Switch Lighting announces unique LED replacement lamps
Switch Lighting announces unique LED replacement lamps22 Apr 2011Replacement lamp design relies on inert liquid for cooling allowing Switch Lighting to drive the LEDs at higher current achieving greater brightness with fewer components.

Ventured-funded, San Jose, California-based startup Switch Lighting plans to launch a line of solid-state-lighting (SSL) retrofit lamps at the upcoming Lightfair International event and says they will have products on shelves at major retailers in the 4th quarter. The unique lamp design mounts LEDs facing outward on metal fingers and an inert liquid inside the globe cools the components allowing for higher drive currents and brighter light from fewer components.

Switch Chief Strategy Officer Brett Sharenow boldly compared the Switch design to the Philips 60W replacement lamp that is currently on the market. Sharenow noted that the 12W Philips design utilizes 18 LEDs and outputs 830 lm. The 75W replacement pictured here consumes 16W and uses only 10 LEDs to output 1150 lm.

Of course there are many tradeoffs that come into play when you increase drive currents such as potentially shorter lifetime and greater cost for the cooling system. Plus the comparison with the Philips design is inherently unfair. LED components are constantly improving and the Switch design is likely based on one generation newer components than is the Philips product.

Still Switch’s lamp specs are impressive. The lamps have a 2750K warm-white color temperature and a CRI of 85. The lamps are rated for 18 years of life based on three hours of usage per day. Switch claims the 75W replacement lamp will deliver $140 in energy savings over the life of the product relative to a 75W incandescent.

Switch will also demonstrate 60W and 40W replacements at Lightfair. And Switch plans to offer all three in neutral white as well as warm white color temperature. Sharenow projects that the 60W lamps will sell in the $20 range at retail.

Design delivers radiant lighting

Sharenow also believes the design will deliver superior radiant lighting to LED lamps currently on the market. He said, “We mount the LEDs on the finders to give us the beautiful radiant flux that you get out of an incandescent.”

The LEDs face outwards as you can see in the photos, and the frosted globe distributes light in all directions. While the lamps are at the prototype stage, Sharenow said that Switch has had LM-79 tests performed by Arizona-based Lighting Sciences – recently acquired by UL. Sharenow asserts that the report document its radiance claims.

The prototype pictured here uses LEDs that integrate a lens. The production units will use LEDs with no lens. Sharenow said that the liquid inside the globe has an index of fraction that exactly matches the source and maximizes efficacy. The specs list efficacy at 75 lm/W for the 75W replacement.

The metal fingers upon which the LEDs are mounted combined with the liquid are designed to convect heat to the globe and into the ambient environment. Switch calls the design a self-cooling environment.

With our unique self-cooling technology, we make the brightest warm white LED light bulb available,” said Sharenow. “We offer the most affordable, energy-efficient light bulb on the market that is nearly identical to the regular incandescent bulbs we’ve come to love.”

The Switch design will use LEDs with single emitters as opposed to say the Cree EasyWhite LEDs that use multiple emitters and a mix of light to deliver consistent color. Sharenow expects to be able to source components from multiple vendors. That could mean that the company will have to buy a more-expensive narrow bin to hit the color temperature and CRI specs. Sharenow expects programs such as the program announced at Strategies in Light to supply the needed component consistency.

Sharenow also claims that Switch has developed significant innovations in the driver electronics. The design utilizes a driver IC for a merchant semiconductor vendor that has been customized for Switch according to Sharenow. He said the company will discuss the details of the driver electronics once its patents are approved. Sharenow also said the prototypes have been tested with and approved to work with “every dimmer we could find.”

The Lightfair demonstrations will be a welcome opportunity to see these lamps in operations. The real test, however, for Switch and its venture backer VantagePoint Capital Partners will be production units shipping in volume.

About the Author is the Senior Technical Editor of LEDs Magazine.
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