A Novel Constant Power Control Circuit for HID Electronic Ballast

This paper presents a constant power control circuit for a three-stage high-intensity discharge (HID) electronic ballast. The three-stage electronic ballast is composed of a boost pre-regulator to achieve a high power factor, a DC/DC buck converter to regulate lamp current with constant lamp power, and a full-bridge inverter to drive the HID lamp with a low-frequency ac squarewave current. The buck converter operating in current mode utilizes current sense level-shift technique to achieve constant power output. The proposed constant power control circuit is easily designed and implemented for the three-stage HID electronic ballast. Finally, a laboratory prototype of a 70 W HID electronic ballast is implemented. The measured results show that the proposed ballast can be applied for various HID lamps with low lamp power variation (less than 0.6%).     

基于VK05CFL的CFL电子镇流器设计

基于电子驱动器VK05CFL的CFL电子镇流器可以实现预热、灯寿终保护、灯存在检测和自动重启等功能。文中介绍了VK05CFL的引脚功能和内部结构，给出了用VK05CFL芯片设计高性能电子镇流器的几种实现方案。     

High frequency electronic ballast provides line frequency lampcurrent

Most electronic ballasts for fluorescent lamps provide a sinusoidal lamp current at the switching frequency. The high-frequency current flowing through the lamp can generate significant radiated noise, which is unacceptable in noise-sensitive applications, such as fluorescent lights in airplanes. Using shielded enclosures for the lamps may solve the problem, but it is expensive. A discontinuous conduction mode (DCM) electronic ballast topology is presented which drives the lamp with line frequency current, just like a magnetic ballast. However, compared to a magnetic ballast, its weight is substantially reduced due to operation at 40 kHz switching frequency. The topology also ensures unity power factor at the input and stable lamp operation at the output     

Analysis and experimental results of a single-stagehigh-power-factor electronic ballast based on flyback converter

A new single-stage high-power-factor electronic ballast based on a flyback converter is presented in this paper. The ballast is able to supply a fluorescent lamp assuring a high-input power factor for the utility line. Other features are lamp power regulation against line voltage variations and low lamp current crest factor, both assuring long lamp life. The ballast is analyzed at steady-state operation, and design equations and characteristics are obtained. Also, a procedure for the ballast design is presented. Finally, simulation and experimental results from a laboratory prototype are shown     

New charge pump power-factor-correction electronic ballast with awide range of line input voltage

A new charge pump power-factor-correction (CPPFC) electronic ballast with a wide range of line input voltage is proposed in this paper. Circuit derivation and DC-bus voltage stress at start-up mode are discussed. The average lamp current control with switching frequency modulation is developed to achieve constant lamp power operation and low-crest factor. The proposed CPPFC electronic ballast is analyzed, implemented, and evaluated. It features continuous line input current, low total harmonic distortion (THD), constant lamp power operation, low-crest factor, and less switching current stress with low-DC-bus voltage stress for the line voltages from 180 to 265 V     

Improved start-up scenario for single-stage electronic ballast

This paper presents improved start-up scenario for single-stage electronic ballast derived with a synchronous switch technique (SST). Based on the SST, the derivation of a single-stage inverter (SSI) used for realizing the ballast is then addressed. The SSI can achieve both high power factor and ballasting function. During lamp start-up transition, power imbalance may exist between the power factor correction semi-stage and the ballast semi-stage, and filament preheating is an important issue. Power imbalance usually results in a high DC-link voltage which, in turn, imposes high stress on the switching devices. Investigation of the ballast operation is conducted, from which control strategies for reducing component stresses and hot resistance detection circuits for minimizing electrode sputtering are therefore proposed. Hardware measurements have verified that on-off tests are higher than 18,000 times without significant sputtering     

Single-stage line-coupled half-bridge ballast with unity power factor and ripple-free input current using a coupled inductor

A single-stage line-coupled half-bridge ballast with unity power factor and ripple-free input current using a coupled inductor is proposed. The proposed power-factor-correction circuit can achieve unity power factor and ripple-free input current using a coupled inductor. A saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. The proposed ballast has high energy efficiency, low cost, and high reliability compared to the conventional high-power-factor electronic ballasts. Experimental results obtained on a 30-W fluorescent lamp is discussed.     

A single-stage electronic ballast with high power factor

A single stage electronic ballast with high power factor (HPF) is proposed in this letter. The single-phase boost-type rectifier provides HPF. A saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. Experimental results obtained on a 40 W fluorescent lamp are discussed     

Acoustic-resonance-free electronic ballast for automotive HID lamps

A novel cost-effective and acoustic-resonance-free electronic ballast used to drive automotive high intensity discharging (HID) lamps that utilise a constant lamp power control scheme is proposed. The presented ballast is comprised of a buck-boost flyback converter to provide negative DC voltages and a half-bridge-type inverter to supply the lamp with low-frequency, square-wave AC voltage/ current. Owing to its low-frequency operation, no acoustic resonance occurs on the automotive HID lamps. Design guidelines and experimental results are demonstrated for a 35 Wautomotive HID lamp prototype ballast operating at 400 Hz switching frequency with battery input DC voltage of 12 V.     

Single-stage electronic ballast with high-power factor

This article proposes a single-stage electronic ballast circuit with high-power factor. The proposed circuit was derived by sharing the switches of the power factor correction (PFC) and the half-bridge LCC resonant inverter. This integration of switches forms the proposed single-stage electronic ballast, which provides an almost unity power factor and a ripple-free input current by using a coupled inductor without increasing the voltage stress. In addition, it realises zero-voltage-switching (ZVS) by employing the self-oscillation technique. The saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. Therefore, the proposed single-stage ballast has the advantage of high-power factor, high efficiency, low cost and high reliability. Steady-state analysis of the PFC and the half-bridge LCC resonant inverter are described. The results of experiments performed using a 30 W fluorescent lamp are also presented to confirm the performance of the proposed ballast.     

Electronic Ballast Control IC With Digital Phase Control and Lamp Current Regulation

A digital control architecture is presented for electronic ballasts that provides a phase sweep for reliable, soft lamp ignition and a smooth transition to lamp current regulation mode. The controller is based on an inner phase loop for fast regulation of the resonant tank operating point and an outer current loop for lamp current regulation. The inner loop operates on a simple digital control law that computes the required gate timing relative to the inductor current positive zero crossing. Phase control provides reliable drive of the resonant converter in the presence of large dynamic changes in the load impedance during lamp ignition and warm up and natural tracking of component variations with temperature and time. The primarily digital approach provides programmability for broad application, insensitivity to process and temperature variations, realization in low cost CMOS processes and few external components. Experimental results are presented for an integrated ballast controller fabricated in a 0.8 mum CMOS process used in a 400 W, 150 kHz HID electronic ballast.     

Improving crest factor of electronic ballast-fed fluorescent lampcurrent using pulse frequency modulation

In case where electronic ballast employing a valley-fill passive power-factor correction (PFC) circuit is used for feeding fluorescent tamps, a new method to reduce crest factor of the lamp current is studied in this paper. It is known that a 50% valley-fill passive PFC provided for high input power factor results in undesirable value of crest factor of the fluorescent lamp current, In order to reduce crest factor to a lower value, a pulse frequency modulation technique based on the waveform of the DC-link voltage which is predetermined by the passive PFC circuit is taken into the switching control action of the electronic ballast. An equation-based analysis between the crest factor of lamp current and the effect of varying the inverter switching frequency is comprehensively performed. Several simulation and experiment results illustrate the Effectiveness of the proposed control scheme     

An improved “charge pump” electronic ballast with lowTHD and low crest factor

The “charge pump” electronic ballast circuit, which employs a charging capacitor and a high-frequency AC source to implement power factor correction (PFC), has become an attractive topology for ballasting fluorescent lamps. However, the basic “charge pump” electronic ballast circuit has the problems of high total harmonic distortion (THD) of the input current and high crest factor (CF) of the lamp current. This paper analyzes the origin of the problems and proposes a novel solution. With the addition of two small clamping diodes, good input current (PF>0.99, THD<5%) and lamp current (CF<1.6) can be obtained with open-loop control. Experimental results are provided for verification     

Analysis and Improvement of Automotive High Intensity Discharge Lamp Ballast Based on Microcontroller Unit

The superior performance of high intensity discharge（HID） headlamp is clearly shown for luxury sedans, and the lamp luminescence properties are analyzed. The principle of its ballast technology is analyzed in detail. For against the disadvantage of current ballast technology for sedans lamp, a novel type of electronic ballast for HID is designed based on programmable intelligent computer（PIC） microcontroller unit（MCU） and S1A2410M inverter and it provides guidance and can be easily used in control configuration selection and design. The feasibility and superiority of the system are proved.     

Charge pump power-factor-correction dimming electronic ballast

A voltage-source charge pump power-factor correction (CPPFC) continuous dimming electronic ballast is proposed in this paper. The basic charge pump PFC principle is presented, and its unity power factor condition is then reviewed. Constant lamp power control and crest factor correction technique in dimming mode operation are then discussed. A continuous dimming controller with average lamp current control and duty-cycle modulation is developed so that the lamp is able to operate in constant power and low crest factor from 20% to 100% dimming level. The developed dimming electronic ballast has features of higher than 0.99 power factor, low crest factor, and low-DC-bus voltage     

Investigation of a New Control Strategy for Electronic Ballasts Based on Variable Inductor

In this paper, a new control method for electronic ballasts based on the use of a variable inductor is presented. The main goal is to perform the complete control of the electronic ballast by maintaining the switching frequency constant and without using other parameters of the power converter, such as input voltage or duty cycle. The magnetic regulator is controlled by means of a dc current, which allows performing both lamp soft starting and lamp dimming. Apart from the important advantage of keeping a constant frequency during full electronic ballast operation, the proposed method presents additional advantages when compared to other control methods, such as inherent isolated control, more linear control characteristics, constant electrode power, and higher efficiency. Experimental results from a 36-W linear fluorescent lamp prototype are presented.     

Low-cost high power-density electronic ballast for automotive HIDlamp

A low-cost high-efficiency high power-density electronic ballast for 35 W automotive high intensity discharge (HID) is presented along with the results of theoretical computations and experimental tests. The ballast circuits is based on a 100 kHz resonant inverter, a half-wave rectifier and a 400 Hz operated square-wave inverter. The converter operates at zero turn on losses, nearly zero turn off losses, and at a reduced electromagnetic interference level. The ballast circuit is designed to prevent inappropriate operations due to the acoustic resonances. The lamp voltage waveform has limited dv/dt and no DC component contributing to a long operating life of the lamp. A breadboard of the electronic ballast was designed and experimentally tested on a 35 W lamp, for a DC input voltage ranging from 9 V to 16 V. The electronic ballast performs all the features required to turn-on, warm-up and drive at the steady state a 35 W HID lamp and operates at a maximum steady state efficiency η=84%,     

2.65-MHz Self-Oscillating Complementary Electronic Ballast With Constant-Lamp-Current Control for a Metal Halide Lamp

This paper presents the design and implementation of the 2.65-MHz self-oscillating complementary electronic ballast with a constant-lamp-current control for a metal halide lamp. In order to avoid the inherent acoustic-resonance problem of metal halide lamps, the ballast's switching-frequency level was selected to be 2.65 MHz, which satisfies higher magnitudes of maximum electromagnetic interference (EMI) limitation at frequencies of between 2.5 to 3.0 MHz, within the EMI/electromagnetic compatibility frequency range ldquochimney,rdquo for RF lighting systems. With the constant-lamp-current control scheme, the lamp current can be regulated to be less dependent on the input ac voltage. Finally, a 20-W prototype ballast is implemented to demonstrate the ability to avoid the acoustic-resonance and to provide constant levels of lamp current.     

Digital Control of a Low-Frequency Square-Wave Electronic Ballast With Resonant Ignition

This paper proposes a two-stage low-frequency square-wave (LFSW) electronic ballast with digital control. The first stage of the ballast is a power factor correction (PFC) stage, and the second is a full-bridge (FB) converter used for both lamp ignition and LFSW drive. As a novelty for LFSW ballasts, ignition is achieved without an additional igniter circuit by operating the FB during start-up as a high-frequency resonant inverter. After ignition, the converter operates as an LFSW inverter to avoid exciting acoustic resonances by controlling the FB as a buck converter and regulating alternately positive or negative current to the lamp. Lamp power is regulated by adjusting the average current supplied by the PFC stage. Another contribution of this paper is to utilize digital control as a simple solution to achieve multimode control, including resonant lamp ignition, LFSW transitions, and lamp current and power regulation.      

基于半桥双Buck功率变换器的电子镇流器

低频方波驱动模式是目前小功率金属卤化物灯电子镇流器抑制声谐振最有效的方法。本文提出了半桥双降压(Buck)型准方波谐振功率变换器,使所有的半导体开关器件都可以在零电压的条件下开通。并将其应用到70W金属卤化物灯电子镇流器中,达到了金属卤化物灯正常工作的要求。