Power supply makers target LED PSUs
AC-DC power supply makers are introducing constant-current models for lighting manufacturers moving into the LED illumination market, writes our Technology Editor Steve Bush.
High efficiency is particularly important because maximum luminair dissipation is restricted by law in many parts of the world.
TDK-Lambda has developed a range of supplies with an output efficiency of 82% for both indoor and outdoor lighting.
The 12W LDC12 series (LDV12 is a voltage output variant) is IP66-rated and accepts universal AC inputs.
Constant current is either 350mA, the de-facto standard set by Lumileds’ original 1W Luxeon Star, or 700mA.
These PSUs are convection cooled, operating between -10e_SDgrC and +60e_SDgrC without derating, and guaranteed to start at -20e_SDgrC.
Standard features include short-circuit, overload and over-voltage protection. Over-voltage protection is particularly important in constant-current supplies to avoid self-destruction should the LED string become open circuit.
The units measure 90×34.5x21mm and are mounted in a vibration and shock resilient case.
Read the full article >>Tags: ac dc, dissipation, outdoor lighting, short circuit, vibration