Abstract: Embodiments of the present disclosure relate to an emergency inverter and an emergency lighting system. The emergency inverter comprises a power detecting module and a dimming signal generating module. The power detecting module is configured to detect an output power of the emergency inverter in an emergency state. The dimming signal generating module is coupled to the power detection module and configured to generate a dimming signal based on the output power of the emergency inverter in the emergency state.

Abstract: Embodiments of the present disclosure relate to an emergency inverter and an emergency lighting system. The emergency inverter comprises a power detecting module and a dimming signal generating module. The power detecting module is configured to detect an output power of the emergency inverter in an emergency state. The dimming signal generating module is coupled to the power detection module and configured to generate a dimming signal based on the output power of the emergency inverter in the emergency state.

Abstract: An electronic ballast with dimming circuit including an electronic ballast dimming circuit receiving an analog dimming signal, the electronic ballast dimming circuit including an input dimming circuit (210) operable to receive the analog dimming signal (252) at an analog dimming signal input (212); and an output dimming circuit (220) operably connected to the input dimming circuit (210), the output dimming circuit (220) being operable to receive a fixed frequency signal (222) having a variable duty cycle and to generate an analog dimming control signal (224) in response to the analog dimming signal (252). Output voltage at the analog dimming signal input (212) is a function of the variable duty cycle of the fixed frequency signal (222) when the analog dimming signal (252) is not present at the analog dimming signal input (212).

Abstract: An electronic ballast with dimming circuit including an electronic ballast dimming circuit receiving an analog dimming signal, the electronic ballast dimming circuit including an input dimming circuit (210) operable to receive the analog dimming signal (252) at an analog dimming signal input (212); and an output dimming circuit (220) operably connected to the input dimming circuit (210), the output dimming circuit (220) being operable to receive a fixed frequency signal (222) having a variable duty cycle and to generate an analog dimming control signal (224) in response to the analog dimming signal (252). Output voltage at the analog dimming signal input (212) is a function of the variable duty cycle of the fixed frequency signal (222) when the analog dimming signal (252) is not present at the analog dimming signal input (212).

Abstract: An HID lamp ignitor for a lamp including a transformer (92) having a primary winding (94) inductively coupled to a secondary winding (96) operably connected to a lamp output (98); a first switch circuit (100) operably connected between DC voltage (102) and a junction point (104), the first switch circuit (100) being responsive to a first switch signal (112); a second switch circuit (120) operably connected between the junction point (104) and common (124), the second switch circuit (120) being responsive to a second switch signal (132); and an LC tank circuit (140) having the primary winding (94) operably connected in series with a capacitor (142), the LC tank circuit (140) being operably connected between the junction point (104) and the common (124). The first switch signal (112) alternates with the second switch signal (132) to close the first switch circuit (100) and the second switch circuit (120).

Abstract: A driver (10) for driving a gas discharge lamp (L) comprises a current generator (1; 2) for generating a lamp current with a main lamp current component and, for arc-straightening purposes, a ripple current component. A controller (3) controls the current generator such as to set the ripple frequency (fR) and ripple amplitude (M). A memory (5) contains data defining a set point (SP) for the ripple frequency and ripple amplitude. A measuring device (4) provides at least one measuring signal indicative of arc curvature and arc stability. The controller is capable of operating in a ripple optimization mode in which the controller makes small adjustments to the ripple frequency and ripple amplitude to find improved arc-straightening, and, if such improvement is found, controls the current generator on the basis of the adjusted set point or otherwise resumes operation on the basis of the original set point (SP) in the memory (5).

Abstract: The invention is related to high pressure sodium lamp having a nominal power Pla. The lamp, which is designed to be operated at a very high frequency (VHF), has a discharge tube with a ceramic wall and an internal vessel diameter Dint, which encloses a discharge space in which a pair of electrodes at a mutual electrode distance ed and a filling of Na-amalgam with a sodium mol fraction (smf). According to the invention the discharge tube has a ratio ed/Dint of at most 7, preferably between about 5.5 and 4.0.

Abstract: An electric circuit for igniting a discharge lamp includes a voltage source, and at least one condenser electrically connected to the voltage source. Further, a series chain is provided, electrically connected in parallel with the condenser, of at least one ignition and at least one inductor. A discharge lamp is electrically connected in parallel with the ignition.

Abstract: The invention relates to an electric circuit for igniting a discharge lamp, comprising a voltage source, at least one first condenser electrically connected to the voltage source, a series chain, electrically connected in parallel with the first condenser, of at least one ignition and at least one first inductor, and a discharge lamp electrically connected in parallel with the ignition, which discharge lamp is provided with a discharge vessel. The invention also relates to an electrical component module for use in such an electric circuit. The invention further relates to a discharge lamp for use in such an electric circuit.

Abstract: A method and ballast for driving a high intensity discharge (HID) lamp include generating a very high frequency driving signal for the HID lamp, generating a low frequency modulating signal, amplitude modulating the driving signal with the modulating signal at a predetermined low initial modulation level, measuring a lamp voltage across the HID lamp, determining a standard deviation of the lamp voltage, comparing the standard deviation with a predetermined minimum level, if the standard deviation is above the predetermined minimum level, incrementally increasing the modulation level and repeating the amplitude modulating step, the measuring step, the determining step and the comparing step, and if the standard deviation is below the predetermined minimum level, maintaining the amplitude modulation at the determined level.

Abstract: An improved high frequency ballast is disclosed. The high frequency ballast establishes a lamp current for a gas discharge lamp during a starting operation of the gas discharge lamp wherein an operating ampere level of the lamp current facilitates a substantial achievement by the gas discharge lamp of a color specification associated with the gas discharge lamp. Thereafter, during a stable operation of the gas discharge lamp, the high frequency ballast applies a frequency modulation to an operating frequency of the lamp current and/or an amplitude modulation of the lamp current.

Abstract: A method and ballast for driving a high intensity discharge (HID) lamp include generating a very high frequency driving signal for the HID lamp, generating a low frequency modulating signal, amplitude modulating the driving signal with the modulating signal at a predetermined low initial modulation level, measuring a lamp voltage across the HID lamp, determining a standard deviation of the lamp voltage, comparing the standard deviation with a predetermined minimum level, if the standard deviation is above the predetermined minimum level, incrementally increasing the modulation level and repeating the amplitude modulating step, the measuring step, the determining step and the comparing step, and if the standard deviation is below the predetermined minimum level, maintaining the amplitude modulation at the determined level.

Abstract: An improved high frequency ballast is disclosed. The high frequency ballast establishes a lamp current for a gas discharge lamp during a starting operation of the gas discharge lamp wherein an operating ampere level of the lamp current facilitates a substantial achievement by the gas discharge lamp of a color specification associated with the gas discharge lamp. Thereafter, during a stable operation of the gas discharge lamp, the high frequency ballast applies a frequency modulation to an operating frequency of the lamp current and/or an amplitude modulation of the lamp current.

Abstract: A ballast including a single sense element and a single controller for mulitple lamp operation. The ballast avoids the need for separate feedpaths for sensing individual lamp conditions and/or the need for separate controllers for controlling the individual lamp conditions. Consequently, the ballast scheme avoids the use of expensive components (e.g. controllers and chokes) and minimizes the number of components required in order to operate multiple lamps.

Abstract: Power-driven work tool including a shank (2, 3), a drive motor (4), and a working tool (1) driven by the motor. The working tool is rotatable around at least one axis perpendicular to the shank by a controller (8). The controller is attached to the shank and connected to the working tool or a bracket thereof by a wire or rod (10), which transmits pulling or pushing force. The motor (4) is at one end of the shank (2, 3) and adapted to drive the working tool (1) provided at the other end of the shank via a drive shaft extending through the shank. The shank is provided at the end thereof connected to the working tool with a hinge (6) for angular movement of the working means, and the drive shaft provided in the shank (2, 3) is connected to the working tool via a flexible shaft extending through the hinge (6).

Abstract: A dimming interface for translating the conduction pulse width of a signal produced by a triac dimmer into a proportional rectified average voltage serving as a dimming signal. The dimming signal is supplied as an input to an IC driver for controlling the level of lamp illumination. The proportional rectified average voltage can be converted into a signal representing a duty cylce whereby a variation in the mains line voltage does not affect the dimming signal.

Abstract: A resonant mode power supply includes a soft-start circuit for, at start-up, for sweeping the frequency of the power supply from a maximum value to a minimum value. The soft-start circuit performs this frequency sweep using the functionF(x)=1-e.sup.-tUsing this function, change in the frequency, and correspondingly the increase of the output voltage decreases over time, thereby allowing a feedback circuit of the resonant mode power supply to respond to the level of the output voltage and to begin regulation when the output voltage achieves the desired regulation level. As such, overshoot of the output voltage with respect to the regulation level is lessened, if not eliminated.

Abstract: A triac dimmable electronic ballast having a single stage feedback power factor inverter is configured to isolate the resonant circuit current from a DC bias, or a DC transient caused by activations of the triac. The resonant circuit is driven by a high frequency inverter, and contains a feedback path to a DC storage element. Two DC blocking devices are provided, one between the resonant circuit and the inverter, and one between the resonant circuit and the DC storage element.

Abstract: A ballast feedback scheme including a single stage current feedback inverter. To avoid overboosting of the voltage impressed across a buffer capacitor only a portion of the high frequency lamp current is fedback to the buffer capacitor during both ignition and steady state operation of the lamp. Ignition of the lamp is well controlled.

Abstract: A resonant mode power supply includes a d.c. voltage source and switching elements for alternatively connecting an oscillating circuit, including the primary winding of a transformer, to the d.c. voltage source and to ground. In order to detect faults in the load on a secondary side of the transformer which would cause the resonant mode power supply to attempt to supply and inordinate amount of power, the power on the primary side is detected and if this primary power exceeds a predetermined threshold value, the frequency of oscillation is increased to reduce the power. If the fault condition persists, the switching of the switching elements is discontinued.