circuit controls a demagnetization current to its demagnetization coil by means of a PTC thermistor with positive characteristic. The PTC thermistor is connected in series with and thermally coupled to a heat-sensitive switch. An NTC thermistor with negative characteristic for suppressing rush current of the voltage source is also thermally coupled to the heat-sensitive switch. After a power switch is closed, the heat-sensitive switch is opened by the heat emitted from the PTC thermistor and remains open by the heat from the NTC thermistor. The two thermistors and the heat-sensitive switch are contained in a case for easy handling and to make the component compact.

Abstract: A CPU is designed so as to put a demagnetizing circuit in an operative state in accordance with a result of detecting, among other quantities or events, the number of operations to turn on a power counted by a counter, the lapse of time under a predetermined condition measured by a timer since the pulling-out of an AC plug, the movement of the main body of a display device sensed by a sensor unit, an external magnetic field sensed by a sensor unit or a residual magnetism in a CRT itself sensed by a sensor unit. Instead of carrying out demagnetization each time the power is turned on, demagnetization is performed only under certain conditions when necessary, diminishing the problem of wasteful power consumption. On the top of that, the number of cases in which sound and picture vibration are generated due to a demagnetizing operation carried out right after the turning-on of the power is reduced, resulting in a product easy to handle by the user.

Abstract: The strip-type retainer device for fitting a degaussing coil of a cathode ray tube in a display device is provided. The retainer device comprises a first end section, a contact section, a middle section and a second end section. The contact section has a plurality of positioning slots. The middle section has a first passage allowing passage of the first end section. The first passage defines a periphery around the passage. A latch is provided on the periphery of the first passage to cooperate with one of a plurality of positioning slots. A second end section has a second passage allowing passage of the lug. The retainer device is removably attached to the peripheral edge of the cathode ray tube. The first end section passes through the first passage and the degaussing coil contacts with the funnel-shape surface of the cathode ray tube tightly by selecting an appropriate positioning slot to cooperate with the latch.

Abstract: An automatic degaussing circuit provides a video display apparatus with a degaussing capability over a wide range of ac mains sources. An ac mains source is coupled to a degaussing coil by a series interconnection of first and second temperature-sensitive resistances. The temperature-sensitive resistances have oppositely-tending temperature coefficients, so that a total dc impedance of the automatic degaussing circuit initially decreases after power is applied to the circuit.

Abstract: A television receiver has a switched mode power supply controller, which may be deflection synchronized, which produces pulses in a power transformer. To power the controller during startup, before the internal power supply has started, a storage capacitor on the power supply input of the controller is coupled through a current limiting resistance to a rectified voltage from the AC mains so as to charge the storage capacitor during first polarity phases of the AC mains. The current limiting resistance includes a positive temperature coefficient (PTC) element which increases its impedance as it heats, to reduce power dissipation after initial connection of the television receiver to AC mains. In addition, a diode is coupled in a current path to the storage capacitor to charge the capacitor to the same polarity during opposite polarity phases of the AC mains.

Abstract: A color cathode ray tube display device comprises a color cathode ray tube including a neck portion (1a), a funnel portion (1b), and a panel portion (1c), a compensating coil (7) which generates a compensating magnetic field for eliminating the influence of an external magnetic field that acts vertically on electron beams which will intersect a display screen of the color cathode ray tube (1), a current supply unit (4,5) for passing a sawtooth current synchronized with the vertical deflection cycle of a video signal into the compensating coil (7) so that the compensating coil generates the compensating magnetic field, and a memory (5b) for storing information about the sawtooth current passing through the compensating coil (7).

Abstract: Method and apparatus for the reduction of the intensity of magnetic field emissions from display devices and other magnetic field emitters comprising an active magnetic field bucking system and a passive magnetic shield, for use either singularly or in combination. Various circuits are disclosed for generating a bucking current necessary to buck the emitted magnetic field. The magnetic shield comprises a material selected from the group consisting of manganese or aluminum doped yttrium aluminum or yttrium iron garnet, iron doped glass, iron based thin films, ferrous fluoride, ferrous borate, and combinations thereof.

Abstract: Color display tube with a shadow mask, a shield of a ferromagnetic material and a demagnetizing device having a set of demagnetizing coils. The demagnetizing device is provided with means for energizing the demagnetizing coils in two steps which are shifted in time with respect to each other, while the location of the turns of the demagnetizing coils is such that upon the passage of current through only the one coil, the magnetic field generated by the coil is capable of demagnetizing those parts of color selection electrode and screen which are not demagnetized upon the passage of current through only the other coil, and conversely.

Abstract: In a television receiver, to prevent interference between the magnetic field used for degaussing and the magnetic field of the vertical yoke, a switch is used for delaying turning on the vertical deflection circuit during degaussing.

Abstract: A degaussing circuit comprising a rectifying circuit for rectifying an AC voltage inputted therein into a DC voltage, a capacitor for smoothing the DC voltage from the rectifying circuit, a RC charging circuit for charging with the DC voltage smoothed by the capacitor, a positive temperature coefficient resistor having a resistance which is increased with an increase in a temperature due to an AC current flowing therethrough upon power supply, a degaussing coil for removing a magnetic field in response to the AC current flowing through the positive temperature coefficient resistor thereto, a relay for controlling the flow of the AC current through the positive temperature coefficient resistor to the degaussing coil, and a relay driving circuit for controlling an ON/OFF state of the relay in response to the voltage charged on the RC charging circuit.

Abstract: A magnetism-erasing circuit for use in cathode ray tubes of portable televisions or the like for erasing the magnetism from the cathode ray tubes is disclosed. The magnetism-erasing circuit includes: a) automatic trigger for an automatically generating trigger signals when a D-C supply is initially applied to the magnetism-erasing circuit, b) trigger detecting means, c) delay and second trigger means for generating second trigger pulses which are delayed by a specified time interval by the detected trigger signals from the trigger detecting means, and d) means for controlling the driving of the magnetism-coil by applying currents to a magnetism-erasing coil. The magnetism-erasing circuit of the present invention further includes manual trigger means for manually generating trigger signals under the condition where a D-C supply has already been applied to the circuit.

Abstract: A degaussing system for color monitors is disclosed. During a degaussing cycle, the system successively reverses the coupling in a bridge circuit between a degaussing coil and a storage capacitor so as to generate oppositely directed degaussing currents through the coil. To insure that the residual magnetism after degaussing is substantially zero, feedback signals are developed in a feedback circuit and applied through a control circuit to the bridge circuit to successively decrease the coil's current magnitudes until they reach a predetermined threshold. Simultaneously, the feedback signals are adjusted to cause the time-integrated current in one direction of the coil to substantially equal the time-integrated current in the other coil direction.

Abstract: A magnetizing device for generating a high current magnetizing pulse includes a plurality of charge storage devices and a source of current connected by selector switches for charging selected ones of the charge storage devices to a predetermined voltage level. When the selected charge storage devices are charged the selector switches are opened and the selected charge storage devices are discharged through diode circuits coupled to a common SCR. In this way the current pulse does not flow through the selector switches. A peak current meter using a current transformer provides a display of the peak current of the magnetizing pulse.