Ballast Resistor Research Articles

Design consideration of the thermal and electro stability of multi-finger HBTs based on different device structures

The thermal and electro stability of multi-finger heterojunction bipolar transistors (HBTs) with different structures were analyzed and discussed simultaneously. The thermal stability of the devices with different layout structures was assessed by the DC-IV test and thermal resistance calculation. Their electro stability was assessed by the calculation of the stability factor K based on the S parameter of the HBT. It is found that HBTs with higher thermal stability are prone to lower electro stability. The trade-off relationship between the two types of stability was explained and discussed by using a compact K-factor analytic formula which is derived from the small signal equivalent circuit model of HBT. The electro stability of the device with a thermal ballasting resistor was also discussed, based on the analytic formula.

Gas chemical studies using corona discharge reactors

Corona discharges with voltages up to 60 kV (DC) were studied with the aim to induce chemical reactions in flue gases at atmospheric pressure. Various plasma reactors with different geometries of multi-needle arrays were tested. The power input was optimised by studying the electrical parameters of the set-up systematically. Both, solid and liquid electrodes were used in combination with the needle arrays. A precise positioning of the corona needles allowed operation without a ballast resistor. Formation rates for CO and the sum of NO2 and O3 are reported and discussed. Three catalytic anode-coatings were tested for their potential to decompose carbon dioxide.

Penta-Phase Series-Parallel $LC_{s}{C}_{p}$ Resonant Inverter to Drive 1-kW HPS Lamps

This paper presents the analysis and design of a new configuration of a resonant inverter suitable for high-pressure sodium lamp ballast applications. The proposed inverter is the result of the parallel connection of five class D LCsCp resonant inverters. Since the load current is shared among five equal sections, the circuit is able to drive lamps over 1 kW using low-cost power MOSFETs and achieves better efficiency than single class D solutions due to the reduction of the conduction losses. The regulation is implemented at constant frequency, modifying the phase displacement of the output voltage of one inverter section with respect to the others.

EMI Noise Prediction for Electronic Ballasts

The design of electromagnetic (EM) interference filters for converter systems is usually based on measurements with a prototype during the final stages of the design process. Predicting the conducted EM noise spectrum of a converter by simulation in an early stage has the potential to save time/cost and to investigate different noise reduction methods, which could, for example, influence the layout or the design of the control integrated circuit. Therefore, the main sources of conducted differential-mode (DM) and common-mode (CM) noise of electronic ballasts for fluorescent lamps are identified in this paper. For each source, the noise spectrum is calculated and a noise propagation model is presented. The influence of the line impedance stabilizing network (LISN) and the test receiver is also included. Based on the presented models, noise spectrums are calculated and validated by measurements.

High-Power-Density Igniter With Integrated $LC$ Resonator for Low-Wattage HID Ballast

This paper presents the design of a high-power-density igniter with integrated LC resonator for low-wattage high-intensity discharge lamp ballasts. Electromagnetic integration technology is applied to reduce the number of passive components and the overall volume of the igniter. By applying the interwinding capacitance as the resonant capacitance, the integrated igniter is simply composed of a magnetic core and two magnet wire windings. By selecting the proper terminals and exploiting the advantage of an integrated LC resonant structure, the obtained output voltage is twice as much as an ordinary LC resonator. The design and implementation of the igniter are presented, while the experimental results of a small-signal measurement and a high-voltage test are given. The experiment results show that the application of passive integration technology into low-wattage passive modules is promising.

A Novel Constant-Power Control for Metal-Halide Lamp Electronic Ballasts with Dimming Capability

In this paper, a new dimmable electronic ballast for metal-halide (MH) lamps based on a three-stage structure is proposed. The presented dimmable electronic ballast can dim smoothly without acoustic resonance from 50% to 100% brightness. A novel current-control method with constant-power capability is also presented to solve the power-drifting problem resulting from the V- I characteristic variations between lamps or caused by the aging of lamp. The dimming capability allows the ballast to adjust its working condition according to the environments or the dimming command; this further improves the energy efficiency. Finally, a 150-W MH lamp ballast prototype is built to verify the feasibility of the proposed methods.

The Implications of Fluorescent Lamp Electronic Ballast Dimming —An Experimental Study

In recent years, fluorescent lamp dimming controls are an integral part of daylight artificial light integrated schemes intended for realization of energy savings. However, dimming, like any lighting option, presents its own particular challenges and potential tradeoffs. In view of this, the present manuscript depicts the preliminary work progress carried out to arrive at a comprehensive idea on dimming implications on key factors: electrical characteristics, photometric distributions of lighting systems and influence on quality as well as quantity of visual environment. The objective is to experimentally establish the acceptable range of dimming control voltage that would satisfy both electrical and photometric performance of luminaire. The vital part of the paper is devoted towards presentation of measurement results. For the experimental analysis, three representative samples of different commercial analog 1-10VDC electronic dimmable ballasts and fluorescent fixtures are compared and evaluated over their control voltage dimming range.

A Case Study of Problems in JEDEC HBM ESD Test Standard

There is a current need for modification of EIA/JEDEC Human-Body model (HBM) electrostatic discharge (ESD) test standard, which does not define start and step test voltages. In the current standard, some measurements start at several kilovolts, which ignore the fact that ESD protection devices may fail under low voltage stresses. In this paper, a grounded-gate structure with an n-well ballast resistor connecting its drain and PAD is investigated for HBM ESD sustaining levels. When tested with a Zapmaster starting from 1 kV, the withstand voltage exceeds 8 kV, whereas the structure failed at 350 V when the test starts from 50 V. The test results from a transmission-line-pulsing system validate the phenomenon. The reason for the failure is also studied and confirmed with optical-beam-induced resistor change system failure analysis results. To address this general issue, a suggestion for improving the present HBM ESD testing standards for industry applications is made.

On stabilization of multipoint negative corona by using ballast resistances

The I-V characteristics of a negative corona discharge initiated by a multipoint cathode in an argon flow are experimentally studied. It is found that adjustable ballast resistances connected to the corona points provide stable operation and uniform filling of the discharge gap by the plasma.

Design and Realization of Electrostatic Discharge Protected DC to 2GHz GaAs Monolithic Microwave Integrated Circuits SP4T Switch for TDMA Communication Applications

This paper discusses the small signal simulated and measured results of a DC to 2GHz monolithic GaAs SP4T switch which has been designed and realized. The measured 1 dB compression point of SP4T switch at different frequency range has also been presented. The DC to 2GHz switch has been designed using series-shunt FETs topology. This topology has worked over very large bandwidth. In this topology series MESFETs allows the SP4T switch to operate down to DC. The SP4T switch has been achieved better than 1.1dB of insertion loss, better than 32 dB of input to “Off” port isolation and better than 16 dB of the input and output return loss @2GHz. The performance of the SP4T switch has been measured on an FR4 PCB eval board. The on-chip higher value of ballast resistor has been used for ESD protection. The switch has designed using 0.7 μm Ion-Implanted recessed gates MESFET technology and used in switching matrices for TDMA communication system. The major advantages of the solid-state integrated switch are low power consumption, small size and lightweight. These fea tures of solid state switch are more attractive for com munication applications. The chip dimension is 1.2 × 1.2 mm.

Experimental study of a multipoint cathode corona in an argon flow

Results are presented from experimental studies of a multipoint negative corona in an atmospheric-pressure argon flow. It is shown that a decrease in the interpoint distance, gas circulation through the discharge gap, and the adjustment of ballast resistances in the corona supply circuit allow one to stabilize the discharge and enlarge the operating range of discharge currents.

A Novel Discrete Dimming Ballast for Linear Fluorescent Lamps

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A novel discrete dimming ballast for linear fluorescent lamps is proposed in this paper. A proposed dimming control circuit is combined with a ballast module for multiple lamps to realize control of three discrete lighting levels. Compared with conventional step dimming or <emphasis emphasistype="smcaps">on</emphasis>– <emphasis emphasistype="smcaps">off</emphasis> control methods, the proposed discrete dimming method has the following advantages: 1) digital signal is generated by the dimming control circuit to control the lamps' turn- <emphasis emphasistype="smcaps">on</emphasis> and -<emphasis emphasistype="smcaps">off</emphasis>, which makes the system more reliable and integrated; 2) the proposed discrete dimming system replaces relays, which are necessary in conventional lamp <emphasis emphasistype="smcaps">on</emphasis>–<emphasis emphasistype="smcaps">off</emphasis> control, and therefore decreases the system cost; 3) the proposed dimming ballast can be installed by keeping the original wiring system. This makes the upgrading of a lighting system more effective and efficient; 4) the dimming control circuit also provides a good isolation for operating the low-voltage wall switches by hand safely. Both theoretical, simulation, and experimental results are in good agreement. </para>

Simulation of streamer-induced pulsed discharges in atmospheric-pressure air

Dynamics of the controlled streamer-to-spark transition in atmospheric-pressure air is simulated. Results of calculation show that at proper selection of the parameters (the feeding capacitor, the ballast resistor) of power-supply electric circuit it is possible to produce non-thermal plasma filaments of radii about 10 −2 cm, the mean gas temperature inside the filament being about 2000-3000 K and the electron number density being 10 13 –10 14 cm −3 .

Fabrication of carbon nanomaterials by atmospheric pressure microplasma

Atmospheric pressure microplasma was produced in a scanning electron microscope (SEM) chamber for synthesising carbon nanomaterials. The SEM observation is convenient for both adjusting the gap length and observing the electrode surface before and after experiments. After adjusting the gap length, the electrodes were housed in a small removable gas cell equipped in the SEM chamber and CH 4 discharge gas was introduced into the gas cell. It was found that the discharge was pulsated automatically because of slow discharge through a large ballast resistor and fast discharge through gas breakdown, even though a DC voltage was applied. The peak pulse current density was almost 60 kA cm 2 , the peak power density in the microplasma volume was approximately 555 MW cm 3 and the pulse width was 10 ns typically. Spherical and nanotube-like carbon nanomaterials were found on the cathode surface after microplasma discharge for 1-5 s. With the discharge time increasing, the spherical substance changes into nanotube-like carbon nanomaterials.

Adaptive fluorescent lamp start control strategy for dimmable magnetic ballast system

Based on the environmental concern a novel central dimming system with magnetic ballast driven lighting system, Dimmable Magnetic Ballast System (DMBS), was presented to replace the electronic ballast driven lighting system. To make the DMBS work at a wide range of input voltages for dimming, an Adaptive Fluorescent Lamp Starter (AFLS) which can provide an adaptive preheating time and constant fire voltage for different operation voltage and environmental temperature is proposed in this paper. Experimental results show that features of an adaptive preheating time, a single‐pulse ignition with constant fire voltage, and zero glow current can be achieved. Compared with conventional electronic starters, the proposed AFLS can stretch the lifetime and operating voltage range of the DMBS.

DC Discharges in Atmospheric Air and Their Transitions

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We present images and basic characteristics and describe transition mechanisms between three dc discharges in atmospheric air point-to-plane or point-to-water gap. With increasing applied voltage, a streamer corona transits to a transient spark: a repetitive spark with very short (<formula formulatype="inline"><tex>$\sim$</tex></formula> 100-ns) current pulses (<formula formulatype="inline"><tex>$\sim$</tex></formula>1 A) of very limited energy. With an appropriate ballast resistor, this transient regime evolves into a pulseless glow discharge. These three discharges generate nonequilibrium plasmas of high chemical activity interesting for environmental and biomedical applications. </para>

A Generalized Study of Multiphase Parallel Resonant Inverters for High-Power Applications

A generalized study of the parallel connection of N Class-D parallel resonant (LCP) inverters is presented. Steady-state analysis and design considerations are provided in detail, evaluating the current distribution, output power and efficiency of the circuit as a function of the number, N, of phases. Inductor equivalent series resistance and MOSFET conduction losses are considered in order to foresee and optimize the inverter efficiency. The power supplied to the load can be controlled at constant switching frequency by using the phase displacement of the output voltages of each Class-D leg, although for the interests of this specific application, only one inverter is phase shifted. The applicability of the general analysis is demonstrated on two practical designs with three and five phases, resulting in 400-W and 1-kW high-pressure sodium lamp ballasts, respectively.

A differential HBT power cell and its model

AbstractA differential heterojunction bipolar transistor (HBT) power cell has been designed and modeled with additional model extraction patterns. The differential power cell, which is composed of a unit differential amplifier with a common emitter ballast resistor, has no gain degradation by the ballast resistors and has been implemented in InGaP/GaAs HBT technology. DC and AC characteristics are extracted from a half circuit of the differential power cell and thermal characteristics are extracted from a common‐mode circuit of that. Using the extracted model, a 5‐GHz differential power amplifier has been designed and fabricated with on‐chip output networks. The 5‐GHz differential power amplifier delivers 26 dBm of P1dB with 30% collector efficiency. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2262–2268, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23684

Measurement of total energy flux density at a substrate during TiOx thin film deposition by using a plasma jet system

The total energy flux density delivered to an electrically isolated substrate in a low-pressure pulsed DC hollow cathode plasma jet sputtering system during TiO2 thin film deposition has been quantified. The plasma source was operated in constant average current mode and in a mixture of argon and oxygen or only in pure argon working gas. A titanium nozzle served as the hollow cathode. The total energy flux density measurements were made using a planar calorimeter probe. The main results from the calorimeter probe showed clearly that the total energy flux density at the electrically isolated substrate decreases significantly with duty cycle from 100% (DC mode) to 10% at a given pulsing frequency 2.5kHz. A local maximum at duty cycle 60% for only pure argon operation has been observed. In addition, the voltage waveforms on the hollow cathode and before the ballast resistor have been saved for pulsed DC measurements for both pure argon and argon+oxygen mixture. A similar transient phenomenon on the cathode voltage and discharge current as observed recently in mid-frequency pulsed DC magnetron discharge has been discovered in the hollow cathode plasma jet sputtering system. We can conclude from these preliminary measurements that the main asset of the pulsed DC hollow cathode plasma jet discharge as distinct from the DC driving of the same plasma system lies in the possibility to reduce or to increase energy influx on the floating substrate within the change of duty cycle.

Efficient algorithm for simulating a multidimensional glow discharge

A normal glow discharge in nitrogen between two infinite plane-parallel electrodes is simulated numerically in three dimensions in the drift-diffusion model. An algorithm is proposed that is based on solving the model equations by a hybrid of the sweep and relaxation methods and that combines a satisfactorily fast rate of convergence with the efficiency of individual iterations. The algorithm developed was used to carry out a three-dimensional simulation of a discharge in nitrogen at the pressures p = 5 and 1 Torr, the source voltage and ballast resistance being 2 kV and 300 kΩ, respectively. It was found that, at the pressure p = 1 Torr, the current density and charged particle densities change to a torioidal distribution in the anode region.