Power Integrations has a reference design for an 85%-efficient, 15W PAR38 downlight driver that it claims will deliver flicker-free dimming without the use of electrolytic bulk capacitors.
Based around the firm’s LNK405EG LED driver IC, it is designed to provide flicker-free performance across a broad range of triac dimmers.
Typical TRIAC dimmers were designed for incandescent lights that use an order of magnitude more power than LED lights of equivalent lumen output.
According to the supplier, the low current requirement of LED lights, especially when dimmed, can cause triacs to switch off unexpectedly or oscillate, creating an annoying flickering effect.
This can be addressed by storing energy in an electrolytic bulk capacitor, with bulb lifetime implications, or by allowing a continuous flow of current into the bulb, wasting energy and thereby defeating the main benefit of LED lighting.
The DER-281 reference design provides an alternative approach without the need for electrolytic bulk capacitors.
Referring to the first box installed in Moscow, he added: 'This Sleepbox has attracted such a great deal of interest from passengers and big companies that the chances are first commercially operated boxes will be installed at airports and in the city by the end of this year.'
Other possible locations would include railway stations, exhibition centres and shopping centres.
In countries with a warm climate, Sleepbox can be used outdoors.
The spokesman continued: 'It allows everybody in unforeseen circumstances to spend a night safely and inexpensively or simply to kill a few hours without leaving the luggage.
'Currently we offer one, two, or three-bed Sleepboxes, which can be made of MDF , metal, and glass-reinforced plastic.
'The price varies depending on the number of hours in use: the more the user pays for, the less it costs per hour.'
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