The brightness drop is caused by the voltage drop that occurs over the length of the LED strip, i.e. the output voltage gradually drops due to resistance from the LEDs and the copper trace, so that the brightness at the end of the strip also becomes lower due to the significantly lower voltage.
To avoid the brightness drop, please follow the tips below:
1. Use applications with the highest possible voltage (e.g. 24Vdc vs. 12Vdc). Higher voltage reduces the current flow in the circuit and thus also the power loss and heating.
2. Cut LED strips and operate the shortened strips in parallel. The shorter the connected LED strips are, the less resistance and voltage drop occurs in the circuit.
3. If the aforementioned multiple feed-in is difficult to achieve, and the length of an LED strip exceeds 5 meters, the connected LED strip can also be fed in from both sides.
4. Mount LED strips on an aluminum profile so that the heat can dissipate quickly and the resistance does not increase as the temperature rises.
Which part fits?
Constant voltage vs. constant current, which transformer do I need?
Constant voltage driver keeps the output voltage constant (12Vdc, 24Vdc, 48Vdc, etc.), while the current can vary to adjust the required power. Typical constant voltage LEDs are LED strips (SMD, COB, RGB, etc.) and LED spots of certain sockets (G4, GU4, GU5.3, GY6.25, etc.). Multiple constant voltage LEDs must be connected in parallel.
Constant current driver, on the other hand, keeps the output current constant (350mA, 700mA, 1000mA, etc.), while the voltage can vary to adjust the required power. Typical constant current LEDs are LED panels and individual LED chips installed in ceiling and wall lights. Multiple constant current LEDs must be connected in series.
If you are still not sure whether your lamp uses constant voltage or constant current LED drivers (e.g. there is no clear indication of the output voltage or output current on the transformer), please contact us and send us a photo of the transformer so that we can check and recommend a suitable replacement.
12Vdc, 24Vdc or 48Vdc, which voltage should I choose?
The higher the operating voltage, the less current is required to transmit the same power (power = voltage x current). Lower current contributes to less power loss and at the same time higher light output (brightness), because heating caused by electrical resistance is proportionally reduced.
Higher voltages such as 24Vdc and 48Vdc are therefore more suitable for applications with high power or long cable routes. In contrast, 12Vdc currently has broader compatibility, and 12Vdc devices are often cheaper.
12Vdc: short LED strips, LED spots, small electrical devices
24Vdc: normal LED strips in parallel connection
48Vdc: extra-long LED strips in large spaces (hall, corridor, parking lot)
If the constant voltage LEDs to be used are already present, then an LED driver of the same voltage can be used directly. Please note that some LEDs can be operated with 12Vac (alternating current), and a 12Vac electrical transformer must also be used for this.
What do I have to pay attention to when I use LED spots with G4, GU4, GU5.3, GY6.35 and AR111 sockets?
LEDs with the aforementioned sockets have a built-in AC/DC converter that allows them to be connected to both 12Vdc and 12Vac (some also to 24Vdc and 24Vac). This converter consumes a large amount of extra energy when switched on than indicated, so that the LED driver is easily overloaded, and the LEDs will then constantly blink.
If you rebuild your lamp and still have the old 12Vac transformer (for halogen), you can connect such LED spots directly to it and continue using it. Otherwise, you must take extra leeway into account for the connected power when purchasing the new LED driver. Normally, the maximum power of the LED driver must be 50% higher than the total power of the LEDs (e.g. 15W transformer for 2 x 5W GU5.3 LED spots). New branded products (Osram, Philips) behave better, meaning 25% to 30% more power is sufficient.
Furthermore, this AC/DC converter has its own design from different manufacturers, so some converters can block the dimming signal of the transformer, and the LEDs can then hardly be dimmed. For TRIAC and DALI dimming, we each have an LED driver that is particularly compatible with LED spots from Osram and Philips:
A detailed list of compatible models can be found in the respective product descriptions and data sheets.
How to install?
What must be considered when installing LEDs in furniture / walls?
For electrical installation in a confined space on a flammable surface, overheating of the electrical appliance must be avoided. The MM mark is a fire protection symbol affixed to an electrical appliance, signaling that the electrical appliance will not heat up to more than 95°C during operation. To eliminate the fire hazard of furniture, ceilings and walls, please always use electrical appliances with the MM mark.
Furthermore, the LED drivers with ultra-flat design (installation height <= 20mm) can be optimally hidden and ventilated, and are better suited for furniture installation.
What should be considered when installing LEDs in wet environments?
Electrical installation in a wet environment (outdoor area, kitchen, bathroom, etc.) requires above all waterproof components with a high degree of protection (IP rating).
The first digit of the IP rating stands for protection against foreign bodies (dust):
0: No protection
1: Protection against objects >= 50 mm (e.g. a large ball)
2: Protection against objects >= 12.5 mm (e.g. a finger)
3: Protection against objects >= 2.5 mm (e.g. a screwdriver)
4: Protection against objects >= 1 mm (e.g. wire)
5: Dust-protected (limited ingress)
6: Dust-tight
The second digit of the IP rating stands for protection against water:
0: No protection
1: Protection against dripping water
2: Protection against dripping water when housing tilted up to 15 degrees
3: Protection against spraying water
4: Protection against splashing water from any direction
5: Protection against water jets
6: Protection against powerful water jets
7: Protection against temporary immersion (up to 1 meter for 30 minutes)
8: Protection against continuous immersion
9: Protection against high pressure and temperature water jets
The IP rating of the electrical appliance should be at least IP44 for installation in a damp indoor room (shower room, kitchen), and at least IP65 (ideally IP67) for outdoor areas.
Furthermore, waterproof cable connectors or junction boxes must be used to connect the other waterproof components and to extend the cables.
