Electronic Control Gear
General
- Mains lines
- Terminal pairs
- Life
- Secondary voltage
- SELV designation
- Circuit breaker
- Temperatures
- Line cross sections
- Dimming via the 1...10 V interface
- Line distance
- Transformers with direct current
- Secondary voltage form
- Dimming
- Measuring the output voltage
- Dimmers
- Shielded cables secondary side
- Secondary side switching or dimming
- Secondary voltage partial load behavior
- Operating frequency
Mains lines
Question
Is it possible to loopthrough mains lines in the case of HALOTRONIC transformers?
Answer
Four devices from the HT... L series and the HTM 150 and HT 120 LF devices offer this possibility. A max. current of 16 A may be looped through.
Terminal pairs
Question
For HALOTRONIC transformer featuring 2 or 3 terminal pairs on the secondary side, can the entire load also be tapped off via just one terminal pair?
Answer
Yes, as each pair of terminals is designed for the entire load (current value).
Life
Question
What is the average life of the various HALOTRONIC transformers?
Answer
When specifying the average life of the HALOTRONIC transformer, it is assumed that the temperature at the test point tc of the device does not exceed the specified maximum permissible values during operation.
The following average lifespan figures apply to the individual types of device, based on a failure rate of max. 2 % per 10,000 hours.
| Device range | HT...L, device HT 120 LF | 50,000 hrs |
| HTM / HTN | 30,000 hrs. |
Secondary voltage
Question
How high is the secondary voltage for the HALOTRONIC transformers?
Answer
The secondary voltage depends on the type of transformer, the supply voltage and the power consumption of the connected lamps. Operated at rated values, the secondary voltage lies always below 12 V. Even in the event of lamp failure in the lighting system, no critical voltage values for the remaining lamp(s) occur, as the electronic transformer displays very good partial load behavior compared with conventional alternatives. Further details may be found in the OSRAM catalog "Lighting Programme".
SELV designation
Question
What does the designation SELV on the HALOTRONIC transformer denote?
Answer
SELV stands for Safety Extra Low Voltage. The Safety Extra Low Voltage must be generated potential-free, that is without grounding and without connection to electrical circuits with other voltages.
HALOTRONIC transformers from OSRAM feature safe galvanic separation, and the dielectric strength between the primary and secondary side is tested with 4 kV at each device.
Circuit breaker
Question
How many HALOTRONIC transformers is it possible to connect to an automatic line protector?
Answer
The number of devices that can be connected depends upon, among other things, the type of automatic protector and the load. It is generally the case that with an electronic transformer, the excess transient current is lower than in the case of electronic lamp ballasts, since it has no ELKO memory in the input circuit, which in the case of the ballast draws a very high current, albeit for a very short duration.The list below contains examples of the maximum permissible number of HALOTRONIC transformers for an N-circuit breakers with a tripping characteristic B and 16 A (B16):
| Transformer | HT 70 L | HT 105 L | HT 150 L | HT 210 L | HT 120 LF | HTN 75 |
| Number | 59 | 31 | 22 | 11 | 21 | 53 |
| Transformer | HTM 70 | HTM 105 | HTM 150 |
| Number | 59 | 38 | 26 |
Further details are contained in the OSRAM catalog "Lighting Programme".
Temperatures
Question
What are the critical temperatures for the HALOTRONIC transformers, and are there upper limit values?
Answer
The corresponding details (limit values) for the individual transformers are printed on top of the casing, indicating the values for ta and tc.These values represent safety-related details, so safety is guaranteed only if this value is adhered to. Value ta indicates the maximum ambient environmental temperature (ambient temperature under standardized conditions) for the transformer. This value must not be exceeded in operation. The value tc (case temperature) is the maximum permissible value at the test point (indicated by a circle) on the transformer casing. In the interests of the safe functioning of the transformers and its useful life, the tc temperature must not be exceeded either under unfavorable thermal conditions in the application concerned.
Example: Device HTM 150
max. ta permissible 45°C
max. tc permissible 80°C
In the case of critical built-in situations, a measurement should be taken at point tc if applicable. Where equipment is installed in recessed ceilings, a sufficiently large gap should be ensured between fixtures and transformer(s) for the purposes of thermal decoupling.
Line cross sections
Question
What line cross sections can be used for the line on the lamp side for the HALOTRONIC transformers?
Answer
To minimize voltage drop, a line cross section of 1.5 mm² is recommended. The lines must be laid closely parallel or twisted. Under these conditions, the voltage drop for a device with an operating frequency of 40 kHz and a 100 W constant lamp load at the end of a 2 m line is around 0.8 V, while for 1 m the figure is about 0.3 V.Each lamp is to be supplied individually (each lamp with its own feed line).
Dimming via the 1...10 V interface
Question
Is it possible to dim HALOTRONIC transformers via the 1...10 V interface?
Answer
Yes, in conjunction with the HT 1-10 DIM module. A maximum transformer load of 700 W can be connected to a module of this type, subject to a max. ambient temperature of 45°C, while at 40°C, the value increases to 750 W.
Notes on other modules and the circuit are contained in the OSRAM catalog "Lighting Programme".
Line distance
Question
What is the maximum allowed line distance allowed from the HALOTRONIC transformer to the lamp or lamps?
Answer
For reasons of safe operation, line lengths on the secondary side exceeding 2 m are not permissible. In extreme cases, the device may fail. In addition, the noise suppression of the devices cannot be guaranteed.
It is thus possible to install the lights within a 4 m diameter circle around the electronic transformer.If the installation of longer lines is absolutely unavoidable, this is currently only possible with conventional transformers and a corresponding cross-section (at least 4 mm²).
Transformers with direct current
Question
Which of OSRAM's electronic transformers can also be operated with direct current, e.g. for emergency lighting systems using a central battery?
Answer
Electronic transformers used for this type of application must be suitable for both alternating current (AC) and direct current (DC). The HT 70 L, HT 105 L, HT 150 L and HT 210 L devices are suitable for operation with DC within the specified rated voltage range and in this regard are also VDE-tested. The permissible DC range is from 207 to 244 V. However as the electronic shutoff functions which protect the device against overloading, overheating and short circuits are only actuated for alternating current, the device may be damaged in such cases when used in DC operation.
Secondary voltage form
Question
What form does the output signal of an electronic transformer take?
Answer
This takes the form of an alternating current with an effective value of < 12 V at rated duty. The signal is highly complicated (high frequency with phase and frequency modulation).
Dimming
Question
Are HALOTRONIC transformers dimmable?
Answer
Yes, HALOTRONIC units can be dimmed with all trailing-edge phase dimmers.
The HTM 70, 105 and 150 can be dimmed with leading-edge phase dimmers (for inductive loads) and trailing-edge phase dimmers.
Measuring the output voltage
Question
How can the output voltage at the transformer be measured?
Answer
A device for measuring the secondary voltage must permit measurement of the effective value, and feature a bandwidth of > 500 kHz (-3 dB). Other measuring devices deliver false values. As in the complex output signal also very high frequencies occur, a reliable measurement is possible only with the appropriate equipment.
Dimmers
Question
Which dimmers can be used for HALOTRONIC transformers?
Answer
Customary dimmers follow either the leading-edge or the trailing-edge phase principle. Depending on the transformer type, either leading-edge or trailing-edge dimmers may be considered for electronic transformers, with one or other of the types of dimmer predominating in the individual countries (e.g. trailing-edge phase control dimmers in Germany).
Dimmers und electronic transformers bear a pictogram consisting of a rectangle containing a ramp and one or more alphabetic characters. Leading-edge phase dimmers for inductive loads bear the letter L , trailing-edge phase dimmers the letter C; the same arrangement of letters is employed for the particular electronic transformers too. It is important for the proper working of the dimmer transformer system that at least one letter in the dimmer and transformer designations tallies, e.g. a transformer HT...L marked C, can be operated with a dimmer marked C.
For trailing-edge phase control dimmers, the corresponding symbol in the pictogram is the letter C
HT 70 L, HT 105 L, HT 150 L, HT 210 L, HT 120 LF
HTM 70, HTM 105, HTM 150
HTN 75
For leading-edge phase control dimmers, the corresponding symbol in the pictogram is the letter L
HTM 70, HTM 105, HTM 150
The HTM series of transformers bears the symbol L and C, meaning that both of the dimmers cited above can be used
Note: A flickering lamp is nearly always a sign of an unsuitable device/dimmer combination. Thus it is important to avoid operation with the incorrect dimmer, as the device may otherwise fail.
Shielded cables secondary side
Question
Do shielded cables in the secondary line reduce radio interference?
Answer
No, line-bound radio interference in particular cannot be reduced by means of a shielded cable.
Secondary side switching or dimming
Question
Can halogen lamps be switched on the secondary side?
Answer
The switching and dimming of HALOTRONIC on the secondary side is not permissible.
Secondary voltage partial load behavior
Question
What is the partial load behavior of electronic transformers in terms of output voltage?
Answer
In contrast to conventional transformers, the electronic transformer exhibits very good partial load behavior within the specified power range. The output voltage here lies more or less constantly just under 12 V at rated duty.
Operating frequency
Question
At what frequency do OSRAM's HALOTRONIC transformers operate?
Answer
Depending on the type, the operating frequency of HALOTRONIC transformers varies within the range 32 to 70 kHz. Some values are listed below:
| HTi DALI 150 | approx. 20-35 kHz |
| HT 120 LF | approx. 50 kHz |
| HT 70 L | approx. 45 kHz |
| HT 105 L | approx. 32 kHz |
| HT 150 L | approx. 35 kHz |
| HT 210 L | approx. 35 kHz |
| HTM 70 | approx. 48 kHz |
| HTM 105 | approx. 40 kHz |
| HTM 150 | approx. 35 kHz |
| HTN 75 | approx. 50 kHz |
Although the basic frequencies are specified in each case, the full spectrum is much wider.