Abstract:
A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit according to a waveform of the drive power. The waveform has n launching periods and a low-power mode lighting period. The n launching periods include a first launching period in which the drive power increases toward refresh power that is equal to or above drive power in a low-power mode and equal to or below rated power, and (n−1) launching periods in which the drive power is maintained at the refresh power. The control unit, in an x-th launching period, supplies the discharge lamp with a drive current having a drive frequency equal to or below a drive frequency of a drive current supplied to the discharge lamp in an (x−1)th launching period.
Abstract:
A system provides post-match control of microwaves in a radial waveguide. The system includes the radial waveguide, and a signal generator that provides first and second microwave signals that have a common frequency. The signal generator adjusts a phase offset between the first and second signals in response to a correction signal. The system also includes first and second electronics sets, each of which amplifies a respective one of the first and second microwave signals. The system transmits the amplified, first and second microwave signals into the radial waveguide, and matches an impedance of the amplified microwave signals to an impedance presented by the waveguide. The system also includes at least two monitoring antennas disposed within the waveguide. A signal controller receives analog signals from the monitoring antennas, determines the digital correction signal based at least on the analog signals, and transmits the correction signal to the signal generator.
Abstract:
A multi-strike ballast to ignite an electrodeless lamp is disclosed, and includes an inverter circuit, a protection circuit, and a controller. The inverter circuit, upon activation, sends an ignition pulse to the lamp. The inverter circuit shuts down upon receiving a deactivation signal, and activates upon receiving an activation signal, triggering another ignition pulse. The protection circuit senses a change in a voltage associated with the lamp. The sensed changed may indicate that the lamp has not yet ignited or that the lamp is broken. The controller receives the sensed change in voltage and, in response, sends a deactivation signal to the inverter circuit. The controller waits a predetermined time and then sends an activation signal to the inverter circuit. The controller repeats until a change in voltage associated with the lamp is not sensed, or until a predefined number of repeats occur, providing multiple ignition pulses to the lamp.
Abstract:
An amount of filament voltage supplied by a reconfigurable ballast may be adjusted based on a lamp type with which the ballast is operating. The filament voltage may be reconfigured dynamically and/or may be reconfigured via a user-provided value. An electronic dimming ballast may include a control circuit configured to control generation of the AC filament voltage in accordance with a reconfigurable AC filament voltage value. Reconfiguring an electronic dimming ballast may include reconfiguring an AC filament voltage applied by the electronic dimming ballast to a filament of a lamp installed with the electronic dimming ballast. Reconfiguring the AC filament voltage may include computing a hot-to-cold cathode resistance ratio associated with the filament. Reconfiguring the AC filament voltage may include determining whether the computed hot-to-cold cathode resistance ratio is within a range specified for the electronic dimming ballast.
Abstract:
A high intensity discharge (HID) ballast circuit comprises a trigger circuit, a power half-bridge self-excited oscillation circuit, which is arranged to enable self-excited oscillation by energizing an angle capacitor Cgs with a Miller capacitor Cdg of a power MOSFET when an original single pulse output by the trigger circuit is excited, and then output self-excited oscillation signals; and a filter loop which is arranged to match impedance for the self-excited oscillation signals, thereby converting a low-impedance voltage source to a high-impedance constant current source. The inherent phase relationship of the power MOSFET is utilized, and oscillation signals are generated by a power half-bridge self-excited oscillation circuit, and then impedance matching for the oscillation signals is performed by the filter loop, and finally an HID lamp is triggered. As a result, damages to human eyes caused by stroboscopic effect can be avoided and electro magnetic compatibility test can be passed.
Abstract:
An apparatus to supply power to at least one gas lamp, the apparatus including a half bridge driver having a striation control circuit which determines an on time (Ton) for a cycle in accordance with a fifty percent duty cycle, the cycle having a plurality of segments and lasting for a predetermined period of time and modulates on times Ton1 and Ton2 of first and second power switches, respectively, of a half-bridge circuit in accordance with a striation control technique for each of the plurality of segments.
Abstract:
A multi-strike ballast to ignite an electrodeless lamp is disclosed, and includes an inverter circuit, a protection circuit, and a controller. The inverter circuit, upon activation, sends an ignition pulse to the lamp. The inverter circuit shuts down upon receiving a deactivation signal, and activates upon receiving an activation signal, triggering another ignition pulse. The protection circuit senses a change in a voltage associated with the lamp. The sensed changed may indicate that the lamp has not yet ignited or that the lamp is broken. The controller receives the sensed change in voltage and, in response, sends a deactivation signal to the inverter circuit. The controller waits a predetermined time and then sends an activation signal to the inverter circuit. The controller repeats until a change in voltage associated with the lamp is not sensed, or until a predefined number of repeats occur, providing multiple ignition pulses to the lamp.
Abstract:
An optical reactor has a reactor enclosure defining a reaction chamber. In the reaction chamber, a light source operating at a very high frequency is arranged to radiate light to a fluid to be treated. A low voltage electrode is arranged to surround the light source. The light source is energized by a driving circuit which is arranged adjacent to the reactor enclosure. The driving circuit has a high voltage output terminal connected to a high voltage input terminal of the light source. The driving circuit has a low voltage output terminal which is connected to the low voltage electrode.
Abstract:
A UV curing lamp has variable resistive ballast provided by at least one resistance alloy wire and a set of switches tapping varying positions along the resistance alloy wire. The variable resistance ballast defines the lamp's maximum operating power consistent with the power supply. The wire in combination with a fan also doubles as thermal ballast provided by air flowing across the wire onto the UV lamp. A detachable reflector in a generally parabolic cylinder shape directs light from the lamp located on the reflector's focal axis. The curing lamp with resistive ballast can be in the form of a handheld unit or as a floor unit with rotating lamps within the housing.
Abstract:
A fluorescent lamp controlling circuit reduces and/or prevents a fluorescent lamp from suddenly flickering when a power switch is turned on and/or off. Switching operation of a switch that supplies a direct current voltage to the fluorescent lamp is restricted during a transient period to delay a reset signal so that undesired flicker of the fluorescent lamp can be reduced and/or prevented.