摘要:
An improved ignition circuit for a high intensity discharge (HID) lamp is disclosed. The ignition voltage is provided across a single capacitor, and at the end of the ignition phase, a second capacitor is switched into the circuit to divide the voltage across two capacitors, and provide a steady state square wave current and voltage.
摘要:
A dimmable electronic ballast for an HID lamp includes a rectifier stage for rectifying an AC input and providing a rectified DC output, a power factor correction stage for modifying a power factor of the AC input and for providing an increased voltage DC output from the rectified DC output, an electronic ballast control circuit for providing a driving signal comprising a pulse train for controlling a switching operation of an output switch stage driving the HID lamp; the output switch stage having at least one electronic switching element coupled to the increased voltage DC output for providing a pulsed power signal to the HID lamp to power the lamp, the electronic ballast control circuit having a feedback input comprising a signal related to the power dissipated by the HID lamp for maintaining the power at a desired level, the desired level being set by a dimming control input to the electronic ballast control circuit. The circuit provides high frequency power, typically above 50 kHz, to the HID lamp.
摘要:
Sodium high-pressure lamps can be operated by a circuit arrangement which rectifies the AC line voltage and, dispensing with smoothing, feeds it directly to an inverter for generating a frequency above 1 kHz. Via an RF inductor and an ignition transformer, the lamp, which preferably contains a xenon filling above 1 bar, is fed the voltage modulated with twice the line frequency. The saving in electric energy of the lamp/ballast system is 30% by comparison with an inductor-driven Hg-free standard lamp, given the same luminous flux. The use of a microprocessor to control the half bridge permits an externally controlled or automatic lowering of power with a further potential energy saving of 35% on average over the year, and an end-of-life shutdown of the system in order to avoid cycling.
摘要:
A high pressure discharge lamp includes a light-transmissive ceramic discharge vessel with an envelope having a maximum outer diameter D1 and open ends, a metal pipe having one end, i.e., a top end fused in the open end of the light-transmissive ceramic discharge vessel and the other end, i.e., a base end protruding from the light-transmissive ceramic discharge vessel, a pair of electrodes each having one end, i.e., a base end connectively supported on the base end of the metal pipe and the other end, i.e., a top end extending within the light-transmissive ceramic discharge vessel, and a discharge agent which is filled in the light-transmissive ceramic discharge vessel, wherein it is also characterized by that the high pressure discharge lamp has an overall length L1, and the overall length L1 and the maximum outer diameter of D1 satisfies a following equation. 1.5nullL1/D1null4.5
摘要:
A lighting device for an electric discharge lamp comprises an LC series resonant circuit, and control means for controlling an inverter circuit. Immediately after the occurrence of a dielectric breakdown in the electric discharge lamp. AC voltage with a relatively low frequency is applied to the lamp so as to pass a heavy current therethrough. Subsequently, the frequency is increased stepwise by a relatively small variation until a terminal voltage of the electric discharge lamp reaches a predetermined value. Thereafter, the frequency is increased stepwise by a relatiely large variation until the electric discharge lamp assumes a discharge stable state.
摘要:
Ballast apparatus operates a HID lamp at high frequency and high power factor. Series-connected current-limiting input inductor and input capacitor connect across apparatus input and are tuned off resonance to pass predetermined lagging current. An additional input capacitor is connected across input terminals to that input power factor approaches unity. Full-wave diode bridge has input connected across series-connected input capacitor and filter capacitor connects across bridge rectifier output. During normal operation, the filter capacitor develops a DC potential which is current limited by series-connected inductor and capacitor. Inverter has input connected across filter capacitor and inverter an output that drives the HID lamp through a high-voltage generating and variable impedance resonant circuit. When HID lamp is not operating, resonant circuit impresses high voltage across lamp to start same in warm or cold condition and resonant circuit exhibits relatively low impedance which decreases current-limited potential across filter capacitor. When HID lamp is normally operating, resonant circuit exhibits relatively high impedance which increases DC potential across filter capacitor. Additional pair of series-connected diodes connect across bridge rectifier output and incandescent lamp connects between predetermined input terminal and voltage responsive control and switching means, which connects to interconnection of additional diodes. Voltage responsive switching means responds to decreased voltage across filter capacitor when HID lamp is not operating to energize standby incandescent lamp. When HID lamp is operating, voltage-responsive switching means responds to increased voltage across filter capacitor to maintain incandescent lamp de-energized.
摘要:
A power supply for an arc lamp comprises a power source and an inverter, the power source being a constant current source and the inverter a bridge network of field effect transistors switched by square wave pulses from an oscillator so that the output of the bridge network comprises alternating square wave pulses of equal duration for driving the lamp. The oscillator pulses are fed by way of opto-isolators to the bridge transistors. The constant current source and bridge network are provided as a power module for parallel connection with like modules and the oscillator is of modular form and serves as a common oscillator for the power modules.
摘要:
A circuit arrangement for operating a high-pressure gas discharge lamp (14) with high frequency current in which a direct voltage is supplied to a transistor bridge (5 to 8) having a transverse branch in which is arranged a choke coil (13). The clock (switching) frequency of the transistor bridge is varied within each period of the AC mains alternating voltage in dependence upon the current derived from the AC mains voltage.
摘要:
A variable frequency AC source drives a gas discharge lamp which is connected in parallel with the capacitance of a series resonant circuit. The polarity of the voltage applied to the resonant circuit is commutated at such times as the rate-of-change of current flow in the resonant circuit is at or near zero. The source frequency is thus maintained at or near the circuit resonant frequency to maintain high output voltage when the lamp is starting or reigniting.The polarity is also commutated at such times as the current flow from the source reaches a predetermined level. Lamp current is thus controlled in the running mode.
摘要:
A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the drive patterns has a plurality of drive parameters. The plurality of drive patterns includes a first drive pattern and a second drive pattern different from each other in a value of at least one of the plurality of drive parameters. The control section is configured to execute the first drive pattern and the second drive pattern in accordance with at least one of accumulated lighting time of the discharge lamp and an individual of the discharge lamp in a case in which an inter-electrode voltage of the discharge lamp is at a predetermined voltage value.