Abstract: The invention relates to a sensor device, particularly a limit or threshold value sensor device with a sensor system for detecting an external measured quantity, a switching device being provided for switching a load circuit. The known design of the switching device by means of transistors or electromechanical relays has always necessitated compromises with regards to the electronic functionality, design of the circuit and arrangement on or with the sensor device. The solution provided by the invention is a switching device with an almost wattless drive and galvanic separation or isolation between the control circuit and output circuit, the sensor system being constructed independent of the load circuit.

Abstract: In one general aspect, a system to control and monitor an electrical system includes a switchgear housing unit connected to the electrical system that includes a switchgear mechanism for controlling a connection within the electrical system and electronic controls for monitoring and controlling the switchgear mechanism, where the electronic controls are embedded within the switchgear housing unit to form a single, self-contained unit.

Abstract: Power distribution busses and methods are disclosed that provide flexible protection and alarming capabilities. Various embodiments provide interchangeability of fuses and circuit breakers within the same power distribution bus configuration. These various embodiments also provide discrete alarming for fused lines, discrete alarming for lines with circuit breakers, combined alarming for lines having mixed forms of protection, and/or selectable alarming such as combined versus discrete in relation to employing all fused lines, employing all circuit breaker protected lines, or employing mixed line protection.

Abstract: A signal source identification system and associated method are disclosed that utilize wavelet-based signal processing to facilitate signal source identification. In particular, the wavelet-based signal processing enables the extraction of fingerprint type signatures for signal sources using wavelet packet processing, and supplementary signal processing can be used to further enhance the accuracy of the system. This signal source identification system can be used for identifying signal sources within a received data signal, used for providing security features by verifying the identify of a transmitting device, and/or used in other environments where it is desirable to identify or differentiate among signal sources. Other features and variations can be implemented, if desired.

Abstract: A frequency harmonic identifier for detecting series arcs on a power line includes a frequency analyzer for providing the harmonic content of a sensed current signal and a decision logic for comparing a tested signal to at least one reference signal band. The reference signal band or bands may represent a variety of common loads and if the tested signal does not match any of the sets of reference signal bands, then the logic determines the tested signal to be a series arc signal. The frequency harmonic identifier may be provided within a circuit interrupter and may issue a trip signal if the tested signal is determined to be a series arc signal. Also disclosed is a method for detecting series arcs, and a storage medium having instructions for causing a computer to implement the method.

Abstract: A protection circuit (1) is coupled to a processor (2) and a memory device (3) which preferably form a physical unit, and prevents unauthorized access to the memory device (3) by combining internal and/or external signals (s2, s3, s4; s1) in a logic device (5) for detecting the unauthorized access. These signals are control signals of the processor-memory system and correspond to the status of the latter. In the event of an unauthorized memory access, the logic device (5) disables an externally accessible data interface (6) and/or inhibits the control signals (s5) necessary for access to the memory device (3).

Abstract: A High Speed Transfer System which comprises three Protection and Control devices. A first and a second of said Protection and Control devices are used for failure detection on the feeder bus-bar; the third of said Protection and Control devices is used for the High Speed Transfer System co-ordination functionalities.

Abstract: Resettable circuit interrupting devices, such as GFCI devices, that include neutral fault test simulation.

Abstract: A chassis built in a panel is provided with a supporter for supporting a printed wiring board mounted with an electronic component, and the printed wiring board is provided with a board-opening portion in the proximity of this supporter. When a load F applied on a knob from a predetermined direction, the printed wiring board can be ruptured from the board-opening portion to get detached from the supporter, thereby lowering the height of the outward projection of the knob from the panel.

Abstract: An apparatus for interrupting an electrical short circuit current in an electrical distribution system having a plurality of phases is disclosed. The apparatus includes a housing, a plurality of separable conduction paths, an operating mechanism in operable communication with the plurality of conduction paths, an electronic trip unit in signal communication with each of the plurality of conduction paths and in operable communication with the operating mechanism, and an electromagnetic trip unit in signal communication with each of the plurality of conduction paths and in operable communication with the operating mechanism. The electromagnetic trip unit is configured to be operably responsive to a first half-cycle waveform of the short circuit current prior to the electronic trip unit being operably responsive to a second multi-cycle waveform of the short circuit current.

Abstract: A failure detecting device is provided, which includes the transistor for driving the excitation coil of the relay connected to the battery, the power supply monitors for monitoring an output of the relay, the EEPROM for storing failure presence or absence information, and the microcomputer for writing the failure presence or absence information in the EEPROM at the time of power OFF, reading the failure presence or absence information from the EEPROM at the time of power ON, and judging a failure state based on a voltage value detected by the power supply monitor in the case in which a failure is present.

Abstract: The present invention provides an apparatus and method of interrupting the current in a circuit wherein the magnetic pressure induced by current flow through a conductor causes the conductor to flow and thereby open the associated circuit. Magnetic pressure may be derived from Lorenz equations. Gravity is not relied upon to cause the conductor material to flow. The invention may be used in circuits having high currents relative to conductor size and material selection.

Abstract: A power controller is positioned within a current path between the line side and the load side of an electrical circuit. The power controller closes the current path in the presence of a control supply and opens the current path in the absence of the control supply. A power supply electrically connected to the current path provides the control supply. A sensor system receives power from the power supply, monitors the current in the current path and outputs a sensor signal indicative of a current condition within the current path. A logic controller also receives power from the power supply, receives the sensor signal and removes the control supply from the power controller when the sensor signal does not satisfy an established criteria. The sensor system may include one or both of an imbalance sensor for monitoring the current balance among two or more electrical lines and over-current sensors for monitoring current in individual lines.

Abstract: An electromagnetic circuit breaker assembly, comprising at least one circuit breaker, is provided with a reverse polarity circuit that reduces the voltage presented to the terminals of the circuit breaker to which it is electrically connected when the terminals are further connected to a source of voltage in reverse polarity. The circuit breaker assembly is tripped due to the reverse polarity set-up, and remains tripped until the polarity is corrected. The electromagnetic coil is continuous provided with sufficient voltage so that the breaker may not be manually reset until the polarity is corrected. Preferably, the breaker is mechanically connected with another circuit breaker to create an assembly that will protect circuitry and devices against both a reverse polarity condition and an overload condition under normal operation. To this end, the reverse polarity circuit does not affect operation of the circuit breaker assembly if the polarity is in accordance with the normal set-up.

Abstract: A circuit interrupting device having a reverse wiring protection function is disclosed. The circuit interrupting device includes a housing having a cover and a base, a mounting plate, and an electrical component mounting member, a pair of input hot and neutral conductors and a pair of output hot and neutral conductors, a differential transformer for detecting a leakage current, a disconnecting mechanism for connecting and disconnecting the output conductors to and from input conductors, and a mechanism for preventing reverse wiring, which includes a coil connected to the input hot and neutral conductors and a moveable piece that moves when the coil is energized. The input and output conductors are electrically connected only when the coil is energized by correctly connecting the power wires to the input conductors of the device. This device thus provides both leakage current protection and reverse wiring protection that protects against incorrect wiring during installation.

Abstract: Disclosed is a device for shielding an electromagnetic wave. The electromagnetic wave shield device comprises a relay having a contact selectively connected to a first terminal or a second terminal of a power receptacle; a controller controlling the connection between the contact of the relay and the first terminal or the connection between the contact of the relay and the second terminal, comparing the first voltage value generated by the connection between the contact of the relay and the first terminal with the second voltage generated by the connection between the contact of the relay and the second terminal, and controlling the relay so that the contact of the relay is connected to the terminal having the lower voltage value; and an electromagnetic wave shielding unit for providing the electromagnetic wave generated by an electric and electronic device to the terminal having the lower voltage value.

Abstract: Protection systems for electrical systems such as substation power dividers are described. The protection systems may be designed and used to detect and clear faults that may occur within the substation power dividers. For example, a first Rogowski coil may be used to detect current along a primary conductor, and output a corresponding current signal to a multi-function, differential relay having multiple voltage and current inputs. Similarly, additional Rogowski coils may be used at each of a plurality of secondary feeders, where power from the primary feeder may be distributed to the secondary feeders using a connection bus. By comparing the signals from the first Rogowski coil and the additional Rogowski coils, the differential relay may determine whether a fault exists at some point along the conductor(s) and between the first Rogowski coils and the additional Rogowski coils, including whether a fault is associated with the connection bus.

Abstract: Device for actuating a plurality of actuators (1) in a transportation device, which has a plurality of output stages (2, 3, 4, 5) and a control circuit for actuating the output stages (2, 3, 4, 5), the output stages (2, 3, 4, 5) each connecting through the current in order to activate the actuators (1) and each output stage (2, 3, 4, 5) being connected in electrically conductive fashion to an actuator (1, 9). A plurality of output stages (2, 3, 4, 5) is additionally connected to in each case, one further actuator (1, 9) by the control circuit. The control circuit is actuated in such a way that an output stage (2, 3, 4, 5) can actuate either the first or the further actuator (1, 9) with the output stages (2, 3, 4, 5) being interconnected to one another and/or to the actuators (1, 9) in the manner of a matrix so that a plurality of row lines (6) and a plurality of column lines (7), at whose points of intersection (8) the actuators (1) are arranged, are provided.

Abstract: The invention intends to provide a direct current load breaking contact point constitution that can make and break an electrical circuit under both direct current loads of direct current resistance load and direct current inductance load over a long period of time without causing problems such as {circle around (1)} the conduction defect due to the consumption of the contact point, {circle around (2)} the locking due to material transfer from one contact point to the other contact point, {circle around (3)} the welding between the contact points, and {circle around (4)} the abnormal arc continuation, and a direct current load breaking switching mechanism such as a relay, a switch and so on that has the contact point constitution.

Abstract: Failure prediction for complex processes is performed utilizing one or more nonlinear regression models to relate operational variable values measured at two or more times to predicted process metric values and maintenance variable values.

Abstract: An electrical system includes a solid state relay (1) and an electrical connector (2) that connects solid state relay (1) to a load (4). The solid state relay (1) includes a power MOSFET (Q1) for switching power to the load (4). A PNP transistor (Q2) monitors the voltage drop across the power MOSFET (Q1), and shuts the power MOSFET off when the voltage drop exceeds a reference level. The solid state relay circuitry floats when the power MOSFET is commanded OFF so there is no leakage to ground. The relay (1) can be used with an electrical connector that includes a short pin (34) or shunt (16) that is disconnected before male and female terminals (12, 22) are unmated. Disconnection of the shunt (16) or the short pin (34) causes the power MOSFET to be commanded OFF so that there is no current flowing through the male and female terminals (12, 22) when they reach an arc susceptible position. The solid state relay (1) and the connector (2) are suitable for use in a 42 Volt automotive electrical system.

Abstract: A protection device for monitoring current in a power cable to an electrical device and for controlling a remotely located starter for the electrical device in response to a system controller. The device includes a transformer magnetically linked with the power cable to produce a voltage signal in response to the presence of a changing current within the power cable. An input circuit located in a single housing together with the transformer is electrically connected to the transformer so as to receive the voltage signal. The input circuit produces, in response to the voltage signal, either a first signal or a first circuit condition at the output terminal of the input circuit, representative of the changing current in the power cable. A switch circuit also in the same container with the transformer has a terminal for sensing either a second signal or a second circuit condition of the remotely located system controller.

Abstract: An improved probe includes a conductive tubular housing or body containing a coil spring and a conductive plunger movable in the housing and having a contact tip outwardly extending from one end of the housing. The plunger and tip are urged to a normally outward position by the bias force of the spring. The opposite end of the housing has an opening for mating with a conductive pin of a connector. The connector is retained in a mounting plate of an associated fixture and has terminal ends of desired configuration. The terminal end may include a wire-wrap pin, a crimp type terminal or wire jack for attachment to a wire, or the terminal may include a spring loaded pin for engagement with an associated electrical contact. An air tight seal may be provided between the probe and the connector and the connector may be mounted in a mounting such that when vacuum is applied to an associated test fixture, air cannot be drawn through the fixture or through the body of the probe.

Abstract: An operational check of the safety unit or the safety circuit takes place within the delay time of the relay, assigned to each motor, caused by the pick-up delay or the release delay. Also, the control unit can be equipped such with at least one safety component and/or safety circuit for controlling the control unit that an operational check of the control unit takes place between the operation of an operating element of the hand switch and the starting of the motor or motors. The operating time and the release time of the relay may be delayed by a suitable component so that sufficient time is available for the operational check.

Abstract: A safety apparatus for an output level-adjustable microwave oven includes a fuse disposed in a power supply line that connects a high power relay or a low power relay with a primary coil of a high voltage transformer of the microwave oven. Where a wrong operation occurs due to defects in the relays, such as a melting of any one of the relays, the fuse disposed in the power supply line connected to the primary coil of the high voltage transformer is cut off. Accordingly, a potential fire resulting from the wrong operation is prevented.

Abstract: If an activation error occurs, after activation is executed for all devices, a device in which the activation error has occurred is reactivated. When the power supply of a television receiver is turned on, a control unit reads last conditions from a memory, and executes initialization according to the last conditions. When the television receiver is activated or the contents of settings are modified, if an activation error occurring in a tuner, a video processing unit, a sound output system, or any other device is detected, the activation error is recorded in a nonvolatile memory by setting a flag. A device recorded with the flag set is then restored (reactivated).

Abstract: An integrated solenoid system including a single housing containing a solenoid, a controller and one or more electrical connections. The controller includes temperature compensating means and/or voltage compensating means thereby providing predetermined, substantially constant currents to said solenoid. The housing includes an integral two-part end cover.

Abstract: A microtransformer for a high-performance system-on-chip power supply is disclosed. Through-wafer openings in a substrate allow the primary and secondary wiring on both surfaces of the silicon substrate. An insulating silicon oxide layer is first deposited on all surfaces of the substrate. A magnetic film is further deposited on the silicon oxide layer followed by the application of another insulating layer. Coils are fabricated next by patterned deposition on both sides of the substrate and through the holes. The coils can be, e.g., single coils or primary or secondary coils of a transformer structure, with secondary having one or more output taps to supply different output voltages. For better flux closure, various magnetic layers and insulators can be deposited on top of the windings.

Abstract: Disclosed herein is an anisotropically conductive sheet capable of holding charge in its surfaces under an unpressurised state, and moving the charge held in the surface in a thickness-wise direction thereof in a state pressurised in the thickness-wise direction, thereby controlling the quantity of the charge at the surface. This anisotropically conductive sheet comprises a sheet base composed of an elastomer and conductive particles exhibiting magnetism contained in the sheet base in a state oriented so as to arrange in rows in a thickness-wise direction of the sheet base, and dispersed in a plane direction thereof. Supposing that a volume resistivity in the thickness-wise direction under an unpressurised state is R0, and a volume resistivity in the thickness-wise direction in a state pressurised under a pressure of 1 g/mm2 in the thickness-wise direction is R1, the volume resistivity R1 is 1×107 to 1×1012 ?·m, and a ratio (R0/R1) of the volume resistivity R0 to the volume resistivity R1 is 1×101 to 1×104.

Abstract: Power supply systems and methods can enable an electromagnetic device, such as an electrical contactor, to ride-through both voltage sags and dropouts. In an illustrative embodiment, a rectifier is used to generate a DC input voltage from an AC supply voltage. An interface circuit supplies the DC input voltage to an electrical contactor to provide the necessary power for operating the contactor. In general, an electrical contactor that is intended to operate from an AC voltage will operate equally well from a lower magnitude DC voltage. The interface circuit uses this difference in magnitudes between the AC voltage source and an operationally equivalent DC voltage source to maintain the DC input voltage at a desired level even if the AC voltage source sags below its normal operating level. In addition, an energy storage device may be used to store at least some of the DC input voltage.

Abstract: The trip device comprises a system-powered power supply circuit comprising a capacitor for power supply of a trip coil. When the trip device is powered on, the capacitor charges and its voltage is regulated according to a first reference voltage sufficient to activate the trip coil if necessary. After a preset period, regulation of the voltage at the terminals of the capacitor is performed according to a second reference voltage, lower than the first voltage. The reference voltage reverts to the first value during the same preset period when the measured current reaches a preset threshold, which constitutes an indication of the presence of a fault that will lead to tripping being required. The capacitor is therefore generally charged at a lower voltage than that which is necessary for tripping, thus enabling its size to be reduced.

Abstract: A protective control apparatus and method is disclosed for protecting the operation of a power device upon detection of an internal fault condition. The power device has a circuit breaker for connecting the power device to a power supply. The protective control apparatus comprises a current measuring unit operatively connected to the power device for measuring currents within the power device and a protective relay processing unit connected to the current measuring unit for receiving the measured currents and connected to the circuit breaker for providing a control signal thereto. The protective relay processing unit performs a multi-resolution analysis of the measured currents preferably using Wavelet Packet Transform decomposition, to detect the internal fault condition, and upon detection of the internal fault condition, provides a control signal to disable the circuit breaker.

Abstract: The invention concerns a control and protection module (10) for a low voltage multipolar switch device that is comprised of a connector base (50), a control electromagnet (41) and a trip mechanism (42) capable of acting upon the moving contacts (52) in order to open and break the power poles. The detachable control and protection unit (10), an electronic board (20) which has a processing unit (30), a control device (31) and a protection device (32), responsible respectively for operating the electromagnet and the trip mechanism in response respectively to a control signal (310) and a trip signal (320) transmitted by the processing unit (30). The processing unit can suppress the control signal (310) from the electromagnet (41) in the event of malfunction of the protection device (32).

Abstract: Certain exemplary embodiments provide a method comprising: providing system electrical load information for an electric power system to one or more neural networks; and via the one or more neural networks, predicting a system electrical load for a predetermined immediate future period.

Abstract: A protective arrangement in a device that protects the device and personnel or users of the device when undesirable conditions develop within the device. The protective arrangement de-couples a power source from the device, prevents access to the device that may harm a user or aggravate the undesirable condition, and actuate an alarm when the undesirable condition occurs.

Abstract: A charge control circuit for controlling a micro-electromechanical system (MEMS) device having variable capacitor formed by first conductive plate and a second conductive plate separated by a variable gap distance. The charge control circuit comprises a switch circuit configured to receive a reference voltage having a selected voltage level and configured to respond to an enable signal having a duration at least as long as an electrical time constant constant of the MEMS device, but shorter than a mechanical time constant of the MEMS device, to apply the selected voltage level across the first and second plates for the duration to thereby cause a stored charge having a desired magnitude to accumulate on the variable capacitor, wherein the variable gap distance is a function of the magnitude of the stored charge.

Abstract: An acoustic transducer comprising a substrate; and a diaphragm formed by depositing a micromachined membrane onto the substrate. The diaphragm is formed as a single silicon chip using a CMOS MEMS (microelectromechanical systems) semiconductor fabrication process. The curling of the diaphragm during fabrication is reduced by depositing the micromachined membrane for the diaphragm in a serpentine-spring configuration with alternating longer and shorter arms. As a microspeaker, the acoustic transducer of the present invention converts a digital audio input signal directly into a sound wave, resulting in a very high quality sound reproduction at a lower cost of production in comparison to conventional acoustic transducers. The micromachined diaphragm may also be used in microphone applications.

Abstract: Microporous membranes useful as a microarray for testing, e.g., biomolecules are created by exposure to a laser beam by means of which a grid having a predetermined pattern of reduced porosity is established.

Abstract: An external storage device connected to electronic equipment through a cable includes a switch for selecting functions of the main unit of the external storage device. A user freely sets the function of the external storage device by simply operating the switch. This arrangement eliminates the need for disassembling the external storage device to switch the function thereof. The switch may be externally exposed out of the case of the external storage device.

Abstract: A computer chassis compliant with the Intelligent Platform Management Interface includes a central baseboard management controller (CBMC) and at least one computer board set. The computer board set includes a microcontroller that operates simultaneously as a satellite management controller to receive system management requests from the CBMC and to provide system management information to the CBMC, and as a local baseboard management controller to receive system management information about the computer board set and to provide the system management information about the computer board set to the computer board set. The computer board set detects a local event, which is entered in a local system event log. The satellite management controller determines if the event was requested by the CBMC, and if so, transmits a corresponding event message to the CBMC. The local baseboard management controller determines if local action is required and performs the local action.

Abstract: A circuit breaker system has been provided for the controlled interruption of at least one circuit, with a mechanical breaker element and an adjustment device coupled to the breaker element, so that the mechanical breaker element can be placed in at least a first, second, and third position in order to selectively break or let pass neighboring circuits in the first, second, or third position. The breaker element is rotatably secured in a fastening device, connected with one foot. The interruption conditions are provided by a magnetic coil, which exerts power by way of a magnetic field on a permanent magnet, which is secured to the breaker element. In the simplest case the circuit breaker system has three conditions at its disposal, by which one of two circuits can be broken. When the coil is without power, one circuit is broken. The other circuit is broken by reversing the circuit direction.

Abstract: A receptacle interrupts a power circuit including a glowing contact and a gas, such as hydrogen chloride, carbon dioxide, carbon monoxide or a combination of those gases, associated with the glowing contact. The receptacle includes a set of separable contacts for interrupting the power circuit, an operating mechanism controlling the set of separable contacts, and a trip mechanism, such as a trip coil, cooperating with the operating mechanism to open the set of separable contacts in response to a trip signal. A gas detector detects the gas and outputs a gas concentration signal based upon a level of the gas. A microprocessor outputs the trip signal responsive to the gas concentration signal whenever a predetermined concentration level of the gas is detected.

Abstract: Disclosed is a main switch conveying apparatus for a vacuum circuit breaker.

Abstract: A shock absorbing body is interposed between an internal component such as a hard disk drive (HDD) and the inside surface of an enclosure for an electronic apparatus such as a notebook personal computer. The shock absorbing body includes a first receiving surface defined at one end of the shock absorbing body so as to receive the internal component. A second receiving surface is defined at the other end of the shock absorbing body so as to receive the inside surface of the enclosure. A constriction is formed in the shock absorbing body between the first and second receiving surfaces. When a larger impact is applied to the enclosure, the shock absorbing body is allowed to suffer from a fracture at the constriction. The energy of the impact is transformed into the energy of the fracture at the constriction. The impact energy is sufficiently consumed in this manner. The internal component can be protected from the larger impact.

Abstract: The present invention relates to a safety switching device for safely switching off an electrical load such as an electrically driven machine. The safety switching device has a failsafe disconnection unit and a non-failsafe signaling unit, both of which are supplied with an external control signal. The disconnection unit fail-safely switches off the electrical load as a function of the control signal but with a first delay. The signaling unit produces an external reporting signal as a function of the control signal in a non-delayed and non-failsafe manner.

Abstract: An electronic component, in which a chip can be mounted on a certain predetermined place of the package at a high accuracy level, which package having a stepped level-difference in the inner wall of a cavity. The package 13 is provided with a stepped level-difference 26 in the inner wall surface, and an internal contact electrode 14 formed on the upper surface of the stepped level-difference 26. At the bottom of the package 13 is a shield electrode 15, on which a chip 17 is mounted via an adhesion layer 16. The chip 17 and the internal contact electrode 14 are electrically connected by an interconnection wire 19. Location aligning for the chip 17 and the interconnection wire 19, at least either one of these, is conducted by making use of a region 18a, 18b, which is non-electrode portion, provided on the inner bottom surface of the package 13.

Abstract: A method and apparatus for protecting a conductor in an integrated circuit. A protective covering can be disposed over a conductor for a substantial length along the conductor while allowing a portion of the conductor to be exposed. The protective covering can be configured as a tunnel which runs for a substantial length along the conductor and can be operable to prevent the occurrence of electrical shorts during operation of the integrated circuit. According to one embodiment of the invention the integrated circuit can be configured as a micromachined device with active mechanical components exposed to the atmosphere.

Abstract: An electrical timer having pre-set options, electronically set via e-prom and microprocessor or other solid-state circuitry, for the activation of an electrical receptacle, with ground-fault circuit protection, contained within the timer housing. This timer is novel and differs from others, as it is designed for user-activation and instantaneous energizalion of said receptacle, based upon immediate need and for fixed and pre-set durations, independent of time-of-day, chronological, calendar-based, or other pre-scheduled means, using simplified selections and modalities, and providing ongoing visual status of timer activity. The timer also has a manual reset (off) function. According to a further aspect, switching-times mechanism is co-located within the timer housing, which includes a suitable electrical plug, an electrical receptacle, an electrical switch operable with the timer, and shock protection via ground-fault circuit interruption circuitry.

Abstract: The invention concerns a high coulomb transfer switch useful for high current pulse supplies, employing a self-bouncing arc mechanism, wherein two cylindrical electrodes are coaxially arranged and the pathway of current inside the switch is specially designed such that arc current sheet positioned between the coaxially arranged electrodes makes a self bouncing movement in an axial and/or circumferential direction. The self-bouncing arc switch according to the present invention makes it possible to maximize the working area of the electrodes, thereby spread arc energy effectively over the electrodes.

Abstract: A recording medium for a computer contains sectors, each of which represents a section of data that has originally been supplied by a user. As the user data is sent to the recording medium from the memory of the computer, an adjust bit determining circuit determines the adjust bit for a block of the write data. The adjust bit-value is such that the sum of the DC levels for the write data at a given point is equal to zero or approaches zero. The user data is converted using RLL(1,7) codes and PWM is performed to derive the write data. The circuit includes an encoder for receiving the user data two bits at a time. The encoder outputs DSV values for the 2-bit user data. A first circuit group for accumulating the DSV values from the encoder is used acquire block DSV values of data belonging to the plurality of blocks of the data section. A second circuit group accumulates these block DSV values computed by the first circuit group and calculates a temporary sector DSV value.