Glossary technical terms from a - z

The glossary explains technical terms used in lighting electronics and special features of BAG electronics products.

Pulses per mains cycle

This value gives the number of ignition pulses per mains period, which are superimposed on the mains voltage.

Asymmetric ignition

In case of asymmetric ignition, the entire ignition voltage with reference to earth potential is provided to one lampholder pole. Lamps with E40 socket and opposite second pole require imperatively this kind of ignition as the E40 socket itself is designed for voltages not higher than max. 5 kV. In the event a higher voltage is provided, this will result in arc-overs between lampholder and socket and may overheat and destroy them. Therefore, this type of lamps requires the entire high voltage to be provided to the second pole of the lamp whereas the conductor at the E40 socket leads neutral (N) or phase potential (L).

Automatic ignition

Hot restrike igniters with automatic ignition have a firmly programmed, maximum ignition time. However, they switch off immediately, once the lamp has been ignited successfully. In the event of poorly igniting lamps or lamps which are showing Cycling effect and are frequently extinguishing during operation, further ignition attempts are automatically carried out. The single ignition times are added together until the maximum ignition time has expired. A reset of the internal timer and new ignition attempts are only realised upon a mains interruption. Circuit determined, the height of the ignition voltage as well as the number of the ignition pulses per mains period may vary depending on the lamp and mains voltage. Igniters of BAG electronics with automatic ignition are marked with the index –II in their reference.

Load capacity, maximum

To achieve the specified ignition voltage, the maximum load capacity of the igniter has to be respected. The load capacity is determined by the nature, length and wiring of the lamp connecting leads as well as by the self-capacitance of the lamp. Thereof resulting is the basic requirement to keep the connecting path between lamp and igniter as short as possible. The empirical formula as below may serve to determine its maximum length.In practice, it can be assumed that high voltage cables show a self capacitance of 70 to 100 pF/m. Assuming, e.g. a maximum load capacity of the instant restrike igniter being 30 pF and the application of a cable with 75 pF/m, a distance of maximum 0.4 m is given as a result. A reduction of the connecting lead capacity can be achieved via longer distances to conductive parts. The measurement can be done by means of a mains independent C-measuring bridge. Superimposed igniters with a higher permissible load capacity can be used for longer distances, e.g. the igniter MZN 400/2000 with 2000 pF. Thus it is possible to calculate that the maximum length of wiring to the lamp is about 24 metres assuming a typical supply line capacity of 85 pF/m.

CE mark

On the market of the european economic area (EU und EFTA countries w/o Switzerland) the products have to be labeled with the CE mark. This mark shows, that the manufacturer ensures to comply with the essential EU directives.

Cut-Off technology

For the ignition of a fluorescent lamp it is necessary to cumulate a certain number of electrons in the electric field between the electrodes. This electrons can be provided by glow emission, when preheating current flows through the electrodes. The Cut-Off technology prevents permanent heating current through the electrodes during operation. This results in less load to the electrodes and avoids additional power loss. In combination with T5 fluorescent lamps, this circuit concept gains additional substantial importance. An increase in temperature in the surroundings of the electrodes, e.g. via permanent heating, leads to a considerable depreciation of the luminous flux. In conjunction with the power loss produced in addition, this would cause a reduction of the energy efficiency of the ballast-lamp system. The Cut-Off technology is introduced in every ECG of the D and MLS range from BAG as well as in most of SCS types for T5 lamps.


The abbreviation “DALI” stands for Digital Addressable Lighting Interface. The manufacturer-independent DALI standard, specified in IEC standard 60929, defines a standardized digital ballast interface, which ensures interchangeability and inter operability of ballasts from various manufacturers. The new standard is not merely a digital interface in addition to the current analogue 1-10 V control technology. Rather, it will gradually replace the latter because of its clear advantages. AG DALI is a working group set up by leading manufacturers and institutions in the field of digital lamp/luminaire control to promote DALI technology and applications.

Response/cut-out voltage

The response/cut-out voltage is defined while the igniter is operated without lamp or while the lamp is not ignited. In that case, the voltage applied to the igniter corresponds to the mains voltage. The response voltage indicates the limiting value above which ignition pulses are generated. Ignition is interrupted as soon as cut-out voltage deteriorates . Both values differ slightly due to the circuit design. A sufficiently high cut-out voltage ensures that no ignition pulses are created while the lamp is burning in order to prevent disadvantageous influence on the service lamp life.

Single ignition

Hot restrike igniters with single ignition have a constant ignition time. That means that the unit only switches off after the expiration of that time, irrespective of the lamp’s condition. A reset of the internal timer and new ignition attempts are only realised upon a mains interruption.Circuit determined, the height of the ignition voltage as well as the number of the ignition pulses per mains period may vary depending on the lamp and mains voltage. Igniters of BAG electronics with single ignition are marked with the index –I in their reference.

External Influence Protection, EIP

EIP refers to a specially integrated protective circuit of the igniter. This protects the igniter from extreme current and voltage stress, which can occur at the start and end of life of discharge lamps, for example, an especially distinct. In these cases, EIP ensures that no thermal overload of the ignition occurs.

Color rendering index

The Color Rendering Index (CRI) of a light source has the range from zero to one hundred and describes, how good the color rendering quality is compared with the radiation of a black body.


The gateway connects two networks with different protocols and is able to work on any layer of the OSI model of network communication (opposite to a router, that just interfaces on layer 3).


Abbreviation for “International Electrotechnical Commission”. International standards organisation for electrical and electronic matters. Founded 1906 in London. Current headquarters in Geneve.


Abbreviation for “International Lamp COding System”, which was introduced to provide a unified identification marking for lamps.

Interval ignition

Interval-ignition is the term used to describe an ignition process with a defined chronological sequence of ignition pulses. TriLogic igniters have two different starting cycles with programmed sequences of pulses in order to ensure the safe ignition of cold and warm lamps.

Lamp holders

On principle, the application of hot restrike igniters requires lampholders which are particularly developed for that purpose. They are designed to stand a dielectric strength of up to 35 kV and feature special, directly connected cables. In order to avoid arc-overs, they should be mounted onto a heat-resistant, nonconducting base, such as Teflon.

Lamp leads

The high voltage conducting lamp leads have to be appropriate for the supplied high ignition voltage. In most of the cases, single-core high-voltage cables with an electric strength of up to 20 kV in the scope of rated voltage are used in various types. The lamp leads have to be guided separately from mains and control lines. In favour of additional protection against contact, moisture or mechanical damage, the cables can be laid individually, in corrugated pipes, hoses or conduits made of plastic. In order to prevent the occurrence of ionisation, the wires should be fixed with plastic fasteners and installed at a distance from metal parts. Sharp-edged or spiky metal parts close to the lamp wires are to be avoided as arc-overs or corona discharges may as well result around these spots. In the event of distances being too small, materials like Teflon, ceramic and silicone will provide an improved isolation between the parts. One deciding criteria for the choice of the corresponding material is, in addition to the isolation resistance, as well the thermal resistance. In case of connections by means of non-insulated conductors and connectors a creepage and clearance distance of approx. 1.5 mm/kV from adjacent potentials, such as reflectors, cable through holes, etc. has to be respected. In the event of symmetric igniters, both wires should be of the same length and laid separated from each other.

Low Loss

In many applications the igniter is installed together with the ballast in an extremely confined space inside a luminaire. In order to cope with the increased thermal requirements that are thus caused, igniters can be used in the next-higher power class. Reduced internal losses lead to a diminution in internal heat in low-loss igniters and thus to greater thermal safety. The low-loss characteristics also provide additional protection in the case of break-downs at increased lamp currents, e.g. at the end of a lamp’s service life.

Phase position

The phase position defines the point in time at which the first ignition pulse occurs relative to the mains sinus voltage. Typical values for the phase position are 60 … 90° el/240 … 270° el, i.e. the ignition pulses start before the mains voltage maximum in each case during the positive and negative mains half-wave.

Pulse width

The pulse width of an ignition impulse states its width in terms of time at the moment when the voltage is still at 90 percent of the peak value. In the case of successive pulses during a half-wave the pulse width corresponds to the sum of the individual values.

Peak value

The peak value is equivalent to the maximum value of an ignition impulse.

Protection classes

IEC 61140 defines 4 classes of protection via earth connection.

Class 0:
This devices have no connection with protective-earth.

Class 1:
All conductive parts of the housing have to be connected to electrical earth. The design of the plag guarantees, that the protective-earth is the first to get connected, and will be the last to be interrupted in a malfunction.

Class 2:
This devices are designed in a way, that they do not need PE-connection, as live parts are separated from housing parts by using reinforced of double insulation.

Class 3:
The safety extra-low voltage of max. 120VDC or 60VAC for a class 3 device has to be provided by a specialy protected power source or a battery to prevent mains voltage from getting in contact with mains voltage.

Safety switch-off in case of abnormal lamp operation, EOL T.2

BAG electronics ECG feature automatic recognition and safety switch-off in case of abnormal lamp operation. This includes e.g. defective lamp electrodes or highly resistive discharging distances caused by leaky tubes. As well, the critical operating condition at the end of service life of fluorescent lamps is detected. The at that time arising rectifier effect leads to increased lamp burning voltage in the surroundings of the electrodes and thus to raised temperature in that area. This process results from the loss of emitter material arising in the course of operating time. Particular importance inheres in this so called End-of-Life phenomenon when T5 lamps are considered. Due to the decreased tube diameter being 16 mm, the raise in temperature is more significant than in case of T8 lamps with a diameter of 26 mm. As a consequence of the possible endangerments caused by thermal overload, the safety regulation EN 61347-2-3 for electronic control gear units includes the examination of a functional End-of-Life switch-off. There are three test methods available which of especially for T5 lamps the procedure “Test 2” is known to be particularly reliable. ECG from BAG electronics, marked with the symbol shown besides, are tested and approved according to the criteria required there.


Igniters of the type produced by BAG electronics with softstart ensure an instantaneous, low flicker and lamp-preserving start. Any pulse loads that may occur because of extreme voltages and currents, as can happen particularly during the start of warm lamps and during so-called “flashing”, are thus prevented. The softstart protects the igniter and ensures a maximum service life for the lamp.

Symmetric ignition

The hot restrike igniter has to provide high ignition voltages to re-ignite a hot high-pressure discharge lamps. In the case of symmetric ignition, one halfeach of the required ignition voltage is split toboth lamp electrodes. In the event of a totalvoltage of e.g. 30 kV and with reference toearth potential, only 15 kV are provided to thelamp electrodes respectively. The splitting ofthe ignition voltage leads to a reduction ofconstructional efforts with regard to the isolationof conductors and lampholders.

TriLogic technology

The distinguishing features of TriLogic here are its facility for combining all these functionalities:
  • interval-ignition
  • cycling recognition
  • automatic switch-off
On the basis of a digital circuit concept, the individual functions are programmecontrolled and are executed precisely. At the same time the necessity is obviated for different timer-igniters with different switch-off times because a TriLogic igniter can be used universally for a variety of different lamps. Igniters of this product family bear the additional designation ‘TU’, e.g. NI 400 LE 4K-TU.

Gate switches

A useful safety function of our Zirius igniters For maintenance purposes of luminaires, it is recommended to plan during their construction a so-called gate switch assuring that no high voltage pulses are generated while the luminaire is being opened. In most of the cases, this switch will interrupt the mains voltage of the luminaire and has thus to be appropriate to withstand the maximum arising current and the applied voltage. BAG electronics igniters of the ZIRIUS family allow for the application of micro switches. For this special purpose, the igniters feature an additional two pole control input. As only low control current is flowing, there are no special requirements to be met by the gate switch.

Vacuum impregnation

A quality feature of inductive ballasts
  • Improved heat abstraction for application at higher ambient temperatures
  • Extremely low noise emission
  • Improved operating safety and longer service life as a result of greater dielectric strength

ZIRIUS igniters

The igniters of the ZIRIUS family present a product series outstanding for innovative and enhanced characteristics. Thanks to a microprocessor and a fully electronic circuit design,a significant improvement of the starting performance of high-pressure discharge lamps isachieved. As a result, this recent technology offers for the first time their unrestricted application in general interior lighting and thus new lighting concepts. The intelligent ignition management system ensures an optimum and reliable lamp start at any time – lamp preserving, flicker-free and low-noise. An essential pre-condition to be met is the exact adaptation of the ignition to the respective lamp. Moreover, cold and hot lamps have to be considered. Thus, the lamp service life is virtually independent of the switching frequency.

Ignition voltages

The ignition voltages in the technical data correspond to the highest peak value of all the high-voltage pulses that occur. These values only apply if the corresponding load capacities are adhered to.



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