HISTORY The Concept For years, many ballast designers have wondered if it was possible to operate a discharge (HMI, MSR or UV) lamp at high frequency, instead of the more commonplace 50Hz – 150Hz of square wave or 50/60Hz sine wave drive provided by most ballast manufacturers today. The logic behind this approach could mean that the ballast (power supply) could be made smaller and therefore lightweight. Some designers went on to do just this but their success has been limited to low power (<250W) lamps and only then to cold strike applications. 1999: A new ballast is developed Power Gems known for its ballast products in the motion picture field, decided to investigate if it would be possible to drive a 575W lamp at high frequency and furthermore to be able to hot re-strike it – it’s not a good idea to have actors hanging around whilst the lamp cooled before it could be turned on again! Once the problem of acoustic resonance was overcome – a phenomenon whereby the arc can resonate with such force it can actually extinguish itself – a cold strike prototype was built to examine how well such a system would perform. This however only provided one element of the hot re-strike system and a new ignitor technique, far from conventional, had to be designed. With a lamp drive frequency in excess of 300kHz, conventional ignitors would simply burn out. The solution to this problem is unique, patented and combines both ballast and ignitor components. 2003: Why choose the name Cleararc®? Early tests at the Philips laboratories in Belgium showed clearly the difference between lamps that had operated for 1,000 hours on low frequency square wave ballasts compared to the Power Gems high frequency sine wave ballast. De-vitrification was considerably reduced and the hf lamp ‘looked almost new’ with a clear envelope and little arc burn back! This is a great benefit for all users but particularly for customers such as moving light companies, who need to have a clear point source of light for their optical systems to be effective (de-vitrification both diffuses and reduces light output). 2003: 575W products launched. 2003: Award Winner Power Gems took the prestigious Plasa Award for Technology Innovation in the Lighting Category, September 2003, at the Plasa Show London. 2004: 1200W product launched at LDI show |
