Abstract: A clock generator is configured to generate, on the basis of an oscillation frequency clock of a voltage-controlled oscillator, a first signal having a phase the same as the oscillation frequency clock, a second signal having a phase delayed by a first phase amount to the first signal and a third signal having a phase delayed by a second phase amount to the first signal. A phase detection circuit is configured to provide a phase control on the basis of a phase difference between the third signal and an input signal. A frequency detection circuit is configured to sample the first and second signals in synchronism with the input signal, thereby performing a frequency control for the voltage-controlled oscillator on the basis of the sampled signals.

Abstract: The invention provides a PLL circuit wherein, even if the duty ratio of an input signal varies, the convergence time required for frequency detection of a frequency detection circuit is short and wrong operation of the frequency detection circuit with a control signal is less likely to occur. A clock generator produces, based on an oscillation frequency clock of a VCO, a first clock signal of the same phase, a second clock signal having a phase delayed by 90 degrees from that of the first clock signal, and a third clock signal having a phase delayed by 45 degrees from that of the first clock signal. A phase detection circuit performs phase control based on the phase difference between the third clock signal and an input signal, and a frequency detection circuit fetches the first and second clock signals in synchronism with the input signal and performs frequency control based on the fetched signals.

Abstract: The invention provides a PLL circuit wherein, even if the duty ratio of an input signal varies, stabilized PLL operation is achieved. The PLL circuit includes a phase detection circuit and a frequency detection circuit. The frequency detection circuit includes a pair of D-type flip-flops for sampling first and second clock signals having different phases from each other in synchronism with an input signal at each rising or falling changing point of the input signal for each period, and a control logic circuit for logically operating the signals sampled by the D-type flip-flops and the signals sampled successively subsequently by the D-type flip-flops. The control logic circuit generates an UP pulse signal or a DOWN pulse signal based on a result of the arithmetic operation.

Abstract: The invention provides a PLL circuit wherein, even if the duty ratio of an input signal varies, the convergence time required for frequency detection of a frequency detection circuit is short and wrong operation of the frequency detection circuit with a control signal is less likely to occur. A clock generator produces, based on an oscillation frequency clock of a VCO, a first clock signal of the same phase, a second clock signal having a phase delayed by 90 degrees from that of the first clock signal, and a third clock signal having a phase delayed by 45 degrees from that of the first clock signal. A phase detection circuit performs phase control based on the phase difference between the third clock signal and an input signal, and a frequency detection circuit fetches the first and second clock signals in synchronism with the input signal and performs frequency control based on the fetched signals.

Abstract: In a low-pressure casting in which molten metal is introduced into a cavity of a casting mold under a pressure applied to the surface of the molten metal according to a preset reference pressurizing pattern, the reference pressurizing pattern is corrected when that the cavity has been filled with molten metal is detected and the pressure applied to the molten metal surface is controlled according to the reference pressurizing pattern after the correction. The pressure difference between a set pressure at a predetermined time in the reference pressurizing pattern after the correction and a set pressure at the corresponding time in the reference pressurizing pattern before the correction, is calculated and a set pressure for the period up to the time the cavity is filled with molten metal in the reference pressurizing pattern for the next casting cycle is corrected on the basis of the calculated pressure difference.

Abstract: An air conditioning system including a refrigerant circulation route, a compressor, a condenser, an expansion valve, an evaporator and a pressure sensor for detecting pressure in the circulation route comprises a refrigerant phase detecter provided on the circulation route between the condenser and the evaporator where the refrigerant should be in a liquid phase for detecting whether the refrigerant is in a liquid phase or in a vapor phase and a control for determining whether the compressor is in a locked state in accordance with the signals from the refrigerant phase detecter and the pressure sensor. The air conditioning system can precisely determine and detect both compressor lock up and refrigerant leakage without providing a rotation detecting sensor for the compressor.

Abstract: An air conditioning system including a refrigerant circulation route, a compressor, a condenser, an expansion valve, an evaporator and a pressure sensor for detecting pressure in the circulation route comprises a refrigerant phase detector provided on the circulation route between the condenser and the evaporator where the refrigerant should be in a liquid phase for detecting whether the refrigerant is in a liquid phase or in a vapor phase and a control for determining whether the compressor is in a locked state in accordance with the signals from the refrigerant phase detector and the pressure sensor. The air conditioning system can precisely determine and detect both compressor lock up and refrigerant leakage without providing a rotation detecting sensor for the compressor.

Abstract: The present invention relates to novel vitamin D.sub.3 derivatives which have a carboxyl group or its ester group at the 22-position, processes for the preparation thereof, and antigens, which comprise said vitamin D.sub.3 derivative and an immunogenic carrier material, to be used for the preparation of antibodies for enzymeimmunoassay or radioimmunoassay and antibodies obtained therefrom.The determination of such activated vitamin D.sub.3 compounds as 25-hydroxy vitamin D.sub.3, 24, 25-dihydroxy vitamin D.sub.3, etc. can be made satisfactorily according to the present invention.

Abstract: A compound represented by the following formula ##STR1## wherein R.sup.1 represents a hydrogen atom, an acyl group or an alkoxycarbonyl group; X.sup.1 represents an alkylene group having 3 to 6 carbon atoms, a 1,4-cyclohexylene group, or a 1,4-phenylene group, the alkylene group may be substituted by an alkyl group having 1 to 6 carbon atoms, and the 1,4-phenylene group may be substituted by 1 or 2 substituents selected from halogen atoms and alkoxy groups having 1 to 6 carbon atoms; R.sup.2 represents a hydrogen atom or a hydroxyl group and R.sup.3 represents hydrogen atom, or R.sup.2 and R.sup.3 together may form an oxo group (.dbd.O), and when X.sup.1 is other than the 1,4-phenylene group, R.sup.2 represents a hydrogen atom and R.sup.3 represents a bond between the carbon atoms to which R.sup.3 is bonded and that carbon atom of X.sup.1 which is adjacent to said carbon atom; X.sup.

Abstract: The present invention relates to a novel process for the preparation of active-type vitamin D.sub.3 compounds and their intermediates. In accordance with the present invention, a large amount of an active-type vitamin D.sub.3 compounds, for example 1.alpha.-hydroxycholecalciferol, 1.alpha.,25-dihydroxycholecalciferol and the like, is efficiently prepared with high industrial advantages by a novel processes, which comprises (i) reacting hydroxycholesta-5-enes having the hydroxyl groups protected with lower alkoxycarbonyl group as a starting material with allylic brominating agent and dehydrobrominating agent to prepare the corresponding hydroxycholesta-5,7-dienes, (ii) exposing the hydroxycholesta-5,7-dienes to ultraviolet irradiation or to a combination of the irradiation with thermal isomerization to obtain a mixture of the unreacted hydroxycholesta-5,7-dienes and previtamin D.sub.3 compounds or a mixture of the unreacted hydroxycholesta-5,7-dienes and the protected active-type vitamin D.sub.

Abstract: A process for producing a steroid compound having an oxo group in the side chain, which comprises condensing an acid halide having a steroid skeleton with an organozinc compound at the halocarbonyl group of the acid halide in an inert organic medium in the presence of a catalytic amount of an ether capable of forming a complex with the organozinc compound, and if desired, hydrolyzing the product. The process produces the steroid compound at a high yield, and often at an almost quantitative yield. The steroid compound is an important intermediate for the production of vitamin D.sub.3 analogs such as active forms of vitamin D.sub.3. In one preferred embodiment, an industrially advantageous process from the standpoint of operation is provided.

Abstract: This invention relates to novel 25-hydroxy-24-oxocholestane derivatives and a process for preparing them.The novel 25-hydroxy-24-oxocholestane derivatives of this invention can easily be converted to 24,25-dihydroxycholecalciferol or 1.alpha.,24,25-trihydroxycholecalciferol which is known as useful for medicine controlling the calcium metabolism of warm-blooded animals. Moreover, 25-hydroxy-24-oxocholestane derivatives can be converted to novel 25-hydroxy-24-oxocholecalciferol expressed by the following formula ##STR1## and novel 1.alpha.,25-dihydroxy-24-oxocholecalciferol of the formula ##STR2## which are useful for medicine. The new 25-hydroxy-24-oxocholestane derivatives in the present invention are very useful as the intermediates for the synthesis of a variety of active vitamin D.sub.3.

Abstract: Novel 1.alpha.,3.beta.-dihydroxy-24-oxocholesta-5,7-diene and the hydroxyl group-protected derivatives thereof.Said novel 1.alpha.-hydroxy-24-oxovitamin D.sub.3 and said novel intermediates are also useful as the intermediates of 1.alpha.,24-dihydroxyvitamin D.sub.3.1.alpha.,3.beta.-Dihydroxy-24-oxocholesta-5,7-diene and the hydroxyl group-protected derivatives thereof are prepared from fucosterol via 1.alpha.,3.beta.-diprotected hydroxy-24(24)-ethylenedioxycholest-5-ene. 1.alpha.-hydroxy-24-oxovitamin D.sub.3 is prepared by irradiation with ultraviolet rays to 1.alpha.,3.beta.-dihydroxy-24-oxocholesta-5,7-diene or a hydroxyl group-protected derivatives thereof, isomerization using heat energy, and, when necessary, elimination of the protecting groups.

Abstract: Novel 1.alpha., 24-dihydroxycholecalciferol and derivatives thereof which are useful with reduced side-effects for the treatment of abnormal metabolism of calcium and phosphorus caused by liver failure, renal failure, gastrointestinal tract failure and parathyroid failure, and related bone diseases. Preparation of the novel 1.alpha., 24-dihydroxycholecalciferol and their derivatives starts from 1.alpha., 24-dihydroxycholesterol prepared by reacting 1.alpha., 2.alpha.-epoxy-24-keto-cholesta-4,6-dien-3-one with an alkali metal and a proton donor in the presence of liquid ammonia or a liquid amine. Reaction of the 1.alpha., 24-dihydroxycholesterol with an allylic brominating agent, followed by contacting with a dehydrobrominating agent, affords 1.alpha.,3.beta., 24-trihydroxycholesta-5,7-diene derivative, which can then be converted to 1.alpha., 24-dihydroxycholocalciferol by ultraviolet irradiation in a organic solvent, followed by isomerization. Processes are also provided for separating 1.alpha.

Abstract: A process for the preparation of desmosterol of which the hydroxyl group at the 3-position is protected, or bis-form derivatives thereof in high purity and with high yields, which comprises reacting 24-hydroxycholesterol of which the hydroxyl group at the 3-position is protected, or bis-form derivatives thereof, withA. phosphorus pentoxide or acid potassium sulfate, orB. phosphorus oxychloride, thionyl chloride, or sulfonyl chlorides, in the presence of tertiary amine.