Abstract: An AC-DC converter is provided which suppresses a harmonic current and improves power factor at low cost. Such an AC-DC converter includes a rectifier connected to an AC power supply via a reactor, capacitors connected in series across the output terminals of the rectifier, a first bidirectional switch having one end connected to one input terminal of the rectifier and the other end connected to a connecting point of capacitors, a second bidirectional switch having one end connected to the other input terminal of the rectifier and the other end connected to the other end of the first bidirectional switch, and a control circuit for actuating the first and second bidirectional switches during a half cycle of the AC power supply so as to control a voltage inputted to the rectifier to a desired output voltage.

Abstract: The present invention relates to a method of surface-treating an aluminum heat exchanger for vehicles in which a sufficient amount of photocatalytic metal oxide particles are retained on a surface of the heat exchanger in a state capable of exhibiting a photocatalytic activity thereof to remove VOC in a compartment of the vehicles by irradiating an ultraviolet ray thereto in an efficient manner. The method of surface-treating an aluminum heat exchanger for vehicles according to the present invention includes (1) a step of dispersing photocatalytic metal oxide particles whose surface is modified with apatite in an aqueous solution in which a low-temperature heat-decomposable resin is dissolved, to prepare a slurry; (2) a step of applying the slurry onto a surface of the heat exchanger; and (3) a step of drying the heat exchanger at a temperature of from 150 to 280° C. to decompose and remove a part of the low-temperature heat-decomposable resin on the surface of the photocatalytic metal oxide particles.

Abstract: A fuel pump includes a pump part, a motor part, two brushes, two pigtails, and an urging member. Each pigtail is made of a linear conductive member and includes one end portion electrically and mechanically connected to its corresponding brush. The urging member includes one end engaged with a motor casing, and the other end pressing and urging each brush against a commutator from its other axial end face. A distance between an inclined surface of the brush and a sliding surface of the commutator in an axial direction of the brush becomes longer toward a rear side of the brush in a rotation direction of the commutator. A side surface of each brush and an inner wall of the motor casing, which defines two brush accommodating chambers, define a clearance therebetween. Each pigtail includes an extension portion extending from its one end portion toward the rear side in the rotation direction of the commutator.

Abstract: An AC-DC converter is provided which suppresses a harmonic current and improves power factor at low cost. Such an AC-DC converter includes a rectifier connected to an AC power supply via a reactor, capacitors connected in series across the output terminals of the rectifier, a first bidirectional switch having one end connected to one input terminal of the rectifier and the other end connected to a connecting point of capacitors, a second bidirectional switch having one end connected to the other input terminal of the rectifier and the other end connected to the other end of the first bidirectional switch, and a control circuit for actuating the first and second bidirectional switches during a half cycle of the AC power supply so as to control a voltage inputted to the rectifier to a desired output voltage.

Abstract: Provided are, a converter section (30) which converts a commercial AC voltage (VAC) into a DC voltage (VDC); an inverter section (60) which converts the DC voltage (VDC) into an output AC voltage (VOUT) of a predetermined frequency by a pulse-width modulation system based on an assigned PWM width, and supplies the output AC voltage (VOUT) to a compressor motor (70). Further, an instantaneous DC voltage detecting section (50) detects an instantaneous DC voltage (VDCS); and an arithmetic processing section (100) corrects the PWM width so as to maintain the output AC voltage (VOUT) at a desired value following the variation in the instantaneous DC voltage (VDCS). It is possible to operate a compressor motor (70) in an optimum state of load characteristics and efficiency.

Abstract: Provided are, a converter section (30) which converts a commercial AC voltage (VAC) into a DC voltage (VDC); an inverter section (60) which converts the DC voltage (VDC) into an output AC voltage (VOUT) of a predetermined frequency by a pulse-width modulation system based on an assigned PWM width, and supplies the output AC voltage (VOUT) to a compressor motor (70). Further, an instantaneous DC voltage detecting section (50) detects an instantaneous DC voltage (VDCS); and an arithmetic processing section (100) corrects the PWM width so as to maintain the output AC voltage (VOUT) at a desired value following the variation in the instantaneous DC voltage (VDCS). It is possible to operate a compressor motor (70) in an optimum state of load characteristics and efficiency.

Abstract: An apparatus which secures a heat sink to an electrical component connected to a circuit board, including a first outer cover which engages a portion of the heat sink and a portion of the circuit board. In addition, the first outer cover encloses the electrical component, and the electrical component has at least two pins, a first surface facing the circuit board, and a second surface facing the heat sink. Further, a majority of heat dissipating surfaces of the heat sink are outside a space enclosed by the first outer cover and the circuit board.

Abstract: A compact indoor air conditioner may be produced by mounting a fan unit within the installation space of a heat exchanger inside the housing of the air conditioner. An air conditioner having such structure comprises a housing comprising a frame body, a front cover attached to the front of the frame body and having air inlets in the upper surface and in the front and an air outlet in the front lower part, a suction grille that is attached detachably to the front cover and which can be opened or closed, a heat exchanger disposed in the housing and having two cut-out portions defining an upright section, a rearward inclined section and a forward inclined section, wherein the rearward inclined section and the forward inclined section comprise the upper part of the heat exchanger and have an inverted V-shape, and a fan disposed rearward of the upright section and rearward inclined section of the heat exchanger.

Abstract: A method of chemically converting metal surfaces of a combination of iron steel and/or galvanized steel and an aluminum alloy with a phosphate solution satisfying the following conditions:2.0.ltoreq.Na ion+K ion.ltoreq.15.0 (g/l)1.0.ltoreq.Mn ion+Ni ion.ltoreq.5.0 (g/l)1.6-0.02T.ltoreq.Zn ion.ltoreq.2.5-0.02T (g/l)3.2T.sup.-1 .ltoreq.free F ion.ltoreq.8.0T.sup.-1 (g/l)0.014T-0.02(free F ion).sup.-1 .ltoreq.free acidity.ltoreq.0.027T-0.02(free F ion ).sup.-1 (g/l)where T represents a treatment solution temperature (.degree. C.).

Abstract: A prescribed amount of a simple fluoride is added to a zinc phosphate treatment solution, which is a target solution, the HF concentration in the target solution is measured with a silicon electrode meter after the addition, and the concentration of the consumed HF is calculated to evaluate the activity of the target solution, for adding the simple fluoride to the zinc phosphate treatment solution so that its activity is in a control reference range.

Abstract: The degreasing composition comprises a surfactant composition comprising a compound (a) represented by the general formula (1):R.sup.1 O(AO).sub.n H (1)wherein R.sup.1 is a substituted or unsubstituted hydrocarbon group having 6 or more carbon atoms; A is at least one group selected from the group consisting of an ethylene group, a propylene group, a butylene group and a styrene group, provided that an ethylene group in A is 5 mol or more per 1 mol of R.sup.1, and that the ethylene group is 50 mol % or more per 100 mol % of said A; and n is an integer of 5-50;a compound (b1) represented by the general formula (2): ##STR1## wherein R.sup.2 is a substituted or unsubstituted hydrocarbon group having 6 or more carbon atoms, E is an ethylene group, and n is an integer of 1-20; and a compound (b2) represented by the general formula (3): ##STR2## wherein R.sup.

Abstract: A method for treating a metal surface with zinc phosphate of this invention can treat an iron-based surface, a zinc-based surface, an aluminum-based surface as well as a metal surface having two kinds or more of these surfaces with the same zinc phosphate treating solution, and even if treating times increases, the method makes it possible to form a coating film having superior adhesion and high corrosion resistance under a stable condition, and also, it prevents a precipitate formed by a metal ion eluted from a metal surface to be treated, especially, by an aluminum ion. A complex fluoride compound contained in said zinc phosphate treating solution of coming in contact with a metal surface is added so that a concentration (unit: g/l) converted into at least one of a hexafluorosilicic acid group (SiF.sub.6.sup.2-) and a tetrafluoroboric acid group (BF.sub.4.sup.-), with an aluminum ion concentration (unit: g/l) contained in said treating solution, is satisfactory for the following equation (I).