Legacy to LED – Dimming in One Smooth Curve

With the advent of LED lighting, the relationship between legacy dimming technology and LED lamps has become an uneasy one.  Here MEGAMAN® shows how to overcome such difficulties.

New for old?

One of the big areas for dimming problems comes when home owners decide to switch out all of their traditional lamps for LEDs, but don’t change the dimmers at the same time.  This is largely down to the lack of public knowledge about the fact that trying to combine old and new technologies can lead to all kinds of issues. 

The problems that can occur when new and old are combined include: lamp flicker, flashing, an inability to dim as low as required and failures with the LED and/or dimmer.  Even if the LED lamps seem to initially respond well to dimming, over time, the use of LED light sources on a legacy dimmer can have longer-term implications that lead to call-backs, weeks or months after installation.

The root of the problem

Almost all legacy dimmers designed for incandescent light sources are leading edge or trailing edge dimmers that commonly use a TRIAC/transistor as the key control device.  This chops out parts of the voltage and reduces power to the light source in order to achieve the dimming performance.  Though these work with incandescent lamps, LED lamps have an internal filtering circuit that distorts the supply signal and can result in system oscillations that are observed as flickering or flashing.

As well as encountering flickering and variable dimming performance, in extreme cases incompatible dimmer switches cannot be turned on, or suddenly shut off, can burn out, or permanently damage the LED lamps.  In addition, traditional dimmers have a minimum load requirement of 40W or 60W, something that causes problems when replacing them with low wattage LED equivalents.

GU10’s - the LED opportunity

With halogen directional reflector lamps being phased out across Europe from September 2016*, there will be an increased push from homeowners for LED replacements.  With the advances in LED lighting technology, there are now a wide range of exceptional alternatives to halogen lamps. 

However, dimmable LED GU10 lamps are complex pieces of engineering, as they have to house a transformer, as well as dimmable driver components.  There are at present a lot of dubious dimmable LED replacement lamps on the market.  As with most things, you get what you pay for.  So avoid the lower end of the market and choose a trusted LED manufacturer. 

MEGAMAN has just launched its new selection of GU10 lamps (that incorporate the company’s new Hybrid Reflector and U-DIM™ technology – see below for more on this).  Available in both the popular Economy range and Professional range, these lamps are compatible with the widest possible range of existing dimmers, whether they are leading-edge or trailing-edge.

Overcoming LEDs and Dimming Problems: 

Solution One: When keeping the traditional dimmer

For those installers faced with a homeowner who wants to keep their dimmers, wants LEDs and yet doesn’t know what type of dimmer has been installed, a solution is now at hand.  MEGAMAN has developed its new U-DIM™ technology, which takes the headache out of switching to dimmable LEDs.

MEGAMAN U-DIM dimmable LEDs are compatible with the widest range of existing dimmers, whether they are leading-edge or trailing-edge dimmers.  With the mains voltage halogen reflector lamps being phased out in Europe from 1st September 2016, home owners will need new lamps to operate perfectly with their existing dimmers and this dimming solution is a giant step in that direction.  U-DIM LEDs are easy to use and it is possible to ‘plug-and-play’ to upgrade a lighting scheme.

MEGAMAN U-DIM technology is offered as a standard feature on MEGAMAN Dimming LEDs and they offer superior performance and flicker-free dimming from 100% right down to just 5%.

Solution Two: When replacing with new LED dimmers

Dedicated LED dimmers are a good way to overcome many of the traditional dimmer/LEDs issues.  This is because they use micro control units to monitor and eliminate waveform noise and distortion, generating a digital signal to the control component that creates a stable and clean chopped waveform.  If these dimmers are combined with LED lamps that have been tested and approved for compatibility (this is usually found on the dimming and/or LED lamp manufacturer’s website) – see the MEGAMAN one here as an example, then smooth LED dimming is guaranteed from day one of installation.

Dimming LEDs Checklist:

  • Buy dimmable LEDs from a brand you trust

They will have tested a wide variety of dimmers with their lamps and have more comprehensive dimming compatibility lists

  • Trailing edge dimmers work best with LEDs

However, if the client doesn’t want to replace their leading edge dimmers, then use LEDs that have been proven to dim well with this technology, such as MEGAMAN U-DIM LEDs

  • If in doubt, contact the LED manufacturer

Unsure of whether the dimmer and LEDs are compatible?  Check with the manufacturer’s online compatibility list, or contact their team for more advice

*For more information on the halogen ban – visit www.planfortheban.eu