LED Trafo - definition and application examples
Transformer stands as short form for transformer with the task to transform (convert) alternating voltage. Thus, for example, from a 230V AC voltage at the input, an output voltage of 12V or 24V, or any application-dependent voltage is generated.
Today, devices called LED transformers are usually special electronic ballasts with a low minimum load and small ripple.
What is AC or DC?
No, this has nothing to do with a music band :-), but describes the form of the output voltage and is important to know for the particular application. The respective signal form is generated by the corresponding electronics in the LED transformer.
AC stands for "Alternating Current". The output provides an alternating voltage and is suitable e.g. for 12V AC retrofit lamps such as LED spotlight 12V with GU5.3.
Recommended product is e.g. the TCI MW70.
Dimming is possible here exclusively via phase dimming. Phase cut-off dimmers are preferred. Please make absolutely sure that the connected LED lamps are also dimmable.
If the dimmability is to be maintained, all three components must match. The LED lamp must be dimmable, the power supply 12V transformer must also be suitable for dimming, and also be compatible with the phase on, or section dimmer. Since there is no standardized interface here, a look at the compatibility lists is worthwhile to avoid flickering, for example. In general, however, this solution requires a compromise in terms of dimming comfort.
DC, on the other hand, stands for "Direct Current". The output voltage is polarized, like a battery with positive and negative pole.
Applications are usually LED strips or LED modules with integrated constant current sources.
LED strips in particular are preferably operated with 24V as an alternative to 12V. The reason is the halving of the current at the same power. Thus, the voltage losses in the supply line and on the LED strip are lower.
When selecting the right LED transformer for e.g. LED strips, the following criteria should be considered:
- Power range:
For e.g. 22m LED ribbon with 10W/m each, a 240W power supply is perfect, such as the HLG-240H-24 alternatively the newer Meanwell PWM series.
This e.g. is equipped with an additional control input in version B. The power supply can be dimmed via an external potentiometer or a control voltage (1-10V).led transformers, led transformer e.g. HLG-240.
We recommend to check the used power range and the dimming characteristic in advance.
- DALI Control
The perfect way to dim. Modern LED transformers have a DALI control input similar to the 1-10V input.
e.g. from the Meanwell ELG series or Meanwell PWM series.
- Phase dimming is also available for electronic DC transformers. Due to EMC restrictions, we only offer LED transformers up to 80W.
For outdoor use, there is a choice of LED transformer IP65 / IP67.
Depending on the version, there is IP 65 up to IP 67 protection against ingress of water and dust. This makes them ideal for use in street lights or other outdoor luminaires. According to our experience, our customers like to use them as control gear for LED strips. Examples of applications are winter garden, facade lighting, railing, and bridge lighting, etc.