PureSpectrum Develops Ballast Circuitry To Enable Fully Dimmable CFL

January 28, 2008 by Jeff Shepard

PureSpectrum Inc. announced that independent testing has confirmed that the company has developed ballast technology that will allow lamp manufacturers to produce a fully dimmable CFL bulb, which PureSpectrum claims will perform better and cost less to manufacture than any commercially available dimmable CFL bulb.

In photometric tests conducted at a NVLAP-certified laboratory in Colorado, a PureSpectrum prototype was dimmed at 5% increments from 100% of perceived light output down to below 10%. At every interval, the prototype functioned without interruption and showed no signs of instability.

According to the announcement, the PureSpectrum prototype was tested against market-leading dimmable CFL bulbs made by GE and MaxLite. Neither brand name bulb dimmed in proportion to power input – the MaxLite extinguished at 60% of perceived light out while the GE extinguished at around 40% of perceived light output. The PureSpectrum prototype continued to operate through the full range of light output.

The tests were performed using a two-wire dimmer specially developed by PureSpectrum’s engineering team to be compatible with a fully dimmable CFL bulb. When PureSpectrum began development of its dimmable CFL bulb, it was quickly discovered that there was not a commercially available dimmer which was built to work with a truly dimmable CFL bulb.

"In many ways, we started from scratch and created something that did not exist before we began work on this project," said PureSpectrum President and CEO Lee Vanatta. "It is not an overstatement to say that this is one of the most important breakthroughs in the history of the development of CFL bulbs. We have basically created the technological gateway to the first and only truly dimmable CFL bulb that functions the way a consumer would expect a dimmable bulb to function."

PureSpectrum claims that, while most leading brand name lighting manufacturers include a dimmable CFL in their product lines, the popularity of these bulbs among consumers has been hindered by performance volatility and a prohibitively high price point. The PureSpectrum ballast model contains only 25 electronic components compared to 69 parts for the GE dimmable CFL and 30 parts for the MaxLite dimmable bulb. The lower component count should allow manufacturers to build the bulbs for a lower cost and drastically reduce the cost of dimmable CFL bulbs.