Notes on using LED bulbs as a replacement for an 12 V halogen system
1) Replacement LED bulbs can not be used with electronic ballasts for halogen lighting!
The internal circuit of the LED bulbs does not withstand the high frequency output voltage of electronic ballasts. Use LED bulbs only with conventional transformers or electronic ballasts specifically designed for LED lighting.
2) The LED bulbs operate on a voltage of 12 V. Higher voltage can damage the bulb prematurely.
Check the output voltage of the ballast!
Installations using halogen bulbs from 20 W, 35 W or 50 W, are equipped with powerful transformers with an output voltage of 100 VA to 600 VA. In order to be able to supply a voltage of 12 V these transformers have an open circuit voltage up to 30 V.
By replacing the halogen bulbs with LED bulbs, the load on these transformers becomes negligible and the output voltage is above the 12 V (between 15 and 18 V).
Example:
- System 5 halogen bulbs of 35 W = 175 VA.
- Transformer used: 200 VA <the transformer supplies 12 V @ 200 VA.
- The open circuit output voltage of this transformer is approximately 18 V.
- The consumed current of halogen bulbs is 175 VA / 12 V = 14,5 A.
- Replace the halogen bulbs with 1 W LED bulbs with 1,25 W @ 12 V consumption. The current consumed is therefore only 520 mA.
- The transformer, designed to supply 12 V @ 16 A, will have an output voltage almost equal to the open circuit voltage!
- The LED bulbs will receive a voltage of about 18 V instead of 12 V, a surge of 150%!
Conclusion
By replacing halogen bulbs with LED bulbs:
- use only a conventional transformer or an electronic ballast for LEDs and not an electronic transformer;
- using a conventional transformer, measure the open-circuit output voltage of the transformer; replace the transformer or use a series resistor if necessary.
Multilingual version .pdf: https://www.econologie.info/share/partag ... 0iXncV.pdf
Example of power supplies compatible with LEDs:
https://www.econologie.com/shop/alimenta ... p-363.html
Other models: https://www.econologie.com/shop/rubans-d ... -led-c-104
Read also:
https://www.econologie.com/forums/ampoule-le ... t8772.html
https://www.econologie.com/forums/quel-trans ... t2719.html