摘要:
A high frequency link power converter apparatus includes a power source, a circulating current type AC-AC converter having an output terminal connected to the power source, a high frequency phase-advancing capacitor connected to an input terminal of the AC-AC converter, a phase controller for controlling a firing phase of the AC-AC converter, an external oscillator for supplying phase reference signals to the phase controller, a first circuit for controlling a crest value of voltages applied to the phase-advancing capacitor, a second circuit for detecting a phase difference between the reference signals and the voltages applied to the phase-advancing capacitor, and a third circuit for controlling the phase difference, so that the magnitude of the phase difference becomes substantially zero.
摘要:
A method for producing a glass preform for an optical fiber comprising forming a fine glass particle mass by flame hydrolysis of a glass raw material, dehydrating the fine glass particle mass in an oxygen atmosphere containing chlorine or a chlorine-containing compound at such temperature that the soot preform is not considerably shrunk and heating the soot preform at a temperature at which the soot preform is sintered and made transparent, the glass preform produced by which method contains less hydroxyl groups, structural defects and an optical fiber fabricated from said glass preform has stable light transmission characteristics for a long time.
摘要:
An apparatus according to this invention includes a DC power source, a DC-AC power converter having an output terminal coupled to the DC power source via a DC reactor, a high-frequency, phase-advanced capacitor coupled to an input terminal of the DC-AC power converter, a circulating current type cycloconverter having an input terminal coupled to the phase-advanced capacitor, and an AC motor coupled to the output terminal of the cycloconverter. In this apparatus, a current supplied from the DC power source is controlled by the DC-AC power converter, so that a crest value of a voltage applied to the phase-advanced capacitor is substantially constant. The cycloconverter controls to supply a sine wave current of a variable frequency (0 to several hundred Hz) to the AC motor.
摘要:
A semiconductor memory for writing or reading data words in response to prescribed bank address data and bit address data, each word having a prescribed amount of bits, is described. The memory includes a memory array for storing the data words. The memory array includes at least two memory banks adjacent to one another, each bank having a bit area corresponding to the prescribed amount of bits, buffer memory for temporarily storing the data word for writing into the memory array or the data word read from the memory array, a first source for applying the bank address data to the memory array to access the memory banks, a second source for applying the bit address data to the memory banks to access prescribed bit locations of the memory banks, and logic circuitry responsive to the bit address data for cyclically shifting the data word stored in the buffer memory by an amount corresponding to the value of the received bit address data.
摘要:
A rotary anode type X-ray apparatus includes an arithmetic unit for calculating the optimum number of revolutions of the anode, on the basis of the previously measured and stored temperature-characteristic data of the X-ray tube, at least one of the tube voltages applied to the X-ray tube, the X-ray radiation time, and the tube current. According to frequency of revolution data derived from the arithmetic unit, the motor controller drives the motor to rotate the rotary anode at an appropriate number of revolutions. This number is determined by the X-ray tube drive conditions, including the tube current.
摘要:
A parallel multiplicator including adder circuits based on Booth's algorithm is disclosed. All of the adders of a plurality of rows are constructed based on the carry save system. When the negative partial-product signal is input, the "2's complement" generating signals CB0 to CB3 for the LSB of the negative partial-product signal are input to the bit adder in the lowest order row which corresponds to the LSB of the negative partial-product signal.
摘要:
A product obtained by subjecting an isolated soybean protein and corn starch used as the raw materials to pressing and heating treatments in a twin-screw extruder exhibits its fibrous properties when it is immersed in warm water to dissolve out a part of the corn starch and a little amount of the soybean protein. This product is relatively tough. The corn starch is dissolved out in only a small amount upon the immersion in warm water and, therefore, the yield is high.
摘要:
A control system for a cycloconverter of the circulating current type produces an ac current of a variable frequency. The cycloconverter is configured to connect a power factor compensating capacitor at its receiving-end, thus to control a lagging reactive power due to a circulating current flowing in the cycloconverter so as to cancel a leading reactive power due to the power factor compensating capacitor. Such a control is carried out under the condition of an operation below the rated load. In contrast, under the condition of an operation above the rated load, a control is effected so that the circulating current flowing in the cycloconverter is substantially kept constant.
摘要:
A power converter apparatus has at least two converters CONV1 and CONV2. The DC side of each of the converters CONV1 and CONV2 is connected to a filtering capacitor Cd which serves as a DC power source for a load device LOAD. The AC side of the converter CONV1 is connected to the secondary winding of a first transformer TR1. The AC side of the converter CONV2 is connected to the secondary winding of a second transformer TR2. The primary winding of transformer TR1 is connected in series to the primary winding of transformer TR2. The series circuit of the primary windings of transformers TR1 and TR2 is coupled to an AC power supply SUP via a single AC reactor Ls. A control method of the invention is adapted to the power converter apparatus in which plural PWM converters are used. The phase of a modulating wave (carrier) of one PWM converter differs by a predetermined degree from that of another PWM converter.
摘要:
An automatic running work vehicle adapted to repeatedly work on the ground while automatically changing its running direction and provided with means for controlling the vehicle body so that the vehicle body will be automatically positioned, upon a change of direction after finishing one course, for the next course with its orientation and position in match with the boundary of the course.