An automotive (ignition system) ballast resistor An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit. Image File history File links Ballast. ...
Image File history File links Ballast. ...
Electric current is the flow (movement) of electric charge. ...
Electricity (from New Latin Ä“lectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ...
Look up circuit in Wiktionary, the free dictionary. ...
Ballasts vary greatly in complexity. They can be as simple as a series resistor as commonly used with small neon lamps. For higher-power installations, too much energy would be wasted in a resistive ballast, so alternatives are used that depend upon the reactance of inductors, capacitors, or both. Finally, ballasts can be as complex as the computerized, remote-controlled electronic ballasts used with fluorescent lamps. Resistor symbols (non-European) Resistor symbols (Europe, IEC) Axial-lead resistors on tape. ...
Lighting neon lamp, two 220/230 volt and 110 V neon lamps and a screwdriver with neon lamp inside A neon lamp is a gas discharge lamp containing primarily neon gas at low pressure. ...
It has been suggested that Electric reactance be merged into this article or section. ...
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
See Capacitor (component) for a discussion of specific types. ...
Fluorescent lamps in Shinbashi, Tokyo, Japan Assorted types of fluorescent lamps. ...
Necessity for current limiting
Ballasts are most commonly needed when an electrical circuit or device presents a negative (differential) resistance to the supply. If such a device were connected to a constant-voltage power supply, it would draw an ever-increasing amount of current until it was destroyed or caused the power supply to fail. To prevent this, a ballast provides a positive resistance or reactance that limits the ultimate flow of current to an appropriate level. In this way, the 'ballast' provides for the proper operation of the negative resistance device. Examples of such negative-resistance devices are gas discharge tubes and lamps. Look up circuit in Wiktionary, the free dictionary. ...
A VI curve with a negative differential resistance region Negative resistance or negative differential resistance (NDR) is a property of electrical circuit elements composed of certain materials in which, over certain voltage ranges, current is a decreasing function of voltage. ...
International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ...
Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...
It has been suggested that Electric reactance be merged into this article or section. ...
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Look up Lamp in Wiktionary, the free dictionary. ...
Ballasts can also be used simply to deliberately reduce the current flow in an ordinary, positive-resistance circuit. Prior to the advent of solid-state ignition, automobile ignition systems commonly included a ballast resistor to regulate the voltage applied to the ignition system. The ignition system of an internal-combustion engine is an important part of the overall engine system that provides for the timely burning of the fuel mixture within the engine. ...
Resistors The term ballast resistor primarily refers to a resistor which compensates for normal or incidental changes in the physical state of a system. It may be a fixed or variable resistor. Resistor symbols (non-European) Resistor symbols (Europe, IEC) Axial-lead resistors on tape. ...
Fixed resistors For simple, low-powered loads such as a neon lamp, a fixed resistor is commonly used. Because the resistance of the ballast resistor is large it dominates the flow of current in the circuit even in the face of negative resistance introduced by the lamp. A VI curve with a negative differential resistance region Negative resistance or negative differential resistance (NDR) is a property of electrical circuit elements composed of certain materials in which, over certain voltage ranges, current is a decreasing function of voltage. ...
The term also refers to an automobile engine component that lowers the supply voltage to the ignition system after the engine has been started. Because cranking the engine causes a very heavy load on the battery, the system voltage can drop quite low during cranking. To allow the engine to start, the ignition system must be designed to operate on this lower voltage. But once cranking is completed, the normal operating voltage is regained; this voltage would overload the ignition system. To avoid this problem, a ballast resistor is inserted in series with the supply voltage feeding the ignition system. Occasionally, this ballast resistor will fail and the classic symptom of this failure is that the engine runs while being cranked (while the resistor is bypassed) but stalls immediately when cranking ceases (and the resistor is reinserted in the circuit). “Car†and “Cars†redirect here. ...
A colorized automobile engine The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. ...
International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ...
The ignition system of an internal-combustion engine is an important part of the overall engine system that provides for the timely burning of the fuel mixture within the engine. ...
A battery is of one or more electrochemical cells, which store chemical energy and make it available in an electrical form. ...
Modern electronic ignition systems do not require a ballast resistor as they are flexible enough to operate on the low cranking voltage or the ordinary operating voltage.
In old AC/DC receivers, the vacuum tube filaments are connected in series. Since the voltage drop across all the filaments in series may be less than the full 117 volts from house's line voltage, it was necessary to get rid of the excess voltage. The resistive component use for this purpose was often referred to as a ballast resistor. The All American Five was a mass-produced, superheterodyne radio receiver with five vacuum tubes first designed and produced in the USA in the 1930s. ...
Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ...
This is a list of countries and territories, with the plugs, voltages and frequencies they use for providing electrical power to small appliances and some major appliances. ...
Self-variable resistors Some ballast resistors have the property of increasing in resistance as current flowing through them increases, and decreasing in resistance as current decreases. Physically, some such devices are often built quite like incandescent lamps. Like the tungsten filament of an ordinary incandescent lamp, if current increases, the ballast resistor gets hotter, its resistance goes up, and its voltage drop increases. If current decreases, the ballast resistor gets colder, its resistance drops, and the voltage drop decreases. Therefore the ballast resistor tends to maintain a constant current flowing through it, despite variations in applied voltage or changes in the rest of an electric circuit. These devices are sometimes termed barretters. Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...
The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ...
For other uses, see Tungsten (disambiguation). ...
Electric current is the flow (movement) of electric charge. ...
Electric current is the flow (movement) of electric charge. ...
This article or section does not cite its references or sources. ...
Electric current is the flow (movement) of electric charge. ...
An electrical network or electrical circuit is an interconnection of analog electrical elements such as resistors, inductors, capacitors, diodes, switches and transistors. ...
The Hot wire barretter was a demodulating detector invented in 1902 by Reginald Fessenden that found limited use in early radio receivers. ...
This property can lead to more precise current control than merely choosing an appropriate fixed resistor. The power lost in the resistive ballast is also minimized because a smaller portion of the overall power is dropped in the ballast compared to what might be required with a fixed resistor.
In times past, household clothes dryers sometimes incorporated a germicidal lamp in series with an ordinary incandescent lamp; the incandescent lamp operated as the ballast for the germicidal lamp. A commonly used light in the home in the 1960s in 220-240V countries was a circleline tube ballasted by an under-run regular mains filament lamp. Self ballasted mercury-vapor lamps incorporate ordinary tungsten filaments within the overall envelope of the lamp to act as the ballast, and it supplements the otherwise lacking red area of the light spectrum produced. An electric clothes dryer A clothes dryer or tumble dryer is a household appliance that is used to remove the residual moisture from a load of clothing and other textiles, generally shortly after they are cleaned in a washing machine. ...
A 9W germicidal lamp in a modern compact fluorescent lamp form factor Close-up of the electrodes and the safety warning An EPROM. The small quartz window admits UV light during erasure. ...
A Mercury-vapor lamp is a gas discharge lamp which uses mercury in an excited state to produce light. ...
Reactive ballasts
Several typical magnetic ballasts for fluorescent lamps. The top is a high-power factor, lead-lag ballast for two 30-40W lamps. The middle is a low power factor ballast for a single 30-40W lamp while the bottom ballast is a simple inductor used with a 15W preheat lamp. Because of the power that would be lost, resistors are not used as ballasts for lamps of more than a watt or two. Instead, a reactance is used. In an ideal or theoretically perfect reactance, no power would be lost while limiting the current flow; realistically, losses due to resistance can only be minimized, not eliminated entirely. Image File history File links Download high resolution version (1260x1065, 134 KB) Summary Several typical styles of magnetic ballasts for one or two fluorescent lamps Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Electrical ballast ...
Image File history File links Download high resolution version (1260x1065, 134 KB) Summary Several typical styles of magnetic ballasts for one or two fluorescent lamps Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Electrical ballast ...
Fluorescent lamps in Shinbashi, Tokyo, Japan Assorted types of fluorescent lamps. ...
It has been suggested that Electric reactance be merged into this article or section. ...
An inductor is very common in line-frequency ballasts to provide the proper starting and operating electrical condition to power a fluorescent lamp, neon lamp, or high intensity discharge (HID) lamp. (Because of the use of the inductor, such ballasts are usually called magnetic ballasts.) The inductor has two benefits: An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
Fluorescent lamps in Shinbashi, Tokyo, Japan Assorted types of fluorescent lamps. ...
Lighting neon lamp, two 220/230 volt and 110 V neon lamps and a screwdriver with neon lamp inside A neon lamp is a gas discharge lamp containing primarily neon gas at low pressure. ...
15 kW Xenon short-arc lamp used in IMAX projectors High-intensity discharge (HID) lamps include these types of electrical lamps: mercury vapor, metal halide (also HQI), high-pressure sodium (Son), low-pressure sodium (Sox) and less common, xenon short-arc lamps. ...
- Its reactance limits the power available to the lamp with only minimal power losses in the inductor
- The voltage spike produced when current through the inductor is rapidly interrupted is used in some circuits to first strike the arc in the lamp.
A disadvantage of the inductor is that current is shifted out of phase with the voltage, producing a poor power factor. In more expensive ballasts, a capacitor is often teamed up with the inductor to correct the power factor. In ballasts that control two or more lamps, line-frequency ballasts commonly use different phase relationships between the multiple lamps. This not only mitigates the flicker of the individual lamps, it also helps maintain a high power factor. These ballasts are often called lead-lag ballasts because the current in one lamp leads the mains phase and the current in the other lamp lags the mains phase. Voltage spikes are fast, short duration surges in the electric potential in a given circuit. ...
The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power, and is a number between 0 and 1. ...
See Capacitor (component) for a discussion of specific types. ...
In most parts of the world, the mains voltage is sufficient to strike and maintain an arc in the lamp[citation needed]. In the USA, the mains voltage is not sufficient for the larger lamps so an autotransformer is used to step-up the voltage[citation needed]. The autotransformer is designed with enough leakage inductance so that the flow of current is appropriately limited[citation needed]. An autotransformer is an electrical transformer with only one winding. ...
Leakage inductance is that property of an electrical transformer that causes a winding to appear to have some pure inductance in series with the mutually-coupled transformer windings. ...
Because of the large inductors and capacitors that must be used, reactive ballasts operated at line frequency tend to be large and heavy. They commonly also produce acoustic noise (line-frequency hum). This article is about noise as in sound. ...
A hum is a sound with a particular timbre (or sound quality), usually a monotone or with slightly varying tones, often produced by machinery in operation or by insects in flight. ...
Prior to 1980 in the United States, PCB-based oils were used as dielectric in the capacitors contained in many ballasts (see transformer oil). “PCB†redirects here. ...
Transformer oil is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. ...
Electronic ballasts An electronic lamp ballast uses solid state electronic circuitry to provide the proper starting and operating electrical condition to power one or more fluorescent lamps and more recently HID lamps. Electronic ballasts usually change the frequency of the power from the standard mains (e.g., 60 Hz in U.S.) frequency to 20,000 Hz or higher, substantially eliminating the stroboscopic effect of flicker (100 or 120 Hz, twice the line frequency) associated with fluorescent lighting (see photosensitive epilepsy). In addition, because more gas remains ionized in the arc stream, the lamps actually operate at about 9% higher efficiency above approximately 10 kHz. Lamp efficiency increases sharply to about 10 kHz and continues to improve until approximately 20 kHz.[1] Because of the high frequency of operation, electronic ballasts are generally smaller, lighter, and more efficient (and thus run cooler) than line frequency magnetic ballasts. Image File history File links Integrated electronic ballast (starter) of a fluorescent lamp. ...
Image File history File links Integrated electronic ballast (starter) of a fluorescent lamp. ...
A spiral type compact fluorescent lamp. ...
In electronics, solid state circuits are those that do not contain vacuum tubes. ...
An electronic circuit is an electrical circuit that also contains active electronic devices such as transistors or vacuum tubes. ...
Temporal aliasing is the technical term for a phenomenon also known as the stroboscopic effect or the wagon-wheel effect. ...
Photosensitive epilepsy is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns. ...
In addition, the higher operating frequency means that it is often practical to use a capacitor as the current-limiting reactance rather than the inductor required at line frequencies. Capacitors tend to be much lower in loss than inductors, allowing them to more closely approach an "ideal reactance".
Electronic ballasts are often based on the SMPS topology, first rectifying the input power and then chopping it at a high frequency. Advanced electronic ballasts may allow dimming via pulse-width modulation and remote control and monitoring via networks such as LonWorks, DALI, DMX-512, DSI or simple analog control using a 0-10V DC brightness control signal. A switching-mode power supply for laboratory use. ...
An example of PWM: the supply voltage (blue) modulated as a series of pulses results in a sine-like flux density waveform (red) in a magnetic circuit of electromagnetic actuator. ...
LonWorks is a networking platform specifically created to address the unique performance, reliability, installation, and maintenance needs of control applications. ...
The Digitally Adressable Lighting Interface (DALI) is a digital protocol for the controlling of lighting in buildings (e. ...
DMX512, often shortened to DMX (Digital MultipleX), is a communications protocol used mainly to control stage lighting. ...
DSI is a protocol for dimming lighting (initially ballasts) it was created in 1991 by Austrian company Tridonic ATCO and is based on Manchester-coded 8 bit protocol, data rate of 1200 baud : 1 start bit, 8 data bits (dimming value), 4 stop bits and is the basis of the...
0-10V is one of the earliest and simplest electronic lighting control signalling systems; simply put, it is a DC voltage that varies between zero and ten volts. ...
Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ...
Instant start Starts lamps without heating the cathodes at all by using a high voltage (around 600 V). It is the most energy efficient type, but gives the least number of starts from a lamp as emissive oxides are blasted from the cold cathode surfaces each time the lamp is started. This is the best type for installations where lamps are not turned on and off very often.
Rapid start Applies voltage and heats the cathodes simultaneously. Provides superior lamp life and more cycle life, but uses slightly more energy as the cathodes in each end of the lamp continue to consume heating power as the lamp operates.
Programmed start More advanced version of rapid start. Applies power to the filaments first, then after a short delay to allow the cathodes to preheat, applies voltage to the lamps to strike an arc. Gives the best life and most starts from lamps. This is the preferred type of ballast for applications with very frequent power cycling such as vision examination rooms and restrooms with a motion detector switch.
References - ^ IES Lighting Handbook 1984
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