Abstract: A bias circuit of a resistance load differential amplifier comprises a first differential pair and a control unit for controlling a tail current of the first differential pair, and making an output current of the first differential pair being in inverse proportion to a load resistance in the resistance load differential amplifier when applying a constant potential difference to an input of the first differential pair. The control unit further controls a tail current of a second differential pair constituting the resistance load differential amplifier, and makes the tail current of the second differential pair being in direct proportion to the tail current of the first differential pair.

Abstract: A comparator compares the voltage of an envelope signal by applying envelope detection to a signal amplitude-modulated by a digital signal encoded by a Manchester code with the terminal voltage of a capacitor constituting a filter for converting the output current of a charge pump into a voltage. The charge pump charges/discharges the capacitor by discharging or charging current, according to the result of the comparison.

Abstract: This is a filter circuit for keeping a Q value constant and stabilizing the gain ripple and group delay ripple of a filter by keeping the unity gain frequency of an operational amplifier (op-amp). The filter circuit using an op-amp for keeping the cut-off frequency constant by making a resistance or a capacitance value variable comprises a unity gain angular frequency stabilizing circuit provided with a circuit obtained by copying the input differential stage of the operational amplifier, for connecting a current generating source for generating current under the control of keeping the cut-off frequency constant, for adjusting the output of the copy of the input differential stage and feeding back/inputting the adjusted output to the gate of a transistor, and a circuit for inputting the output of the unity gain angular frequency stabilizing circuit to the gate of the transistor for generating the bias current of the input differential stage of each op-amp.

Abstract: A frequency measurement circuit measures a frequency of an input signal. The frequency measurement circuit includes a frequency measurement unit for counting a reference clock during a counting period having a predetermined number of waves of the input signal. The frequency measurement unit counts the reference clock by using a lighter amount of weighting to each count at a starting time and an ending time of the counting period than the amount of weighting at the other times of the counting period.

Abstract: A frequency measurement circuit comprises a plurality of frequency measurement units 10, 20, K0 each of which counts a reference clock Cb during a counting period having a predetermined number of waves of an input signal Cin, each of the frequency measurement units counts the reference clock, with shifted counting periods, respectively. Moreover, an adder 14 is provided to add the counted numbers of the plurality of the frequency measurement units. By shift the counting periods, even if the phase of the input signal agrees with the phase of the reference clock at the time counting starts and at the time counting ends on a certain frequency measurement unit, there is scarcely any possibility of agreement of the phases on other frequency measurement units. Therefore, by utilization of the added number of counts, frequency can be measured with high accuracy. In addition, by making the counting periods being shifted with overlaping each other, extension of the measurement time is not required any longer.

Abstract: A frequency measurement circuit comprises a plurality of frequency measurement units 10, 20, K0 each of which counts a reference clock Cb during a counting period having a predetermined number of waves of an input signal Cin, each of the frequency measurement units counts the reference clock, with shifted counting periods, respectively. Moreover, an adder 14 is provided to add the counted numbers of the plurality of the frequency measurement units. By shift the counting periods, even if the phase of the input signal agrees with the phase of the reference clock at the time counting starts and at the time counting ends on a certain frequency measurement unit, there is scarcely any possibility of agreement of the phases on other frequency measurement units. Therefore, by utilization of the added number of counts, frequency can be measured with high accuracy. In addition, by making the counting periods being shifted with overlaping each other, extension of the measurement time is not required any longer.

Abstract: The signal distribution apparatus includes a plurality of processors and a distribution portion. The distribution portion is prepared per distribution unit and is set in at least one of the plurality of processors. Each distribution portion receives receiving control signals and distributing the control signal to one of the plurality of processors.

Abstract: A device for suppressing spurious signals generated by a fractional-N synthesizer. The fractional-N synthesizer generates an output frequency where an underlying PLL circuit uses a frequency divider for dividing the output frequency by a frequency-division ratio to obtain a comparison frequency and performs phase-comparison operations between a reference frequency and the comparison frequency to control the output frequency. The output frequency is changed by a frequency interval smaller than the reference frequency by making a temporal change to the frequency-division ratio once in every predetermined number of cycles.

Abstract: A filter characteristic regulating apparatus for regulating a characteristic frequency of a filter device capable of regulating a characteristic frequency includes a measuring signal generator for generating a measuring signal having a known cycle of a response waveform when inputted to a filter device having a desired characteristic frequency, a selector for selecting and inputting this measuring signal to the filter device when the filter device is not used, a response waveform cycle measuring instrument for measuring the cycle of the response waveform of the input measuring signal to the filter device, and a controller for comparing the cycle of the response waveform measured by the response waveform cycle measuring instrument with a known response waveform cycle, and regulating the characteristic frequency of the filter device to a desired value on the basis of the comparison result.

Abstract: A fractional N-frequency synthesizer includes an accumulator outputting an output value, and a spurious signal cancel circuit. The spurious signal cancel circuit includes a pulse forming circuit, receiving a spurious signal cancelling reference signal, a reset signal and the output value of the accumulator, and outputting, in synchronism with the spurious signal cancelling reference signal, a pulse voltage signal having a pulse width proportional to the output value of the accumulator from a time when the reset signal is received, and a constant current circuit controlled by the pulse voltage signal and outputting an output current of the spurious signal cancel circuit.

Abstract: A gas-insulated switchgear apparatus comprising two power-receiving units with a cable head on power-receiving side, a wattage metering unit, and two lead-out units with a cable head on lead-out side. The two power-receiving units are arranged on one side of the wattage metering unit, and the two lead-out units on the other side. The gas-insulated switchgear apparatus is thus simplified, electrical connection facilitated between the units, and the floor space of the whole apparatus reduced.

Abstract: In a gas insulated switching apparatus, a pair of buses are made up of coaxially disposed conductors or the like and disconnectors are connected to one of the buses. The buses and the disconnectors are integrally configured in one gas section of a gas tube path having a plurality of sections so as to reduce the size of the apparatus significantly.

Abstract: A compact-type gas-insulated switchgear apparatus is disclosed, in which movable contacts of a disconnector and a ground switch arranged in a cable head casing are adapted for switching operation in parallel to the axis of the cable head casing. A connecting conductor connecting stators of the disconnector and the ground switch is arranged in a position perpendicular to the axis of the cable head casing. A connecting opening is formed in the side wall of the cable head casing at a part thereof corresponding to the end of the connecting conductor. It is thus not necessary to increase the diameter of the cable head casing for the movable contacts of the disconnector and the ground switch performing substantially parallel operation, and other electrical equipment may be connected along the extention of the connecting conductor connecting the stators of the disconnector and the ground switch without modifying the cable head casing.

Abstract: A three-phase combined type gas insulated bus is disclosed which comprises at least one eddy current conductor for passing the eddy current caused secondarily by the current flowing in high voltage conductors, thus solving the problem of a newly-found phenomenon that the temperature of a sealed casing increases by the flow of the eddy current. This eddy current conductor is made of such a material of good electrical conductivity as aluminum or copper. Even in the case where the sealed casing is reduced in diameter to such an extent as to pose a problem of temperature increase by the eddy current flow, the eddy current is reduced or completely eliminated in the best case, so that the sealed casing can be made of a low cost soft steel.

Abstract: An insulating gas-filled disconnecting switch comprises a metallic container filled hermetically with an insulation gas, and a movable electrode and a stationary electrode disposed within the metallic container and electrically insulated from the latter. Means for guiding an arc possibly produced between both electrodes upon separation of the movable electrode from the stationary electrode positively toward a center portion of an opposite end of the stationary electrode, to thereby prevent the arc propagation toward the stationary electrode from reaching the metallic container from the stationary electrode.

Abstract: A gas insulated power switch gear apparatus of a reduced height comprising gas insulated circuit breakers arranged horizontally and disconnecting switches operated vertically is disclosed. Each of the disconnecting switches includes a first sheath portion inserted into an interrupted point of a main bus bar and mechanically connected with the sheath of the main bus bar through an insulating spacer for defining a gas section, and a second sheath portion communicating with the first sheath portion and crossing and extending in the direction perpendicular to the first sheath portion. A collector electrically connected with the conductor of a feeding bus bar is arranged within the second sheath portion, and a movable contactor normally electrically connected with the collector is movable vertically. A fixed contactor electrically connected with the main bus bar conductor and engageable with the movable contactor is arranged within the first sheath portion.

Abstract: A gas-insulated switchgear apparatus is disclosed in which three-phase power transmission lines are anchored to associated entry gantries respectively while maintaining a required vertical open-air insulation distance between the power transmission lines, and line feeder switching units for electrically connecting the power transmission lines to gas-insulated main buses disposed substantially in parallel with the extending direction of the entry gantries are arranged to extend in a horizontal direction orthogonal with respect to the axial direction of the main buses.

Abstract: In a gas-insulated electric apparatus, such as a gas-insulated switchgear and a gas-insulated bus, having an insulating-gas-filled metallic container or sheath within which an electric conductor carrying a high-voltage current is supported by an insulating supporter, a potential detected by a first potential detector through at least a portion of the insulating supporter and another potential detected as a reference value by a second potential detector through an electro-static capacity disposed between the metallic container and the second potential detector are fed to the inputs of a differential amplifier of a partial discharge detecting device to thereby detect possible partial discharges along the insulating supporter with high sensitivity.

Abstract: A gas insulated switch-gear apparatus having first and second base planes is disclosed. Arranged on the first and second base planes are feeder switching apparatus comprising gas filled circuit breakers and first and second gas insulated disconnecting switches at opposite sides of each of the gas filled circuit breakers. Gas insulated busbar devices are arranged to be horizontally spaced from the feeder switching apparatus. On the first and second base planes, the first gas insulated disconnecting switches are connected to the gas insulated busbar devices while the second gas insulated disconnecting switches are connected to bushings. Axial lines of the feeder switching apparatus along which the first and second gas insulated disconnecting switches are arranged traverse axial lines of the gas insulated busbar devices. The axial lines of the gas insulated busbar devices arranged on the first and second base planes lie in a common vertical plane containing the axial lines and lie in the base planes.

Abstract: Gas-insulated switchgear apparatus wherein a device providing a first disconnect gap and a second disconnect gap is located in a sheath filled with an insulating gas and kept at ground potential. The disconnect gaps providing device comprises a first movable contact and a second movable contact which are insulatedly supported by a support device with respect to the sheath. There is provided a device for individually actuating the movable contacts which device comprises a pair of insulated actuating rods disposed adjacent and extending parallel to the insulating support device.