Abstract: A lighting circuit according to embodiments includes: a self-hold element connected in series to an AC power source that generates power for lighting an illumination load, together with the illumination load, the self-hold element being configured to control supply of the power provided by the AC power source to the illumination load by the self-hold element being turned on/off; a noise prevention circuit connected in parallel to the self-hold element; and a damping circuit configured to connect a damping resistance to the noise prevention circuit parallely only for a predetermined period from turning-on of the self-hold element, thereby preventing the self-hold element from being repeatedly turned on/off during a period in which the self-hold element is on under normal conditions, due to a transient during power supply.

Abstract: Alighting system includes: a light-discharging portion configured to irradiate a space with light from a duct configured to propagate outside light; a light-diffusing portion disposed so as to cover the light-discharging portion and configured to diffuse light entering an incident surface and going out from a light-emitting surface facing the space; and a light source unit including a light source configured to emit light directed toward the incident surface of the light-diffusing portion. Accordingly, light emission of the light-emitting surface is controlled irrespective of the condition of the outside light and hence desired illumination is realized.

Abstract: According to one embodiment, an LED lighting device includes a DC source, a non-insulated step-down chopper and a light emitting diode. The non-insulated step-down chopper includes: a first circuit in which a switching element, a current detecting impedance element and an inductor are connected in series to each other; a second circuit in which the inductor and a freewheel diode are connected in series to each other; and a control portion for controlling the switching element. A power portion including the switching element and the control portion are constituted by a single package IC, and the current detecting impedance element and inductor are attached to the outside of the IC.

Abstract: There is provided an LED lighting device having a satisfactory temperature characteristic and a small amount of variation in output current. The step-down chopper is provided with a first circuit including the switching element, the impedance means and a first inductor connected in series and a second circuit including the first inductor and a diode connected in series. A self-excited drive signal generation circuit is provided with a second inductor magnetically coupled with the first inductor and applies a voltage induced in the second inductor to the switching element to keep the switching element on. A turn-off circuit outputs an output voltage when the voltage of the impedance means detected by a comparator exceeds the reference value, and the output voltage allows a switching element to turn on to short-circuit the output terminals of the self-excited drive signal generation circuit, resulting in that the switching element is turned off.

Abstract: An electrolytic capacitor includes: a case including a case body, in which an electrolytic capacitor element is disposed in a sealed manner and filled up with an electrolytic solution, and a safety valve is mounted to the case body for jetting an evaporated gas of the electrolytic solution filling the electrolytic capacitor element; a cover member mounted to the case so as to cover the safety valve provided for the case; a first fixing unit mounted to the cover member so as to prevent the cover member from dismounting when the evaporated gas of the electrolytic solution is jetted outward; and a second fixing unit disposed in association with the first fixing unit and adopted to reinforce and assist a function of the first fixing unit to thereby prevent the cover member from being dismounted. An electric equipment includes a lighting circuit including circuit components, and an electrolytic capacitor of the structure mentioned above.

Abstract: According to one embodiment, there is provided a lighting fixture including a fixture body, straight-tube type LED lamps each having semiconductor light emitting elements, and a dedicated power source for lighting the semiconductor light emitting elements. The dedicated power source outputs current having a trapezoidal waveform a period of a peak portion of which is 54% or more of one cycle, and thus lights the semiconductor light emitting elements.

Abstract: An LED lamp system which suppresses flickering of an LED element is provided. The LED lamp system includes straight-tube type LED lamps each having LED elements and a dedicated power source for lighting the LED elements. The dedicated power source full-wave rectifies and smoothes a commercial AC power source, outputs constant current having a ripple factor of 1.3 or smaller and thus lights the LED elements.

Abstract: According to one embodiment, an LED lighting device includes a DC source, a non-insulated step-down chopper and a light emitting diode. The non-insulated step-down chopper includes: a first circuit in which a switching element, a current detecting impedance element and an inductor are connected in series to each other; a second circuit in which the inductor and a freewheel diode are connected in series to each other; and a control portion for controlling the switching element. A power portion including the switching element and the control portion are constituted by a single package IC, and the current detecting impedance element and inductor are attached to the outside of the IC.

Abstract: A lighting circuit according to embodiments includes: a self-hold element connected in series to an AC power source that generates power for lighting an illumination load, together with the illumination load, the self-hold element being configured to control supply of the power provided by the AC power source to the illumination load by the self-hold element being turned on/off; a noise prevention circuit connected in parallel to the self-hold element; and a damping circuit configured to connect a damping resistance to the noise prevention circuit parallely only for a predetermined period from turning-on of the self-hold element, thereby preventing the self-hold element from being repeatedly turned on/off during a period in which the self-hold element is on under normal conditions, due to a transient during power supply.

Abstract: An electrolytic capacitor includes: a case including a case body, in which an electrolytic capacitor element is disposed in a sealed manner and filled up with an electrolytic solution, and a safety valve is mounted to the case body for jetting an evaporated gas of the electrolytic solution filling the electrolytic capacitor element; a cover member mounted to the case so as to cover the safety valve provided for the case; a first fixing unit mounted to the cover member so as to prevent the cover member from dismounting when the evaporated gas of the electrolytic solution is jetted outward; and a second fixing unit disposed in association with the first fixing unit and adopted to reinforce and assist a function of the first fixing unit to thereby prevent the cover member from being dismounted. An electric equipment includes a lighting circuit including circuit components, and an electrolytic capacitor of the structure mentioned above.

Abstract: There is provided an LED lighting device having a satisfactory temperature characteristic and a small amount of variation in output current. The step-down chopper is provided with a first circuit including the switching element, the impedance means and a first inductor connected in series and a second circuit including the first inductor and a diode connected in series. A self-excited drive signal generation circuit is provided with a second inductor magnetically coupled with the first inductor and applies a voltage induced in the second inductor to the switching element to keep the switching element on. A turn-off circuit outputs an output voltage when the voltage of the impedance means detected by a comparator exceeds the reference value, and the output voltage allows a switching element to turn on to short-circuit the output terminals of the self-excited drive signal generation circuit, resulting in that the switching element is turned off.

Abstract: The inverter circuit is feedback-controlled by a substantial current flowing into the discharge lamp, which is detected by the current detecting means. A high starting voltage is supplied to the discharge lamp with the operation frequency lowered by the control circuit after the end of a preheating action. The inverter circuit is controlled so that the current of the discharge lamp becomes a desired current value as soon as the current detecting means detects the current substantially flowing into the discharge lamp. The discharge lamp can be prevented from being instantaneously brightly lit without separately providing any structure for detecting lighting of the discharge lamp.

Abstract: The present invention provides a lighting device capable of controlling finely modulated light control without stopping other processing regardless of an operation clock. The light modulation signal generating portion calculates a cycle of a PWM signal based on the lighting state of lamp, which is detected by state detecting portion and a predetermined operation clock. A PWM signal of the cycle calculated by the state detecting portion is generated by the light modulation signal generating portion capable of generating the PWM signal corresponding to the cycle of a non-integral number of times of the operation clock, wherein the cycle of the PWM signal can be continuously and finely varied without stopping other processing regardless of operation clocks, and fine modulated light control is enabled.

Abstract: An electrical apparatus comprises a circuit board, providing an electrolytic condenser and electrical components, and a housing. The housing accommodates the circuit board. The electrical components include resin containing one or more halogen compounds of about 1% by weight or less in terms of bromine (Br).

Abstract: An electrical apparatus comprises a circuit board, providing an electrolytic condenser and electrical components, and a housing. The housing accommodates the circuit board. The electrical components include resin containing one or more halogen compounds of about 1% by weight or less in terms of bromine (Br).

Abstract: A power supply apparatus includes a direct current power source having a pair of terminals. First and second switching elements are connected in series between the pair of terminals of the direct current power. A load circuit, which includes a resonance inductance and a resonance capacitance, receives a high-frequency alternating current generated by a switching of the first and second switching elements. An unsaturated transformer has a first winding connected to the load circuit, and a second winding generating an induced voltage in proportion to a current flowing in the load circuit. A drive resonance circuit includes a capacitance, and an inductance of the second winding. The drive resonance circuit produces a resonance output to cause the first and second switching elements to alternately conduct. The power supply may be used in a ballast for a discharge lamp.

Abstract: A power supply apparatus includes a direct current power supply having a pair of terminals. First and second switching elements are connected in series between the pair of terminals of the direct current power. A load circuit, which includes a resonance inductance and a resonance capacitance, receives a high-frequency alternating current generated by a switching of the first and second switching elements. An unsaturated transformer has a first winding connected to the load circuit, and a second winding generating an induced voltage in proportion to a current flowing in the load circuit. A drive resonance circuit includes a capacitance, and an inductance of the second winding. The drive resonance circuit produces a resonance output to cause the first and second switching elements to alternately conduct. The power supply may be used in a ballast for a discharge lamp.

Abstract: The present invention provides self destruct arrangements for self ballasted fluorescent lamps and lighting fixtures using them. The ballast power supply includes at least one element that breaks down at high temperature. The lamp arrangements are constructed such that there is close proximity between at least one electrode of the lamp and the breakdown element of the ballast power supply. In one embodiment the breakdown element is a FET switch. In another embodiment, the breakdown element is a capacitor.

Abstract: A self ballasted fluorescent lamp includes a rectifier which full wave rectifies AC power from a commercial source. A smoothing capacitor smoothes the rectified power. The smoothed, rectified power is provided to a high frequency generating circuit which drives the fluorescent lamp. The capacitance value C of the smoothing capacitor is selected such that W.gtoreq..alpha.C, where W (in watts)is the rated service power of the fluorescent lamp, and .alpha. is related to a ratio of W to C0 (in .mu.F). C0 is a capacitance value of the smoothing capacitor for which the 5th harmonic component of the input current is 61% of the fundamental component of the input current when the fluorescent lamp operates under fixed conditions. When the above condition is met, the percentage of harmonic content falls within IEC standards, etc.

Abstract: An image forming apparatus includes a rotational body having a rotation shaft, marks provided on a circumferential surface of the rotational body at a predetermined positional interval each other, a rotational photoreceptor provided on the rotation shaft, a driving system to drive the photoreceptor, a light source to emit a light onto the marks, a line sensor having a plurality of pixels in a row in which each pixel outputs an electric signal in accordance with a light intensity of the light projected, an image formation lens to focus the light reflected from the marks onto the plurality of pixels of the line sensor, a detector to detect a rotational information of the photoreceptor on the basis of the electric signal obtained by the line sensor. The apparatus further includes a control circuit to control the drive system on the basis of the rotational information detected by the detector to control a rotation of the photoreceptor.