studiosfert.blogg.se - Backlit led lights

BACKLIT LED LIGHTS DRIVER

LEDs generate some heat and this needs to be dissipated if their life is not to be shortened further. This is more effective as a heat sink than a (cheaper) plastic body. The better back-lit panels use a metal body. Compared with designs using more LEDs, this is less efficient (LEDs perform most efficiently with low drive currents), generates more heat, shortens the life of the LEDs and hastens the lumen depreciation. Too few LEDs (generally 36 or less) means that they have to be driven at a high current to generate the light output needed. This leads some manufacturers to promote back-lit panels as a low-cost option. What are the problems with cheap back-lit LED panels?īecause they have no LGP it is possible to make back-lit panels relatively cheaply.

BACKLIT LED LIGHTS DRIVER

This is because the rear of the panel is the most convenient position for the driver and, because we offer 5 and 7 years warranties, we are keen that the driver should remain as cool as possible. Here at NVC we have had both designs in our product range, but we have decided that edge-lit is marginally better. The lighting market now accepts back-lit panels as readily as edge-lit panels. Because cheaper edge-lit panels used LGPs with a low light transmission, eliminating the LGP altogether, as with a back-lit panel, has meant that back-lit panels have a reputation for being more efficient.Micro-prismatic diffusers have become more common, less expensive and more effective, so the double action of the LGP/diffuser combination is no longer required.Lenses have become cheaper to produce and modern adhesives mean that they can be securely fixed to each LED to create an even light distribution without the risk that they will fall off – a failing with some earlier and cheaper back-lit panels.LEDs have become more efficient, so the thermal advantage inherent in the side-lit design is now reduced, though not eliminated.Technical advances have allowed back-lit LED panels to be introduced. Also, PS has a lower light transmission % than PMMA.

Polystyrene (PS) LGPs are now used by some manufacturers, but if UV stabilisers are not added these will yellow with age and the panel will become dull in the centre while the periphery remains bright. In an effort to reduce the cost of edge-lit panels some manufacturers introduced cheaper materials and assembly processes that impacted on their quality.

Heat from the LED chips is dissipated via the frame, so the rear can be light-weight and it won’t get hot, so the driver can be placed here if required.

No lenses are required and the edge-lit design functions well with a variety of different LED beam angles.

The presence of the LGP means that the diffuser is not solely responsible for spreading the light evenly so low-cost materials can be used in the diffuser, provided they don’t yellow with age.

The best LGPs are made of acrylic (PMMA) which has a very high light transmission % and does not yellow with age.

A light-guide plate (LGP) is an effective and simple way to diffuse the light very evenly, avoiding the risk of bright spots.

The edge-lit design was used first for several reasons: Edge-lit panels were the first to be mass-produced. Back-lit panels are sometimes also known as direct-lit panels.Īre edge-lit or back-lit LED panels best?īoth designs have advantages and drawbacks. Edge-lit panels are sometimes also known as side-lit panels.Ī back-lit LED panel is made of an array of LEDs fitted on a horizontal plate shining vertically down through a diffuser into the space to be illuminated. The LGP directs the light downwards, through a diffuser into the space below. What is the difference between edge-lit and back-lit LED panels?Īn edge-lit LED panel is made of a row of LEDs attached to the frame (or circumference) of the panel, shining horizontally into a light-guide plate (LGP).