Abstract: A DC converter includes a time difference detector to detect a time difference between a point around which a main switch provides a minimum voltage after an auxiliary switch turns off and a point at which the main switch turns on, an integrator to integrate the output of the time difference detector, and a first delay circuit to control a turn-on point of the main switch according to the output of the integrator and the output of the time difference detector. The first delay circuit operates to minimize the output of the time difference detector according to the output of the integrator and controls a turn-on point of the main switch in a pulse-by-pulse manner according to a pulse-by-pulse control signal based on the output of the time difference detector.

Abstract: A DC converter has a transformer with loosely coupled primary and secondary windings, a main switch connected in series with the primary winding of the transformer, and a series circuit connected to ends of one of the primary winding and main switch. The series circuit includes a clamp capacitor and an auxiliary switch. The main and auxiliary switches are alternately turned on/off so that a voltage of the secondary winding of the transformer is synchronously rectified with synchronous rectifiers and is smoothed with smoothing elements, to provide a DC output. The DC converter also includes a tertiary winding tightly coupled with the primary winding of the transformer, a voltage source to supply a voltage lower than a voltage generated by the tertiary winding of the transformer, and clamp diodes to clamp the voltage generated by the tertiary winding with the use of the voltage source. The clamp diodes provide voltage-clamped signals to drive the synchronous rectifiers.

Abstract: The object of the present invention is to provide a fuel cell vehicle capable of generating running noise that does not feel unnatural based on the driving situation by noting and effectively utilizing the fact that a muffling section is provided on a gas piping line of a fuel cell system. In a fuel cell vehicle (1) in which a fuel cell system (3) equipped with a muffling section (20) on a gas piping line (5) is mounted, the muffling capability of the muffling section (20) is variable based on the driving situation of the fuel cell vehicle (1). In a low-speed driving situation, the muffling capability of the muffling section (20) is lowered. For example, the muffling section (20) has a direction control valve (24) that changes over between a muffler (21) and a bypass passage (23), based on the driving situation. The direction control valve (24) may be mechanically operated based on the gas flow speed, or its changeover operation may be controlled by means of a control device (51).

Abstract: Provided is a direct-current converter which can reduce power consumption at light load by reducing switching losses of a main switch. The direct-current converter is provided with: a first serial circuit which is connected to both ends of a direct current power supply Vdc1 and in which a primary winding P of a transformer T and a main switch Q1 are serially connected to each other; a second serial circuit which is connected both ends of the primary winding P of the transformer T and in which an auxiliary switch Q2 and a snubber capacitor C2 are serially connected to each other; rectifying/smoothing circuits D5, D6, L1 and C5 which rectify and smooth a voltage generated in a secondary winding S of the transformer T by energy supplied from the primary winding P of the transformer T when the main switch Q1 is turned on; and a control circuit 10 which turns on/off the main switch Q1 and the auxiliary switch Q2 alternately using a signal with predetermined switching frequency.

Abstract: A DC converter has a main switch connected in series to a primary winding of a transformer, and a series circuit of a capacitor and an auxiliary switch that is connected to both ends of the primary winding of the transformer or to both ends of the main switch, and also rectifies and smoothes a voltage of a secondary winding of the transformer to provide a DC output by alternate ON/OFF operations of the main switch and the auxiliary switch. This DC converter includes an error detector that detects an error by comparing the DC output to a reference voltage, a control circuit that controls ON/OFF of the main switch and the auxiliary switch based on the error detected by the error detector, and an activator that activates the control circuit by supplying, as power, an output of a joint of the auxiliary switch and a capacitor to the control circuit.

Abstract: A DC conversion apparatus includes a switch converting a DC voltage of a DC power source to a high-frequency voltage by being turned ON/OFF via a primary winding of a transformer, a series circuit of a switch and a clamp capacitor being connected to both ends of the primary winding, a synchronous rectifying circuit performing synchronous rectification of a high-frequency voltage generated at a secondary winding, a smoothing circuit smoothing a rectified output of the synchronous rectifying circuit by a smoothing reactor and a smoothing capacitor, a capacitor storing energy stored in the smoothing reactor due to a current backflow of the synchronous rectifying circuit caused under light load condition, a switch being turned ON in synchronization with the switch and returning the energy stored in the capacitor to the clamp capacitor on the primary side via the transformer, and a control circuit turning the switch and the switch ON/OFF states alternately.

Abstract: A DC converter alternately turns on and off a main switch Q1 connected in series with a primary winding P1 of a transformer T and a sub-switch Q2 contained in a series circuit connected to each end of the primary winding P1 of the transformer T or to each end of the main switch Q1, rectifies and smoothes a voltage of a secondary winding S1 of the transformer T, and provides a DC output. The DC converter includes a time difference detection circuit 13 to detect an interval between when the main switch Q1 reaches a minimum voltage after the sub-switch Q2 is turned off and when the main switch Q1 is turned on and a first delay circuit 14 to delay the ON timing of the main switch Q1 according to an output from the time difference detection circuit 13 so that the main switch Q1 is turned on at around the minimum voltage.

Abstract: A DC converter includes a time difference detector to detect a time difference between a point around which a main switch provides a minimum voltage after an auxiliary switch turns off and a point at which the main switch turns on, an integrator to integrate the output of the time difference detector, and a first delay circuit to control a turn-on point of the main switch according to the output of the integrator and the output of the time difference detector. The first delay circuit operates to minimize the output of the time difference detector according to the output of the integrator and controls a turn-on point of the main switch in a pulse-by-pulse manner according to a pulse-by-pulse control signal based on the output of the time difference detector.

Abstract: A DC converter has a transformer with loosely coupled primary and secondary windings, a main switch connected in series with the primary winding of the transformer, and a series circuit connected to ends of one of the primary winding and main switch. The series circuit includes a clamp capacitor and an auxiliary switch. The main and auxiliary switches are alternately turned on/off so that a voltage of the secondary winding of the transformer is synchronously rectified with synchronous rectifiers and is smoothed with smoothing elements, to provide a DC output. The DC converter also includes a tertiary winding provided for the transformer, tightly coupled with the primary winding, and configured to generate a voltage that drives the synchronous rectifiers.

Abstract: A DC converter has a transformer with loosely coupled primary and secondary windings, a main switch connected in series with the primary winding of the transformer, and a series circuit connected to ends of one of the primary winding and main switch. The series circuit includes a clamp capacitor and an auxiliary switch. The main and auxiliary switches are alternately turned on/off so that a voltage of the secondary winding of the transformer is synchronously rectified with synchronous rectifiers and is smoothed with smoothing elements, to provide a DC output. The DC converter also includes a tertiary winding tightly coupled with the primary winding of the transformer, a voltage source to supply a voltage lower than a voltage generated by the tertiary winding of the transformer, and clamp diodes to clamp the voltage generated by the tertiary winding with the use of the voltage source. The clamp diodes provide voltage-clamped signals to drive the synchronous rectifiers.

Abstract: What is provided is a direct-current converter which improves unstableness of operations owing to an error of a bottom detection circuit and fluctuations of a detection point which are caused by disturbance.

Abstract: A DC converter has a main switch connected in series to a primary winding of a transformer, and a series circuit of a capacitor and an auxiliary switch that is connected to both ends of the primary winding of the transformer or to both ends of the main switch, and also rectifies and smoothes a voltage of a secondary winding of the transformer to provide a DC output by alternate ON/OFF operations of the main switch and the auxiliary switch. This DC converter includes an error detector that detects an error by comparing the DC output to a reference voltage, a control circuit that controls ON/OFF of the main switch and the auxiliary switch based on the error detected by the error detector, and an activator that activates the control circuit by supplying, as power, an output of a joint of the auxiliary switch and a capacitor to the control circuit.

Abstract: A DC conversion apparatus includes a switch converting a DC voltage of a DC power source to a high-frequency voltage by being turned ON/OFF via a primary winding of a transformer, a series circuit of a switch and a clamp capacitor being connected to both ends of the primary winding, a synchronous rectifying circuit performing synchronous rectification of a high-frequency voltage generated at a secondary winding, a smoothing circuit smoothing a rectified output of the synchronous rectifying circuit by a smoothing reactor and a smoothing capacitor, a capacitor storing energy stored in the smoothing reactor due to a current backflow of the synchronous rectifying circuit caused under light load condition, a switch being turned ON in synchronization with the switch and returning the energy stored in the capacitor to the clamp capacitor on the primary side via the transformer, and a control circuit turning the switch and the switch ON/OFF states alternately.

Abstract: Provided is a direct-current converter which can reduce power consumption at light load by reducing switching losses of a main switch. The direct-current converter is provided with: a first serial circuit which is connected to both ends of a direct current power supply Vdc1 and in which a primary winding P of a transformer T and a main switch Q1 are serially connected to each other; a second serial circuit which is connected both ends of the primary winding P of the transformer T and in which an auxiliary switch Q2 and a snubber capacitor C2 are serially connected to each other; rectifying/smoothing circuits D5, D6, L1 and C5 which rectify and smooth a voltage generated in a secondary winding S of the transformer T by energy supplied from the primary winding P of the transformer T when the main switch Q1 is turned on; and a control circuit 10 which turns on/off the main switch Q1 and the auxiliary switch Q2 alternately using a signal with predetermined switching frequency.

Abstract: What is provided is a direct-current converter which improves unstableness of operations owing to an error of a bottom detection circuit and fluctuations of a detection point which are caused by disturbance.

Abstract: A fire-resistant heat insulating material excellent in resistance to heat, resistance to slag, resistance to molten iron, resistance to wear, and resistance to mechanical impulse is provided. A highly endurable heat insulating material characterized by being provided on the surface of a layer of inorganic heat insulating fibers through the medium of a coating film of surface hardening material with a flame sprayed film of a fire-resistant ceramic substance.

Abstract: A fire-resistant heat insulating material excellent in resistance to heat, resistance to slag, resistance to molten iron, resistance to wear, and resistance to mechanical impulse is provided. A highly endurable heat insulating material characterized by being provided on the surface of a layer of inorganic heat insulating fibers through the medium of a coating film of surface hardening material with a flame sprayed film of a fire-resistant ceramic substance.

Abstract: The present invention provides a refractory and heat insulating material excellent in heat resistance, slag resistance, molten steel resistance, wear resistance, and mechanical impact resistance, and relates to a highly durable heat insulating material characterized by having a thermally sprayed film of refractory ceramic on a surface of a formed body of an inorganic refractory fiber which surface is covered with a cloth material or was covered with the cloth material until it burned out by flame fusion coating of refractory ceramic powder material during the fabricating process of the heat insulating material, with an application film of a surface hardening material acting as an intermediary layer between the thermally sprayed film and the fiber body.

Abstract: Fluid containing organic substances, which has not processed yet, is fed to a plurality of cylinders, using a slurry pump. A free piston is included in each cylinder, the fluid which has not yet been processed is introduced into one of two chambers in the cylinder partitioned by the piston, and processed high-pressure fluid which has been processed is introduced into the other one of the two chamber in the cylinder. The piston pressurizes the fluid with which the cylinder has been filled up. A pressure holding valve is provided in a processed high-pressure fluid system to pressurize an organic substance processing system, and this pressure holding valve suppresses changes in the pressure in the processed high-pressure fluid system.

Abstract: A novel urethane compound utilized as a raw material of block isocyanate, diisocyanate, developing agent for thermosensible paper, powder paint and the like is provided, and it is a biscarbamate represented by the following general formula (1): (wherein, R1 and R2 may be the same or different and represent a straight or branched alkyl group, (substituted) cycloalkyl group or (substituted) aryl group.). Further disclosed is a method for producing a polycyclic aliphatic diisocyanate by thermally-decomposing a biscarbamate represented by the general formula (1).