Description

The main purpose of the power supply is to convert the rectified AC Input to DC regulated current for 6 LEDs.  The power supply provides protection for the LEDs: limits the transient input voltage and protect against inrush current at plug in.  The overall power supply conformity (e.g. mains harmonics (EN): mains interference: international safety standards etc.) are not approved for all the applicable European Norms (EN).The principle of this power supply is a step down. It is regulated by the 350ma average current with a fixed Toff time.  At the heart of the power supply is the controller LM3445 current mode control from National Semiconductor.  The LM3445 switching frequency is set at a nominal 45 kHz.With the LM3445 National Semiconductor provides a device that avoids visible flickering caused by a TRIAC forward or reverse phase dimmer.   The LM3445 overcomes this challenge by translating the TRIAC-chopped waveform to a DIM signal and decoding it to a DC signal.  In fact: the LED current is linearly regulated according to the dimming signal.