Abstract
A single ended primary inductor converter (SEPIC) converter based light emitting diode (LED) power supply, which can achieve power factor correction (PFC) and constant-current driver for the LED in the critical conduction mode, is presented in this paper. The circuit principle is described in detail. Meanwhile the formulas for metal-oxide semiconductor field-effect transistor (MOSFET) switch-on time, switching frequency and the main influences of power factor are given. Experimental results show that the power can drive the LED with high efficiency in virtue of its high power factor, low power loss and stable output. Furthermore, it can be applied to low power lighting occasions with the simple structure and the high reliability.
