Abstract: A lighting apparatus includes a control circuit configured to control a power supply circuit such that a measurement value of an output current measured by a current measuring device approaches a target value. The control circuit is configured to execute a control mode alternatively selected from the plurality of control modes to control the power supply circuit. The plurality of control modes of the control circuit includes at least a first control mode and a second control mode. The first control mode is a control mode of adjusting the target value in accordance with a first direct-current voltage. The second control mode is a control mode which includes adjusting the target value regardless of the first direct-current voltage.

Abstract: A lighting apparatus includes a step-up converter, at least one step-down converter, and a controller. The step-up converter is configured to step up a voltage of a direct-current power supply to obtain an output voltage having a first voltage value and output the output voltage. The at least one step-down converter is configured to step down the output voltage of the step-up converter to have a second voltage value to output a current having a current value according to the second voltage value to a light source. The controller is configured to acquire information about a specification of the light source, control the step-down converter such that the current value becomes a current value according to the specification, and control the step-up converter such that the first voltage value changes in accordance with the specification.

Abstract: A lighting apparatus includes a control circuit configured to control a power supply circuit such that a measurement value of an output current measured by a current measuring device approaches a target value. The control circuit is configured to execute a control mode alternatively selected from the plurality of control modes to control the power supply circuit. The plurality of control modes of the control circuit includes at least a first control mode and a second control mode. The first control mode is a control mode of adjusting the target value in accordance with a first direct-current voltage. The second control mode is a control mode which includes adjusting the target value regardless of the first direct-current voltage.

Abstract: A power supply includes a casing including a heat-conducting material and having an inner surface and an outer surface. The casing is a one-piece component having a substantially tubular shape. The power supply also includes a circuit board disposed in the casing. The circuit board has a first surface on which one or more circuit components are mounted and a second surface on an opposing side of the first surface. The power supply also includes a first cover disposed over a first opening at a first end portion of the casing on a tubular axis, and a second cover disposed over a second opening at a second end portion of the casing on the tubular axis. The first surface of the circuit board faces the inner surface of the casing.

Abstract: A lighting device includes a current outputter, a load characteristic obtainer and a controller. The current outputter is configured to supply a current to a light source of at least one light source unit. The load characteristic obtainer is configured to obtain load information from a corresponding load information outputter of the at least one light source unit, by supplying the electric power to the load information outputter. The controller is configured to control the current of the current outputter, which is supplied to the light source, based on the load information. The load characteristic obtainer is configured to supply the electric power to the corresponding load information outputter only during a time period of obtaining the load information, but stop supply of the electric power to the corresponding load information outputter during a time period other than the time period of obtaining the load information.

Abstract: A lighting device includes a current outputter, a load characteristic obtainer and a controller. The current outputter is configured to supply a current to a light source of at least one light source unit. The load characteristic obtainer is configured to obtain load information from a corresponding load information outputter of the at least one light source unit, by supplying the electric power to the load information outputter. The controller is configured to control the current of the current outputter, which is supplied to the light source, based on the load information. The load characteristic obtainer is configured to supply the electric power to the corresponding load information outputter only during a time period of obtaining the load information, but stop supply of the electric power to the corresponding load information outputter during a time period other than the time period of obtaining the load information.

Abstract: An apparatus that creates, based on shape data of an object to be machined and grinding allowance data for the shape data, a numerically controlled machining program that has the grinding allowance data reflected in the shape data, is configured to include storing means 2 and 4 that store the shape data of the object to be machined and the grinding allowance data; a shape data modification means 5 that modifies the shape data to create, based on the grinding allowance data, shape data having a grinding allowance; and a numerically controlled machining program creation means 6 that creates a numerically controlled machining program for the modified shape data, with the apparatus enabling easy and efficient creation of a numerically controlled machining program having the grinding allowance reflected in the shape data.

Abstract: A lighting device includes: a power conversion unit which converts a direct current (DC) power into a power required by a load; an output current detection unit which detects an output current of the power conversion unit; and a source voltage detection unit which detects a source voltage. Further, the lighting device includes an operation unit which calculates an output current command value so as not to exceed an upper limit of the output current command value set according to a resistance value of an externally connected resistor; and a control unit which controls the power conversion unit such that the output current thereof the power conversion unit becomes the output current command value.

Abstract: In a power supply device according to the embodiment, a second capacitor is inserted between a terminal of a capacitor at the high voltage side and an input terminal. Therefore, when earth fault is occurred at an output terminal of the low voltage side, an input side connected to a DC power supply is galvanically separated from an output side connected to a load by the second capacitor. As a result, earth fault current does not flow continually. Accordingly, the power supply device can reduce current leakage flowing through circuit to zero or near zero in the case where electric leakage is occurred, and therefore can prevent problems (the circuit's malfunction or the like) associated with the electric leakage.

Abstract: An apparatus that creates, based on shape data of an object to be machined and grinding allowance data for the shape data, a numerically controlled machining program that has the grinding allowance data reflected in the shape data, is configured to include storing means 2 and 4 that store the shape data of the object to be machined and the grinding allowance data; a shape data modification means 5 that modifies the shape data to create, based on the grinding allowance data, shape data having a grinding allowance; and a numerically controlled machining program creation means 6 that creates a numerically controlled machining program for the modified shape data, with the apparatus enabling easy and efficient creation of a numerically controlled machining program having the grinding allowance reflected in the shape data.

Abstract: A lighting device includes: a power conversion unit which converts a direct current (DC) power into a power required by a load; an output current detection unit which detects an output current of the power conversion unit; and a source voltage detection unit which detects a source voltage. Further, the lighting device includes an operation unit which calculates an output current command value so as not to exceed an upper limit of the output current command value set according to a resistance value of an externally connected resistor; and a control unit which controls the power conversion unit such that the output current thereof the power conversion unit becomes the output current command value.

Abstract: A power supply device includes a series circuit including a first capacitor and a first and second inductors connected to both terminals of the first capacitor; a switching element having one terminal connected to a node between one terminal of the first inductor and the first capacitor; a rectifier having an anode connected to a node between the first capacitor and one terminal of the second inductor; and a second capacitor connected between the other terminal of the switching element and a cathode of the rectifier. Further, a DC power supply source is connected between the other terminal of the first inductor and the other terminal of the switching element such that the other terminal of the first inductor is connected to a positive electrode side of the DC power supply source. A load is connected between the other terminal of the second inductor and the cathode of the rectifier.

Abstract: An LED driver circuit is provided for protecting one (or more) LEDs connected in series from over-current damages which may result from a short circuit condition. The driver circuit includes a current control circuit for receiving an input signal from a power source and providing a current output for powering the LED. A voltage sensor detects a voltage across the LED. An LED current restriction circuit such as a switching element restricts a current flow into the LED. A short circuit response circuit controls the LED current restriction circuit dependent on a comparison between the voltage detected by the voltage sensor and a predetermined threshold value. When the detected voltage is less than or equal to the threshold value, the response circuit determines a short circuit, and a signal is sent to the current restriction circuit to restrict current flow into the one or more LEDs.

Abstract: An LED driver circuit is provided for protecting one (or more) LEDs connected in series from over-current damages which may result from a short circuit condition. The driver circuit includes a current control circuit for receiving an input signal from a power source and providing a current output for powering the LED. A voltage sensor detects a voltage across the LED. An LED current restriction circuit such as a switching element restricts a current flow into the LED. A short circuit response circuit controls the LED current restriction circuit dependent on a comparison between the voltage detected by the voltage sensor and a predetermined threshold value. When the detected voltage is less than or equal to the threshold value, the response circuit determines a short circuit, and a signal is sent to the current restriction circuit to restrict current flow into the one or more LEDs.

Abstract: A DC-DC converter reduces a surge voltage developed across a switching element (30) in making the voltage conversion with the use of a transformer (20) inherently having considerable leakage. A snubber circuit is included to absorb the surge energy and transferring it to a load, or output end of the converter, reducing the surge voltage across the switching element (30). A snubber capacitor (51) is provided to absorb the surge energy developed by the transformer (20) when the switching element (30) is off. Thus absorbed energy is collected in a storage capacitor (53) through a reactor (54) while the switching element (30) is on and off, and is then transferred from the storage capacitor (53) to the load, i.e., the output side of the converter, leaving only a minimum voltage being applied across the switching element (30).

Abstract: A DC-DC converter reduces a surge voltage developed across a switching element (30) in making the voltage conversion with the use of a transformer (20) inherently having considerable leakage. A snubber circuit is included to absorb the surge energy and transferring it to a load, or output end of the converter, reducing the surge voltage across the switching element (30). A snubber capacitor (51) is provided to absorb the surge energy developed by the transformer (20) when the switching element (30 ) is off. Thus absorbed energy is collected in a storage capacitor (53) through a reactor (54) while the switching element (30) is on and off, and is then transferred from the storage capacitor (53) to the load, i.e., the output side of the converter, leaving only a minimum voltage being applied across the switching element (30).

Abstract: An electronic ballast for a discharge lamp has a controller that increase luminous flux of the lamp to a stabilized level in a constant time irrespective of possible variations in lamp characteristic. The controller utilizes a reference lamp power table and a reference lamp voltage table respectively defining a reference lamp power and a reference voltage varying with time. The controller includes a voltage deviation detector that gives a voltage correction index indicating a voltage deviation between the reference voltage and a monitored lamp voltage. The voltage correction index is processed at an offset provider that gives an offset power. A target power generator is included to correct the reference lamp power in view of the offset power, thereby generating a target lamp power which is constantly updated and is supplied to the lamp.

Abstract: An improved ballast for a discharge lamp includes a DC—DC converter which receives an input DC voltage from a voltage source to provide a pre-starting voltage to make the lamp ready for being ignited or started. The DC—DC converter has a switching element which is driven to turn on and off for generating the pre-starting voltage. A start-accelerating means in included in the ballast in order to vary at least one of the switching frequency and the on-period of the switching element based upon the monitored input DC voltage in a direction of accelerating the increase of the output DC voltage to the pre-starting voltage until the output DC voltage reaches the pre-starting voltage.

Abstract: An electronic ballast for a discharge lamp has a controller that increase luminous flux of the lamp to a stabilized level in a constant time irrespective of possible variations in lamp characteristic. The controller utilizes a reference lamp power table and a reference lamp voltage table respectively defining a reference lamp power and a reference voltage varying with time. The controller includes a voltage deviation detector that gives a voltage correction index indicating a voltage deviation between the reference voltage and a monitored lamp voltage. The voltage correction index is processed at an offset provider that gives an offset power. A target power generator is included to correct the reference lamp power in view of the offset power, thereby generating a target lamp power which is constantly updated and is supplied to the lamp.

Abstract: A ballast for a discharge lamp includes a DC-DC converter which provides a regulated DC output so as to start and keep operating the lamp. A controller is included to give a closed-loop control for regulating the DC output based upon a monitored DC output. The controller also provides an open-loop control which interrupts the closed-loop control for a limited period immediately after the initiation of the lamp discharge in order to supplement a sufficient lamp current which would not expected with the closed-loop control, thereby successfully complementing the lamp start and proceeding to the stable lamp operation.