摘要:
A direct current output voltage is switched by two switching units and a current alternately changing directions is supplied to a primary winding of a transformer. An alternating voltage induced in a secondary winding of the transformer is rectified and smoothed, and is applied to a control circuit. A bidirectional switching unit is connected in parallel with the primary winding, and is controlled by the control circuit so that the primary winding is short-circuited by the bidirectional switching unit and an exciting energy of the transformer is held continuously.
摘要:
The present invention provides a battery-driven electronic device for which a long time use of the battery can be achieved and mobile communications equipment such as a portable telephone. Even if the time at which the output voltage of a battery 201 becomes below the supply voltage required by a load 206 including a power amplifier for wireless communications comes earlier than a conventional lithium ion battery because of its discharge characteristics that the battery voltage change ratio is 0.25 or more, a step-up and -down converter 200 operates as follows. When the output voltage of the battery is higher than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-down operation mode. When the output voltage of the battery is decreased and becomes lower than the supply voltage required by the load, the voltage is set to a predetermined supply voltage by the step-up operation mode. Thus, even for a battery employing a new material having a high energy density, a long term use of the battery can be achieved.
摘要:
In a DC-DC converter equipped with an operation mode (standby operation mode) which is only for reducing consumption power in a light load state such as at the time of a start-up, there is an output power dive detecting circuit disposed which outputs a result of a comparison of an upper limit output voltage E1, which is higher a predetermined voltage than a target output voltage E0, with an output DC voltage Vo. The DC-DC converter does not enter the standby operation mode when the output DC voltage Vo is higher than the upper limit output voltage E1, which greatly improves a response speed at which the output DC voltage Vo efficiently reaches the target output voltage E0.
摘要:
A switching power supply device which includes a series circuit constituted by a first switching element which is connected to an input voltage and which is at least repeatedly turned on and off and a second switching element which is repeatedly turned on and off alternating with the first switching element. A first capacitor is connected to one end of the second switching element. A transformer having a primary winding is connected to the second switching element and the first capacitor. A series circuit constituted by a second capacitor and a rectifier diode is connected across the secondary winding of the transformer, and a series circuit constituted by an inductance element and a smoothing capacitor is connected across the rectifier diode. A control circuit controls the turning on and off of the first and second switching elements based on the voltage across the smoothing capacitor. The voltage across the smoothing capacitor is supplied as the output.
摘要:
A switching power supply supplies a regulated output voltage for an electronic apparatus in industrial or commercial use and suppresses generation of a spike voltage and a spike current due to a transformer, and a recovery voltage of a rectifying diode due to switching and it results in reduction of noise interference and power loss. A series connection of a first switching means and a second switching means repeating on/off action alternately is connected to a d-c source. A series connection of a first capacitor and a primary winding of a transformer is connected in parallel with the second switching means. An induced voltage in a secondary winding is supplied to an output through a rectifying/filtering means. A series resonance current in a closed circuit comprising the first capacitor and a leakage inductance suppresses spike voltage, spike current, and recovery voltage of the rectifying diode.
摘要:
Disclosed is a switching power source device for supplying a DC stabilized voltage to industrial or household electronic appliances. The power source device can restrict a change in the switching frequency due to the change in load so that low noise and high efficiency can be realized. The power source device includes a first rectifying and smoothing circuit and a second rectifying and smoothing circuit. The first rectifying and smoothing circuit includes a rectifying diode and a smoothing capacitor. The second rectifying and smoothing circuit includes a rectifying diode and a smoothing capacitor. In a closed circuit composed of the first rectifying and smoothing circuit and second rectifying and smoothing circuit which are connected by a transformer, leakage inductance between the primary winding and secondary winding of the transformer is caused to resonate with the first or second rectifying and smoothing circuit so that a resonance current due to the resonance is taken as the current from the secondary winding to restrict occurrence of noise.
摘要:
The present invention provides a multilayer ceramic capacitor in which electrode metal layers and dielectric ceramic layers are laminated alternately and its dielectric constant peak is present at a temperature below −50° C. The multilayer ceramic capacitor is at least one selected from a multilayer ceramic capacitor to be incorporated into an electric circuit in which an electric field of at least 200 V/mm is applied to dielectric layers as a DC bias electric field and an alternating current at a frequency of at least 20 kHz is superimposed and a multilayer ceramic capacitor to be incorporated into an electric circuit in which an electric field of at least 200 V/mm is applied to dielectric layers as an AC electric field. As the dielectric ceramic, a ceramic containing lead atoms whose amount is indicated by being measured in the form of PbO, which is at least 30 mol %, particularly a compound with a perovskite structure represented by ABO3 is used. Thus, an inexpensive large-capacity multilayer capacitor that has thermal resistance and is stable for a high DC bias voltage and a high frequency voltage, and a low loss switching power supply using this capacitor can be provided.
摘要:
A switching power supply supplies a regulated output voltage and suppresses spike voltage and spike current generated by a switching action of transformers, and suppresses switching frequency drift due to load variation. Output stability of multi-output design is improved and recovery of rectifying diodes by a current resonance are suppressed. A reduction of noise interference to electronic equipments and power loss in the switching power supply itself results. A series connection of a primary winding of a first transformer and a first switching means, which repeats an on/off action is connected across a d-c power source. A series connection of a second switching means, which repeats an on/off action alternately with the first switching means, and a first capacitor is connected in parallel with the primary winding of the first transformer. A series connection of a primary winding of the second transformer and a second capacitor is connected in parallel with the second switching means. Regulated d-c outputs are taken out from each secondary winding of the transformers through rectifiers/filters. A control circuit supplies on/off signals, which on/off-ratios are varied according to one of the regulated d-c outputs, to the first and the second switching means.
摘要:
It is to provide photodynamic therapy (PDT) and photodynamic diagnosis (PDD) which are suitable for the diagnosis and therapy of a part requiring a certain degree of deep penetration, such as subcutaneous cancer and lymph nodes surrounded by blood vessels and fat. This is solved by performing PDT and PDD targeting cancer by administering a composition comprising a photosensitizing agent such as a tetrapyrrole-based compound (photofrin, protoporphyrin IX, etc.) or ALAs such as 5-aminolevulinic acid (ALA), ALA methyl ester, ALA ethyl ester, ALA propyl ester, ALA butyl ester, ALA pentyl ester, or a hydrochloride, phosphate, or sulfate thereof followed by irradiation with excitation light at a wavelength of 480 to 580 nm.
摘要:
A high-precision slide bearing includes a substrate of sintered metal and a synthetic resin layer. The bearing can be used for rotary shafts in compressors of room air-conditioners or in transmissions of motor vehicles and construction machines to support relatively large radial and axial loads. The resin layer is integrally superposed on the radially inner surface of the sintered metal substrate of the slide bearing, which is a cylindrical member. The resin layer is made of a resin composition of an aromatic polyetherketone resin containing a fibrous filler. The fibrous filler is made up of fibers dispersed in the resin layer and oriented such that their length directions intersect the rotational direction of the bearing at angles of 45 to 90 degrees. The resin layer has a thickness of 0.1 to 0.7 mm.