LED Light Sources

Votes: 2
Views: 3387

A range of LED lighting sources for home, office and street lighting including A19 and PAR bulb sizes, equivalent in lumen output (900/1400) to 60/75/100W incandescent bulbs but which have very high driver efficiency of 96/98% (on 120/220V respectively) and PF of 0.993, negligible EMI, low cost and extremely long overall lifetime of 100,000 hours at 45C and up to 400,000 hours at 25C due to the radically different design techniques employed. This allows a virtually permanent light source fitment to be offered. The color rendering is improved over that of existing high-brightness LED bulbs by addition of saturated colors to the main higher efficiency cool white, thus resulting in high luminous efficacy of 90-110 lumens/watt. User adjustable SELF-dimming based on ambient light levels is incorporated in all light sources and saves even more energy. These are not 'sno-cone' designs, but give close to 360 Degree illumination. The bulbs are very light and almost unbreakable.

A remote dimmer is also designed to work with these sources, allowing highly efficient dimming without triac legacy dimmer losses, and without the user having to get up and move to the door switch to operate the dimmer. This remote control has both a 'finder' LED which flashes in dark conditions and has been designed to match the long life of the light sources by having a self charging capability which means that battery replacement is not required. Versions without remote are designed to work very efficiently with legacy triac or reverse phase dimmers. Unlike other designs there is virtually zero flicker (2%PP) when dimmed.

A new (and patent applied for) method of presence detection which can cut lighting power by another 60% can be incorporated in both these office and street lights allows precision detection of moving or static objects from relatively static office workers to pedestrians and even vehicles at several hundred meters.

A new (and patent applied for) switching device control method coined semi-resonance provides true zero voltage switching and this method is upwards compatible with all power factor control front ends, realizing efficiency of 98% and gains of 10-20% in many cases, with a virtually negligible EMI signature. The same method is applicable to many other sorts of switching regulator, especially solar boost converters which also are designed to run as Maximum Power Point Tracking supplies.

The attached pictures show an early SLA model of a case and assembly which fits in an E26/27 base and work is presently ongoing to adapt this to smaller case sizes and other formats.


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  • Name:
    Alistair Macfarlane
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    Spectrum Microcap 10
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    Electronics, Skiing, walking driving
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    As a senior electronic designer with some 48 years of all sorts of design under my belt, I still really enjoy the challenge of new innovative electronic designs, and improving the efficiency of existing ones.
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    Spectrum Microcap V10
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