Abstract: An apparatus for diagnosing abnormal operation of a rotor. The apparatus includes a first sensor provided around a shaft in order to detect vibration occurring while the shaft provided in a rotor axially rotates, a second sensor to generate a periodic pulse signal over time whenever the shaft rotates once, and a controller to determine an operation state of the rotor by receiving signals detected by the first and second sensors. When an aperiodic pulse signal is detected in the rotor, the controller determines a position of the rotor at which the aperiodic pulse signal is generated, and a display indicates the position of the rotor in which the aperiodic pulse signal is generated, according to information calculated by the controller.

Abstract: An LED driver includes a transformer, current control loop and current adjustment circuit. The primary side of the transformer transfers energy to the secondary side of the transformer responsive to an input signal. The secondary side delivers output current to one or more LEDs at a magnitude corresponding to the amount of energy transferred to the secondary side. The current control loop controls current in the primary side so that the output current equals a reference current signal. The current adjustment circuit injects a current adjustment signal into the current control loop responsive to a phase-cut signal which removes a portion of the input signal. The current control loop also decreases the current in the primary side responsive to the current adjustment signal so that a brightness of each LED connected to the secondary side is decreased by an amount corresponding to the magnitude of the current adjustment signal.

Abstract: The present invention provides a driving circuit, a backlight module and a display apparatus using the same. The driving circuit comprises a first inductor, a second inductor, a first power switch, a second power switch, a driving circuit unit and a push-pull circuit. The first inductor and the second inductor are connected between the light-emitting diodes and a power supply. The first power switch is connected between the first inductor and the light-emitting diodes. The second power switch is connected between the second inductor and the light-emitting diodes. The push-pull circuit is connected to the first power switch and the second power switch. The driving circuit unit is connected to the push-pull circuit. An electrolytic capacitor or a capacitor having high capacitance can be omitted in this invention.

Abstract: A discharge lamp lighting apparatus for lighting a plurality of discharge lamps comprises: a control circuit adapted to output driving signals; a plurality of step-up transformers; and a plurality of bridge circuits, each of which is connected to a DC power supply, and drives the primary side of each of the step-up transformers according to the driving signals from the control circuit so as to light each of the discharge lamps connected respectively to the secondary sides of the step-up transformers. In the discharge lamp lighting apparatus, each of the bridge circuits is connected to the control circuit via synchronous switching elements, and the synchronous switching elements, according to each of synchronizing signals applied thereto, switch on and off the driving signals from the control circuit so as to controllably cause each of the bridge circuits to start and stop its operation.

Abstract: The selection of the dead time in the case of a half-bridge inverter influences the efficiency thereof. The optimal dead time, and thus the optimal switching-on time of a lower half-bridge transistor (T2) is accomplished according to the invention by virtue of the fact that switching on is delayed until the current in a level shift transistor (T3) has dropped below a given threshold. A further aspect of the invention consists in that the delay in switching on the lower half-bridge transistor (T2) is immediately suppressed whenever a charging current flows in a trapezoidal capacitor, and this is accompanied by the rise of the half-bridge output voltage (UHB) after the traversal of a minimum.

Abstract: A discharge-lamp illumination circuit has a DC power supply circuit, a DC-AC conversion circuit, and a control circuit for controlling a voltage from the DC power supply circuit. The DC power supply circuit has a transformer and a first switching element connected in series with a primary coil of the transformer. The activation/deactivation of the first switching element is controlled by the control signal from the control circuit. The transformer is equipped with secondary coils equal in number with the discharge lamps. Each secondary coil is equipped with a second switching element whose activation or deactivation is controlled by a signal from the control circuit. The secondary coils provide different voltages by means of control of the second switching elements.

Abstract: The magnitude and axial orientation of birefringence of the anterior and the posterior segments of the human eye are determined. The anterior segment includes essentially the combined birefringence of the cornea and the crystalline lens, and the posterior segment includes regions at the fundus. The optical axis and the magnitude of the birefringence of the anterior segment is first determined, then the birefringence of the posterior segment is nulled by a variable retarder. The birefringence of the posterior segment is then determined without interference of the birefringence of the anterior segment. The apparatus and method are applicable to the measurement of the birefringence of the retinal nerve fiber layer at the peripapillary region and the birefringence of the Henle fiber layer at the macular region of the retina.

Abstract: In a ballast circuit for operating a lamp, which comprises a bridge circuit and a control circuit for controlling the bridge switches, the control circuit comprises a microprocessor. The control signal for controlling the switches is generated by a separate circuit comprising a signal generator, a timer, two comparators and two reference signal generators. The microprocessor is used only to set the reference signals to the desired values, thereby dimming the lamp.

Abstract: An electronic ballast for a gas discharge lamp has a power source section for receiving a commercial AC to provide a DC voltage, and an inverter section, in response to a pair of switching driving signals, for switching and transforming an output voltage of the power source section at a high speed as an AC power source that is supplied to the gas discharge lamp. For controlling the switching of the inverter section, an inverter controlling section generates a pair of switching driving signals respectively having a predetermined dead time in a switching-ON time interval with a phase difference of 180 degrees from each other to supply them to the inverter section.

Abstract: The actuator is connected in series between the power supply and the flashing light. It includes a switch which is connected in series between the power supply and the flashing light so that when the switch is closed the light turns on and when the switch is open the light is turned off. A comparator controls the opening and closing of the switch at a frequency determined by an RC timer. Also, the duty cycle of the flashing light is controlled by the timer. A current overload protector lowers the duty cycle of the flashing light as the magnitude of the overload is increased and, in the event of a short circuit, decreases the duty cycle to approximately zero.